LdCanvas maintenance.
* Rename ld_canvas_translate_*_coordinates() to ld_canvas_*_to_*_coords(). * Add missing parameter assertions to those functions. * Rename local variables in draw_grid(). * Use gdk_cairo_rectangle() in expose-event handler. * Update comments.
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@ -27,7 +27,7 @@
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* @short_description: A canvas.
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* @see_also: #LdDiagram
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*
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* #LdCanvas is used for displaying #LdDiagram objects.
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* #LdCanvas displays and enables the user to manipulate with an #LdDiagram.
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*/
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/* Milimetres per inch. */
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@ -478,7 +478,7 @@ ld_canvas_get_scale_in_px (LdCanvas *self)
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}
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/**
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* ld_canvas_translate_canvas_coordinates:
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* ld_canvas_widget_to_diagram_coords:
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* @self: An #LdCanvas object.
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* @x: The X coordinate to be translated.
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* @y: The Y coordinate to be translated.
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@ -487,27 +487,28 @@ ld_canvas_get_scale_in_px (LdCanvas *self)
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* into diagram coordinates.
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*/
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void
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ld_canvas_translate_canvas_coordinates (LdCanvas *self, gdouble *x, gdouble *y)
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ld_canvas_widget_to_diagram_coords (LdCanvas *self, gdouble *x, gdouble *y)
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{
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GtkWidget *widget;
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gdouble scale;
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g_return_if_fail (LD_IS_CANVAS (self));
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g_return_if_fail (x != NULL);
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g_return_if_fail (y != NULL);
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widget = GTK_WIDGET (self);
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scale = ld_canvas_get_scale_in_px (self);
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/* We know diagram coordinates of the center of the canvas, so we may
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* translate the given X and Y coordinates to this center and then scale
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* them by dividing them by the length of the base unit in pixels
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* times zoom of the canvas.
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* them by dividing them by the current scale.
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*/
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*x = self->priv->x + (*x - (widget->allocation.width * 0.5)) / scale;
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*y = self->priv->y + (*y - (widget->allocation.height * 0.5)) / scale;
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}
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/**
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* ld_canvas_translate_diagram_coordinates:
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* ld_canvas_diagram_to_widget_coords:
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* @self: An #LdCanvas object.
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* @x: The X coordinate to be translated.
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* @y: The Y coordinate to be translated.
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@ -515,18 +516,20 @@ ld_canvas_translate_canvas_coordinates (LdCanvas *self, gdouble *x, gdouble *y)
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* Translate diagram coordinates into canvas coordinates.
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*/
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void
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ld_canvas_translate_diagram_coordinates (LdCanvas *self,
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ld_canvas_diagram_to_widget_coords (LdCanvas *self,
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gdouble *x, gdouble *y)
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{
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GtkWidget *widget;
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gdouble scale;
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g_return_if_fail (LD_IS_CANVAS (self));
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g_return_if_fail (x != NULL);
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g_return_if_fail (y != NULL);
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widget = GTK_WIDGET (self);
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scale = ld_canvas_get_scale_in_px (self);
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/* Just the reversal of ld_canvas_translate_canvas_coordinates(). */
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/* Just the reversal of ld_canvas_widget_to_diagram_coords(). */
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*x = scale * (*x - self->priv->x) + 0.5 * widget->allocation.width;
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*y = scale * (*y - self->priv->y) + 0.5 * widget->allocation.height;
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}
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@ -544,8 +547,7 @@ on_expose_event (GtkWidget *widget, GdkEventExpose *event, gpointer user_data)
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data.exposed_rect.width = event->area.width;
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data.exposed_rect.height = event->area.height;
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cairo_rectangle (data.cr, data.exposed_rect.x, data.exposed_rect.y,
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data.exposed_rect.width, data.exposed_rect.height);
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gdk_cairo_rectangle (data.cr, &event->area);
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cairo_clip (data.cr);
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/* Paint the background white. */
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@ -562,26 +564,26 @@ on_expose_event (GtkWidget *widget, GdkEventExpose *event, gpointer user_data)
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static void
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draw_grid (GtkWidget *widget, DrawData *data)
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{
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gdouble x_top, y_top;
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gdouble x_init, y_init;
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gdouble x, y;
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cairo_set_source_rgb (data->cr, 0.5, 0.5, 0.5);
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cairo_set_line_width (data->cr, 1);
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cairo_set_line_cap (data->cr, CAIRO_LINE_CAP_ROUND);
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/* Get coordinates of the most top-left grid point. */
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x_top = data->exposed_rect.x;
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y_top = data->exposed_rect.y;
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ld_canvas_translate_canvas_coordinates (data->self, &x_top, &y_top);
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x_top = ceil (x_top);
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y_top = ceil (y_top);
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ld_canvas_translate_diagram_coordinates (data->self, &x_top, &y_top);
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/* Get coordinates of the top-left point. */
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x_init = data->exposed_rect.x;
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y_init = data->exposed_rect.y;
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ld_canvas_widget_to_diagram_coords (data->self, &x_init, &y_init);
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x_init = ceil (x_init);
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y_init = ceil (y_init);
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ld_canvas_diagram_to_widget_coords (data->self, &x_init, &y_init);
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/* Iterate over all the points. */
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for (x = x_top; x <= data->exposed_rect.x + data->exposed_rect.width;
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for (x = x_init; x <= data->exposed_rect.x + data->exposed_rect.width;
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x += data->scale)
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{
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for (y = y_top; y <= data->exposed_rect.y + data->exposed_rect.height;
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for (y = y_init; y <= data->exposed_rect.y + data->exposed_rect.height;
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y += data->scale)
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{
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cairo_move_to (data->cr, x, y);
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@ -643,7 +645,7 @@ draw_symbol (LdDiagramSymbol *diagram_symbol, DrawData *data)
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x = ld_diagram_object_get_x (LD_DIAGRAM_OBJECT (diagram_symbol));
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y = ld_diagram_object_get_y (LD_DIAGRAM_OBJECT (diagram_symbol));
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ld_canvas_translate_diagram_coordinates (data->self, &x, &y);
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ld_canvas_diagram_to_widget_coords (data->self, &x, &y);
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/* TODO: Rotate the space for other orientations. */
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cairo_save (data->cr);
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@ -70,9 +70,9 @@ LdDiagram *ld_canvas_get_diagram (LdCanvas *self);
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void ld_canvas_set_library (LdCanvas *self, LdLibrary *library);
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LdLibrary *ld_canvas_get_library (LdCanvas *self);
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void ld_canvas_translate_canvas_coordinates (LdCanvas *self,
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void ld_canvas_widget_to_diagram_coords (LdCanvas *self,
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gdouble *x, gdouble *y);
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void ld_canvas_translate_diagram_coordinates (LdCanvas *self,
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void ld_canvas_diagram_to_widget_coords (LdCanvas *self,
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gdouble *x, gdouble *y);
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/* TODO: The rest of the interface. */
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