Merge branch 'release-0.2.0'

CMakeLists.txt

@@ -6,8 +6,8 @@ SET (PROJECT_LOWERCASE_NAME "cairo-chart")
 SET (PROJECT_DESCRIPTION "GtkChart for Gtk.DrawingArea (Cairo).")
 
 SET (MAJOR 0)
-SET (MINOR 1)
+SET (MINOR 2)
-SET (PATCH 1)
+SET (PATCH 0)
 
 LIST (APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/backbone)
 

cmake/backbone

@@ -1 +1 @@
-Subproject commit 5aec8e830a52e88f61c8844ac15dca72b1ef7f06
+Subproject commit 9ba1995060ebb1c65ac9855e3671b3992c859059

src/Area.vala

@@ -0,0 +1,128 @@
+namespace CairoChart {
+
+	/**
+	 * Area rectangle.
+	 */
+	public class Area {
+
+		/**
+		 * Left bound.
+		 */
+		public double x0 = 0;
+
+		/**
+		 * Top bound.
+		 */
+		public double x1 = 1;
+
+		/**
+		 * Right bound.
+		 */
+		public double y0 = 0;
+
+		/**
+		 * Bottom bound.
+		 */
+		public double y1 = 1;
+
+		/**
+		 * ``Area`` width.
+		 */
+		public virtual double width {
+			get {
+				return x1 - x0;
+			}
+			set {
+				x1 = x0 + value;
+			}
+		}
+
+		/**
+		 * ``Area`` height.
+		 */
+		public virtual double height {
+			get {
+				return y1 - y0;
+			}
+			set {
+				y1 = y0 + value;
+			}
+		}
+
+		/**
+		 * Constructs a new ``Area``.
+		 */
+		public Area () { }
+
+		/**
+		 * Constructs a new ``Area`` by other ``Area``.
+		 * @param area ``Area`` instance.
+		 */
+		public Area.with_area (Area area) {
+			this.x0 = area.x0;
+			this.y0 = area.y0;
+			this.x1 = area.x1;
+			this.y1 = area.y1;
+		}
+
+		/**
+		 * Constructs a new ``Area`` with absolute coordinates.
+		 * @param x0 left bound.
+		 * @param y0 top bound.
+		 * @param x1 right bound.
+		 * @param y1 bottom bound.
+		 */
+		public Area.with_abs (double x0, double y0,
+		                      double x1, double y1) {
+			this.x0 = x0;
+			this.y0 = y0;
+			this.x1 = x1;
+			this.y1 = y1;
+		}
+
+		/**
+		 * Constructs a new ``Area`` by 2 points.
+		 * @param p0 top left position.
+		 * @param p1 bottom right position.
+		 */
+		public Area.with_points (Point p0, Point p1) {
+			this.x0 = p0.x;
+			this.y0 = p0.y;
+			this.x1 = p1.x;
+			this.y1 = p1.y;
+		}
+
+		/**
+		 * Constructs a new ``Area`` with relative coordinates.
+		 * @param x0 left bound.
+		 * @param y0 top bound.
+		 * @param width ``Area`` width.
+		 * @param height ``Area`` height.
+		 */
+		public Area.with_rel (double x0,    double y0,
+		                      double width, double height) {
+			this.x0 = x0;
+			this.y0 = y0;
+			this.width = width;
+			this.height = height;
+		}
+
+		/**
+		 * Constructs a new ``Area`` by ``Cairo.Rectangle``.
+		 * @param rectangle ``Cairo.Rectangle`` instance.
+		 */
+		public Area.with_rectangle (Cairo.Rectangle rectangle) {
+			this.x0 = rectangle.x;
+			this.y0 = rectangle.y;
+			this.width = rectangle.width;
+			this.height = rectangle.height;
+		}
+
+		/**
+		 * Gets a copy of the ``Chart``.
+		 */
+		public virtual Area copy () {
+			return new Area.with_area(this);
+		}
+	}
+}

src/Axis.vala

@@ -1,46 +1,102 @@
-namespace Gtk.CairoChart {
+namespace CairoChart {
-	// If one of axis:title or axis:min/max are different
+
-	// then draw separate axis for each/all series
+	/**
-	// or specify series name near the axis
+	 * ``Chart`` axis.
+	 */
 	public class Axis {
-		Float128 _min = 0;
+
-		Float128 _max = 0;
+		protected unowned Chart chart;
-		public Float128 min {
+		protected unowned Series ser;
-			get { return _min; }
+		protected string _format = "%.2Lf";
-			set { _min = zoom_min = value; }
+		protected string _date_format = "%Y.%m.%d";
-			default = 0;
+		protected string _time_format = "%H:%M:%S";
-		}
+		protected int _dsec_signs = 2; // 2 signs = centiseconds
-		public Float128 max {
+		protected bool is_x;
-			get { return _max; }
+
-			set { _max = zoom_max = value; }
+		/**
-			default = 1;
+		 * ``Axis`` title.
-		}
+		 */
-		public Float128 zoom_min = 0;
+		public Text title;
-		public Float128 zoom_max = 1;
+
-		public Text title = new Text ("");
+		/**
-		public enum Type {
+		 * ``Axis`` range/limits.
-			NUMBERS = 0,
+		 */
-			DATE_TIME
+		public Range range = new Range();
-		}
+
-		public enum ScaleType {
+		/**
-			LINEAR = 0,		// default
+		 * ``Axis`` relative range/limits.
-			// LOGARITHMIC, // TODO
+		 */
-			// etc
+		public Range place = new Range();
-		}
+
-		public Type type;
+		/**
-		public ScaleType scale_type;
+		 * ``Axis`` position.
+		 */
 		public enum Position {
+			/**
+			 * Bottom/Left ``Axis``.
+			 */
 			LOW = 0,
+
+			/**
+			 * Top/Right ``Axis``.
+			 */
 			HIGH = 1,
+
+			/**
+			 * 2 ``Axes``.
+			 */
 			BOTH = 2
 		}
+
+		/**
+		 * Position.
+		 */
 		public Position position = Position.LOW;
 
-		string _format = "%.2Lf";
+		/**
-		string _date_format = "%Y.%m.%d";
+		 * Data type.
-		string _time_format = "%H:%M:%S";
+		 */
-		int _dsec_signs = 2; // 2 signs = centiseconds
+		public enum DType {
-		public string format {
+			/**
+			 * Float128 numbers.
+			 */
+			NUMBERS = 0,
+
+			/**
+			 * Date/Time.
+			 */
+			DATE_TIME
+		}
+
+		/**
+		 * Data type.
+		 */
+		public DType dtype;
+
+		/**
+		 * ``Axis`` scale type.
+		 */
+		public enum Scale {
+			/**
+			 * Linear scale.
+			 */
+			LINEAR = 0,
+
+			/**
+			 * Logarithmic scale.
+			 */
+			// LOGARITHMIC,
+		}
+
+		/**
+		 * Scale type.
+		 */
+		public Scale scale;
+
+		/**
+		 * Float128 numbers print string format.
+		 */
+		public virtual string format {
 			get { return _format; }
 			set {
 				// TODO: check format
@@ -48,7 +104,11 @@ namespace Gtk.CairoChart {
 			}
 			default = "%.2Lf";
 		}
-		public string date_format {
+
+		/**
+		 * Date print string format.
+		 */
+		public virtual string date_format {
 			get { return _date_format; }
 			set {
 				// TODO: check format
@@ -56,7 +116,11 @@ namespace Gtk.CairoChart {
 			}
 			default = "%Y.%m.%d";
 		}
-		public string time_format {
+
+		/**
+		 * Time print string format.
+		 */
+		public virtual string time_format {
 			get { return _time_format; }
 			set {
 				// TODO: check format
@@ -64,7 +128,13 @@ namespace Gtk.CairoChart {
 			}
 			default = "%H:%M:%S";
 		}
-		public int dsec_signs {
+
+		/**
+		 * Number of second's signs after point.
+		 *
+		 * 2 signs means centiseconds, 3 signs means milliseconds, etc...
+		 */
+		public virtual int dsec_signs {
 			get { return _dsec_signs; }
 			set {
 				// TODO: check format
@@ -72,30 +142,441 @@ namespace Gtk.CairoChart {
 			}
 			default = 2;
 		}
-		public FontStyle font_style = FontStyle ();
-		public Color color = Color ();
-		public LineStyle line_style = LineStyle ();
-		public double font_indent = 5;
 
-		public Axis copy () {
+		/**
-			var axis = new Axis ();
+		 * ``Axis`` Font style.
+		 */
+		public Font font = new Font ();
+
+		/**
+		 * ``Axis`` color.
+		 */
+		public Color color = Color ();
+
+		/**
+		 * ``Axis`` line style.
+		 */
+		public LineStyle grid_style = LineStyle(Color(0, 0, 0, 0.25)); // Color(), 1, {2, 3});
+
+		/**
+		 * Number of equally placed points to evaluate records sizes.
+		 */
+		public int nrecords = 8;
+
+		/**
+		 * Constructs a new ``Axis``.
+		 * @param chart ``Chart`` instance.
+		 * @param ser ``Series`` instance.
+		 * @param is_x is X-axis or not (Y-axis otherwise).
+		 */
+		public Axis (Chart chart, Series ser, bool is_x) {
+			this.chart = chart;
+			this.ser = ser;
+			this.is_x = is_x;
+			title = new Text (chart, "");
+		}
+
+		/**
+		 * Gets a copy of the ``Axis``.
+		 */
+		public virtual Axis copy () {
+			var axis = new Axis (chart, ser, is_x);
 			axis._date_format = this._date_format;
 			axis._dsec_signs = this._dsec_signs;
 			axis._format = this._format;
 			axis._time_format = this._time_format;
 			axis.color = this.color;
-			axis.font_indent = this.font_indent;
+			axis.font = this.font.copy();
-			axis.font_style = this.font_style;
+			axis.grid_style = this.grid_style;
-			axis.line_style = this.line_style;
+			axis.range = this.range.copy();
-			axis.max = this.max;
+			axis.place = this.place.copy();
-			axis.min = this.min;
 			axis.position = this.position;
-			axis.scale_type = this.scale_type;
+			axis.scale = this.scale;
 			axis.title = this.title.copy();
-			axis.type = this.type;
+			axis.dtype = this.dtype;
+			axis.nrecords = this.nrecords;
 			return axis;
 		}
 
