OK In progress...

src/Axis.vala

@@ -4,7 +4,8 @@ namespace CairoChart {
 	// or specify series name near the axis
 	public class Axis {
 		public Range range = new Range();
-		public Text title = new Text ("");
+		Chart chart;
+		public Text title;
 		public enum Type {
 			NUMBERS = 0,
 			DATE_TIME
@@ -65,7 +66,7 @@ namespace CairoChart {
 		public double font_spacing = 5;
 
 		public virtual Axis copy () {
-			var axis = new Axis ();
+			var axis = new Axis (chart);
 			axis._date_format = this._date_format;
 			axis._dsec_signs = this._dsec_signs;
 			axis._format = this._format;
@@ -84,7 +85,10 @@ namespace CairoChart {
 			return axis;
 		}
 
-		public Axis () {}
+		public Axis (Chart chart) {
+			this.chart = chart;
+			title = new Text (chart, "");
+		}
 
 		public int nrecords = 128;
 
@@ -103,8 +107,8 @@ namespace CairoChart {
 				Float128 x = (int64)(range.zmin + range.zrange / nrecords * i) + 1.0/3.0;
 				switch (type) {
 				case Axis.Type.NUMBERS:
-					var text = new Text (format.printf((LongDouble)x) + (horizontal ? "_" : ""), font_style);
+					var text = new Text (chart, format.printf((LongDouble)x) + (horizontal ? "_" : ""), font_style);
-					var sz = text.get_size(chart.ctx);
+					var sz = text.size;
 					max_rec_width = double.max (max_rec_width, sz.width);
 					max_rec_height = double.max (max_rec_height, sz.height);
 					break;
@@ -114,14 +118,14 @@ namespace CairoChart {
 
 					var h = 0.0;
 					if (date_format != "") {
-						var text = new Text (date + (horizontal ? "_" : ""), font_style);
+						var text = new Text (chart, date + (horizontal ? "_" : ""), font_style);
-						var sz = text.get_size(chart.ctx);
+						var sz = text.size;
 						max_rec_width = double.max (max_rec_width, sz.width);
 						h = sz.height;
 					}
 					if (time_format != "") {
-						var text = new Text (time + (horizontal ? "_" : ""), font_style);
+						var text = new Text (chart, time + (horizontal ? "_" : ""), font_style);
-						var sz = text.get_size(chart.ctx);
+						var sz = text.size;
 						max_rec_width = double.max (max_rec_width, sz.width);
 						h += sz.height;
 					}

src/Chart.vala

@@ -43,7 +43,7 @@ namespace CairoChart {
 		/**
 		 * ``Chart`` Title.
 		 */
-		public Text title = new Text("Cairo Chart");
+		public Text title;
 
 		/**
 		 * Legend.
@@ -99,6 +99,8 @@ namespace CairoChart {
 		 */
 		public Chart () {
 			cursors = new Cursors (this);
+			title = new Text(this, "Cairo Chart");
+
 		}
 
 		/**
@@ -336,13 +338,13 @@ namespace CairoChart {
 			ctx.stroke ();
 		}
 		protected virtual void draw_title () {
-			var sz = title.get_size(ctx);
+			var sz = title.size;
 			var title_height = sz.height + title.vspacing * 2;
 			evarea.y0 += title_height;
 			evarea.height -= title_height;
 			color = title.color;
 			ctx.move_to (area.width/2 - sz.width/2, sz.height + title.vspacing);
-			title.show(ctx);
+			title.show();
 		}
 		protected virtual void draw_haxes () {
 			for (var si = series.length - 1, nskip = 0; si >=0; --si)

