Add basic print functionality

Sadly, the line width depends on the widget's DPI, which seems to
even cause uneven lines on Windows, where virtual printers claim
high DPI.  It might also be an unrelated problem.

Similarly, selected objects are exported highlighted.

Other than that, it works quite well.

Add a manifest to make the print dialog look nice with the older
GTK+ bundle we depend upon.

The RC file could theoretically be scanned for /\s+"([^"]+)"\s*$/,
unescaped, and the results configure_file()-stamped.

1 files changed, 168 insertions, 45 deletions

diff --git a/liblogdiag/ld-diagram-view.c b/liblogdiag/ld-diagram-view.c
index 23cbb4c..3ff7599 100644
--- a/liblogdiag/ld-diagram-view.c
+++ b/liblogdiag/ld-diagram-view.c
@@ -2,7 +2,7 @@
  * ld-diagram-view.c
  *
  * This file is a part of logdiag.
- * Copyright 2010, 2011, 2012, 2015 Přemysl Eric Janouch
+ * Copyright 2010 - 2021 Přemysl Eric Janouch
  *
  * See the file LICENSE for licensing information.
  *
@@ -335,7 +335,7 @@ static void oper_select_begin (LdDiagramView *self, const LdPoint *point);
 static void oper_select_end (LdDiagramView *self);
 static void oper_select_get_rectangle (LdDiagramView *self, LdRectangle *rect);
 static void oper_select_queue_draw (LdDiagramView *self);
-static void oper_select_draw (GtkWidget *widget, DrawData *data);
+static void oper_select_draw (DrawData *data);
 static void oper_select_motion (LdDiagramView *self, const LdPoint *point);
 
 static void oper_move_selection_begin (LdDiagramView *self,
@@ -374,13 +374,19 @@ static void on_drag_leave (GtkWidget *widget, GdkDragContext *drag_ctx,
 	guint time, gpointer user_data);
 
 static gboolean on_draw (GtkWidget *widget, cairo_t *cr, gpointer user_data);
-static void draw_grid (GtkWidget *widget, DrawData *data);
-static void draw_diagram (GtkWidget *widget, DrawData *data);
-static void draw_terminal (GtkWidget *widget, DrawData *data);
+static void draw_grid (DrawData *data);
+static void draw_diagram (DrawData *data);
+static void draw_terminal (DrawData *data);
 static void draw_object (LdDiagramObject *diagram_object, DrawData *data);
 static void draw_symbol (LdDiagramSymbol *diagram_symbol, DrawData *data);
 static void draw_connection (LdDiagramConnection *connection, DrawData *data);
 
+/* Export. */
+
+static void get_diagram_bounds (LdDiagramView *self, LdRectangle *rect);
+static gboolean get_object_bounds (LdDiagramView *self, LdDiagramObject *object,
+	LdRectangle *rect);
+
 
 G_DEFINE_TYPE_WITH_CODE (LdDiagramView, ld_diagram_view, GTK_TYPE_DRAWING_AREA,
 	G_IMPLEMENT_INTERFACE (GTK_TYPE_SCROLLABLE,
@@ -1045,6 +1051,27 @@ ld_diagram_view_diagram_to_widget_coords (LdDiagramView *self,
 	*wy = scale * (dy - self->priv->y) + 0.5 * allocation.height;
 }
 
+static void
+ld_diagram_view_diagram_to_widget_coords_rect (LdDiagramView *self,
+	const LdRectangle *area, LdRectangle *rect)
+{
+	gdouble x1, x2, y1, y2;
+
+	ld_diagram_view_diagram_to_widget_coords (self,
+		area->x,
+		area->y,
+		&x1, &y1);
+	ld_diagram_view_diagram_to_widget_coords (self,
+		area->x + area->width,
+		area->y + area->height,
+		&x2, &y2);
+
+	rect->x = floor (x1);
+	rect->y = floor (y1);
+	rect->width  = ceil (x2) - rect->x;
+	rect->height = ceil (y2) - rect->y;
+}
+
 /**
  * ld_diagram_view_get_x:
  * @self: an #LdDiagramView object.
@@ -1612,14 +1639,12 @@ get_symbol_clip_area (LdDiagramView *self,
 }
 
 static gboolean
-get_symbol_area (LdDiagramView *self, LdDiagramSymbol *symbol,
+get_symbol_area_in_diagram_units (LdDiagramView *self, LdDiagramSymbol *symbol,
 	LdRectangle *rect)
 {
 	gdouble object_x, object_y;
 	LdSymbol *library_symbol;
 	LdRectangle area;
-	gdouble x1, x2;
-	gdouble y1, y2;
 	gint rotation;
 
 	g_object_get (symbol, "x", &object_x, "y", &object_y,
@@ -1633,24 +1658,23 @@ get_symbol_area (LdDiagramView *self, LdDiagramSymbol *symbol,
 
 	rotate_symbol_area (&area, rotation);
 