-		public Axis () {}
+		/**
+		 * Gets screen position by real ``Axis`` value.
+		 * @param axis_value real ``Axis`` value.
+		 */
+		public virtual double scr_pos (Float128 axis_value) {
+			return is_x ? chart.plarea.x0 + chart.plarea.width * (place.zmin + (axis_value - range.zmin) / range.zrange * place.zrange)
+			            : chart.plarea.y0 + chart.plarea.height * (1 - (place.zmin + (axis_value - range.zmin) / range.zrange * place.zrange));
+		}
+
+		/**
+		 * Gets real ``Axis`` value by screen position.
+		 * @param scr_pos screen position.
+		 */
+		public virtual Float128 axis_val (double scr_pos) {
+			return is_x ? range.zmin + ((scr_pos - chart.plarea.x0) / chart.plarea.width - place.zmin) * range.zrange / place.zrange
+			            : range.zmin + ((chart.plarea.y1 - scr_pos) / chart.plarea.height - place.zmin) * range.zrange / place.zrange;
+		}
+
+		/**
+		 * Prints date/time to strings with a current formats.
+		 * @param date returns formatted date string.
+		 * @param time returns formatted time string.
+		 */
+		public virtual void print_dt (Float128 x, out string date, out string time) {
+			date = time = "";
+			var dt = new DateTime.from_unix_utc((int64)x);
+			date = dt.format(date_format);
+			var dsec_str =
+				("%."+(dsec_signs.to_string())+"Lf").printf((LongDouble)(x - (int64)x)).offset(1);
+			if (time_format != "")
+				time = dt.format(time_format) + dsec_str;
+		}
+
+		/**
+		 * Gets compact placement position on the screen.
+		 * @param axis_value real ``Axis`` value.
+		 * @param text to place on the screen.
+		 */
+		public virtual double compact_rec_pos (Float128 axis_value, Text text) {
+			return is_x ? scr_pos(axis_value) - text.width / 2 - text.width * (axis_value - (range.zmin + range.zmax) / 2) / range.zrange
+			            : scr_pos(axis_value) + text.height / 2 + text.height * (axis_value - (range.zmin + range.zmax) / 2) / range.zrange;
+		}
+
+		/**
+		 * Zooms out ``Axis``.
+		 */
+		public virtual void zoom_out () {
+			range.zoom_out();
+			place.zoom_out();
+		}
+
+		/**
+		 * Draws axis.
+		 * @param nskip number of series to skip printing.
+		 */
+		public virtual void draw (ref int nskip) {
+			if (!ser.zoom_show) return;
+
+			var si = Math.find_arr<Series>(chart.series, ser);
+			if (si == -1) return;
+
+			if ((is_x && chart.joint_x || !is_x && chart.joint_y) && si != chart.zoom_1st_idx) return;
+
+			// 1. Detect max record width/height by axis.nrecords equally selected points using format.
+			double max_rec_width, max_rec_height;
+			calc_rec_sizes (this, out max_rec_width, out max_rec_height, is_x);
+
+			// 2. Calculate maximal available number of records, take into account the space width.
+			long max_nrecs = (long) (is_x ? chart.plarea.width * place.zrange / max_rec_width
+			                              : chart.plarea.height * place.zrange / max_rec_height);
+
+			// 3. Calculate grid step.
+			Float128 step = Math.calc_round_step (range.zrange / max_nrecs, dtype == DType.DATE_TIME);
+			if (step > range.zrange)
+				step = range.zrange;
+
+			// 4. Calculate min (range.zmin / step, round, multiply on step, add step if < range.zmin).
+			Float128 min = 0;
+			if (step >= 1) {
+				int64 min_nsteps = (int64) (range.zmin / step);
+				min = min_nsteps * step;
+			} else {
+				int64 round_axis_min = (int64)range.zmin;
+				int64 min_nsteps = (int64) ((range.zmin - round_axis_min) / step);
+				min = round_axis_min + min_nsteps * step;
+			}
+			if (min < range.zmin) min += step;
+
+			// 4.2. Cursor values for joint axes
+			if (chart.cursors.has_crossings)
+				if (    is_x && chart.joint_x && chart.cursors.style.orientation == Cursors.Orientation.VERTICAL
+					|| !is_x && chart.joint_y && chart.cursors.style.orientation == Cursors.Orientation.HORIZONTAL) {
+					var tmp = 0.0;
+					if (is_x) tmp = max_rec_height + font.vspacing;
+					else      tmp = max_rec_width + font.hspacing;
+					switch (position) {
+					case Position.LOW:
+						if (is_x) chart.evarea.y1 -= tmp;
+						else      chart.evarea.x0 += tmp;
+						break;
+					case Position.HIGH:
+						if (is_x) chart.evarea.y0 += tmp;
+						else      chart.evarea.x1 -= tmp;
+						break;
+					}
+				}
+
+			var max_rec_spacing = 2 * (is_x ? font.vspacing : font.hspacing);
+			var max_title_width = title.text == "" ? 0 : title.width + font.hspacing;
+			var max_title_height = title.text == "" ? 0 : title.height + font.vspacing;
+
+			var dx = max_rec_width + max_rec_spacing + max_title_width;
+			var dy = max_rec_height + max_rec_spacing + max_title_height;
+			chart.evarea.x0 -= dx; chart.evarea.x1 += dx; chart.evarea.y0 -= dy; chart.evarea.y1 += dy;
+
+			if (nskip != 0)
+				--nskip;
+			else {
+				var max_rec_height_all = max_rec_height;
+				var max_rec_width_all = max_rec_width;
+				if (is_x)
+					join_rel_axes (si, true, ref max_rec_width_all, ref max_rec_height_all, ref max_rec_spacing, ref max_title_height, ref nskip);
+				else
+					join_rel_axes (si, true, ref max_rec_width_all, ref max_rec_height_all, ref max_rec_spacing, ref max_title_width, ref nskip);
+
+				if (is_x && (!chart.joint_x || si == chart.zoom_1st_idx)) {
+					var tmp = max_rec_height_all + max_rec_spacing + max_title_height;
+					switch (position) {
+					case Position.LOW: chart.evarea.y1 -= tmp; break;
+					case Position.HIGH: chart.evarea.y0 += tmp; break;
+					}
+				}
+				if (!is_x && (!chart.joint_y || si == chart.zoom_1st_idx)) {
+					var tmp = max_rec_width_all + max_rec_spacing + max_title_width;
+					switch (position) {
+					case Position.LOW: chart.evarea.x0 += tmp; break;
+					case Position.HIGH: chart.evarea.x1 -= tmp; break;
+					}
+				}
+			}
+
+			// 4.5. Draw Axis title
+			if (title.text != "") {
+				if (is_x) {
+					var scr_x = chart.plarea.x0 + chart.plarea.width * (place.zmin + place.zmax) / 2;
+					var scr_y = 0.0;
+					switch (position) {
+					case Position.LOW: scr_y = chart.evarea.y1 - font.vspacing; break;
+					case Position.HIGH: scr_y = chart.evarea.y0 + font.vspacing + title.height; break;
+					}
+					chart.ctx.move_to(scr_x - title.width / 2, scr_y);
+					chart.color = color;
+				} else {
+					var scr_y = chart.plarea.y0 + chart.plarea.height * (1 - (place.zmin + place.zmax) / 2);
+					switch (position) {
+					case Position.LOW:
+						var scr_x = chart.evarea.x0 + font.hspacing + title.width;
+						chart.ctx.move_to(scr_x, scr_y + title.height / 2);
+						break;
+					case Position.HIGH:
+						var scr_x = chart.evarea.x1 - font.hspacing;
+						chart.ctx.move_to(scr_x, scr_y + title.height / 2);
+						break;
+					}
+				}
+				if (is_x && chart.joint_x || !is_x && chart.joint_y)
+					chart.color = chart.joint_color;
+				else
+					chart.color = color;
+				title.show();
+			}
+
+			if (is_x) draw_recs (min, step, max_rec_height);
+			else draw_recs (min, step, max_rec_width);
+
+			chart.evarea.x0 += dx; chart.evarea.x1 -= dx; chart.evarea.y0 += dy; chart.evarea.y1 -= dy;
+
+			chart.ctx.stroke ();
+		}
+
+		/**
+		 * Joins equal axes.
+		 * @param nskip returns number of series to skip printing.
+		 */
+		public virtual void join_axes (ref int nskip) {
+			if (!ser.zoom_show) return;
+			if (nskip != 0) {--nskip; return;}
+			var max_rec_width = 0.0, max_rec_height = 0.0;
+			calc_rec_sizes (this, out max_rec_width, out max_rec_height, is_x);
+			var max_rec_spacing = 2 * (is_x ? font.vspacing : font.hspacing);
+			var max_title_width = title.text == "" ? 0 : title.width + font.hspacing;
+			var max_title_height = title.text == "" ? 0 : title.height + font.vspacing;
+
+			var si = Math.find_arr<Series>(chart.series, ser);
+			if (si == -1) return;
+
+			if (is_x)
+				join_rel_axes (si, true, ref max_rec_width, ref max_rec_height, ref max_rec_spacing, ref max_title_height, ref nskip);
+			else
+				join_rel_axes (si, true, ref max_rec_width, ref max_rec_height, ref max_rec_spacing, ref max_title_width, ref nskip);
+
+			// for 4.2. Cursor values for joint X axis
+			if (si == chart.zoom_1st_idx && chart.cursors.has_crossings) {
+				switch (chart.cursors.style.orientation) {
+				case Cursors.Orientation.VERTICAL:
+					if (is_x && chart.joint_x) {
+						var tmp = max_rec_height + font.vspacing;
+						switch (position) {
+						case Position.LOW: chart.plarea.y1 -= tmp; break;
+						case Position.HIGH: chart.plarea.y0 += tmp; break;
+						}
+					}
+					break;
+				case Cursors.Orientation.HORIZONTAL:
+					if (!is_x && chart.joint_y) {
+						var tmp = max_rec_width + font.hspacing;
+						switch (position) {
+						case Position.LOW: chart.plarea.x0 += tmp; break;
+						case Position.HIGH: chart.plarea.x1 -= tmp; break;
+						}
+					}
+					break;
+				}
+			}
+			if (is_x && (!chart.joint_x || si == chart.zoom_1st_idx)) {
+				var tmp = max_rec_height + max_rec_spacing + max_title_height;
+				switch (position) {
+				case Position.LOW: chart.plarea.y1 -= tmp; break;
+				case Position.HIGH: chart.plarea.y0 += tmp; break;
+				}
+			}
+			if (!is_x && (!chart.joint_y || si == chart.zoom_1st_idx)) {
+				var tmp = max_rec_width + max_rec_spacing + max_title_width;
+				switch (position) {
+				case Position.LOW: chart.plarea.x0 += tmp; break;
+				case Position.HIGH: chart.plarea.x1 -= tmp; break;
+				}
+			}
+		}
+
+		protected virtual void calc_rec_sizes (Axis axis, out double max_rec_width, out double max_rec_height, bool horizontal = true) {
+			max_rec_width = max_rec_height = 0;
+			for (var i = 0; i < axis.nrecords; ++i) {
+				Float128 x = (int64)(axis.range.zmin + axis.range.zrange / axis.nrecords * i) + 1/3.0;
+				switch (axis.dtype) {
+				case DType.NUMBERS:
+					var text = new Text (chart, axis.format.printf((LongDouble)x) + (horizontal ? "_" : ""), axis.font);
+					max_rec_width = double.max (max_rec_width, text.width + 2 * text.font.hspacing);
+					max_rec_height = double.max (max_rec_height, text.height + 2 * text.font.vspacing);
+					break;
+				case DType.DATE_TIME:
+					string date, time;
+					axis.print_dt(x, out date, out time);
+
+					var h = 0.0;
+					if (axis.date_format != "") {
+						var text = new Text (chart, date + (horizontal ? "_" : ""), axis.font);
+						max_rec_width = double.max (max_rec_width, text.width + 2 * text.font.hspacing);
+						h = text.height;
+					}
+					if (axis.time_format != "") {
+						var text = new Text (chart, time + (horizontal ? "_" : ""), axis.font);
+						max_rec_width = double.max (max_rec_width, text.width + 2 * text.font.hspacing);
+						h += text.height;
+					}
+					max_rec_height = double.max (max_rec_height, h);
+					break;
+				}
+			}
+		}
+
+		protected virtual void join_rel_axes (int si,
+		                                      bool calc_max_values,
+		                                      ref double max_rec_width,
+		                                      ref double max_rec_height,
+		                                      ref double max_rec_spacing,
+		                                      ref double max_title_size,
+		                                      ref int nskip) {
+			for (int sj = si - 1; sj >= 0; --sj) {
+				var s2 = chart.series[sj];
+				if (!s2.zoom_show) continue;
+				bool has_intersection = false;
+				Axis a2 = s2.axis_x; if (!is_x) a2 = s2.axis_y;
+				for (int sk = si; sk > sj; --sk) {
+					var s3 = chart.series[sk];
+					if (!s3.zoom_show) continue;
+					Axis a3 = s3.axis_x; if (!is_x) a3 = s3.axis_y;
+					if (Math.coord_cross(a2.place.zmin, a2.place.zmax, a3.place.zmin, a3.place.zmax)
+					    || a2.position != a3.position || a2.dtype != a3.dtype) {
+						has_intersection = true;
+						break;
+					}
+				}
+				if (!has_intersection) {
+					if (calc_max_values) {
+						var tmp_max_rec_width = 0.0, tmp_max_rec_height = 0.0;
+						calc_rec_sizes (a2, out tmp_max_rec_width, out tmp_max_rec_height, is_x);
+						max_rec_width = double.max (max_rec_width, tmp_max_rec_width);
+						max_rec_height = double.max (max_rec_height, tmp_max_rec_height);
+						max_rec_spacing = double.max (max_rec_spacing, 2 * (is_x ? a2.font.vspacing : a2.font.hspacing));
+						max_title_size = double.max (
+						    max_title_size,
+						    a2.title.text == "" ? 0
+						                        : is_x ? a2.title.height + font.vspacing
+						                               : a2.title.width + font.hspacing
+						);
+					}
+					++nskip;
+				} else {
+					break;
+				}
+			}
+		}
+
+		protected virtual void draw_recs (Float128 min, Float128 step, double max_rec_size) {
+			for (Float128 v = min; Math.point_belong (v, min, range.zmax); v += step) {
+				if (is_x && chart.joint_x || !is_x && chart.joint_y) {
+					chart.color = chart.joint_color;
+					grid_style.color.red = chart.joint_color.red;
+					grid_style.color.green = chart.joint_color.green;
+					grid_style.color.blue = chart.joint_color.blue;
+				} else
+					chart.color = color;
+				string text = "", time_text = ""; var time_text_t = new Text(chart); var crpt = 0.0;
+				switch (dtype) {
+				case DType.NUMBERS: text = format.printf((LongDouble)v); break;
+				case DType.DATE_TIME:
+					print_dt(v, out text, out time_text);
+					time_text_t = new Text(chart, time_text, font, color);
+					crpt = compact_rec_pos (v, time_text_t);
+					break;
+				}
+				var scr_v = scr_pos (v);
+				var text_t = new Text(chart, text, font, color);
+				var tthv = title.text == "" ? font.vspacing : title.height + 2 * font.vspacing;
+				var ttwh = title.text == "" ? font.hspacing : title.width + 2 * font.hspacing;
+				var dtf = (date_format == "" ? 0 : text_t.height + font.vspacing);
+				var py0 = chart.plarea.y0, ey0 = chart.evarea.y0 + max_rec_size + tthv, ey1 = chart.evarea.y1 - tthv;
+				var px0 = chart.plarea.x0, ex0 = chart.evarea.x0 + max_rec_size + ttwh, ex1 = chart.evarea.x1 - ttwh;
+				var ph = chart.plarea.height, pw = chart.plarea.width;
+				if (is_x) {
+					var crp = compact_rec_pos (v, text_t);
+					switch (position) {
+					case Position.LOW:
+						chart.ctx.move_to (crp, ey1); text_t.show();
+						chart.ctx.move_to (crpt, ey1 - dtf); time_text_t.show();
+						ser.axis_x.grid_style.apply(chart);
+						double y = ey1 - max_rec_size; chart.ctx.move_to (scr_v, y);
+						if (chart.joint_x) chart.ctx.line_to (scr_v, py0);
+						else chart.ctx.line_to (scr_v, double.min (y, py0 + ph * (1 - ser.axis_y.place.zmax)));
+						break;
+					case Position.HIGH:
+						chart.ctx.move_to (crp, ey0); text_t.show();
+						chart.ctx.move_to (crpt, ey0 - dtf); time_text_t.show();
+						ser.axis_x.grid_style.apply(chart); chart.ctx.move_to (scr_v, ey0);
+						if (chart.joint_x) chart.ctx.line_to (scr_v, chart.plarea.y1);
+						else chart.ctx.line_to (scr_v, double.max (ey0, py0 + ph * (1 - ser.axis_y.place.zmin)));
+						break;
+					}
+				} else {
+					var crp = compact_rec_pos (v, text_t);
+					switch (position) {
+					case Position.LOW:
+						chart.ctx.move_to (ex0 - text_t.width, crp);
+						text_t.show(); ser.axis_y.grid_style.apply(chart);
+						chart.ctx.move_to (ex0, scr_v);
+						if (chart.joint_y) chart.ctx.line_to (chart.plarea.x1, scr_v);
+						else chart.ctx.line_to (double.max (ex0, px0 + pw * ser.axis_x.place.zmax), scr_v);
+						break;
+					case Position.HIGH:
+						chart.ctx.move_to (ex1 - text_t.width, crp);
+						text_t.show(); ser.axis_y.grid_style.apply(chart);
+						double x = ex1 - max_rec_size; chart.ctx.move_to (x, scr_v);
+						if (chart.joint_y) chart.ctx.line_to (px0, scr_v);
+						else chart.ctx.line_to (double.min (x, px0 + pw * ser.axis_x.place.zmin), scr_v);
+						break;
+					}
+				}
+			}
+		}
 	}
 }

src/Color.vala

@@ -1,12 +1,46 @@
-namespace Gtk.CairoChart {
+namespace CairoChart {
+
+	/**
+	 * R/G/B/A Color.
+	 */
 	public struct Color {
+
+		/**
+		 * Red component.
+		 */
 		double red;
+
+		/**
+		 * Green component.
+		 */
 		double green;
+
+		/**
+		 * Blue component.
+		 */
 		double blue;
+
+		/**
+		 * Alpha component.
+		 */
 		double alpha;
 
-		public Color (double red = 0.0, double green = 0.0, double blue = 0.0, double alpha = 1.0) {
+		/**
-			this.red = red; this.green = green; this.blue = blue; this.alpha = alpha;
+		 * Constructs a new ``Color``.
+		 * @param red red component.
+		 * @param green green component.
+		 * @param blue blue component.
+		 * @param alpha alpha component.
+		 */
+		public Color (double red = 0,
+		              double green = 0,
+		              double blue = 0,
+		              double alpha = 1
+		) {
+			this.red = red;
+			this.green = green;
+			this.blue = blue;
+			this.alpha = alpha;
 		}
 	}
 }