src/Cursor.vala

@@ -209,15 +209,15 @@ namespace CairoChart {
 			size = Point128 ();
 			string date, time;
 			s.axis_x.format_date_time(p.x, out date, out time);
-			var date_t = new Text (date, s.axis_x.font_style, s.axis_x.color);
+			var date_t = new Text(chart, date, s.axis_x.font_style, s.axis_x.color);
-			var time_t = new Text (time, s.axis_x.font_style, s.axis_x.color);
+			var time_t = new Text(chart, time, s.axis_x.font_style, s.axis_x.color);
-			var x_t = new Text (s.axis_x.format.printf((LongDouble)p.x), s.axis_x.font_style, s.axis_x.color);
+			var x_t = new Text(chart, s.axis_x.format.printf((LongDouble)p.x), s.axis_x.font_style, s.axis_x.color);
-			var y_t = new Text (s.axis_y.format.printf((LongDouble)p.y), s.axis_y.font_style, s.axis_y.color);
+			var y_t = new Text(chart, s.axis_y.format.printf((LongDouble)p.y), s.axis_y.font_style, s.axis_y.color);
 			double h_x = 0.0, h_y = 0.0;
-			if (show_x) { var sz = x_t.get_size(chart.ctx); size.x = sz.width; h_x = sz.height; }
+			if (show_x) { var sz = x_t.size; size.x = sz.width; h_x = sz.height; }
-			if (show_date) { var sz = date_t.get_size(chart.ctx); size.x = sz.width; h_x = sz.height; }
+			if (show_date) { var sz = date_t.size; size.x = sz.width; h_x = sz.height; }
-			if (show_time) { var sz = time_t.get_size(chart.ctx); size.x = double.max(size.x, sz.width); h_x += sz.height; }
+			if (show_time) { var sz = time_t.size; size.x = double.max(size.x, sz.width); h_x += sz.height; }
-			if (show_y) { var sz = y_t.get_size(chart.ctx); size.x += sz.width; h_y = sz.height; }
+			if (show_y) { var sz = y_t.size; size.x += sz.width; h_y = sz.height; }
 			if ((show_x || show_date || show_time) && show_y) size.x += double.max(s.axis_x.font_spacing, s.axis_y.font_spacing);
 			if (show_date && show_time) h_x += s.axis_x.font_spacing;
 			size.y = double.max (h_x, h_y);
@@ -287,16 +287,16 @@ namespace CairoChart {
 						case Axis.Type.NUMBERS: text = s.axis_x.format.printf((LongDouble)x); break;
 						case Axis.Type.DATE_TIME: s.axis_x.format_date_time(x, out text, out time_text); break;
 						}
-						var text_t = new Text(text, s.axis_x.font_style, s.axis_x.color);
+						var text_t = new Text(chart, text, s.axis_x.font_style, s.axis_x.color);
-						var sz = text_t.get_size(chart.ctx);
+						var sz = text_t.size;
-						var time_text_t = new Text(time_text, s.axis_x.font_style, s.axis_x.color);
+						var time_text_t = new Text(chart, time_text, s.axis_x.font_style, 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_spacing
 								                    - (chart.legend.position == Legend.Position.BOTTOM ? chart.legend.height : 0);
 								break;
 							case Axis.Position.HIGH:
-								var title_height = chart.title.get_height(chart.ctx) + (chart.legend.position == Legend.Position.TOP ?
+								var title_height = chart.title.height + (chart.legend.position == Legend.Position.TOP ?
 								                   chart.title.vspacing * 2 : chart.title.vspacing);
 								print_y = chart.area.y0 + title_height + s.axis_x.font_spacing
 								          + (chart.legend.position == Legend.Position.TOP ? chart.legend.height : 0);
@@ -306,7 +306,7 @@ namespace CairoChart {
 									break;
 								case Axis.Type.DATE_TIME:
 									print_y += (s.axis_x.date_format == "" ? 0 : sz.height)
-									           + (s.axis_x.time_format == "" ? 0 : time_text_t.get_height(chart.ctx))
+									           + (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_spacing);
 									break;
 								}
@@ -317,13 +317,13 @@ namespace CairoChart {
 
