[anjuta-extras] class-inheritance: Removed font size hack and set correct canvas scrolling

[Naba Kumar <naba src gnome org>]

commit ef3094c0700b15e7b21fa80ea1d402b2050121a1
Author: Naba Kumar <naba gnome org>
Date:   Thu Feb 25 00:48:57 2010 +0200

    class-inheritance: Removed font size hack and set correct canvas scrolling
    
    Font size in points is translated between screen DPI and graphviz (assumed)
    DPI. Aligned icons correctly in middle. Used node box extremes to get
    real extremes canvas extremes for requesting canvas size.

 plugins/class-inheritance/class-inherit.c |   81 +++++++++++++++++++---------
 1 files changed, 55 insertions(+), 26 deletions(-)
---
diff --git a/plugins/class-inheritance/class-inherit.c b/plugins/class-inheritance/class-inherit.c
index 0079c5c..599c240 100644
--- a/plugins/class-inheritance/class-inherit.c
+++ b/plugins/class-inheritance/class-inherit.c
@@ -66,7 +66,6 @@ create_canvas_arrow_item (GtkWidget *canvas, CanvasArrowDir direction,
                           /* Bounding box */
                           gint x1, gint y1, gint x2, gint y2)
 {
-	gint i;
 	GnomeCanvasItem *item;
 	const gint offset = 4;
 
@@ -160,9 +159,17 @@ class_inheritance_get_symbol_from_agnode_key_name (AnjutaClassInheritance *plugi
 static void
 cls_inherit_graph_init (AnjutaClassInheritance *plugin, gchar* graph_label)
 {
+	Agsym_t *sym;
+	gchar dpi_text[16];
+
+	snprintf (dpi_text, 16, "%d", INCH_TO_PIXELS_CONVERSION_FACTOR);
 	aginit ();
 	plugin->graph = agopen (graph_label, AGDIGRAPH);
 	plugin->gvc = gvContext();
+
+	if (!(sym = agfindattr(plugin->graph->proto->n, "dpi")))
+		sym = agraphattr(plugin->graph, "dpi", dpi_text);
+	agxset(plugin->graph, sym->index, dpi_text);
 }
 
 /*----------------------------------------------------------------------------
@@ -355,7 +362,7 @@ cls_inherit_add_node (AnjutaClassInheritance *plugin, const IAnjutaSymbol *node_
 		/* set the margin for icons */
 		if (!(sym = agfindattr(plugin->graph->proto->n, "margin")))
 			sym = agnodeattr(plugin->graph, "margin", "0.11,0.055");
-		agxset(graph_node, sym->index, "0.3,0.02");
+		agxset(graph_node, sym->index, "0.3,0.03");
 
 		g_string_free (label, TRUE);
 	}
@@ -384,8 +391,16 @@ cls_inherit_add_node (AnjutaClassInheritance *plugin, const IAnjutaSymbol *node_
 		sym = agnodeattr(plugin->graph, "fontsize", "");
 
 	font_size = pango_font_description_get_size (plugin->canvas->style->font_desc)/ PANGO_SCALE;
+
+	/* The above font size in points is with real screen DPI, but graphviz
+	 * rendering is done at fixed INCH_TO_PIXELS_CONVERSION_FACTOR dpi. So
+	 * convert to the right font size points for graphviz.
+	 */
+	font_size = font_size * gdk_screen_get_resolution (gdk_screen_get_default ())
+					/ INCH_TO_PIXELS_CONVERSION_FACTOR;
+	
 	/* hack: set canvas_text_fontsize + 4 points or text would oversize the block */
-	snprintf (font_size_str, FONT_SIZE_STR_LEN, "%d", font_size + 4);
+	snprintf (font_size_str, FONT_SIZE_STR_LEN, "%d", font_size);
 	agxset(graph_node, sym->index, font_size_str);
 
 	if (!(sym = agfindattr(plugin->graph->proto->n, "ratio")))
@@ -609,7 +624,7 @@ cls_inherit_draw_expanded_node (AnjutaClassInheritance *plugin,
 									INCH_TO_PIXELS (node_width)/2 +2),
 									"y", 
 									(gdouble) -node_pos->y -
-									INCH_TO_PIXELS (node_height)/2+(j+0.5)*abs(y1-y2)-5,
+									INCH_TO_PIXELS (node_height)/2+(j+0.5)*abs(y1-y2)-8,
 									"pixbuf", pixbuf,
 									NULL);
 
@@ -669,6 +684,7 @@ cls_inherit_draw_single_node (AnjutaClassInheritance *plugin,
 	gdouble text_width_value;
 	IAnjutaSymbol *node_sym;
 	const gchar* node_sym_name;
+	gint x1, y1, x2, y2;
 
 	node_sym = class_inheritance_get_symbol_from_agnode_key_name (plugin,
 	                                                              graph_node->name);
@@ -682,18 +698,19 @@ cls_inherit_draw_single_node (AnjutaClassInheritance *plugin,
 	node_data->sub_item = NULL;
 		
 	g_object_unref (node_sym);
+
+	x1 = node_pos->x - INCH_TO_PIXELS (node_width)/2;
+	y1 = -(node_pos->y - INCH_TO_PIXELS (node_height)/2);
+	x2 = node_pos->x + INCH_TO_PIXELS (node_width)/2;
+	y2 = -(node_pos->y + INCH_TO_PIXELS (node_height)/2);
 	