src/Cursor.vala

@@ -0,0 +1,634 @@
+namespace CairoChart {
+
+	/**
+	 * {@link Chart} cursors.
+	 */
+	public class Cursors {
+
+		protected unowned Chart chart;
+		protected List<Point?> list = new List<Point?> ();
+		protected Point active_cursor = Point(); // { get; protected set; default = Point128 (); }
+		protected bool is_cursor_active = false; // { get; protected set; default = false; }
+		protected Crossings[] crossings = {};
+
+		/**
+		 * ``Cursors`` lines orientation.
+		 */
+		protected enum Orientation {
+			/**
+			 * Vertical cursors.
+			 */
+			VERTICAL,
+
+			/**
+			 * Horizontal cursors.
+			 */
+			HORIZONTAL
+		}
+
+		/**
+		 * ``Cursors`` style.
+		 */
+		public struct Style {
+			/**
+			 * ``Cursors`` lines orientation.
+			 */
+			public Orientation orientation;
+
+			/**
+			 * Maximum distance between mouse and cursor to remove it.
+			 */
+			public double select_distance;
+
+			/**
+			 * ``Cursors`` line style.
+			 */
+			public LineStyle line_style;
+
+			/**
+			 * Constructs a new ``Style``.
+			 */
+			public Style () {
+				orientation = Orientation.VERTICAL;
+				select_distance = 32;
+				line_style = LineStyle(Color(0.2, 0.2, 0.2, 0.8));
+			}
+		}
+
+		/**
+		 * Cursor style.
+		 */
+		public Style style = Style();
+
+		/**
+		 * Value label style.
+		 */
+		public LabelStyle label_style = new LabelStyle();
+
+		/**
+		 * Has crossings.
+		 */
+		public bool has_crossings { get { return crossings.length != 0; } protected set {} }
+
+		/**
+		 * Constructs a new ``Chart``.
+		 * @param chart ``Chart`` instance.
+		 */
+		public Cursors (Chart chart) {
+			this.chart = chart;
+		}
+
+		/**
+		 * Gets a copy of the ``Cursors``.
+		 */
+		public Cursors copy () {
+			var c = new Cursors (chart);
+			c.list = list.copy();
+			c.active_cursor = active_cursor;
+			c.is_cursor_active = is_cursor_active;
+			c.style = style;
+			c.label_style = label_style.copy();
+			c.crossings = crossings;
+			return c;
+		}
+
+		/**
+		 * Sets active cursor.
+		 * @param p ``Cursor`` position.
+		 * @param remove select for removing or not.
+		 */
+		public virtual void set_active (Point p, bool remove = false) {
+			active_cursor.x = chart.zoom.x0 + (p.x - chart.plarea.x0) / chart.plarea.width * chart.zoom.width;
+			active_cursor.y = chart.zoom.y1 - (chart.plarea.y1 - p.y) / chart.plarea.height * chart.zoom.height;
+			is_cursor_active = ! remove;
+		}
+
+		/**
+		 * Adds active cursor.
+		 */
+		public virtual void add_active () {
+			list.append (active_cursor);
+			is_cursor_active = false;
+		}
+
+		/**
+		 * Removes active cursor.
+		 */
+		public virtual void remove_active () {
+			if (list.length() == 0) return;
+			var distance = 1024.0 * 1024;//width * width;
+			uint rm_indx = 0;
+			uint i = 0;
+			foreach (var c in list) {
+				double d = distance;
+				switch (style.orientation) {
+				case Orientation.VERTICAL: d = (rel2scr_x(c.x) - rel2scr_x(active_cursor.x)).abs(); break;
+				case Orientation.HORIZONTAL: d = (rel2scr_y(c.y) - rel2scr_y(active_cursor.y)).abs(); break;
+				}
+				if (d < distance) {
+					distance = d;
+					rm_indx = i;
+				}
+				++i;
+			}
+			if (distance < style.select_distance)
+				list.delete_link(list.nth(rm_indx));
+			is_cursor_active = false;
+		}
+
+		/**
+		 * Gets delta between 2 cursors values.
+		 * @param delta returns delta value.
+		 */
+		public bool get_delta (out Float128 delta) {
+			delta = 0;
+			if (chart.series.length == 0) return false;
+			if (list.length() + (is_cursor_active ? 1 : 0) != 2) return false;
+			if (chart.joint_x && style.orientation == Orientation.VERTICAL) {
+				Float128 val1 = chart.series[chart.zoom_1st_idx].axis_x.axis_val(rel2scr_x(list.nth_data(0).x));
+				Float128 val2 = 0;
+				if (is_cursor_active)
+					val2 = chart.series[chart.zoom_1st_idx].axis_x.axis_val(rel2scr_x(active_cursor.x));
+				else
+					val2 = chart.series[chart.zoom_1st_idx].axis_x.axis_val(rel2scr_x(list.nth_data(1).x));
+				if (val2 > val1)
+					delta = val2 - val1;
+				else
+					delta = val1 - val2;
+				return true;
+			}
+			if (chart.joint_y && style.orientation == Orientation.HORIZONTAL) {
+				Float128 val1 = chart.series[chart.zoom_1st_idx].axis_y.axis_val(rel2scr_y(list.nth_data(0).y));
+				Float128 val2 = 0;
+				if (is_cursor_active)
+					val2 = chart.series[chart.zoom_1st_idx].axis_y.axis_val(rel2scr_y(active_cursor.y));
+				else
+					val2 = chart.series[chart.zoom_1st_idx].axis_y.axis_val(rel2scr_y(list.nth_data(1).y));
+				if (val2 > val1)
+					delta = val2 - val1;
+				else
+					delta = val1 - val2;
+				return true;
+			}
+			return false;
+		}
+
+		/**
+		 * Gets delta formatted string.
+		 */
+		public string get_delta_str () {
+			Float128 delta = 0;
+			if (!get_delta(out delta)) return "";
+			var str = "";
+			var s = chart.series[chart.zoom_1st_idx];
+			if (chart.joint_x)
+				switch (s.axis_x.dtype) {
+				case Axis.DType.NUMBERS:
+					str = s.axis_x.format.printf((LongDouble)delta);
+					break;
+				case Axis.DType.DATE_TIME:
+					var date = "", time = "";
+					int64 days = (int64)(delta / 24 / 3600);
+					s.axis_x.print_dt(delta, out date, out time);
+					str = days.to_string() + " + " + time;
+					break;
+				}
+			if (chart.joint_y) {
+				str = s.axis_y.format.printf((LongDouble)delta);
+			}
+			return str;
+		}
+
+		/**
+		 * Draws cursors.
+		 */
+		public virtual void draw () {
+			if (chart.series.length == 0) return;
+
+			var all_cursors = get_all_cursors();
+			calc_cursors_value_positions();
+
+			for (var cci = 0, max_cci = crossings.length; cci < max_cci; ++cci) {
+				var low = Point128(chart.plarea.x1, chart.plarea.y1);  // low and high
+				var high = Point128(chart.plarea.x0, chart.plarea.y0); //              points of the cursor
+				unowned Cross[] ccs = crossings[cci].crossings;
+				style.line_style.apply(chart);
+				for (var ci = 0, max_ci = ccs.length; ci < max_ci; ++ci) {
+					var si = ccs[ci].series_index;
+					var s = chart.series[si];
+					var p = ccs[ci].point;
+					var scrp = s.scr_pnt(p);
+					if (scrp.x < low.x) low.x = scrp.x;
+					if (scrp.y < low.y) low.y = scrp.y;
+					if (scrp.x > high.x) high.x = scrp.x;
+					if (scrp.y > high.y) high.y = scrp.y;
+
+					if (chart.joint_x) {
+						switch (s.axis_x.position) {
+						case Axis.Position.LOW: high.y = chart.plarea.y1 + s.axis_x.font.vspacing; break;
+						case Axis.Position.HIGH: low.y = chart.plarea.y0 - s.axis_x.font.vspacing; break;
+						case Axis.Position.BOTH:
+							high.y = chart.plarea.y1 + s.axis_x.font.vspacing;
+							low.y = chart.plarea.y0 - s.axis_x.font.vspacing;
+							break;
+						}
+					}
+					if (chart.joint_y) {
+						switch (s.axis_y.position) {
+						case Axis.Position.LOW: low.x = chart.plarea.x0 - s.axis_y.font.hspacing; break;
+						case Axis.Position.HIGH: high.x = chart.plarea.x1 + s.axis_y.font.hspacing; break;
+						case Axis.Position.BOTH:
+							low.x = chart.plarea.x0 - s.axis_y.font.hspacing;
+							high.x = chart.plarea.x1 + s.axis_y.font.hspacing;
+							break;
+						}
+					}
+
+					chart.ctx.move_to (ccs[ci].scr_point.x, ccs[ci].scr_point.y);
+					chart.ctx.line_to (ccs[ci].scr_value_point.x, ccs[ci].scr_value_point.y);
+				}
+
+				var c = all_cursors.nth_data(crossings[cci].cursor_index);
+
+				switch (style.orientation) {
+				case Orientation.VERTICAL:
+					if (low.y > high.y) continue;
+					chart.ctx.move_to (rel2scr_x(c.x), low.y);
+					chart.ctx.line_to (rel2scr_x(c.x), high.y);
+
+					// show joint X value
+					if (chart.joint_x) {
+						var s = chart.series[chart.zoom_1st_idx];
+						var x = s.axis_x.axis_val(rel2scr_x(c.x));
+						string text = "", time_text = "";
+						switch (s.axis_x.dtype) {
+						case Axis.DType.NUMBERS: text = s.axis_x.format.printf((LongDouble)x); break;
+						case Axis.DType.DATE_TIME: s.axis_x.print_dt(x, out text, out time_text); break;
+						}
+						var text_t = new Text(chart, text, s.axis_x.font, s.axis_x.color);
+						var time_text_t = new Text(chart, time_text, s.axis_x.font, s.axis_x.color);
+						var print_y = 0.0;
+						switch (s.axis_x.position) {
+							case Axis.Position.LOW: print_y = chart.area.y1 - s.axis_x.font.vspacing
+								                    - (chart.legend.position == Legend.Position.BOTTOM ? chart.legend.height : 0);
+								break;
+							case Axis.Position.HIGH:
+								var title_height = chart.title.height + (chart.legend.position == Legend.Position.TOP ?
+								                   chart.title.font.vspacing * 2 : chart.title.font.vspacing);
+								print_y = chart.area.y0 + title_height + s.axis_x.font.vspacing
+								          + (chart.legend.position == Legend.Position.TOP ? chart.legend.height : 0);
+								switch (s.axis_x.dtype) {
+								case Axis.DType.NUMBERS:
+									print_y += text_t.height;
+									break;
+								case Axis.DType.DATE_TIME:
+									print_y += (s.axis_x.date_format == "" ? 0 : text_t.height)
+									           + (s.axis_x.time_format == "" ? 0 : time_text_t.height)
+									           + (s.axis_x.date_format == "" || s.axis_x.time_format == "" ? 0 : s.axis_x.font.vspacing);
+									break;
+								}
+								break;
+						}
+						var print_x = s.axis_x.compact_rec_pos (x, text_t);
+						chart.ctx.move_to (print_x, print_y);
+
+						switch (s.axis_x.dtype) {
+						case Axis.DType.NUMBERS:
+							text_t.show();
+							break;
+						case Axis.DType.DATE_TIME:
+							if (s.axis_x.date_format != "") text_t.show();
+							print_x = s.axis_x.compact_rec_pos (x, time_text_t);
+							chart.ctx.move_to (print_x, print_y - (s.axis_x.date_format == "" ? 0 : text_t.height + s.axis_x.font.vspacing));
+							if (s.axis_x.time_format != "") time_text_t.show();
+							break;
+						}
+					}
+					break;
+				case Orientation.HORIZONTAL:
+					if (low.x > high.x) continue;
+					chart.ctx.move_to (low.x, rel2scr_y(c.y));
+					chart.ctx.line_to (high.x, rel2scr_y(c.y));
+
+					// show joint Y value
+					if (chart.joint_y) {
+						var s = chart.series[chart.zoom_1st_idx];
+						var y = s.axis_y.axis_val(rel2scr_y(c.y));
+						var text_t = new Text(chart, s.axis_y.format.printf((LongDouble)y, s.axis_y.font));
+						var print_y = s.axis_y.compact_rec_pos (y, text_t);
+						var print_x = 0.0;
+						switch (s.axis_y.position) {
+						case Axis.Position.LOW:
+							print_x = chart.area.x0 + s.axis_y.font.hspacing
+							          + (chart.legend.position == Legend.Position.LEFT ? chart.legend.width : 0);
+							break;
+						case Axis.Position.HIGH:
+							print_x = chart.area.x1 - text_t.width - s.axis_y.font.hspacing
+							          - (chart.legend.position == Legend.Position.RIGHT ? chart.legend.width : 0);
+							break;
+						}
+						chart.ctx.move_to (print_x, print_y);
+						text_t.show();
+					}
+					break;
+				}
+				chart.ctx.stroke ();
+
+				// show value (X, Y or [X;Y])
+				for (var ci = 0, max_ci = ccs.length; ci < max_ci; ++ci) {
+					var si = ccs[ci].series_index;
+					var s = chart.series[si];
+					var point = ccs[ci].point;
+					var size = ccs[ci].size;
+					var svp = ccs[ci].scr_value_point;
+					var show_x = ccs[ci].show_x;
+					var show_date = ccs[ci].show_date;
+					var show_time = ccs[ci].show_time;
+					var show_y = ccs[ci].show_y;
+
+					// value label background
+					chart.color = label_style.bg_color;
+					chart.ctx.rectangle (svp.x - size.x / 2, svp.y - size.y / 2, size.x, size.y);
+					chart.ctx.fill();
+					// value label frame
+					label_style.frame_style.apply(chart);
+					chart.ctx.move_to (svp.x - size.x / 2, svp.y - size.y / 2);
+					chart.ctx.rel_line_to (size.x, 0);
+					chart.ctx.rel_line_to (0, size.y);
+					chart.ctx.rel_line_to (-size.x, 0);
+					chart.ctx.rel_line_to (0, -size.y);
+					chart.ctx.stroke();
+
+					if (show_x) {
+						chart.color = s.axis_x.color;
+						var text_t = new Text(chart, s.axis_x.format.printf((LongDouble)point.x), s.axis_x.font);
+						chart.ctx.move_to (svp.x - size.x / 2, svp.y + text_t.height / 2);
+						if (chart.joint_x) chart.color = chart.joint_color;
+						text_t.show();
+					}
+
+					if (show_time) {
+						chart.color = s.axis_x.color;
+						string date = "", time = "";
+						s.axis_x.print_dt(point.x, out date, out time);
+						var text_t = new Text(chart, time, s.axis_x.font);
+						var y = svp.y + text_t.height / 2;
+						if (show_date) y -= text_t.height / 2 + s.axis_x.font.vspacing / 2;
+						chart.ctx.move_to (svp.x - size.x / 2, y);
+						if (chart.joint_x) chart.color = chart.joint_color;
+						text_t.show();
+					}
+
+					if (show_date) {
+						chart.color = s.axis_x.color;
+						string date = "", time = "";
+						s.axis_x.print_dt(point.x, out date, out time);
+						var text_t = new Text(chart, date, s.axis_x.font);
+						var y = svp.y + text_t.height / 2;
+						if (show_time) y += text_t.height / 2 + s.axis_x.font.vspacing / 2;
+						chart.ctx.move_to (svp.x - size.x / 2, y);
+						if (chart.joint_x) chart.color = chart.joint_color;
+						text_t.show();
+					}
+
+					if (show_y) {
+						chart.color = s.axis_y.color;
+						var text_t = new Text(chart, s.axis_y.format.printf((LongDouble)point.y), s.axis_y.font);
+						chart.ctx.move_to (svp.x + size.x / 2 - text_t.width, svp.y + text_t.height / 2);
+						if (chart.joint_y) chart.color = chart.joint_color;
+						text_t.show();
+					}
+				}
+			}
+		}
+
+		/**
+		 * Evaluates crossings.
+		 */
+		public void eval_crossings () {
+			var all_cursors = get_all_cursors();
+
+			Crossings[] local_cursor_crossings = {};
+
+			for (var ci = 0, max_ci = all_cursors.length(); ci < max_ci; ++ci) {
+				var c = all_cursors.nth_data(ci);
+				switch (style.orientation) {
+				case Orientation.VERTICAL: if (c.x <= chart.zoom.x0 || c.x >= chart.zoom.x1) continue; break;
+				case Orientation.HORIZONTAL: if (c.y <= chart.zoom.y0 || c.y >= chart.zoom.y1) continue; break;
+				}
+
+				Cross[] crossings = {};
+				for (var si = 0, max_si = chart.series.length; si < max_si; ++si) {
+					var s = chart.series[si];
+					if (!s.zoom_show) continue;
+
+					var points = Math.sort_points (s, s.sort);
+
+					for (var i = 0; i + 1 < points.length; ++i) {
+						switch (style.orientation) {
+						case Orientation.VERTICAL:
+							Float128 y = 0;
+							if (Math.vcross(s.scr_pnt(points[i]), s.scr_pnt(points[i+1]), rel2scr_x(c.x),
+							                chart.plarea.y0, chart.plarea.y1, out y)) {
+								var point = Point128(s.axis_x.axis_val(rel2scr_x(c.x)), s.axis_y.axis_val(y));
+								Point size; bool show_x, show_date, show_time, show_y;
+								cross_what_to_show(s, out show_x, out show_time, out show_date, out show_y);
+								calc_cross_sizes (s, point, out size, show_x, show_time, show_date, show_y);
+								Cross cc = {si, point, size, show_x, show_date, show_time, show_y};
+								crossings += cc;
+							}
+							break;
+						case Orientation.HORIZONTAL:
+							Float128 x = 0;
+							if (Math.hcross(s.scr_pnt(points[i]), s.scr_pnt(points[i+1]),
+							                chart.plarea.x0, chart.plarea.x1, rel2scr_y(c.y), out x)) {
+								var point = Point128(s.axis_x.axis_val(x), s.axis_y.axis_val(rel2scr_y(c.y)));
+								Point size; bool show_x, show_date, show_time, show_y;
+								cross_what_to_show(s, out show_x, out show_time, out show_date, out show_y);
+								calc_cross_sizes (s, point, out size, show_x, show_time, show_date, show_y);
+								Cross cc = {si, point, size, show_x, show_date, show_time, show_y};
+								crossings += cc;
+							}
+							break;
+						}
+					}
+				}
+				if (crossings.length != 0) {
+					Crossings ccs = {ci, crossings};
+					local_cursor_crossings += ccs;
+				}
+			}
+			crossings = local_cursor_crossings;
+		}
+
+		protected struct Cross {
+			uint series_index;
+			Point128 point;
+			Point size;
+			bool show_x;
+			bool show_date;
+			bool show_time;
+			bool show_y;
+			Point scr_point;
+			Point scr_value_point;
+		}
+
+		protected struct Crossings {
+			uint cursor_index;
+			Cross[] crossings;
+		}
+
+		protected virtual Float128 rel2scr_x(Float128 x) {
+			return chart.plarea.x0 + chart.plarea.width * (x - chart.zoom.x0) / chart.zoom.width;
+		}
+
+		protected virtual Float128 rel2scr_y(Float128 y) {
+			return chart.plarea.y0 + chart.plarea.height * (y - chart.zoom.y0) / chart.zoom.height;
+		}
+
+		protected List<Point?> get_all_cursors () {
+			var all_cursors = list.copy_deep ((src) => { return src; });
+			if (is_cursor_active)
+				all_cursors.append(active_cursor);
+			return all_cursors;
+		}
+
+		protected virtual void scr2cell (int m, int n, Point p, out int i, out int j) {
+			i = (int)((p.x - chart.plarea.x0) / chart.plarea.width * m);
+			j = (int)((p.y - chart.plarea.y0) / chart.plarea.height * n);
+		}
+
+		protected virtual void cell2scr (int m, int n, int i, int j, out Point p) {
+			p = Point(chart.plarea.x0 + chart.plarea.width * (i + 0.5) / m,
+			          chart.plarea.y0 + chart.plarea.height * (j + 0.5)/ n);
+		}
+
+		protected virtual void calc_cursors_value_positions () {
+			// 1. Find maximum width/height of cursors values.
+			var max_width = 1.0, max_height = 1.0;
+			for (var ccsi = 0, max_ccsi = crossings.length; ccsi < max_ccsi; ++ccsi) {
+				for (var cci = 0, max_cci = crossings[ccsi].crossings.length; cci < max_cci; ++cci) {
+					unowned Cross[] cr = crossings[ccsi].crossings;
+					max_width = double.max(max_width, cr[cci].size.x
+					         + 4 * double.max(chart.series[cr[cci].series_index].axis_x.font.hspacing,
+					                          chart.series[cr[cci].series_index].axis_y.font.hspacing));
+					max_height = double.max(max_height, cr[cci].size.y
+					         + 4 * double.max(chart.series[cr[cci].series_index].axis_x.font.vspacing,
+					                          chart.series[cr[cci].series_index].axis_y.font.vspacing));
+				}
+			}
+
+			// 2. Calculate 2D-array sizes.
+			var m = (int.max(1, (int)(chart.plarea.width / max_width))),
+			    n = (int.max(1, (int)(chart.plarea.height / max_height)));
+
+			// 3. Create 2D-array of bool or links to cursors values.
+			var arr2d_e = new bool[m, n];
+
+			// 4. Set Busy/Cross Cells
+			for (var ccsi = 0, max_ccsi = crossings.length; ccsi < max_ccsi; ++ccsi) {
+				for (var cci = 0, max_cci = crossings[ccsi].crossings.length; cci < max_cci; ++cci) {
+					unowned Cross[] cr = crossings[ccsi].crossings;
+					cr[cci].scr_point = chart.series[cr[cci].series_index].scr_pnt (cr[cci].point);
+					int i = 0, j = 0;
+					scr2cell(m, n, cr[cci].scr_point, out i, out j);
+					arr2d_e[i, j] = true;
+				}
+			}
+
+			// 5. Calculate positions.
+			for (var ccsi = 0, max_ccsi = crossings.length; ccsi < max_ccsi; ++ccsi) {
+				for (var cci = 0, max_cci = crossings[ccsi].crossings.length; cci < max_cci; ++cci) {
+					unowned Cross[] cr = crossings[ccsi].crossings;
+					int i = 0, j = 0;
+					scr2cell(m, n, cr[cci].scr_point, out i, out j);
+					for (var radius = 1; radius < int.max(m, n); ++radius) {
+						bool found = false;
+
+						// top, bottom
+						int[] ll = {int.max(0, j - radius), int.min(n - 1, j + radius)};
+						foreach (var l in ll) {
+							for (var k = int.max(0, i - radius); k <= int.min(m - 1, i + radius); ++k) {
+								if (k == i) continue;
+								if (!arr2d_e[k, l]) {
+									arr2d_e[k, l] = true;
+									cell2scr(m, n, k, l, out cr[cci].scr_value_point);
+									found = true;
+									break;
+								}
+							}
+							if (found) break;
+						}
+						if (found) break;
+
+						// left, right
+						int[] kk = {int.max(0, i - radius), int.min(m - 1, i + radius)};
+						foreach (var k in kk) {
+							for (var l = int.max(0, j - radius); l <= int.min(n - 1, j + radius); ++l) {
+								if (l == j) continue;
+								if (!arr2d_e[k, l]) {
+									arr2d_e[k, l] = true;
+									cell2scr(m, n, k, l, out cr[cci].scr_value_point);
+									found = true;
+									break;
+								}
+							}
+							if (found) break;
+						}
+						if (found) break;
+					}
+				}
+			}
+		}
+
+		protected virtual void cross_what_to_show (Series s, out bool show_x, out bool show_time,
+		                                                     out bool show_date, out bool show_y) {
+			show_x = show_time = show_date = show_y = false;
+			switch (style.orientation) {
+			case Orientation.VERTICAL:
+				show_y = true;
+				if (!chart.joint_x)
+					switch (s.axis_x.dtype) {
+					case Axis.DType.NUMBERS: show_x = true; break;
+					case Axis.DType.DATE_TIME:
+						if (s.axis_x.date_format != "") show_date = true;
+						if (s.axis_x.time_format != "") show_time = true;
+						break;
+					}
+				break;
+			case Orientation.HORIZONTAL:
+				if (!chart.joint_y) show_y = true;
+				switch (s.axis_x.dtype) {
+				case Axis.DType.NUMBERS: show_x = true; break;
+				case Axis.DType.DATE_TIME:
+					if (s.axis_x.date_format != "") show_date = true;
+					if (s.axis_x.time_format != "") show_time = true;
+					break;
+				}
+				break;
+			}
+		}
+
+		protected virtual void calc_cross_sizes (Series s, Point128 p, out Point size,
+		                                         bool show_x = false, bool show_time = false,
+		                                         bool show_date = false, bool show_y = false) {
+			if (show_x == show_time == show_date == show_y == false)
+				cross_what_to_show(s, out show_x, out show_time, out show_date, out show_y);
+			size = Point ();
+			string date, time;
+			s.axis_x.print_dt(p.x, out date, out time);
+			var date_t = new Text(chart, date, s.axis_x.font, s.axis_x.color);
+			var time_t = new Text(chart, time, s.axis_x.font, s.axis_x.color);
+			var x_t = new Text(chart, s.axis_x.format.printf((LongDouble)p.x), s.axis_x.font, s.axis_x.color);
+			var y_t = new Text(chart, s.axis_y.format.printf((LongDouble)p.y), s.axis_y.font, s.axis_y.color);
+			var h_x = 0.0, h_y = 0.0;
+			if (show_x) { size.x = x_t.width; h_x = x_t.height; }
+			if (show_date) { size.x = date_t.width; h_x = date_t.height; }
+			if (show_time) { size.x = double.max(size.x, time_t.width); h_x += time_t.height; }
+			if (show_y) { size.x += y_t.width; h_y = y_t.height; }
+			if ((show_x || show_date || show_time) && show_y) size.x += s.axis_x.font.hspacing + s.axis_y.font.hspacing;
+			if (show_date && show_time) h_x += s.axis_x.font.vspacing;
+			size.y = double.max (h_x, h_y);
+		}
+	}
+}