 						switch (s.axis_x.type) {
 						case Axis.Type.NUMBERS:
-							text_t.show(chart.ctx);
+							text_t.show();
 							break;
 						case Axis.Type.DATE_TIME:
-							if (s.axis_x.date_format != "") text_t.show(chart.ctx);
+							if (s.axis_x.date_format != "") text_t.show();
 							print_x = s.compact_rec_x_pos (x, time_text_t);
 							chart.ctx.move_to (print_x, print_y - (s.axis_x.date_format == "" ? 0 : sz.height + s.axis_x.font_spacing));
-							if (s.axis_x.time_format != "") time_text_t.show(chart.ctx);
+							if (s.axis_x.time_format != "") time_text_t.show();
 							break;
 						}
 					}
@@ -337,7 +337,7 @@ namespace CairoChart {
 					if (chart.joint_y) {
 						var s = chart.series[chart.zoom_1st_idx];
 						var y = s.get_real_y(rel2scr_y(c.y));
-						var text_t = new Text(s.axis_y.format.printf((LongDouble)y, s.axis_y.font_style));
+						var text_t = new Text(chart, s.axis_y.format.printf((LongDouble)y, s.axis_y.font_style));
 						var print_y = s.compact_rec_y_pos (y, text_t);
 						var print_x = 0.0;
 						switch (s.axis_y.position) {
@@ -346,12 +346,12 @@ namespace CairoChart {
 							          + (chart.legend.position == Legend.Position.LEFT ? chart.legend.width : 0);
 							break;
 						case Axis.Position.HIGH:
-							print_x = chart.area.x1 - text_t.get_width(chart.ctx) - s.axis_y.font_spacing
+							print_x = chart.area.x1 - text_t.width - s.axis_y.font_spacing
 							          - (chart.legend.position == Legend.Position.RIGHT ? chart.legend.width : 0);
 							break;
 						}
 						chart.ctx.move_to (print_x, print_y);
-						text_t.show(chart.ctx);
+						text_t.show();
 					}
 					break;
 				}
@@ -375,45 +375,45 @@ namespace CairoChart {
 
 					if (show_x) {
 						chart.color = s.axis_x.color;
-						var text_t = new Text(s.axis_x.format.printf((LongDouble)point.x), s.axis_x.font_style);
+						var text_t = new Text(chart, s.axis_x.format.printf((LongDouble)point.x), s.axis_x.font_style);
-						chart.ctx.move_to (svp.x - size.x / 2, svp.y + text_t.get_height(chart.ctx) / 2);
+						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(chart.ctx);
+						text_t.show();
 					}
 
 					if (show_time) {
 						chart.color = s.axis_x.color;
 						string date = "", time = "";
 						s.axis_x.format_date_time(point.x, out date, out time);
-						var text_t = new Text(time, s.axis_x.font_style);
+						var text_t = new Text(chart, time, s.axis_x.font_style);
-						var sz = text_t.get_size(chart.ctx);
+						var sz = text_t.size;
 						var y = svp.y + sz.height / 2;
 						if (show_date) y -= sz.height / 2 + s.axis_x.font_spacing / 2;
 						chart.ctx.move_to (svp.x - size.x / 2, y);
 						if (chart.joint_x) chart.color = chart.joint_color;
-						text_t.show(chart.ctx);
+						text_t.show();
 					}
 
 					if (show_date) {
 						chart.color = s.axis_x.color;
 						string date = "", time = "";
 						s.axis_x.format_date_time(point.x, out date, out time);
-						var text_t = new Text(date, s.axis_x.font_style);
+						var text_t = new Text(chart, date, s.axis_x.font_style);
-						var sz = text_t.get_size(chart.ctx);
+						var sz = text_t.size;
 						var y = svp.y + sz.height / 2;
 						if (show_time) y += sz.height / 2 + s.axis_x.font_spacing / 2;
 						chart.ctx.move_to (svp.x - size.x / 2, y);
 						if (chart.joint_x) chart.color = chart.joint_color;
-						text_t.show(chart.ctx);
+						text_t.show();
 					}
 