 	node_data->canvas_item =
 	gnome_canvas_item_new (gnome_canvas_root (GNOME_CANVAS (plugin->canvas)),
 						   gnome_canvas_rect_get_type (),
-						   "x1",
-						   (gdouble) (node_pos->x - INCH_TO_PIXELS (node_width)/2),
-						   "y1",
-						   (gdouble) -(node_pos->y - INCH_TO_PIXELS (node_height)/2),
-						   "x2",
-						   (gdouble) (node_pos->x + INCH_TO_PIXELS (node_width)/2),
-						   "y2",
-						   (gdouble) -(node_pos->y + INCH_TO_PIXELS (node_height)/2),
+						   "x1", (gdouble) x1,
+						   "y1", (gdouble) y1,
+						   "x2", (gdouble) x2,
+						   "y2", (gdouble) y2,
 						   "fill_color_gdk",
 						   &plugin->canvas->style->base[GTK_STATE_NORMAL],
 						   "outline_color_gdk",
@@ -741,7 +758,7 @@ static void
 cls_inherit_draw_graph (AnjutaClassInheritance *plugin)
 {
 	gint num_nodes;
-	gdouble max_canvas_size_x, max_canvas_size_y;
+	gdouble canvas_x1, canvas_y1, canvas_x2, canvas_y2;
 	GnomeCanvasItem *item;
 	Agnode_t *graph_node;
 	Agedge_t *edge;
@@ -755,9 +772,14 @@ cls_inherit_draw_graph (AnjutaClassInheritance *plugin)
 	
 	/* compiles nodes/edges informations, such as positions, coordinates etc */
 	gvLayout (plugin->gvc, plugin->graph, "dot");
+	/* DEBUG */
+	gvRenderFilename (plugin->gvc, plugin->graph, "png", "class-inheritance-test.png");
+	
 	
 	/* set the size of the canvas. We need this to set the scrolling.. */
-	max_canvas_size_x = max_canvas_size_y = CANVAS_MIN_SIZE;
+	canvas_x1 = canvas_y1 = 0;
+	canvas_x2 = CANVAS_MIN_SIZE;
+	canvas_y2 = -CANVAS_MIN_SIZE;
 	
 	/* check whether we had already drawn something on the canvas.
 	 * In case remove the items so we can clean up the canvas ready
@@ -775,6 +797,7 @@ cls_inherit_draw_graph (AnjutaClassInheritance *plugin)
 	{
 		gdouble node_width;
 		gdouble node_height;
+		gdouble node_x1, node_y1, node_x2, node_y2;
 		point node_pos;
 #ifndef ND_coord_i
 		pointf node_posf;
@@ -787,9 +810,14 @@ cls_inherit_draw_graph (AnjutaClassInheritance *plugin)
 		node_posf = ND_coord(graph_node);
 		PF2P(node_posf,node_pos);
 #endif
-		
+
+		/* Determine node coords and size w.r.t canvas */
 		node_width = ND_width (graph_node);
 		node_height = ND_height (graph_node);
+		node_x1 = node_pos.x - INCH_TO_PIXELS (node_width)/2;
+		node_y1 = -(node_pos.y - INCH_TO_PIXELS (node_height)/2);
+		node_x2 = node_pos.x + INCH_TO_PIXELS (node_width)/2;
+		node_y2 = -(node_pos.y + INCH_TO_PIXELS (node_height)/2);
 
 		if (strcmp ("record", ND_shape (graph_node)->name) == 0 ) 
 		{
@@ -899,18 +927,19 @@ cls_inherit_draw_graph (AnjutaClassInheritance *plugin)
 				g_list_prepend (plugin->drawable_list, item);
 		}
 
-		if (abs(node_pos.x) > max_canvas_size_x ) 
-			max_canvas_size_x = abs(node_pos.x) + INCH_TO_PIXELS (node_width)/2;
-		
-		if (abs(node_pos.y + node_height) > max_canvas_size_y) 
-			max_canvas_size_y = abs(node_pos.y) + INCH_TO_PIXELS (node_height)/2;
+		if (node_x1 < canvas_x1) canvas_x1 = node_x1;
+		if (node_y1 > canvas_y1) canvas_y1 = node_y1;
+		if (node_x2 > canvas_x2) canvas_x2 = node_x2;
+		if (node_y2 < canvas_y2) canvas_y2 = node_y2;
 	}	
-	
-	gtk_widget_set_size_request (plugin->canvas, max_canvas_size_x +100,
-								 max_canvas_size_y +100);
-	gnome_canvas_set_scroll_region (GNOME_CANVAS (plugin->canvas), -50,
-									50, max_canvas_size_x + 50,
-									-max_canvas_size_y -100);
+
+	/* Request extra 20px along x and y for 10px margin around the canvas */
+	gtk_widget_set_size_request (plugin->canvas,
+	                             canvas_x2 - canvas_x1 + 20,
+	                             canvas_y1 - canvas_y2 + 20);
+	gnome_canvas_set_scroll_region (GNOME_CANVAS (plugin->canvas),
+	                                canvas_x1 - 10, canvas_y1 + 10,
+	                                canvas_x2 + 10, canvas_y2 - 10);
 	
 	cls_inherit_graph_cleanup (plugin);
 }