src/Font.vala

@@ -0,0 +1,90 @@
+namespace CairoChart {
+
+	/**
+	 * ``Font`` style.
+	 */
+	[Compact]
+	public class Font : Object {
+
+		/**
+		 * A font family name, encoded in UTF-8.
+		 */
+		public virtual string family { get; set; }
+
+		/**
+		 * The new font size, in user space units.
+		 */
+		public virtual double size { get; set; }
+
+		/**
+		 * The slant for the font.
+		 */
+		public virtual Cairo.FontSlant slant { get; set; }
+
+		/**
+		 * The weight for the font.
+		 */
+		public virtual Cairo.FontWeight weight { get; set; }
+
+		/**
+		 * Font/Text orientation.
+		 */
+		public virtual Gtk.Orientation orient { get; set; }
+
+		/**
+		 * Vertical spacing.
+		 */
+		public double vspacing = 2;
+
+		/**
+		 * Horizontal spacing.
+		 */
+		public double hspacing = 2;
+
+		/**
+		 * Both vertical & horizontal spacing (set only).
+		 */
+		public virtual double spacing {
+			protected get {
+				return 0;
+			}
+			set {
+				vspacing = hspacing = value;
+			}
+			default = 2;
+		}
+
+		/**
+		 * Constructs a new ``Font``.
+		 * @param family a font family name, encoded in UTF-8.
+		 * @param size the new font size, in user space units.
+		 * @param slant the slant for the font.
+		 * @param weight the weight for the font.
+		 * @param orient font/text orientation.
+		 */
+		public Font (string family = "Sans",
+		             double size = 10,
+		             Cairo.FontSlant slant = Cairo.FontSlant.NORMAL,
+		             Cairo.FontWeight weight = Cairo.FontWeight.NORMAL,
+		             Gtk.Orientation orient = Gtk.Orientation.HORIZONTAL,
+		             double vspacing = 2,
+		             double hspacing = 2
+		) {
+			this.family = family;
+			this.size = size;
+			this.slant = slant;
+			this.weight = weight;
+			this.orient = orient;
+		}
+
+		/**
+		 * Gets a copy of the ``Font``.
+		 */
+		public virtual Font copy () {
+			var f = new Font(family, size, slant, weight, orient);
+			f.vspacing = vspacing;
+			f.hspacing = hspacing;
+			return f;
+		}
+	}
+}

src/FontStyle.vala

@@ -1,27 +0,0 @@
-namespace Gtk.CairoChart {
-	public enum FontOrient {
-			HORIZONTAL = 0,
-			VERTICAL
-	}
-
-	public struct FontStyle {
-		string family;
-		Cairo.FontSlant slant;
-		Cairo.FontWeight weight;
-
-		FontOrient orientation;
-		double size;
-
-		public FontStyle (string family = "Sans",
-		                  Cairo.FontSlant slant = Cairo.FontSlant.NORMAL,
-		                  Cairo.FontWeight weight = Cairo.FontWeight.NORMAL,
-		                  double size = 10,
-		                  FontOrient orientation = FontOrient.HORIZONTAL) {
-			this.family = family;
-			this.slant = slant;
-			this.weight = weight;
-			this.size = size;
-			this.orientation = orientation;
-		}
-	}
-}

src/Grid.vala

@@ -1,22 +0,0 @@
-namespace Gtk.CairoChart {
-	public class Grid {
-		/*public enum GridType {
-			PRICK_LINE = 0, // default
-			LINE
-		}*/
-		public Color color = Color (0, 0, 0, 0.1);
-
-		public LineStyle line_style = LineStyle ();
-
-		public Grid copy () {
-			var grid = new Grid ();
-			grid.color = this.color;
-			grid.line_style = this.line_style;
-			return grid;
-		}
-
-		public Grid () {
-			line_style.dashes = {2, 3};
-		}
-	}
-}

src/Label.vala

@@ -0,0 +1,46 @@
+namespace CairoChart {
+
+	/**
+	 * ``Cursors`` values style.
+	 */
+	public class LabelStyle {
+
+		/**
+		 * Background color.
+		 */
+		public Color bg_color;
+
+		/**
+		 * Frame line style.
+		 */
+		public LineStyle frame_style;
+
+		/**
+		 * Font style.
+		 */
+		public Font font;
+
+		/**
+		 * Constructs a new ``LabelStyle``.
+		 * @param font font style.
+		 * @param bg_color background color.
+		 * @param frame_style frame line style.
+		 */
+		public LabelStyle (
+			Color bg_color = Color(1, 1, 1, 1),
+			LineStyle frame_style = LineStyle(Color(0, 0, 0, 0.1)),
+			Font font = new Font()
+		) {
+			this.bg_color = bg_color;
+			this.frame_style = frame_style;
+			this.font = font;
+		}
+
+		/**
+		 * Gets a copy of the ``LabelStyle``.
+		 */
+		public virtual LabelStyle copy () {
+			return new LabelStyle(bg_color, frame_style, font);
+		}
+	}
+}

src/LabelStyle.vala

@@ -1,8 +0,0 @@
-namespace Gtk.CairoChart {
-	public struct LabelStyle {
-		FontStyle font_style;
-		LineStyle frame_line_style;
-		Color bg_color;
-		Color frame_color;
-	}
-}

src/Legend.vala

@@ -1,28 +1,275 @@
-namespace Gtk.CairoChart {
+namespace CairoChart {
+
+	/**
+	 * {@link Chart} ``Legend``.
+	 */
 	public class Legend {
+
+		protected unowned Chart chart;
+		protected double [] max_font_heights;
+
+		/**
+		 * Show legend?
+		 */
+		public bool show = true;
+
+		/**
+		 * ``Legend`` position.
+		 */
 		public enum Position {
-			TOP = 0,	// default
+			/**
+			 * Top position.
+			 */
+			TOP = 0,
+
+			/**
+			 * Left position.
+			 */
 			LEFT,
+
+			/**
+			 * Right position.
+			 */
 			RIGHT,
+
+			/**
+			 * Bottom position.
+			 */
 			BOTTOM
 		}
-		public Position position = Position.TOP;
-		public FontStyle font_style = FontStyle();
-		public Color bg_color = Color(1, 1, 1);
-		public LineStyle border_style = LineStyle ();
-		public double indent = 5;
 
-		public Legend copy () {
+		/**
-			var legend = new Legend ();
+		 * Position.
+		 */
+		public Position position = Position.TOP;
+
+		/**
+		 * ``Legend`` background color.
+		 */
+		public Color bg_color = Color(1, 1, 1);
+
+		/**
+		 * Border line style.
+		 */
+		public LineStyle border_style = LineStyle ();
+
+		/**
+		 * Both vertical & horizontal spacing.
+		 */
+		public double spacing = 5;
+
+		/**
+		 * ``Legend`` width.
+		 */
+		public double width { get; protected set; }
+
+		/**
+		 * ``Legend`` height.
+		 */
+		public double height { get; protected set; }
+
+		/**
+		 * {@link Series} line length.
+		 */
+		public double line_length = 30;
+
+		/**
+		 * Constructs a new ``Legend``.
+		 * @param chart ``Chart`` instance.
+		 */
+		public Legend (Chart chart) {
+			this.chart = chart;
+			border_style.color = Color (0, 0, 0, 0.3);
+		}
+
+		/**
+		 * Gets a copy of the ``Legend``.
+		 */
+		public virtual Legend copy () {
+			var legend = new Legend (chart);
 			legend.position = this.position;
-			legend.font_style = this.font_style;
 			legend.bg_color = this.bg_color;
-			legend.indent = this.indent;
+			legend.spacing = this.spacing;
+			legend.height = this.height;
+			legend.line_length = this.line_length;
+			legend.width = this.width;
+			legend.show = this.show;
+			legend.max_font_heights = this.max_font_heights;
 			return legend;
 		}
 
-		public Legend () {
+		/**
-			border_style.color = Color (0, 0, 0, 0.3);
+		 * Draws the ``Legend``.
+		 */
+		public virtual void draw () {
+			if (!show) return;
+			process (ProcessType.CALC);
+			process (ProcessType.DRAW);
+		}
+
+		protected virtual void draw_rect (out double x0, out double y0) {
+			x0 = y0 = 0;
+			if (chart.ctx != null) {
+				switch (position) {
+				case Position.TOP:
+					x0 = (chart.area.width - width) / 2;
+					var title_height = chart.title.height + (chart.legend.position == Position.TOP ?
+					                   chart.title.font.vspacing * 2 : chart.title.font.vspacing);
+					y0 = title_height;
+				break;
+
+				case Position.BOTTOM:
+					x0 = (chart.area.width - width) / 2;
+					y0 = chart.area.height - height;
+				break;
+
+				case Position.LEFT:
+					x0 = 0;
+					y0 = (chart.area.height - height) / 2;
+				break;
+
+				case Position.RIGHT:
+					x0 = chart.area.width - width;
+					y0 = (chart.area.height - height) / 2;
+				break;
+				}
+				chart.color = bg_color;
+				chart.ctx.rectangle (x0, y0, width, height);
+				chart.ctx.fill();
+				border_style.apply(chart);
+				chart.ctx.move_to (x0, y0);
+				chart.ctx.rel_line_to (width, 0);
+				chart.ctx.rel_line_to (0, height);
+				chart.ctx.rel_line_to (-width, 0);
+				chart.ctx.rel_line_to (0, -height);
+				chart.ctx.stroke ();
+			}
+		}
+
+		protected enum ProcessType {
+			CALC = 0, // default
+			DRAW
+		}
+
+		protected virtual void process (ProcessType process_type) {
+			var legend_x0 = 0.0, legend_y0 = 0.0;
+			var heights_idx = 0;
+			var leg_width_sum = 0.0;
+			var leg_height_sum = 0.0;
+			var max_font_h = 0.0;
+
+			double [] mfh = max_font_heights;
+
+			// prepare
+			switch (process_type) {
+			case ProcessType.CALC:
+				width = 0;
+				height = 0;
+				mfh = {};
+				heights_idx = 0;
+				break;
+			case ProcessType.DRAW:
+				draw_rect(out legend_x0, out legend_y0);
+				break;
+			}
+
+			foreach (var s in chart.series) {
+				if (!s.zoom_show) continue;
+
+				// carry
+				switch (position) {
+				case Position.TOP:
+				case Position.BOTTOM:
+					var ser_title_width = line_length + s.title.width + s.title.font.hspacing * 2;
+					if (leg_width_sum + ser_title_width > chart.area.width) { // carry
+						leg_height_sum += max_font_h;
+						switch (process_type) {
+						case ProcessType.CALC:
+							mfh += max_font_h;
+							width = double.max(width, leg_width_sum);
+							break;
+						case ProcessType.DRAW:
+							heights_idx++;
+							break;
+						}
+						leg_width_sum = 0;
+						max_font_h = 0;
+					}
+					break;
+				}
+
+				switch (process_type) {
+				case ProcessType.DRAW:
+					var x = legend_x0 + leg_width_sum + s.title.font.hspacing;
+					var y = legend_y0 + leg_height_sum + mfh[heights_idx] / 2;
+
+					// series title
+					chart.ctx.move_to (x + line_length, y + s.title.height / 2);
+					chart.color = s.title.color;
+					s.title.show();
+
+					// series line style
+					chart.ctx.move_to (x, y);
+					s.line_style.apply(chart);
+					chart.ctx.rel_line_to (line_length, 0);
+					chart.ctx.stroke();
+					s.marker.draw_at_pos (Point(x + line_length / 2, y));
+					break;
+				}
+
+				switch (position) {
+				case Position.TOP:
+				case Position.BOTTOM:
+					var ser_title_width = line_length + s.title.width + s.title.font.hspacing * 2;
+					leg_width_sum += ser_title_width;
+					max_font_h = double.max (max_font_h, s.title.height + s.title.font.vspacing * 2);
+				break;
+
+				case Position.LEFT:
+				case Position.RIGHT:
+					switch (process_type) {
+					case ProcessType.CALC:
+						mfh += s.title.height + s.title.font.vspacing * 2;
+						width = double.max (width, s.title.font.hspacing * 2 + line_length + s.title.width);
+						break;
+					case ProcessType.DRAW:
+						heights_idx++;
+						break;
+					}
+					leg_height_sum += s.title.height + s.title.font.vspacing * 2;
+				break;
+				}
+			}
+
+			// TOP, BOTTOM
+			switch (position) {
+			case Position.TOP:
+			case Position.BOTTOM:
+				if (leg_width_sum != 0) {
+					leg_height_sum += max_font_h;
+					switch (process_type) {
+						case ProcessType.CALC:
+							mfh += max_font_h;
+							width = double.max(width, leg_width_sum);
+							break;
+					}
+				}
+				break;
+			}
+
+			switch (process_type) {
+			case ProcessType.CALC:
+				height = leg_height_sum;
+				switch (position) {
+					case Position.TOP: chart.evarea.y0 += height + spacing; break;
+					case Position.BOTTOM: chart.evarea.y1 -= height + spacing; break;
+					case Position.LEFT: chart.evarea.x0 += width + spacing; break;
+					case Position.RIGHT: chart.evarea.x1 -= width + spacing; break;
+				}
+				break;
+			}
+
+			max_font_heights = mfh;
 		}
 	}
 }