 					if (show_y) {
 						chart.color = s.axis_y.color;
-						var text_t = new Text(s.axis_y.format.printf((LongDouble)point.y), s.axis_y.font_style);
+						var text_t = new Text(chart, s.axis_y.format.printf((LongDouble)point.y), s.axis_y.font_style);
-						var sz = text_t.get_size(chart.ctx);
+						var sz = text_t.size;
 						chart.ctx.move_to (svp.x + size.x / 2 - sz.width, svp.y + sz.height / 2);
 						if (chart.joint_y) chart.color = chart.joint_color;
-						text_t.show(chart.ctx);
+						text_t.show();
 					}
 				}
 			}

src/Legend.vala

@@ -52,7 +52,7 @@ namespace CairoChart {
 				switch (position) {
 				case Position.TOP:
 					x0 = (chart.area.width - width) / 2;
-					var title_height = chart.title.get_height(chart.ctx) + (chart.legend.position == Legend.Position.TOP ?
+					var title_height = chart.title.height + (chart.legend.position == Legend.Position.TOP ?
 					                   chart.title.vspacing * 2 : chart.title.vspacing);
 					y0 = title_height;
 				break;
@@ -115,7 +115,7 @@ namespace CairoChart {
 
 				if (!s.zoom_show) continue;
 
-				var title_sz = s.title.get_size(chart.ctx);
+				var title_sz = s.title.size;
 
 				// carry
 				switch (position) {
@@ -147,7 +147,7 @@ namespace CairoChart {
 					// series title
 					chart.ctx.move_to (x + line_length, y);
 					chart.color = s.title.color;
-					s.title.show(chart.ctx);
+					s.title.show();
 
 					// series line style
 					chart.ctx.move_to (x, y - title_sz.height / 2);

src/Series.vala

@@ -12,11 +12,11 @@ namespace CairoChart {
 		}
 		public Sort sort = Sort.BY_X;
 
-		public Axis axis_x = new Axis();
+		public Axis axis_x;
-		public Axis axis_y = new Axis();
+		public Axis axis_y;
 
 		public Place place = new Place();
-		public Text title = new Text ();
+		public Text title;
 		public Marker marker = null;
 
 		public Grid grid = new Grid ();
@@ -45,6 +45,9 @@ namespace CairoChart {
 
 		public Series (Chart chart) {
 			this.chart = chart;
+			title = new Text(chart);
+			axis_x = new Axis(chart);
+			axis_y = new Axis(chart);
 			this.marker = new Marker(chart);
 		}
 
@@ -124,8 +127,8 @@ namespace CairoChart {
 			double max_rec_width = 0; double max_rec_height = 0;
 			axis.calc_rec_sizes (chart, out max_rec_width, out max_rec_height, is_x);
 			var max_font_spacing = axis.font_spacing;
-			var max_axis_font_width = axis.title.text == "" ? 0 : axis.title.get_width(chart.ctx) + axis.font_spacing;
+			var max_axis_font_width = axis.title.text == "" ? 0 : axis.title.width + axis.font_spacing;
-			var max_axis_font_height = axis.title.text == "" ? 0 : axis.title.get_height(chart.ctx) + axis.font_spacing;
+			var max_axis_font_height = axis.title.text == "" ? 0 : axis.title.height + axis.font_spacing;
 
