Add copy() method to classes.

src/Axis.vala

@@ -62,9 +62,28 @@ namespace Gtk.CairoChart {
 		}
 		public FontStyle font_style = FontStyle ();
 		public Color color = Color ();
-		public LineStyle line_style = new LineStyle ();
+		public LineStyle line_style = LineStyle ();
 		public double font_indent = 5;
 
+		public Axis copy () {
+			var axis = new Axis ();
+			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_style = this.font_style;
+			axis.line_style = this.line_style;
+			axis.max = this.max;
+			axis.min = this.min;
+			axis.position = this.position;
+			axis.scale_type = this.scale_type;
+			axis.title = this.title.copy();
+			axis.type = this.type;
+			return axis;
+		}
+
 		public Axis () {}
 	}
 }

src/Chart.vala

@@ -16,7 +16,7 @@ namespace Gtk.CairoChart {
 
 		public Series[] series = {};
 
-		protected LineStyle selection_style = new LineStyle ();
+		protected LineStyle selection_style = LineStyle ();
 
 		public Chart () {
 			bg_color = Color (1, 1, 1);
@@ -957,5 +957,46 @@ namespace Gtk.CairoChart {
 		// TODO:
 		protected virtual void draw_cursors () {
 		}
+
+		public Chart copy () {
+			var chart = new Chart ();
+			chart.axis_rec_npoints = this.axis_rec_npoints;
+			chart.bg_color = this.bg_color;
+			chart.border_color = this.border_color;
+			chart.common_x_axes = this.common_x_axes;
+			chart.common_y_axes = this.common_y_axes;
+			chart.context = this.context;
+			chart.cur_x_max = this.cur_x_max;
+			chart.cur_x_min = this.cur_x_min;
+			chart.cur_y_max = this.cur_y_max;
+			chart.cur_y_min = this.cur_y_min;
+			chart.height = this.height;
+			chart.legend = this.legend.copy();
+			chart.legend_height = this.legend_height;
+			chart.legend_line_length = this.legend_line_length;
+			chart.legend_text_hspace = this.legend_text_hspace;
+			chart.legend_text_vspace = this.legend_text_vspace;
+			chart.legend_width = this.legend_width;
+			chart.marker_size = this.marker_size;
+			chart.max_font_heights = this.max_font_heights.copy();
+			chart.plot_area_x_max = this.plot_area_x_max;
+			chart.plot_area_x_min = this.plot_area_x_min;
+			chart.plot_area_y_max = this.plot_area_y_max;
+			chart.plot_area_y_min = this.plot_area_y_min;
+			chart.selection_style = this.selection_style;
+			chart.series = this.series.copy();
+			chart.show_legend = this.show_legend;
+			chart.title = this.title.copy().copy();
+			chart.title_height = this.title_height;
+			chart.title_vindent = this.title_vindent;
+			chart.title_width = this.title_width;
+			chart.width = this.width;
+			chart.zoom = this.zoom;
+			chart.zoom_x0 = this.zoom_x0;
+			chart.zoom_x1 = this.zoom_x1;
+			chart.zoom_y0 = this.zoom_y0;
+			chart.zoom_y1 = this.zoom_y1;
+			return chart;
+		}
 	}
 }

src/Grid.vala

@@ -6,7 +6,14 @@ namespace Gtk.CairoChart {
 		}*/
 		public Color color = Color (0, 0, 0, 0.1);
 
-		public LineStyle line_style = new LineStyle ();
+		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/LabelStyle.vala

@@ -1,8 +1,8 @@
 namespace Gtk.CairoChart {
-	public class LabelStyle {
-		FontStyle font_style = FontStyle();
-		LineStyle frame_line_style = new LineStyle();
-		Color bg_color = Color();
-		Color frame_color = Color();
+	public struct LabelStyle {
+		FontStyle font_style;
+		LineStyle frame_line_style;
+		Color bg_color;
+		Color frame_color;
 	}
 }

src/Legend.vala

@@ -9,9 +9,18 @@ namespace Gtk.CairoChart {
 		public Position position = Position.TOP;
 		public FontStyle font_style = FontStyle();
 		public Color bg_color = Color(1, 1, 1);
-		public LineStyle border_style = new LineStyle ();
+		public LineStyle border_style = LineStyle ();
 		public double indent = 5;
 
+		public Legend copy () {
+			var legend = new Legend ();
+			legend.position = this.position;
+			legend.font_style = this.font_style;
+			legend.bg_color = this.bg_color;
+			legend.indent = this.indent;
+			return legend;
+		}
+
 		public Legend () {
 			border_style.color = Color (0, 0, 0, 0.3);
 		}

src/Series.vala

@@ -25,14 +25,14 @@ namespace Gtk.CairoChart {
 			PRICLE_TRIANGLE
 		}
 
-		public Place place = new Place();
+		public Place place = Place();
 		public Text title = new Text ();
 		public MarkerType marker_type = MarkerType.SQUARE;
 
 		public Grid grid = new Grid ();
 
 		public GLib.List<Float128?> cursors = new List<Float128?> ();
-		public LineStyle line_style = new LineStyle ();
+		public LineStyle line_style = LineStyle ();
 
 		protected Color _color = Color (0.0, 0.0, 0.0, 1.0);
 		public Color color {
@@ -50,8 +50,23 @@ namespace Gtk.CairoChart {
 			default = Color (0.0, 0.0, 0.0, 1.0);
 		}
 
-		public Series () {
+		public Series copy () {
+			var series = new Series ();
+			series._color = this._color;
+			series.axis_x = this.axis_x.copy ();
+			series.axis_y = this.axis_y.copy ();
+			series.cursors = this.cursors.copy ();
+			series.grid = this.grid.copy ();
+			series.line_style = this.line_style;
+			series.marker_type = this.marker_type;
+			series.place = this.place;
+			series.points = this.points.copy();
+			series.sort = this.sort;
+			series.title = this.title.copy();
+			return series;
 		}
 
+		public Series () {
+		}
 	}
 }

src/Text.vala

@@ -47,10 +47,12 @@ namespace Gtk.CairoChart {
 			this.color = color;
 		}
 
-		public Text.by_instance (Text text) {
-			this.text = text.text;
-			this.style = text.style;
-			this.color = text.color;
+		public Text copy () {
+			var text = new Text ();
+			text.text = this.text;
+			text.style = this.style;
+			text.color = this.color;
+			return text;
 		}
 	}
 }