src/Line.vala

@@ -0,0 +1,72 @@
+namespace CairoChart {
+
+	/**
+	 * Line Style.
+	 */
+	public struct LineStyle {
+
+		/**
+		 * Line color.
+		 */
+		Color color;
+
+		/**
+		 * A line width.
+		 */
+		double width;
+
+		/**
+		 * An array specifying alternate lengths of on and off stroke portions.
+		 */
+		double[]? dashes;
+
+		/**
+		 * An offset into the dash pattern at which the stroke should start.
+		 */
+		double dash_offset;
+		/**
+		 * A line join style.
+		 */
+		Cairo.LineJoin join;
+
+		/**
+		 * A line cap style.
+		 */
+		Cairo.LineCap cap;
+
+		/**
+		 * Constructs a new ``LineStyle``.
+		 * @param color line color.
+		 * @param width a line width.
+		 * @param dashes an array specifying alternate lengths of on and off stroke portions.
+		 * @param dash_offset an offset into the dash pattern at which the stroke should start.
+		 * @param join a line join style.
+		 * @param cap a line cap style.
+		 */
+		public LineStyle (Color color = Color(),
+		                  double width = 1,
+		                  double[]? dashes = null,
+		                  double dash_offset = 0,
+		                  Cairo.LineJoin join = Cairo.LineJoin.MITER,
+		                  Cairo.LineCap cap = Cairo.LineCap.ROUND
+		) {
+			this.color = color;
+			this.width = width;
+			this.dashes = dashes;
+			this.dash_offset = dash_offset;
+			this.join = join;
+			this.cap = cap;
+		}
+
+		/**
+		 * Applies current style to the {@link Chart} ``Context``.
+		 */
+		public void apply (Chart chart) {
+			chart.color = color;
+			chart.ctx.set_line_width(width);
+			chart.ctx.set_dash(dashes, dash_offset);
+			chart.ctx.set_line_join(join);
+			chart.ctx.set_line_cap(cap);
+		}
+	}
+}

src/LineStyle.vala

@@ -1,24 +0,0 @@
-namespace Gtk.CairoChart {
-	public struct LineStyle {
-		double width;
-		Cairo.LineJoin line_join;
-		Cairo.LineCap line_cap;
-		double[]? dashes;
-		double dash_offset;
-		Color color;
-
-		public LineStyle (Color color = Color(),
-		                  double width = 1,
-		                  double[]? dashes = null, double dash_offset = 0,
-		                  Cairo.LineJoin line_join = Cairo.LineJoin.MITER,
-		                  Cairo.LineCap line_cap = Cairo.LineCap.ROUND
-		                  ) {
-			this.width = width;
-			this.line_join = line_join;
-			this.line_cap = line_cap;
-			this.dashes = dashes;
-			this.dash_offset = dash_offset;
-			this.color = color;
-		}
-	}
-}

src/Marker.vala

@@ -0,0 +1,100 @@
+namespace CairoChart {
+
+	/**
+	 * {@link Series} Marker.
+	 */
+	public class Marker {
+
+		protected unowned Chart chart;
+
+		/**
+		 * ``Marker`` shape.
+		 */
+		public enum Shape {
+			NONE = 0,
+			SQUARE,
+			CIRCLE,
+			TRIANGLE,
+			PRICLE_SQUARE,
+			PRICLE_CIRCLE,
+			PRICLE_TRIANGLE
+		}
+
+		/**
+		 * ``Marker`` shape.
+		 */
+		public Shape shape;
+
+		/**
+		 * ``Marker`` size.
+		 */
+		public double size;
+
+		/**
+		 * Constructs a new ``Marker``.
+		 * @param chart ``Chart`` instance.
+		 * @param shape ``Marker`` shape.
+		 * @param size ``Marker`` size.
+		 */
+		public Marker (Chart chart,
+		               Shape shape = Shape.NONE,
+		               double size = 8
+		) {
+			this.chart = chart;
+			this.shape = shape;
+			this.size = size;
+		}
+
+		/**
+		 * Gets a copy of the ``Marker``.
+		 */
+		public virtual Marker copy () {
+			return new Marker (chart, shape, size);
+		}
+
+		/**
+		 * Draws the ``Marker`` at specific position.
+		 * @param p coordinates.
+		 */
+		public virtual void draw_at_pos (Point p) {
+			chart.ctx.move_to (p.x, p.y);
+			switch (shape) {
+			case Shape.SQUARE:
+				chart.ctx.rectangle (p.x - size / 2, p.y - size / 2, size, size);
+				chart.ctx.fill();
+				break;
+
+			case Shape.CIRCLE:
+				chart.ctx.arc (p.x, p.y, size / 2, 0, 2 * GLib.Math.PI);
+				chart.ctx.fill();
+				break;
+
+			case Shape.TRIANGLE:
+				chart.ctx.move_to (p.x - size / 2, p.y - size / 2);
+				chart.ctx.rel_line_to (size, 0);
+				chart.ctx.rel_line_to (-size / 2, size);
+				chart.ctx.rel_line_to (-size / 2, -size);
+				chart.ctx.fill();
+				break;
+
+			case Shape.PRICLE_SQUARE:
+				chart.ctx.rectangle (p.x - size / 2, p.y - size / 2, size, size);
+				chart.ctx.stroke();
+				break;
+
+			case Shape.PRICLE_CIRCLE:
+				chart.ctx.arc (p.x, p.y, size / 2, 0, 2 * GLib.Math.PI);
+				chart.ctx.stroke();
+				break;
+
+			case Shape.PRICLE_TRIANGLE:
+				chart.ctx.move_to (p.x - size / 2, p.y - size / 2);
+				chart.ctx.rel_line_to (size, 0);
+				chart.ctx.rel_line_to (-size / 2, size);
+				chart.ctx.rel_line_to (-size / 2, -size);
+				chart.ctx.stroke();
+				break;
+			}
+		}
+	}
+}

src/Math.vala

@@ -0,0 +1,161 @@
+namespace CairoChart {
+
+	namespace Math {
+
+		internal Float128 calc_round_step (Float128 aver_step, bool date_time = false) {
+			Float128 step = 1;
+
+			if (aver_step > 1) {
+				if (date_time) while (step < aver_step) step *= 60;
+				if (date_time) while (step < aver_step) step *= 60;
+				if (date_time) while (step < aver_step) step *= 24;
+				while (step < aver_step) step *= 10;
+				if (step / 5 > aver_step) step /= 5;
+				while (step / 2 > aver_step) step /= 2;
+			} else if (aver_step > 0) {
+				while (step / 10 > aver_step) step /= 10;
+				if (step / 5 > aver_step) step /= 5;
+				while (step / 2 > aver_step) step /= 2;
+			}
+
+			return step;
+		}
+
+		internal bool coord_cross (double a_min, double a_max, double b_min, double b_max) {
+			if (   a_min < a_max <= b_min < b_max
+			    || b_min < b_max <= a_min < a_max)
+				return false;
+			return true;
+		}
+
+		/*internal bool rect_cross (Cairo.Rectangle r1, Cairo.Rectangle r2) {
+			return    coord_cross(r1.x, r1.x + r1.width, r2.x, r2.x + r2.width)
+			       && coord_cross(r1.y, r1.y + r1.height, r2.y, r2.y + r2.height);
+		}*/
+
+		internal bool point_belong (Float128 p, Float128 a, Float128 b) {
+			if (a > b) { Float128 tmp = a; a = b; b = tmp; }
+			if (a <= p <= b) return true;
+			return false;
+		}
+
+		internal bool x_in_range (double x, double x0, double x1) {
+			if (x0 <= x <= x1 || x1 <= x <= x0)
+				return true;
+			return false;
+		}
+
+		internal bool y_in_range (double y, double y0, double y1) {
+			if (y0 <= y <= y1 || y1 <= y <= y0)
+				return true;
+			return false;
+		}
+
+		internal bool point_in_rect (Point p, double x0, double x1, double y0, double y1) {
+			if (x_in_range(p.x, x0, x1) && y_in_range(p.y, y0, y1))
+				return true;
+			return false;
+		}
+
+		internal bool hcross (Point a1, Point a2, double h_x1, double h_x2, double h_y, out double x) {
+			x = 0;
+			if (a1.y == a2.y) return false;
+			if (a1.y >= h_y && a2.y >= h_y || a1.y <= h_y && a2.y <= h_y) return false;
+			x = a1.x + (a2.x - a1.x) * (h_y - a1.y) / (a2.y - a1.y);
+			if (h_x1 <= x <= h_x2 || h_x2 <= x <= h_x1)
+				return true;
+			return false;
+		}
+
+		internal bool vcross (Point a1, Point a2, double v_x, double v_y1, double v_y2, out double y) {
+			y = 0;
+			if (a1.x == a2.x) return false;
+			if (a1.x >= v_x && a2.x >= v_x || a1.x <= v_x && a2.x <= v_x) return false;
+			y = a1.y + (a2.y - a1.y) * (v_x - a1.x) / (a2.x - a1.x);
+			if (v_y1 <= y <= v_y2 || v_y2 <= y <= v_y1)
+				return true;
+			return false;
+		}
+
+		internal delegate int PointComparator(Point128 a, Point128 b);
+
+		internal void sort_points_delegate(Point128[] points, PointComparator compare) {
+			for(var i = 0; i < points.length; ++i) {
+				for(var j = i + 1; j < points.length; ++j) {
+					if(compare(points[i], points[j]) > 0) {
+						var tmp = points[i];
+						points[i] = points[j];
+						points[j] = tmp;
+					}
+				}
+			}
+		}
+
+		internal bool cut_line (Point p_min, Point p_max, Point a, Point b, out Point c, out Point d) {
+			int ncross = 0;
+			Float128 x = 0, y = 0;
+			Point pc[4];
+			if (hcross(a, b, p_min.x, p_max.x, p_min.y, out x))
+				pc[ncross++] = Point(x, p_min.y);
+			if (hcross(a, b, p_min.x, p_max.x, p_max.y, out x))
+				pc[ncross++] = Point(x, p_max.y);
+			if (vcross(a, b, p_min.x, p_min.y, p_max.y, out y))
+				pc[ncross++] = Point(p_min.x, y);
+			if (vcross(a, b, p_max.x, p_min.y, p_max.y, out y))
+				pc[ncross++] = Point(p_max.x, y);
+			c = a;
+			d = b;
+			if (ncross == 0) {
+				if (   point_in_rect (a, p_min.x, p_max.x, p_min.y, p_max.y)
+				    && point_in_rect (b, p_min.x, p_max.x, p_min.y, p_max.y))
+					return true;
+				return false;
+			}
+			if (ncross >= 2) {
+				c = pc[0]; d = pc[1];
+				return true;
+			}
+			if (ncross == 1) {
+				if (point_in_rect (a, p_min.x, p_max.x, p_min.y, p_max.y)) {
+					c = a;
+					d = pc[0];
+					return true;
+				} else if (point_in_rect (b, p_min.x, p_max.x, p_min.y, p_max.y)) {
+					c = b;
+					d = pc[0];
+					return true;
+				}
+			}
+			return false;
+		}
+
+		internal Point128[] sort_points (Series s, Series.Sort sort) {
+			var points = s.points;
+			switch(sort) {
+			case Series.Sort.BY_X:
+				sort_points_delegate(points, (a, b) => {
+				    if (a.x < b.x) return -1;
+				    if (a.x > b.x) return 1;
+				    return 0;
+				});
+				break;
+			case Series.Sort.BY_Y:
+				sort_points_delegate(points, (a, b) => {
+				    if (a.y < b.y) return -1;
+				    if (a.y > b.y) return 1;
+				    return 0;
+				});
+				break;
+			}
+			return points;
+		}
+
+		internal int find_arr<G> (G[] arr, G elem) {
+			for (var i = 0; i < arr.length; ++i) {
+				if (arr[i] == elem)
+					return i;
+			}
+			return -1;
+		}
+	}
+}

src/Place.vala

@@ -1,52 +0,0 @@
-namespace Gtk.CairoChart {
-	public class Place {
-		double _x_low = 0;
-		double _x_high = 0;
-		double _y_low = 0;
-		double _y_high = 0;
-		public double x_low {
-			get { return _x_low; }
-			set { _x_low = zoom_x_low = value; }
-			default = 0;
-		}
-		public double x_high {
-			get { return _x_high; }
-			set { _x_high = zoom_x_high = value; }
-			default = 0;
-		}
-		public double y_low {
-			get { return _y_low; }
-			set { _y_low = zoom_y_low = value; }
-			default = 0;
-		}
-		public double y_high {
-			get { return _y_high; }
-			set { _y_high = zoom_y_high = value; }
-			default = 0;
-		}
-		public double zoom_x_low = 0;
-		public double zoom_x_high = 1;
-		public double zoom_y_low = 0;
-		public double zoom_y_high = 1;
-
-		public Place copy () {
-			var place = new Place ();
-			place.x_low = this.x_low;
-			place.x_high = this.x_high;
-			place.y_low = this.y_low;
-			place.y_high = this.y_high;
-			return place;
-		}
-
-		public Place (double x_low = 0, double x_high = 1, double y_low = 0, double y_high = 1) {
-			this.x_low = x_low;
-			this.x_high = x_high;
-			this.y_low = y_low;
-			this.y_high = y_high;
-			zoom_x_low = x_low;
-			zoom_x_high = x_high;
-			zoom_y_low = y_low;
-			zoom_y_high = y_high;
-		}
-	}
-}

src/Point.vala

@@ -1,9 +1,51 @@
-namespace Gtk.CairoChart {
+namespace CairoChart {
+
+	/**
+	 * 64-bit point.
+	 */
 	public struct Point {
+
+		/**
+		 * X-coordinate.
+		 */
+		double x;
+
+		/**
+		 * Y-coordinate.
+		 */
+		double y;
+
+		/**
+		 * Constructs a new ``Point``.
+		 * @param x x-coordinate.
+		 * @param y y-coordinate.
+		 */
+		public Point (double x = 0, double y = 0) {
+			this.x = x; this.y = y;
+		}
+	}
+
+	/**
+	 * 128-bit point.
+	 */
+	public struct Point128 {
+
+		/**
+		 * X-coordinate.
+		 */
 		Float128 x;
+
+		/**
+		 * Y-coordinate.
+		 */
 		Float128 y;
 