 			if (is_x)
 				s.join_relative_x_axes (si, true, ref max_rec_width, ref max_rec_height, ref max_font_spacing, ref max_axis_font_height, ref nskip);
@@ -200,7 +203,7 @@ namespace CairoChart {
 						max_rec_height = double.max (max_rec_height, tmp_max_rec_height);
 						max_font_spacing = double.max (max_font_spacing, s2.axis_x.font_spacing);
 						max_axis_font_height = double.max (max_axis_font_height, s2.axis_x.title.text == "" ? 0 :
-						                                   s2.axis_x.title.get_height(chart.ctx) + this.axis_x.font_spacing);
+						                                   s2.axis_x.title.height + this.axis_x.font_spacing);
 					}
 					++nskip;
 				} else {
@@ -237,7 +240,7 @@ namespace CairoChart {
 					max_rec_height = double.max (max_rec_height, tmp_max_rec_height);
 					max_font_spacing = double.max (max_font_spacing, s2.axis_y.font_spacing);
 					max_axis_font_width = double.max (max_axis_font_width, s2.axis_y.title.text == "" ? 0
-					                                   : s2.axis_y.title.get_width(chart.ctx) + this.axis_y.font_spacing);
+					                                   : s2.axis_y.title.width + this.axis_y.font_spacing);
 					++nskip;
 				} else {
 					break;
@@ -259,8 +262,8 @@ namespace CairoChart {
 				case Axis.Type.DATE_TIME: axis_x.format_date_time(x, out text, out time_text); break;
 				}
 				var scr_x = get_scr_x (x);
-				var text_t = new Text(text, axis_x.font_style, axis_x.color);
+				var text_t = new Text(chart, text, axis_x.font_style, axis_x.color);
-				var sz = axis_x.title.get_size(ctx);
+				var sz = axis_x.title.size;
 
 				switch (axis_x.position) {
 				case Axis.Position.LOW:
@@ -269,14 +272,14 @@ namespace CairoChart {
 					ctx.move_to (print_x, print_y);
 					switch (axis_x.type) {
 					case Axis.Type.NUMBERS:
-						text_t.show(ctx);
+						text_t.show();
 						break;
 					case Axis.Type.DATE_TIME:
-						if (axis_x.date_format != "") text_t.show(ctx);
+						if (axis_x.date_format != "") text_t.show();
-						var time_text_t = new Text(time_text, axis_x.font_style, axis_x.color);
+						var time_text_t = new Text(chart, time_text, axis_x.font_style, axis_x.color);
 						print_x = compact_rec_x_pos (x, time_text_t);
-						ctx.move_to (print_x, print_y - (axis_x.date_format == "" ? 0 : text_t.get_height(ctx) + axis_x.font_spacing));
+						ctx.move_to (print_x, print_y - (axis_x.date_format == "" ? 0 : text_t.height + axis_x.font_spacing));
-						if (axis_x.time_format != "") time_text_t.show(ctx);
+						if (axis_x.time_format != "") time_text_t.show();
 						break;
 					}
 					// 6. Draw grid lines to the place.zy0.
@@ -297,14 +300,14 @@ namespace CairoChart {
 
 					switch (axis_x.type) {
 					case Axis.Type.NUMBERS:
-						text_t.show(ctx);
+						text_t.show();
 						break;
 					case Axis.Type.DATE_TIME:
-						if (axis_x.date_format != "") text_t.show(ctx);
+						if (axis_x.date_format != "") text_t.show();
-						var time_text_t = new Text(time_text, axis_x.font_style, axis_x.color);
+						var time_text_t = new Text(chart, time_text, axis_x.font_style, axis_x.color);
 						print_x = compact_rec_x_pos (x, time_text_t);
-						ctx.move_to (print_x, print_y - (axis_x.date_format == "" ? 0 : text_t.get_height(ctx) + axis_x.font_spacing));
+						ctx.move_to (print_x, print_y - (axis_x.date_format == "" ? 0 : text_t.height + axis_x.font_spacing));
-						if (axis_x.time_format != "") time_text_t.show(ctx);
+						if (axis_x.time_format != "") time_text_t.show();
 						break;
 					}
 					// 6. Draw grid lines to the place.zy1.
@@ -360,7 +363,7 @@ namespace CairoChart {
 				}
 			}
 
-			var sz = s.axis_x.title.get_size(chart.ctx);
+			var sz = s.axis_x.title.size;
 