-	ld_diagram_view_diagram_to_widget_coords (self,
-		object_x + area.x,
-		object_y + area.y,
-		&x1, &y1);
-	ld_diagram_view_diagram_to_widget_coords (self,
-		object_x + area.x + area.width,
-		object_y + area.y + area.height,
-		&x2, &y2);
+	rect->x = object_x + area.x;
+	rect->y = object_y + area.y;
+	rect->width  = (rect->x + area.width)  - rect->x;
+	rect->height = (rect->y + area.height) - rect->y;
+	return TRUE;
+}
 
-	x1 = floor (x1);
-	y1 = floor (y1);
-	x2 = ceil (x2);
-	y2 = ceil (y2);
+static gboolean
+get_symbol_area (LdDiagramView *self, LdDiagramSymbol *symbol,
+	LdRectangle *rect)
+{
+	LdRectangle intermediate;
 
-	rect->x = x1;
-	rect->y = y1;
-	rect->width  = x2 - x1;
-	rect->height = y2 - y1;
+	if (!get_symbol_area_in_diagram_units (self, symbol, &intermediate))
+		return FALSE;
+
+	ld_diagram_view_diagram_to_widget_coords_rect (self, &intermediate, rect);
 	return TRUE;
 }
 
@@ -1782,7 +1806,7 @@ get_connection_clip_area (LdDiagramView *self,
 }
 
 static gboolean
-get_connection_area (LdDiagramView *self,
+get_connection_area_in_diagram_units (LdDiagramView *self,
 	LdDiagramConnection *connection, LdRectangle *rect)
 {
 	gdouble x_origin, y_origin;
@@ -1799,20 +1823,13 @@ get_connection_area (LdDiagramView *self,
 
 	g_object_get (connection, "x", &x_origin, "y", &y_origin, NULL);
 
-	ld_diagram_view_diagram_to_widget_coords (self,
-		x_origin + points->points[0].x,
-		y_origin + points->points[0].y,
-		&x, &y);
-
-	x_max = x_min = x;
-	y_max = y_min = y;
+	x_max = x_min = x_origin + points->points[0].x;
+	y_max = y_min = y_origin + points->points[0].y;
 
 	for (i = 1; i < points->length; i++)
 	{
-		ld_diagram_view_diagram_to_widget_coords (self,
-			x_origin + points->points[i].x,
-			y_origin + points->points[i].y,
-			&x, &y);
+		x = x_origin + points->points[i].x;
+		y = y_origin + points->points[i].y;
 
 		if (x < x_min)
 			x_min = x;
@@ -1834,6 +1851,19 @@ get_connection_area (LdDiagramView *self,
 	return TRUE;
 }
 
+static gboolean
+get_connection_area (LdDiagramView *self,
+	LdDiagramConnection *connection, LdRectangle *rect)
+{
+	LdRectangle intermediate;
+
+	if (!get_connection_area_in_diagram_units (self, connection, &intermediate))
+		return FALSE;
+
+	ld_diagram_view_diagram_to_widget_coords_rect (self, &intermediate, rect);
+	return TRUE;
+}
+
 
 /* ===== Operations ======================================================== */
 
@@ -2101,7 +2131,7 @@ oper_select_queue_draw (LdDiagramView *self)
 }
 
 static void
-oper_select_draw (GtkWidget *widget, DrawData *data)
+oper_select_draw (DrawData *data)
 {
 	static const double dashes[] = {3, 5};
 	SelectData *select_data;
@@ -2664,19 +2694,19 @@ on_draw (GtkWidget *widget, cairo_t *cr, gpointer user_data)
 	cairo_paint (data.cr);
 
 	if (data.self->priv->show_grid)
-		draw_grid (widget, &data);
+		draw_grid (&data);
 