-		public Point (Float128 x = 0.0, Float128 y = 0.0) {
+		/**
+		 * Constructs a new ``Point128``.
+		 * @param x x-coordinate.
+		 * @param y y-coordinate.
+		 */
+		public Point128 (Float128 x = 0, Float128 y = 0) {
 			this.x = x; this.y = y;
 		}
 	}

src/Range.vala

@@ -0,0 +1,118 @@
+namespace CairoChart {
+
+	/**
+	 * Linear range.
+	 */
+	public class Range {
+
+		protected Float128 _min = 0;
+		protected Float128 _max = 1;
+
+		/**
+		 * Zoomed min bound.
+		 */
+		public Float128 zmin = 0;
+
+		/**
+		 * Zoomed max bound.
+		 */
+		public Float128 zmax = 1;
+
+		/**
+		 * Low bound.
+		 */
+		public virtual Float128 min {
+			get {
+				return _min;
+			}
+			set {
+				zmin = _min = value;
+			}
+		}
+
+		/**
+		 * High bound.
+		 */
+		public virtual Float128 max {
+			get {
+				return _max;
+			}
+			set {
+				zmax = _max = value;
+			}
+		}
+
+		/**
+		 * ``Range`` value.
+		 */
+		public virtual Float128 range {
+			get {
+				return _max - _min;
+			}
+			set {
+				zmax = _max = _min + value;
+			}
+		}
+
+		/**
+		 * ``Range`` zoomed value.
+		 */
+		public virtual Float128 zrange {
+			get {
+				return zmax - zmin;
+			}
+			set {
+				zmax = zmin + value;
+			}
+		}
+
+		/**
+		 * Constructs a new ``Range``.
+		 */
+		public Range () { }
+
+		/**
+		 * Constructs a new ``Range`` with a ``Range`` instance.
+		 * @param range ``Range`` instance.
+		 */
+		public Range.with_range (Range range) {
+			this.min = range.min;
+			this.max = range.max;
+		}
+
+		/**
+		 * Constructs a new ``Range`` with absolute coordinates.
+		 * @param min minimum/low limit.
+		 * @param max maximum/high limit.
+		 */
+		public Range.with_abs (Float128 min, Float128 max) {
+			this.min = min;
+			this.max = max;
+		}
+
+		/**
+		 * Constructs a new ``Range`` with relative coordinates.
+		 * @param min minimum/low limit.
+		 * @param range length of the ``Range``.
+		 */
+		public Range.with_rel (Float128 min, Float128 range) {
+			this.min = min;
+			this.range = range;
+		}
+
+		/**
+		 * Gets a copy of the ``Range``.
+		 */
+		public virtual Range copy () {
+			return new Range.with_range(this);
+		}
+
+		/**
+		 * Zooms out ``Range``.
+		 */
+		public virtual void zoom_out () {
+			zmin = min;
+			zmax = max;
+		}
+	}
+}

src/Series.vala

@@ -1,65 +1,111 @@
 using Cairo;
 
-namespace Gtk.CairoChart {
+namespace CairoChart {
 
+	/**
+	 * ``Chart`` series.
+	 */
 	public class Series {
 
-		public Point[] points = {};
+		protected unowned Chart chart { get; protected set; default = null; }
-		public enum Sort {
-			BY_X = 0,
-			BY_Y = 1,
-			NO_SORT
-		}
-		public Sort sort = Sort.BY_X;
 
-		public Axis axis_x = new Axis();
+		/**
-		public Axis axis_y = new Axis();
+		 * Title of the ``Chart``.
-
+		 */
-		public enum MarkerType {
+		public Text title;
-			NONE = 0,	// default
-			SQUARE,
-			CIRCLE,
-			TRIANGLE,
-			PRICLE_SQUARE,
-			PRICLE_CIRCLE,
-			PRICLE_TRIANGLE
-		}
-
-		public Place place = new Place();
-		public Text title = new Text ();
-		public MarkerType marker_type = MarkerType.SQUARE;
-
-		public Grid grid = new Grid ();
 
+		/**
+		 * ``Series`` line style.
+		 */
 		public LineStyle line_style = LineStyle ();
 
-		protected Color _color = Color (0.0, 0.0, 0.0, 1.0);
+		/**
-		public Color color {
+		 * 128-bit (X;Y) points.
-			get { return _color; }
+		 */
-			set {
+		public Point128[] points = {};
-				_color = value;
+
-				line_style.color = _color;
+		/**
-				axis_x.color = _color;
+		 * ``Marker`` style.
-				axis_y.color = _color;
+		 */
-				grid.color = _color;
+		public Marker marker;
-				grid.color.alpha = 0.5;
+
-				grid.line_style.color = _color;
+		/**
-				grid.line_style.color.alpha = 0.5;
+		 * Sort style.
-			}
+		 */
-			default = Color (0.0, 0.0, 0.0, 1.0);
+		public enum Sort {
+			/**
+			 * Sort by X.
+			 */
+			BY_X = 0,
+
+			/**
+			 * Sort by Y.
+			 */
+			BY_Y = 1,
+
+			/**
+			 * Do not sort points on draw().
+			 */
+			UNSORTED
 		}
 
+		/**
+		 * Sort style.
+		 */
+		public Sort sort = Sort.BY_X;
+
+		/**
+		 * X-axis.
+		 */
+		public Axis axis_x;
+
+		/**
+		 * Y-axis.
+		 */
+		public Axis axis_y;
+
+		/**
+		 * ``Series`` color (set only).
+		 */
+		public Color color {
+			protected get { return Color(); }
+			set {
+				line_style.color = value;
+				axis_x.color = value;
+				axis_y.color = value;
+				axis_x.grid_style.color.red = axis_y.grid_style.color.red = value.red;
+				axis_x.grid_style.color.green = axis_y.grid_style.color.green = value.green;
+				axis_x.grid_style.color.blue = axis_y.grid_style.color.blue = value.blue;
+			}
+			default = Color (0, 0, 0, 1);
+		}
+
+		/**
+		 * Show the ``Series`` in zoomed area or not.
+		 */
 		public bool zoom_show = true;
 
-		public Series copy () {
+		/**
-			var series = new Series ();
+		 * Constructs a new ``Series``.
-			series._color = this._color;
+		 * @param chart ``Chart`` instance.
+		 */
+		public Series (Chart chart) {
+			this.chart = chart;
+			title = new Text(chart);
+			axis_x = new Axis(chart, this, true);
+			axis_y = new Axis(chart, this, false);
+			this.marker = new Marker(chart);
+		}
+
+		/**
+		 * Gets a copy of the ``Series``.
+		 */
+		public virtual Series copy () {
+			var series = new Series (chart);
 			series.axis_x = this.axis_x.copy ();
 			series.axis_y = this.axis_y.copy ();
-			series.grid = this.grid.copy ();
 			series.line_style = this.line_style;
-			series.marker_type = this.marker_type;
+			series.marker = this.marker;
-			series.place = this.place.copy();
 			series.points = this.points;
 			series.sort = this.sort;
 			series.title = this.title.copy();
@@ -67,7 +113,58 @@ namespace Gtk.CairoChart {
 			return series;
 		}
 
-		public Series () {
+		/**
+		 * Gets screen point by real ``Series`` (X;Y) value.
+		 * @param p real ``Series`` (X;Y) value.
+		 */
+		public virtual Point scr_pnt (Point128 p) {
+			return Point(axis_x.scr_pos(p.x), axis_y.scr_pos(p.y));
+		}
+
+		/**
+		 * Gets real ``Series`` (X;Y) value by plot area screen point.
+		 * @param p (X;Y) screen point.
+		 */
+		public virtual Point128 axis_pnt (Point p) {
+			return Point128 (axis_x.axis_val(p.x), axis_y.axis_val(p.y));
+		}
+
+		/**
+		 * Draws the ``Series``.
+		 */
+		public virtual void draw () {
+			var points = Math.sort_points(this, sort);
+			line_style.apply(chart);
+			// draw series line
+			for (int i = 1; i < points.length; ++i) {
+				Point c, d;
+				if (Math.cut_line (
+				        Point(chart.plarea.x0, chart.plarea.y0),
+				        Point(chart.plarea.x1, chart.plarea.y1),
+				        scr_pnt(points[i-1]),
+				        scr_pnt(points[i]),
+				        out c, out d)
+				) {
+					chart.ctx.move_to (c.x, c.y);
+					chart.ctx.line_to (d.x, d.y);
+				}
+			}
+			chart.ctx.stroke();
+			for (int i = 0; i < points.length; ++i) {
+				var p = scr_pnt(points[i]);
+				if (Math.point_in_rect (p, chart.plarea.x0, chart.plarea.x1,
+				                           chart.plarea.y0, chart.plarea.y1))
+					marker.draw_at_pos(p);
+			}
+		}
+
+		/**
+		 * Zooms out the ``Series``.
+		 */
+		public virtual void zoom_out () {
+				zoom_show = true;
+				axis_x.zoom_out();
+				axis_y.zoom_out();
 		}
 	}
 }

src/Text.vala

@@ -1,85 +1,142 @@
-namespace Gtk.CairoChart {
+namespace CairoChart {
-	[Compact]
+
+	/**
+	 * ``CairoChart`` Text.
+	 */
 	public class Text {
-		public string text = "";
+
-		public FontStyle style = FontStyle ();
+		protected unowned Chart chart;
+		protected string _text;
+		protected Font _font;
+		protected Cairo.TextExtents? _ext;
+
+		/**
+		 * ``Text`` string.
+		 */
+		public virtual string text {
+			get {
+				return _text;
+			}
+			set {
+				_text = value;
+				_ext = null;
+			}
+		}
+
+		/**
+		 * ``Text`` font style.
+		 */
+		public virtual Font font {
+			get {
+				return _font;
+			}
+			set {
+				_font = value;
+				_font.notify.connect((s, p) => {
+					_ext = null;
+				});
+				_ext = null;
+			}
+		}
+
+		/**
+		 * ``Text`` color.
+		 */
 		public Color color = Color();
 
-		public Cairo.TextExtents get_extents (Cairo.Context context) {
+		/**
-			context.select_font_face (style.family,
+		 * Cairo ``Text`` extents.
-			                          style.slant,
+		 */
-			                          style.weight);
+		protected virtual Cairo.TextExtents ext {
-			context.set_font_size (style.size);
+			get {
-			Cairo.TextExtents extents;
+				if (_ext == null) {
-			context.text_extents (text, out extents);
+					chart.ctx.select_font_face (font.family, font.slant, font.weight);
-			return extents;
+					chart.ctx.set_font_size (font.size);
-		}
+					chart.ctx.text_extents (text, out _ext);
-
+				}
-		public double get_width (Cairo.Context context) {
+				return _ext;
-			var extents = get_extents (context);
+			}
-			switch (style.orientation) {
+			protected set {
-			case FontOrient.HORIZONTAL: return extents.width;
-			case FontOrient.VERTICAL: return extents.height;
-			default: return 0.0;
 			}
 		}
 
-		public double get_height (Cairo.Context context) {
+		/**
-			var extents = get_extents (context);
+		 * ``Text`` width.
-			switch (style.orientation) {
+		 */
-			case FontOrient.HORIZONTAL: return extents.height;
+		public virtual double width {
-			case FontOrient.VERTICAL: return extents.width;
+			get {
-			default: return 0.0;
+				switch (font.orient) {
+				case Gtk.Orientation.HORIZONTAL: return ext.width + ext.x_bearing;
+				case Gtk.Orientation.VERTICAL: return ext.height;
+				default: return 0;
+				}
+			}
+			protected set {
 			}
 		}
 
-		public double get_x_bearing (Cairo.Context context) {
+		/**
-			var extents = get_extents (context);
+		 * ``Text`` height.
-			switch (style.orientation) {
+		 */
-			case FontOrient.HORIZONTAL: return extents.x_bearing;
+		public virtual double height {
-			case FontOrient.VERTICAL: return extents.y_bearing;
+			get {
-			default: return 0.0;
+				switch (font.orient) {
+				case Gtk.Orientation.HORIZONTAL: return ext.height; // + ext.x_bearing ?
+				case Gtk.Orientation.VERTICAL: return ext.width;    // +- ext.y_bearing ?
+				default: return 0;
+				}
+			}
+			protected set {
 			}
 		}
 
-		public struct Size {
+		/**
-			double width;
+		 * Constructs a new ``Text``.
-			double height;
+		 * @param chart ``Chart`` instance.
-			double x_bearing;
+		 * @param text ``Text`` string.
-		}
+		 * @param font ``Text`` font style.
-
+		 * @param color ``Text`` color.
-		public Size size (Cairo.Context context) {
+		 */
-			var sz = Size();
+		public Text (Chart chart,
-			var extents = get_extents (context);
+		             string text = "",
-			switch (style.orientation) {
+		             Font font = new Font(),
-			case FontOrient.HORIZONTAL:
+		             Color color = Color()
-				sz.width = extents.width;
+		) {
-				sz.height = extents.height;
+			this.chart = chart;
-				sz.x_bearing = extents.x_bearing;
-				break;
-			case FontOrient.VERTICAL:
-				sz.width = extents.height;
-				sz.height = extents.width;
-				sz.x_bearing = extents.y_bearing;
-				break;
-			}
-			return sz;
-		}
-
-		public Text (string text = "",
-		             FontStyle style = FontStyle(),
-		             Color color = Color()) {
 			this.text = text;
-			this.style = style;
+			this.font = font;
 			this.color = color;
 		}
 
-		public Text copy () {
+		/**
-			var text = new Text ();
+		 * Gets a copy of the ``Text``.
+		 */
+		public virtual Text copy () {
+			var text = new Text (chart);
+			text.chart = this.chart;
 			text.text = this.text;
-			text.style = this.style;
+			text.font = this.font.copy();
+			text._ext = this._ext;
 			text.color = this.color;
 			return text;
 		}
+
+		/**
+		 * Show ``Text``.
+		 */
+		public virtual void show () {
+			if (text == "") return;
+			chart.ctx.select_font_face(font.family,
+			                           font.slant,
+			                           font.weight);
+			chart.ctx.set_font_size(font.size);
+			if (font.orient == Gtk.Orientation.VERTICAL) {
+				chart.ctx.rotate(- GLib.Math.PI / 2);
+				chart.ctx.show_text(text);
+				chart.ctx.rotate(GLib.Math.PI / 2);
+			} else {
+				chart.ctx.show_text(text);
+			}
+		}
 	}
 }

src/cairo-chart-float128type.vapi

@@ -1,6 +1,14 @@
-namespace Gtk.CairoChart {
+namespace CairoChart {
+
+	/**
+	 * 128-bit float type.
+	 */
 	[CCode (cname = "cairo_chart_float128", has_type_id = false, cheader_filename = "cairo-chart-float128type.h")]
 	public struct Float128 : double {}
+
+	/**
+	 * Long Double float type.
+	 */
 	[CCode (cname = "cairo_chart_long_double", has_type_id = false, cheader_filename = "cairo-chart-float128type.h")]
 	public struct LongDouble : double {}
 }

test/ChartTest.vala

@@ -1,211 +1,247 @@
 using Gtk, CairoChart;
 
 void plot_chart1 (Chart chart) {
-	var s1 = new Series ();
+	chart.title.text = "Chart №1";
-	var s2 = new Series ();
+	var s1 = new Series (chart);
-	var s3 = new Series ();
+	var s2 = new Series (chart);
+	var s3 = new Series (chart);
 
-	s1.title = new Text("Series 1"); s1.color = Color (1, 0, 0);
+	s1.title = new Text(chart, "Series 1"); s1.color = Color (1, 0, 0);
-	s1.points = {Point(0, 0), Point(2, 1), Point(1, 3)};
+	s1.points = {Point128(0, 0), Point128(2, 1), Point128(1, 3)};
 	s1.axis_x.position = Axis.Position.HIGH;
 	s1.axis_x.format = "%.3Lf";
-	s2.title = new Text("Series 2"); s2.color = Color (0, 1, 0);
+	s2.title = new Text(chart, "Series 2"); s2.color = Color (0, 1, 0);
-	s2.points = {Point(5, -3), Point(25, -18), Point(-11, 173)};
+	s2.points = {Point128(5, -3), Point128(25, -18), Point128(-11, 173)};
-	s3.title = new Text("Series 3"); s3.color = Color (0, 0, 1);
+	s3.title = new Text(chart, "Series 3"); s3.color = Color (0, 0, 1);
-	s3.points = {Point(9, 17), Point(2, 10), Point(122, 31)};
+	s3.points = {Point128(9, 17), Point128(2, 10), Point128(122, 31)};
 	s3.axis_y.position = Axis.Position.HIGH;
 