 			// 4.5. Draw Axis title
 			if (s.axis_x.title.text != "") {
@@ -373,7 +376,7 @@ namespace CairoChart {
 				chart.ctx.move_to(scr_x - sz.width / 2.0, scr_y);
 				chart.color = s.axis_x.color;
 				if (chart.joint_x) chart.color = chart.joint_color;
-				s.axis_x.title.show(chart.ctx);
+				s.axis_x.title.show();
 			}
 
 			s.draw_horizontal_records (step, max_rec_height, x_min);
@@ -402,16 +405,16 @@ namespace CairoChart {
 				else chart.color = axis_y.color;
 				var text = axis_y.format.printf((LongDouble)y);
 				var scr_y = get_scr_y (y);
-				var text_t = new Text(text, axis_y.font_style, axis_y.color);
+				var text_t = new Text(chart, text, axis_y.font_style, axis_y.color);
-				var text_sz = text_t.get_size(ctx);
+				var text_sz = text_t.size;
-				var sz = axis_y.title.get_size(ctx);
+				var sz = axis_y.title.size;
 
 				switch (axis_y.position) {
 				case Axis.Position.LOW:
 					ctx.move_to (chart.evarea.x0 + max_rec_width - text_sz.width + axis_y.font_spacing
 					                 + (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing),
 					                 compact_rec_y_pos (y, text_t));
-					text_t.show(ctx);
+					text_t.show();
 					// 6. Draw grid lines to the place.zx0.
 					var line_style = grid.line_style;
 					if (joint_y) line_style.color = Color(0, 0, 0, 0.5);
@@ -427,7 +430,7 @@ namespace CairoChart {
 					ctx.move_to (chart.evarea.x1 - text_sz.width - axis_y.font_spacing
 					                 - (axis_y.title.text == "" ? 0 : sz.width + axis_y.font_spacing),
 					                 compact_rec_y_pos (y, text_t));
-					text_t.show(ctx);
+					text_t.show();
 					// 6. Draw grid lines to the place.zx1.
 					var line_style = grid.line_style;
 					if (joint_y) line_style.color = Color(0, 0, 0, 0.5);
@@ -480,7 +483,7 @@ namespace CairoChart {
 				}
 			}
 
-			var sz = s.axis_y.title.get_size(chart.ctx);
+			var sz = s.axis_y.title.size;
 
 			// 4.5. Draw Axis title
 			if (s.axis_y.title.text != "") {
@@ -497,7 +500,7 @@ namespace CairoChart {
 				}
 				chart.color = s.axis_y.color;
 				if (chart.joint_y) chart.color = chart.joint_color;
-				s.axis_y.title.show(chart.ctx);
+				s.axis_y.title.show();
 			}
 
 			s.draw_vertical_records (step, max_rec_width, y_min);
@@ -517,13 +520,13 @@ namespace CairoChart {
 		}
 
 		public virtual double compact_rec_x_pos (Float128 x, Text text) {
-			var sz = text.get_size(chart.ctx);
+			var sz = text.size;
 			return get_scr_x(x) - sz.width / 2.0
 			       - sz.width * (x - (axis_x.range.zmin + axis_x.range.zmax) / 2.0) / axis_x.range.zrange;
 		}
 
 		public virtual double compact_rec_y_pos (Float128 y, Text text) {
-			var sz = text.get_size(chart.ctx);
+			var sz = text.size;
 			return get_scr_y(y) + sz.height / 2.0
 			       + sz.height * (y - (axis_y.range.zmin + axis_y.range.zmax) / 2.0) / axis_y.range.zrange;
 		}