-	draw_diagram (widget, &data);
-	draw_terminal (widget, &data);
+	draw_diagram (&data);
+	draw_terminal (&data);
 
 	if (data.self->priv->operation == OPER_SELECT)
-		oper_select_draw (widget, &data);
+		oper_select_draw (&data);
 
 	return FALSE;
 }
 
 static void
-draw_grid (GtkWidget *widget, DrawData *data)
+draw_grid (DrawData *data)
 {
 	gdouble grid_step;
 	gint grid_factor;
@@ -2738,7 +2768,7 @@ draw_grid (GtkWidget *widget, DrawData *data)
 }
 
 static void
-draw_terminal (GtkWidget *widget, DrawData *data)
+draw_terminal (DrawData *data)
 {
 	LdDiagramViewPrivate *priv;
 	LdPoint widget_coords;
@@ -2760,7 +2790,7 @@ draw_terminal (GtkWidget *widget, DrawData *data)
 }
 
 static void
-draw_diagram (GtkWidget *widget, DrawData *data)
+draw_diagram (DrawData *data)
 {
 	GList *objects, *iter;
 
@@ -2905,5 +2935,98 @@ draw_connection (LdDiagramConnection *connection, DrawData *data)
 
 draw_connection_end:
 	ld_point_array_free (points);
-	return;
+}
+
+
+/* ===== Export ============================================================ */
+
+static void
+get_diagram_bounds (LdDiagramView *self, LdRectangle *rect)
+{
+	GList *objects;
+	gboolean initialized = FALSE;
+	LdRectangle partial;
+	gdouble x2, y2;
+
+	g_return_if_fail (LD_IS_DIAGRAM_VIEW (self));
+	g_return_if_fail (rect != NULL);
+
+	memset (rect, 0, sizeof *rect);
+	objects = (GList *) ld_diagram_get_objects (self->priv->diagram);
+	for (; objects != NULL; objects = objects->next)
+	{
+		if (!get_object_bounds (self, objects->data, &partial))
+			continue;
+
+		if (!initialized)
+		{
+			*rect = partial;
+			initialized = TRUE;
+			continue;
+		}
+
+		x2 = MAX (partial.x + partial.width,  rect->x + rect->width);
+		y2 = MAX (partial.y + partial.height, rect->y + rect->height);
+		rect->x = MIN (rect->x, partial.x);
+		rect->y = MIN (rect->y, partial.y);
+		rect->width  = x2 - rect->x;
+		rect->height = y2 - rect->y;
+	}
+}
+
+static gboolean
+get_object_bounds (LdDiagramView *self, LdDiagramObject *object,
+	LdRectangle *rect)
+{
+	if (LD_IS_DIAGRAM_SYMBOL (object))
+		return get_symbol_area_in_diagram_units (self,
+			LD_DIAGRAM_SYMBOL (object), rect);
+	if (LD_IS_DIAGRAM_CONNECTION (object))
+		return get_connection_area_in_diagram_units (self,
+			LD_DIAGRAM_CONNECTION (object), rect);
+	return FALSE;
+}
+
+/**
+ * ld_diagram_view_get_export_bounds:
+ * @self: an #LdDiagramView object.
+ * @rect: (out): diagram boundaries.
+ *
+ * Get the smallest rectangular area containing all objects in the diagram.
+ * The diagram object itself doesn't have any idea of how symbols are rendered.
+ *
+ * Return value: export units per diagram unit.
+ */
+gdouble
+ld_diagram_view_get_export_bounds (LdDiagramView *self, LdRectangle *rect)
+{
+	LdRectangle intermediate;
+
+	get_diagram_bounds (self, &intermediate);
+	ld_diagram_view_diagram_to_widget_coords_rect (self, &intermediate, rect);
+	return ld_diagram_view_get_scale_in_px (self);
+}
+
+/**
+ * ld_diagram_view_export:
+ * @self: an #LdDiagramView object.
+ * @cr: Cairo context to draw on.
+ * @clip: the clip area (the function itself does not clip).
+ *
+ * Get the smallest rectangular area containing all objects in the diagram.
+ * The diagram object itself doesn't have any idea of how symbols are rendered.
+ */
+void
+ld_diagram_view_export (LdDiagramView *self, cairo_t *cr,
+	const LdRectangle *clip)
+{
+	DrawData data;
+
+	data.cr = cr;
+	data.self = self;
+	/* FIXME: Various functions call this directly, this export is a hack. */
+	data.scale = ld_diagram_view_get_scale_in_px (data.self);
+	data.exposed_rect = *clip;
+
+	draw_diagram (&data);
 }