-	s1.axis_x.min = 0; s1.axis_x.max = 2;
+	s1.axis_x.range.min = 0; s1.axis_x.range.max = 2;
-	s1.axis_y.min = 0; s1.axis_y.max = 3;
+	s1.axis_y.range.min = 0; s1.axis_y.range.max = 3;
-	s1.place.x_low = 0.25; s1.place.x_high = 0.75;
+	s1.axis_x.place.min = 0.25; s1.axis_x.place.max = 0.75;
-	s1.place.y_low = 0.3; s1.place.y_high = 0.9;
+	s1.axis_y.place.min = 0.3; s1.axis_y.place.max = 0.9;
 
-	s2.axis_x.min = -15; s2.axis_x.max = 30;
+	s2.axis_x.range.min = -15; s2.axis_x.range.max = 30;
-	s2.axis_y.min = -20; s2.axis_y.max = 200;
+	s2.axis_y.range.min = -20; s2.axis_y.range.max = 200;
-	s2.place.x_low = 0.5; s2.place.x_high = 1;
+	s2.axis_x.place.min = 0.5; s2.axis_x.place.max = 1;
-	s2.place.y_low = 0.0; s2.place.y_high = 0.5;
+	s2.axis_y.place.min = 0.0; s2.axis_y.place.max = 0.5;
 
-	s3.axis_x.min = 0; s3.axis_x.max = 130;
+	s3.axis_x.range.min = 0; s3.axis_x.range.max = 130;
-	s3.axis_y.min = 15; s3.axis_y.max = 35;
+	s3.axis_y.range.min = 15; s3.axis_y.range.max = 35;
-	s3.place.x_low = 0; s3.place.x_high = 0.5;
+	s3.axis_x.place.min = 0; s3.axis_x.place.max = 0.5;
-	s3.place.y_low = 0.5; s3.place.y_high = 1.0;
+	s3.axis_y.place.min = 0.5; s3.axis_y.place.max = 1.0;
 
-	s2.marker_type = Series.MarkerType.CIRCLE;
+	s1.marker.shape = Marker.Shape.SQUARE;
-	s3.marker_type = Series.MarkerType.PRICLE_TRIANGLE;
+	s2.marker.shape = Marker.Shape.CIRCLE;
+	s3.marker.shape = Marker.Shape.PRICLE_TRIANGLE;
 
-	s1.axis_x.title = new Text("Series 1: Axis X.");
+	s1.axis_x.title = new Text(chart, "Series 1: Axis X.");
-	s1.axis_y.title = new Text("Series 1: Axis Y.");
+	s1.axis_y.title = new Text(chart, "Series 1: Axis Y.");
-	s2.axis_x.title = new Text("Series 2: Axis X.");
+	s2.axis_x.title = new Text(chart, "Series 2: Axis X.");
-	s2.axis_y.title = new Text("Series 2: Axis Y.");
+	s2.axis_y.title = new Text(chart, "Series 2: Axis Y.");
-	s3.axis_x.title = new Text("Series 3: Axis X.");
+	s3.axis_x.title = new Text(chart, "Series 3: Axis X.");
-	s3.axis_y.title = new Text("Series 3: Axis Y.");
+	s3.axis_y.title = new Text(chart, "Series 3: Axis Y.");
 
 	chart.series = { s1, s2, s3 };
+
+	chart.title.font.size = 24;
+	//chart.legend.show = false;
+	s1.title.font.size = 16;
+	s2.title.font.size = 16;
+	s2.title.font.slant = Cairo.FontSlant.ITALIC;
+	s2.title.font.weight = Cairo.FontWeight.BOLD;
+	s3.title.font.size = 18;
+	s1.axis_x.title.font.size = 14;
+	s2.axis_x.title.font.size = 14;
+	s2.axis_x.title.font.slant = Cairo.FontSlant.ITALIC;
+	s2.axis_x.title.font.weight = Cairo.FontWeight.BOLD;
+	s3.axis_x.title.font.size = 18;
+	s1.axis_y.title.font.size = 14;
+	s2.axis_y.title.font.size = 14;
+	s2.axis_y.title.font.slant = Cairo.FontSlant.ITALIC;
+	s2.axis_y.title.font.weight = Cairo.FontWeight.BOLD;
+	s3.axis_y.title.font.size = 18;
+	s1.axis_x.font.size = 12;
+	s2.axis_x.font.size = 12;
+	s3.axis_x.font.size = 12;
+	s1.axis_y.font.size = 12;
+	s2.axis_y.font.size = 12;
+	s3.axis_y.font.size = 14;
+	s1.marker.size = 6;
+	s2.marker.size = 8;
+	s3.marker.size = 7;
+	s3.line_style.width = 2;
 }
 
 void plot_chart2 (Chart chart) {
-	var s1 = new Series ();
+	var s1 = new Series (chart);
-	var s2 = new Series ();
+	var s2 = new Series (chart);
-	var s3 = new Series ();
+	var s3 = new Series (chart);
 
-	s1.title = new Text("Series 1"); s1.color = Color (1, 0, 0);
+	s1.title = new Text(chart, "Series 1"); s1.color = Color (1, 0, 0);
-	s1.points = {Point(-12, 0), Point(2, 1), Point(20, 3)};
+	s1.points = {Point128(-12, 0), Point128(2, 1), Point128(20, 3)};
 	s2.axis_y.position = Axis.Position.HIGH;
 	s1.axis_x.format = "%.3Lf";
-	s2.title = new Text("Series 2"); s2.color = Color (0, 1, 0);
+	s2.title = new Text(chart, "Series 2"); s2.color = Color (0, 1, 0);
-	s2.points = {Point(5, -3), Point(25, -18), Point(-11, 173)};
+	s2.points = {Point128(5, -3), Point128(25, -18), Point128(-11, 173)};
-	s3.title = new Text("Series 3"); s3.color = Color (0, 0, 1);
+	s3.title = new Text(chart, "Series 3"); s3.color = Color (0, 0, 1);
-	s3.points = {Point(9, 17), Point(2, 10), Point(-15, 31)};
+	s3.points = {Point128(9, 17), Point128(2, 10), Point128(-15, 31)};
 	s3.axis_y.position = Axis.Position.HIGH;
 
-	s1.axis_x.min = -15; s1.axis_x.max = 30;
+	s1.axis_x.range.min = -15; s1.axis_x.range.max = 30;
-	s1.axis_y.min = 0; s1.axis_y.max = 3;
+	s1.axis_y.range.min = 0; s1.axis_y.range.max = 3;
-	s1.place.x_low = 0.0; s1.place.x_high = 1.0;
+	s1.axis_x.place.min = 0.0; s1.axis_x.place.max = 1.0;
-	s1.place.y_low = 0.3; s1.place.y_high = 0.9;
+	s1.axis_y.place.min = 0.3; s1.axis_y.place.max = 0.9;
 
-	s2.axis_x.min = -15; s2.axis_x.max = 30;
+	s2.axis_x.range.min = -15; s2.axis_x.range.max = 30;
-	s2.axis_y.min = -20; s2.axis_y.max = 200;
+	s2.axis_y.range.min = -20; s2.axis_y.range.max = 200;
-	s2.place.x_low = 0.0; s2.place.x_high = 1.0;
+	s2.axis_x.place.min = 0.0; s2.axis_x.place.max = 1.0;
-	s2.place.y_low = 0.0; s2.place.y_high = 0.5;
+	s2.axis_y.place.min = 0.0; s2.axis_y.place.max = 0.5;
 
-	s3.axis_x.min = -15; s3.axis_x.max = 30;
+	s3.axis_x.range.min = -15; s3.axis_x.range.max = 30;
-	s3.axis_y.min = 15; s3.axis_y.max = 35;
+	s3.axis_y.range.min = 15; s3.axis_y.range.max = 35;
-	s3.place.x_low = 0.0; s3.place.x_high = 1.0;
+	s3.axis_x.place.min = 0.0; s3.axis_x.place.max = 1.0;
-	s3.place.y_low = 0.5; s3.place.y_high = 1.0;
+	s3.axis_y.place.min = 0.5; s3.axis_y.place.max = 1.0;
 
-	s1.marker_type = Series.MarkerType.PRICLE_CIRCLE;
+	s1.marker.shape = Marker.Shape.PRICLE_CIRCLE;
-	s2.marker_type = Series.MarkerType.PRICLE_SQUARE;
+	s2.marker.shape = Marker.Shape.PRICLE_SQUARE;
+	s3.marker.shape = Marker.Shape.SQUARE;
 
-	s1.axis_x.title = new Text("All Series: Axis X.");
+	s1.axis_x.title = new Text(chart, "All Series: Axis X.");
-	s1.axis_y.title = new Text("Series 1: Axis Y.");
+	s1.axis_y.title = new Text(chart, "Series 1: Axis Y.");
-	s2.axis_x.title = new Text("All Series: Axis X.");
+	s2.axis_x.title = new Text(chart, "All Series: Axis X.");
-	s2.axis_y.title = new Text("Series 2: Axis Y.");
+	s2.axis_y.title = new Text(chart, "Series 2: Axis Y.");
-	s3.axis_x.title = new Text("All Series: Axis X.");
+	s3.axis_x.title = new Text(chart, "All Series: Axis X.");
-	s3.axis_y.title = new Text("Series 3: Axis Y.");
+	s3.axis_y.title = new Text(chart, "Series 3: Axis Y.");
 
 	//s1.axis_x.position = s2.axis_x.position = s3.axis_x.position = Axis.Position.HIGH;
-	//s1.axis_x.type = s2.axis_x.type = s3.axis_x.type = Axis.Type.DATE_TIME;
+	//s1.axis_x.dtype = s2.axis_x.dtype = s3.axis_x.dtype = Axis.DType.DATE_TIME;
-	//s1.axis_x.max = s2.axis_x.max = s3.axis_x.max = 5*24*3600;
+	//s1.axis_x.range.max = s2.axis_x.range.max = s3.axis_x.range.max = 5*24*3600;
 
 	chart.series = { s1, s2, s3 };
 }
 
 void plot_chart3 (Chart chart) {
-	var s1 = new Series ();
+	var s1 = new Series (chart);
-	var s2 = new Series ();
+	var s2 = new Series (chart);
-	var s3 = new Series ();
+	var s3 = new Series (chart);
 
-	s1.title = new Text("Series 1"); s1.color = Color (1, 0, 0);
+	s1.title = new Text(chart, "Series 1"); s1.color = Color (1, 0, 0);
-	s1.points = {Point(0, 70), Point(2, 155), Point(1, -3)};
+	s1.points = {Point128(0, 70), Point128(2, 155), Point128(1, -3)};
 	s1.axis_x.position = Axis.Position.HIGH;
 	s1.axis_y.position = Axis.Position.HIGH;
 	s1.axis_x.format = "%.3Lf";
-	s2.title = new Text("Series 2"); s2.color = Color (0, 1, 0);
+	s2.title = new Text(chart, "Series 2"); s2.color = Color (0, 1, 0);
-	s2.points = {Point(5, -3), Point(25, -18), Point(-11, 173)};
+	s2.points = {Point128(5, -3), Point128(25, -18), Point128(-11, 173)};
 	s2.axis_y.position = Axis.Position.HIGH;
-	s3.title = new Text("Series 3"); s3.color = Color (0, 0, 1);
+	s3.title = new Text(chart, "Series 3"); s3.color = Color (0, 0, 1);
-	s3.points = {Point(9, -17), Point(2, 10), Point(122, 31)};
+	s3.points = {Point128(9, -17), Point128(2, 10), Point128(122, 31)};
 	s3.axis_y.position = Axis.Position.HIGH;
 
-	s1.axis_x.min = 0; s1.axis_x.max = 2;
+	s1.axis_x.range.min = 0; s1.axis_x.range.max = 2;
-	s1.axis_y.min = -20; s1.axis_y.max = 200;
+	s1.axis_y.range.min = -20; s1.axis_y.range.max = 200;
-	s1.place.x_low = 0.25; s1.place.x_high = 0.75;
+	s1.axis_x.place.min = 0.25; s1.axis_x.place.max = 0.75;
-	s1.place.y_low = 0.0; s1.place.y_high = 1.0;
+	s1.axis_y.place.min = 0.0; s1.axis_y.place.max = 1.0;
 
-	s2.axis_x.min = -15; s2.axis_x.max = 30;
+	s2.axis_x.range.min = -15; s2.axis_x.range.max = 30;
-	s2.axis_y.min = -20; s2.axis_y.max = 200;
+	s2.axis_y.range.min = -20; s2.axis_y.range.max = 200;
-	s2.place.x_low = 0.5; s2.place.x_high = 1;
+	s2.axis_x.place.min = 0.5; s2.axis_x.place.max = 1;
-	s2.place.y_low = 0.0; s2.place.y_high = 1.0;
+	s2.axis_y.place.min = 0.0; s2.axis_y.place.max = 1.0;
 
-	s3.axis_x.min = 0; s3.axis_x.max = 130;
+	s3.axis_x.range.min = 0; s3.axis_x.range.max = 130;
-	s3.axis_y.min = -20; s3.axis_y.max = 200;
+	s3.axis_y.range.min = -20; s3.axis_y.range.max = 200;
-	s3.place.x_low = 0; s3.place.x_high = 0.5;
+	s3.axis_x.place.min = 0; s3.axis_x.place.max = 0.5;
-	s3.place.y_low = 0.0; s3.place.y_high = 1.0;
+	s3.axis_y.place.min = 0.0; s3.axis_y.place.max = 1.0;
 
-	s2.marker_type = Series.MarkerType.PRICLE_CIRCLE;
+	s1.marker.shape = Marker.Shape.SQUARE;
-	s3.marker_type = Series.MarkerType.TRIANGLE;
+	s2.marker.shape = Marker.Shape.PRICLE_CIRCLE;
+	s3.marker.shape = Marker.Shape.TRIANGLE;
 
-	s1.axis_x.title = new Text("Series 1: Axis X.");
+	s1.axis_x.title = new Text(chart, "Series 1: Axis X.");
-	s1.axis_y.title = new Text("Series 1: Axis Y.");
+	s1.axis_y.title = new Text(chart, "All Series: Axis Y.");
-	s2.axis_x.title = new Text("Series 2: Axis X.");
+	s2.axis_x.title = new Text(chart, "Series 2: Axis X.");
-	s2.axis_y.title = new Text("Series 2: Axis Y.");
+	s2.axis_y.title = new Text(chart, "All Series: Axis Y.");
-	s3.axis_x.title = new Text("Series 3: Axis X.");
+	s3.axis_x.title = new Text(chart, "Series 3: Axis X.");
-	s3.axis_y.title = new Text("Series 3: Axis Y.");
+	s3.axis_y.title = new Text(chart, "All Series: Axis Y.");
 
 	//s1.axis_y.position = s2.axis_y.position = s3.axis_y.position = Axis.Position.LOW;
+	chart.cursors.style.orientation = Cursors.Orientation.HORIZONTAL;
 
 	chart.series = { s1, s2, s3 };
 }
 
 void plot_chart4 (Chart chart) {
-	var s1 = new Series ();
+	var s1 = new Series (chart);
-	var s2 = new Series ();
+	var s2 = new Series (chart);
-	var s3 = new Series ();
+	var s3 = new Series (chart);
-	var s4 = new Series ();
+	var s4 = new Series (chart);
 
-	s1.axis_x.type = Axis.Type.DATE_TIME;
+	s1.axis_x.dtype = Axis.DType.DATE_TIME;
-	s3.axis_x.type = Axis.Type.DATE_TIME;
+	s3.axis_x.dtype = Axis.DType.DATE_TIME;
-	s4.axis_x.type = Axis.Type.DATE_TIME;
+	s4.axis_x.dtype = Axis.DType.DATE_TIME;
 	s4.axis_x.dsec_signs = 5;
 
 	var now = new DateTime.now_local().to_unix();
 	var high = (uint64) (253000000000L);
 