src/Text.vala

@@ -1,10 +1,40 @@
 namespace CairoChart {
+
+	/**
+	 * ``CairoChart`` Text.
+	 */
 	public class Text {
+
+		Chart chart = null;
+
+		/**
+		 * ``Text`` string.
+		 */
 		public string text = "";
+
+		/**
+		 * ``Text`` font style.
+		 */
 		public Font style = Font ();
+
+		/**
+		 * ``Text`` color.
+		 */
 		public Color color = Color();
+
+		/**
+		 * Vertical spacing.
+		 */
 		public double vspacing = 4;
+
+		/**
+		 * Horizontal spacing.
+		 */
 		public double hspacing = 4;
+
+		/**
+		 * Both vertical & horizontal spacing (set only).
+		 */
 		public double spacing {
 			protected get {
 				return 0;
@@ -15,78 +45,130 @@ namespace CairoChart {
 			default = 4;
 		}
 
-		public virtual Cairo.TextExtents get_extents (Cairo.Context ctx) {
+		/**
-			ctx.select_font_face (style.family, style.slant, style.weight);
+		 * Cairo ``Text`` extents.
-			ctx.set_font_size (style.size);
+		 */
-			Cairo.TextExtents extents;
+		public virtual Cairo.TextExtents ext {
-			ctx.text_extents (text, out extents);
+			get {
-			return extents;
+				chart.ctx.select_font_face (style.family, style.slant, style.weight);
+				chart.ctx.set_font_size (style.size);
+				Cairo.TextExtents ext;
+				chart.ctx.text_extents (text, out ext);
+				return ext;
+			}
+			protected set {
+			}
 		}
 
-		public virtual double get_width (Cairo.Context ctx) {
+		/**
-			var extents = get_extents (ctx);
+		 * ``Text`` width.
+		 */
+		public virtual double width {
+			get {
 				switch (style.orient) {
-			case Gtk.Orientation.HORIZONTAL: return extents.width;
+				case Gtk.Orientation.HORIZONTAL: return ext.width;
-			case Gtk.Orientation.VERTICAL: return extents.height;
+				case Gtk.Orientation.VERTICAL: return ext.height;
 				default: return 0.0;
 				}
 			}
+			protected set {
+			}
+		}
 
-		public virtual double get_height (Cairo.Context ctx) {
+		/**
-			var extents = get_extents (ctx);
+		 * ``Text`` height.
+		 */
+		public virtual double height {
+			get {
 				switch (style.orient) {
-			case Gtk.Orientation.HORIZONTAL: return extents.height;
+				case Gtk.Orientation.HORIZONTAL: return ext.height;
-			case Gtk.Orientation.VERTICAL: return extents.width;
+				case Gtk.Orientation.VERTICAL: return ext.width;
 				default: return 0.0;
 				}
 			}
+			protected set {
+			}
+		}
 
+		/**
+		 * ``Text`` size.
+		 */
 		public struct Size {
+			/**
+			 * ``Text`` width.
+			 */
 			double width;
+
+			/**
+			 * ``Text`` height.
+			 */
 			double height;
 		}
 
-		public virtual Size get_size (Cairo.Context ctx) {
+		/**
+		 * ``Text`` @{link Size}.
+		 */
+		public virtual Size size {
+			get {
 				var sz = Size();
-			var extents = get_extents (ctx);
+				var e = ext;
 				switch (style.orient) {
 				case Gtk.Orientation.HORIZONTAL:
-				sz.width = extents.width + extents.x_bearing;
+					sz.width = e.width + e.x_bearing;
-				sz.height = extents.height;
+					sz.height = e.height;
 					break;
 				case Gtk.Orientation.VERTICAL:
-				sz.width = extents.height; // + extents.x_bearing ?
+					sz.width = e.height; // + e.x_bearing ?
-				sz.height = extents.width; // +- extents.y_bearing ?
+					sz.height = e.width; // +- e.y_bearing ?
 					break;
 				}
 				return sz;
 			}
+			protected set {
+			}
+		}
 
-		public virtual void show (Cairo.Context ctx) {
+		/**
-			ctx.select_font_face(style.family,
+		 * Show ``Text``.
+		 */
+		public virtual void show () {
+			chart.ctx.select_font_face(style.family,
 			                           style.slant,
 			                           style.weight);
-			ctx.set_font_size(style.size);
+			chart.ctx.set_font_size(style.size);
 			if (style.orient == Gtk.Orientation.VERTICAL) {
-				ctx.rotate(- GLib.Math.PI / 2.0);
+				chart.ctx.rotate(- GLib.Math.PI / 2.0);
-				ctx.show_text(text);
+				chart.ctx.show_text(text);
-				ctx.rotate(GLib.Math.PI / 2.0);
+				chart.ctx.rotate(GLib.Math.PI / 2.0);
 			} else {
-				ctx.show_text(text);
+				chart.ctx.show_text(text);
 			}
 		}
 
-		public Text (string text = "",
+		/**
+		 * Constructs a new ``Text``.
+		 * @param chart ``Chart`` instance.
+		 * @param text ``Text`` string.
+		 * @param style ``Text`` font style.
+		 * @param color ``Text`` color.
+		 */
+		public Text (Chart chart,
+		             string text = "",
 		             Font style = Font(),
 		             Color color = Color()
 		) {
+			this.chart = chart;
 			this.text = text;
 			this.style = style;
 			this.color = color;
 		}
 
+		/**
+		 * Gets a copy of the ``Text``.
+		 */
 		public virtual Text copy () {
-			var text = new Text ();
+			var text = new Text (chart);
+			text.chart = this.chart;
 			text.text = this.text;
 			text.style = this.style;
 			text.color = this.color;

test/ChartTest.vala

@@ -5,13 +5,13 @@ void plot_chart1 (Chart chart) {
 	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 = {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 = {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 = {Point128(9, 17), Point128(2, 10), Point128(122, 31)};
 	s3.axis_y.position = Axis.Position.HIGH;
 
@@ -34,12 +34,12 @@ void plot_chart1 (Chart chart) {
 	s2.marker.type = Marker.Type.CIRCLE;
 	s3.marker.type = Marker.Type.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 };
 }
@@ -49,13 +49,13 @@ void plot_chart2 (Chart chart) {
 	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 = {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 = {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 = {Point128(9, 17), Point128(2, 10), Point128(-15, 31)};
 	s3.axis_y.position = Axis.Position.HIGH;
 
@@ -78,12 +78,12 @@ void plot_chart2 (Chart chart) {
 	s2.marker.type = Marker.Type.PRICLE_SQUARE;
 	s3.marker.type = Marker.Type.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;
@@ -97,15 +97,15 @@ void plot_chart3 (Chart chart) {
 	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 = {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 = {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 = {Point128(9, -17), Point128(2, 10), Point128(122, 31)};
 	s3.axis_y.position = Axis.Position.HIGH;
 
@@ -128,12 +128,12 @@ void plot_chart3 (Chart chart) {
 	s2.marker.type = Marker.Type.PRICLE_CIRCLE;
 	s3.marker.type = Marker.Type.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.");
 
 	//s1.axis_y.position = s2.axis_y.position = s3.axis_y.position = Axis.Position.LOW;
 
@@ -154,17 +154,17 @@ void plot_chart4 (Chart chart) {
 	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 = {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 = {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 = {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 = {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;
 
@@ -193,14 +193,14 @@ void plot_chart4 (Chart chart) {
 	s3.marker.type = Marker.Type.TRIANGLE;
 	s4.marker.type = Marker.Type.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, "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.");
-	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, "Series 4: Axis Y.");
 
 	chart.series = { s1, s2, s3, s4 };
 }
@@ -432,9 +432,9 @@ int main (string[] args) {
 		var str = chart.cursors.get_cursors_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(ctx);
+			var w = text_t.width;
-			var h = text_t.get_height(ctx);
+			var h = text_t.height;
 			var x0 = chart.plarea.x1 - w - 5;
 			var y0 = chart.plarea.y0 + h + 5;
 			chart.color = chart.legend.bg_color;