-	s1.title = new Text("Series 1"); s1.color = Color (1, 0, 0);
+	s1.title = new Text(chart, "Series 1"); s1.color = Color (1, 0, 0);
-	s1.points = {Point(now, 70), Point(now - 100000, 155), Point(now + 100000, 30)};
+	s1.points = {Point128(now, 70), Point128(now - 100000, 155), Point128(now + 100000, 30)};
 	s1.axis_x.position = Axis.Position.HIGH;
 	s1.axis_y.position = Axis.Position.HIGH;
-	s2.title = new Text("Series 2"); s2.color = Color (0, 1, 0);
+	s2.title = new Text(chart, "Series 2"); s2.color = Color (0, 1, 0);
-	s2.points = {Point(5, -3), Point(25, -18), Point(-11, 173)};
+	s2.points = {Point128(5, -3), Point128(25, -18), Point128(-11, 173)};
 	s2.axis_y.position = Axis.Position.HIGH;
-	s3.title = new Text("Series 3"); s3.color = Color (0, 0, 1);
+	s3.title = new Text(chart, "Series 3"); s3.color = Color (0, 0, 1);
-	s3.points = {Point(high - 2 + 0.73, -17), Point(high - 1 + 0.234, 10), Point(high + 1 + 0.411, 31)};
+	s3.points = {Point128(high - 2 + 0.73, -17), Point128(high - 1 + 0.234, 10), Point128(high + 1 + 0.411, 31)};
 	s3.axis_y.position = Axis.Position.HIGH;
-	s4.title = new Text("Series 4"); s4.color = Color (0.5, 0.3, 0.9);
+	s4.title = new Text(chart, "Series 4"); s4.color = Color (0.5, 0.3, 0.9);
-	s4.points = {Point(high + 0.005, -19.05), Point(high + 0.0051, 28), Point(high + 0.0052, 55), Point(high + 0.0053, 44)};
+	s4.points = {Point128(high + 0.005, -19.05), Point128(high + 0.0051, 28), Point128(high + 0.0052, 55), Point128(high + 0.0053, 44)};
 	s4.axis_y.position = Axis.Position.HIGH;
 
-	s1.axis_x.min = now - 100000; s1.axis_x.max = now + 100000;
+	s1.axis_x.range.min = now - 100000; s1.axis_x.range.max = now + 100000;
-	s1.axis_y.min = -20; s1.axis_y.max = 200;
+	s1.axis_y.range.min = -20; s1.axis_y.range.max = 200;
-	s1.place.x_low = 0.25; s1.place.x_high = 0.75;
+	s1.axis_x.place.min = 0.25; s1.axis_x.place.max = 0.75;
-	s1.place.y_low = 0.0; s1.place.y_high = 1.0;
+	s1.axis_y.place.min = 0.0; s1.axis_y.place.max = 1.0;
 
-	s2.axis_x.min = -15; s2.axis_x.max = 30;
+	s2.axis_x.range.min = -15; s2.axis_x.range.max = 30;
-	s2.axis_y.min = -20; s2.axis_y.max = 200;
+	s2.axis_y.range.min = -20; s2.axis_y.range.max = 200;
-	s2.place.x_low = 0.2; s2.place.x_high = 1;
+	s2.axis_x.place.min = 0.2; s2.axis_x.place.max = 1;
-	s2.place.y_low = 0.0; s2.place.y_high = 1.0;
+	s2.axis_y.place.min = 0.0; s2.axis_y.place.max = 1.0;
 
-	s3.axis_x.min = high - 2; s3.axis_x.max = high + 1;
+	s3.axis_x.range.min = high - 2; s3.axis_x.range.max = high + 1;
-	s3.axis_y.min = -20; s3.axis_y.max = 200;
+	s3.axis_y.range.min = -20; s3.axis_y.range.max = 200;
-	s3.place.x_low = 0; s3.place.x_high = 0.8;
+	s3.axis_x.place.min = 0; s3.axis_x.place.max = 0.8;
-	s3.place.y_low = 0.0; s3.place.y_high = 1.0;
+	s3.axis_y.place.min = 0.0; s3.axis_y.place.max = 1.0;
 
-	s4.axis_x.min = high + 0.0049; s4.axis_x.max = high + 0.0054;
+	s4.axis_x.range.min = high + 0.0049; s4.axis_x.range.max = high + 0.0054;
-	s4.axis_y.min = -20; s4.axis_y.max = 200;
+	s4.axis_y.range.min = -20; s4.axis_y.range.max = 200;
-	s4.place.x_low = 0.2; s4.place.x_high = 1.0;
+	s4.axis_x.place.min = 0.2; s4.axis_x.place.max = 1.0;
-	s4.place.y_low = 0.0; s4.place.y_high = 1.0;
+	s4.axis_y.place.min = 0.0; s4.axis_y.place.max = 1.0;
 
-	s2.marker_type = Series.MarkerType.PRICLE_CIRCLE;
+	s1.marker.shape = Marker.Shape.SQUARE;
-	s3.marker_type = Series.MarkerType.TRIANGLE;
+	s2.marker.shape = Marker.Shape.PRICLE_CIRCLE;
-	s4.marker_type = Series.MarkerType.PRICLE_SQUARE;
+	s3.marker.shape = Marker.Shape.TRIANGLE;
+	s4.marker.shape = Marker.Shape.PRICLE_SQUARE;
 
-	s1.axis_x.title = new Text("Series 1: Axis X.");
+	s1.axis_x.title = new Text(chart, "Series 1: Axis X.");
-	s1.axis_y.title = new Text("Series 1: Axis Y.");
+	s1.axis_y.title = new Text(chart, "All Series: Axis Y.");
-	s2.axis_x.title = new Text("Series 2: Axis X.");
+	s2.axis_x.title = new Text(chart, "Series 2: Axis X.");
-	s2.axis_y.title = new Text("Series 2: Axis Y.");
+	s2.axis_y.title = new Text(chart, "All Series: Axis Y.");
-	s3.axis_x.title = new Text("Series 3: Axis X.");
+	s3.axis_x.title = new Text(chart, "Series 3: Axis X.");
-	s3.axis_y.title = new Text("Series 3: Axis Y.");
+	s3.axis_y.title = new Text(chart, "All Series: Axis Y.");
-	s4.axis_x.title = new Text("Series 4: Axis X.");
+	s4.axis_x.title = new Text(chart, "Series 4: Axis X.");
-	s4.axis_y.title = new Text("Series 4: Axis Y.");
+	s4.axis_y.title = new Text(chart, "All Series: Axis Y.");
+
+	chart.cursors.style.orientation = Cursors.Orientation.HORIZONTAL;
 
 	chart.series = { s1, s2, s3, s4 };
 }
 
 bool point_in_chart (Chart chart, double x, double y) {
-	if (x < chart.plot_area_x_min) return false;
+	if (x < chart.plarea.x0) return false;
-	if (x > chart.plot_area_x_max) return false;
+	if (x > chart.plarea.x1) return false;
-	if (y < chart.plot_area_y_min) return false;
+	if (y < chart.plarea.y0) return false;
-	if (y > chart.plot_area_y_max) return false;
+	if (y > chart.plarea.y1) return false;
 	return true;
 }
 
@@ -230,10 +266,10 @@ int main (string[] args) {
 	var chart2 = new Chart();
 	var chart3 = new Chart();
 	var chart4 = new Chart();
-	var label = new Label ("Chart Test!");
+	var label = new Gtk.Label ("Chart Test!");
 	var button1 = new Button.with_label("Separate axes");
-	var button2 = new Button.with_label("Common X axes");
+	var button2 = new Button.with_label("Joint X axes");
-	var button3 = new Button.with_label("Common Y axes");
+	var button3 = new Button.with_label("Joint Y axes");
 	var button4 = new Button.with_label("Dates/Times");
 	var button5 = new Button.with_label("rm Axis Titles");
 	var button6 = new Button.with_label("Dates only");
@@ -245,12 +281,13 @@ int main (string[] args) {
 	plot_chart3 (chart3);
 	plot_chart4 (chart4);
 
-	chart1.selection_style = LineStyle(Color(0.3, 0.3, 0.3, 0.7), 1);
+	chart1.selection_style = LineStyle(Color(0.3, 0.3, 0.3, 0.7));
 
 	var da = new DrawingArea();
 	da.set_events ( Gdk.EventMask.BUTTON_PRESS_MASK
 	               |Gdk.EventMask.BUTTON_RELEASE_MASK
 	               |Gdk.EventMask.POINTER_MOTION_MASK
+	               |Gdk.EventMask.SCROLL_MASK
 	);
 
 	var chart = chart1;
@@ -270,9 +307,9 @@ int main (string[] args) {
 			case Legend.Position.LEFT: radio_button3.set_active(true); break;
 			case Legend.Position.BOTTOM: radio_button4.set_active(true); break;
 			}
-			switch (chart.cursors_orientation) {
+			switch (chart.cursors.style.orientation) {
-			case Chart.CursorOrientation.VERTICAL: radio_button7.set_active(true); break;
+			case Cursors.Orientation.VERTICAL: radio_button7.set_active(true); break;
-			case Chart.CursorOrientation.HORIZONTAL: radio_button8.set_active(true); break;
+			case Cursors.Orientation.HORIZONTAL: radio_button8.set_active(true); break;
 			}
 	});
 	button2.clicked.connect (() => {
@@ -283,9 +320,9 @@ int main (string[] args) {
 			case Legend.Position.LEFT: radio_button3.set_active(true); break;
 			case Legend.Position.BOTTOM: radio_button4.set_active(true); break;
 			}
-			switch (chart.cursors_orientation) {
+			switch (chart.cursors.style.orientation) {
-			case Chart.CursorOrientation.VERTICAL: radio_button7.set_active(true); break;
+			case Cursors.Orientation.VERTICAL: radio_button7.set_active(true); break;
-			case Chart.CursorOrientation.HORIZONTAL: radio_button8.set_active(true); break;
+			case Cursors.Orientation.HORIZONTAL: radio_button8.set_active(true); break;
 			}
 	});
 	button3.clicked.connect (() => {
@@ -296,9 +333,9 @@ int main (string[] args) {
 			case Legend.Position.LEFT: radio_button3.set_active(true); break;
 			case Legend.Position.BOTTOM: radio_button4.set_active(true); break;
 			}
-			switch (chart.cursors_orientation) {
+			switch (chart.cursors.style.orientation) {
-			case Chart.CursorOrientation.VERTICAL: radio_button7.set_active(true); break;
+			case Cursors.Orientation.VERTICAL: radio_button7.set_active(true); break;
-			case Chart.CursorOrientation.HORIZONTAL: radio_button8.set_active(true); break;
+			case Cursors.Orientation.HORIZONTAL: radio_button8.set_active(true); break;
 			}
 	});
 	button4.clicked.connect (() => {
@@ -309,9 +346,9 @@ int main (string[] args) {
 			case Legend.Position.LEFT: radio_button4.set_active(true); break;
 			case Legend.Position.BOTTOM: radio_button4.set_active(true); break;
 			}
-			switch (chart.cursors_orientation) {
+			switch (chart.cursors.style.orientation) {
-			case Chart.CursorOrientation.VERTICAL: radio_button7.set_active(true); break;
+			case Cursors.Orientation.VERTICAL: radio_button7.set_active(true); break;
-			case Chart.CursorOrientation.HORIZONTAL: radio_button8.set_active(true); break;
+			case Cursors.Orientation.HORIZONTAL: radio_button8.set_active(true); break;
 			}
 	});
 	button5.clicked.connect (() => {
@@ -393,13 +430,13 @@ int main (string[] args) {
 
 	radio_button7.toggled.connect ((button) => {
 		if (button.get_active()) {
-			chart.cursors_orientation = Chart.CursorOrientation.VERTICAL;
+			chart.cursors.style.orientation = Cursors.Orientation.VERTICAL;
 			da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
 		}
 	});
 	radio_button8.toggled.connect ((button) => {
 		if (button.get_active()) {
-			chart.cursors_orientation = Chart.CursorOrientation.HORIZONTAL;
+			chart.cursors.style.orientation = Cursors.Orientation.HORIZONTAL;
 			da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
 		}
 	});
@@ -409,10 +446,10 @@ int main (string[] args) {
 	double sel_x0 = 0, sel_x1 = 0, sel_y0 = 0, sel_y1 = 0;
 	double mov_x0 = 0, mov_y0 = 0;
 
-	da.draw.connect((context) => {
+	da.draw.connect((ctx) => {
-		chart.context = context;
+		chart.ctx = ctx;
-		chart.width = da.get_allocated_width();
+		chart.area.width = da.get_allocated_width();
-		chart.height = da.get_allocated_height();
+		chart.area.height = da.get_allocated_height();
 		chart.clear();
 
 		// user's pre draw operations here...
@@ -422,23 +459,23 @@ int main (string[] args) {
 
 	    // user's post draw operations here...
 		if (mouse_state == MouseState.DRAW_SELECTION)
-			chart.draw_selection (sel_x0, sel_y0, sel_x1, sel_y1);
+			chart.draw_selection (new Area.with_abs(sel_x0, sel_y0, sel_x1, sel_y1));
 
 		// show delta
-		var str = chart.get_cursors_delta_str();
+		var str = chart.cursors.get_delta_str();
 		if (str != "") {
 			var text = "Δ = " + str;
-			var text_t = new Text(text);
+			var text_t = new Text(chart, text);
-			var w = text_t.get_width(context);
+			var w = text_t.width;
-			var h = text_t.get_height(context);
+			var h = text_t.height;
-			var x0 = chart.plot_area_x_max - w - 5;
+			var x0 = chart.plarea.x1 - w - 5;
-			var y0 = chart.plot_area_y_min + h + 5;
+			var y0 = chart.plarea.y0 + h + 5;
-			chart.set_source_rgba(chart.legend.bg_color);
+			chart.color = chart.legend.bg_color;
-			context.rectangle (x0, y0 - h, w, h);
+			ctx.rectangle (x0, y0 - h, w, h);
-			context.fill();
+			ctx.fill();
-			context.move_to (x0, y0);
+			ctx.move_to (x0, y0);
-			chart.set_source_rgba(chart.common_axis_color);
+			chart.color = chart.joint_color;
-			context.show_text(text);
+			ctx.show_text(text);
 		}
 
 		return true;//ret;
@@ -450,11 +487,11 @@ int main (string[] args) {
 		switch (event.button) {
 		case 1:  // start cursor position selection
 			if ((event.state & Gdk.ModifierType.SHIFT_MASK) != 0) { // remove cursor
-				chart.set_active_cursor (event.x, event.y, true);
+				chart.cursors.set_active (Point(event.x, event.y), true);
-				chart.remove_active_cursor();
+				chart.cursors.remove_active();
 				mouse_state = MouseState.FREE;
 			} else { // add cursor
-				chart.set_active_cursor (event.x, event.y);
+				chart.cursors.set_active (Point(event.x, event.y));
 				mouse_state = MouseState.CURSOR_SELECTION;
 			}
 			da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
@@ -482,11 +519,11 @@ int main (string[] args) {
 		switch (event.button) {
 		case 1:  // start cursor position selection
 			if ((event.state & Gdk.ModifierType.SHIFT_MASK) != 0) { // remove cursor
-				//chart.remove_active_cursor ();
+				//chart.remove_active ();
 				//da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
 				//mouse_state = MouseState.FREE;
 			} else { // add cursor
-				chart.add_active_cursor ();
+				chart.cursors.add_active ();
 				mouse_state = MouseState.FREE;
 			}
 			break;
@@ -495,7 +532,7 @@ int main (string[] args) {
 			sel_x1 = event.x;
 			sel_y1 = event.y;
 			if (sel_x1 > sel_x0 && sel_y1 > sel_y0)
-				chart.zoom_in (sel_x0, sel_y0, sel_x1, sel_y1);
+				chart.zoom_in (new Area.with_abs(sel_x0, sel_y0, sel_x1, sel_y1));
 			else
 				chart.zoom_out ();
 			da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
@@ -521,25 +558,32 @@ int main (string[] args) {
 
 		case MouseState.MOVING_CHART:
 			var delta_x = event.x - mov_x0, delta_y = event.y - mov_y0;
-			chart.move (delta_x, delta_y);
+			chart.move (Point(){x = delta_x, y = delta_y});
 			mov_x0 = event.x;
 			mov_y0 = event.y;
 			da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
 			break;
 
 		case MouseState.CURSOR_SELECTION:
-			chart.set_active_cursor (event.x, event.y);
+			chart.cursors.set_active (Point(event.x, event.y));
 			da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
 			break;
 		}
 
 		return true; // return ret;
 	});
-	da.add_events(Gdk.EventMask.SCROLL_MASK);
 	da.scroll_event.connect((event) => {
+		switch (event.direction) {
+		case Gdk.ScrollDirection.UP:
+			chart.zoom_scroll_in(Point(event.x, event.y));
+			break;
+		case Gdk.ScrollDirection.DOWN:
+			chart.zoom_scroll_out(Point(event.x, event.y));
+			break;
+		}
+		da.queue_draw_area(0, 0, da.get_allocated_width(), da.get_allocated_height());
 
 		//var ret = chart.scroll_notify_event(event);
-
 		return true; // return ret;
 	});