Faster resizing

1 files changed, 75 insertions, 4 deletions

diff --git a/siv.c b/siv.c
index 39fcb96..85af15d 100644
--- a/siv.c
+++ b/siv.c
@@ -42,6 +42,8 @@ struct Application
 
     int			zoom_level;
     gboolean		first;
+
+    GtkAllocation	allocation;
 };
 
 #define GET_WIDGET(app,name)				\
@@ -104,7 +106,6 @@ on_expose (GtkWidget *drawing_area, GdkEventExpose *expose, Application *app)
     int win_x, win_y;
     int window_width, window_height;
     GdkRectangle image;
-    gboolean no_background;
     guint32 color1, color2;
 
     if (!app->original)
@@ -162,7 +163,7 @@ on_expose (GtkWidget *drawing_area, GdkEventExpose *expose, Application *app)
 				interp, 0xff,
 				dest.x - image.x, dest.y - image.y,
 				16, color1, color2);
-    
+
     gdk_draw_pixbuf (drawing_area->window, NULL,
 		     tmp, 0, 0, dest.x, dest.y, dest.width, dest.height, GDK_RGB_DITHER_NONE, 0, 0);
 	
@@ -294,7 +295,7 @@ on_various (GtkWidget *widget, Application *app)
     rebuild (app);
 }
 
-static void
+static gboolean
 on_scroll (GtkWidget *widget, GdkEventScroll *event, Application *app)
 {
     g_print ("scroll\n");
@@ -309,7 +310,74 @@ on_scroll (GtkWidget *widget, GdkEventScroll *event, Application *app)
 	    return;
 	
 	rebuild (app);
+	return TRUE;
     }
+
+    return FALSE;
+}
+
+static void
+on_size_allocate (GtkWidget *widget, GtkAllocation *allocation, gpointer data)
+{
+    Application *app = data;
+
+    if (app->allocation.width == 0 || app->allocation.height == 0)
+    {
+	gtk_widget_queue_draw (widget);
+    }
+    else
+    {
+	int w, h;
+	GdkRectangle old;
+	GdkRectangle new;
+	GdkRegion *region;
+	int dx, dy;
+	int old_x, new_x;
+	int old_y, new_y;
+	
+	if (!app->original)
+	    return;
+
+	compute_size (app, &old.width, &old.height);
+	old.x = (app->allocation.width - old.width) / 2;
+	old.y = (app->allocation.height - old.height) / 2;
+
+	new = old;
+	new.x = (allocation->width - old.width) / 2;
+	new.y = (allocation->height - old.height) / 2;
+
+	if (old.width < allocation->width && old.width < app->allocation.width)
+	{
+	    dx = new.x - old.x;
+	}
+	else
+	{
+	    dx = 0;
+
+	    if (old.width < allocation->width || old.width < app->allocation.width)
+		gtk_widget_queue_draw (widget);
+	}
+
+	if (old.height < allocation->height && old.height < app->allocation.height)
+	{
+	    dy = new.y - old.y;
+	}
+	else
+	{
+	    dy = 0;
+
+	    if (old.height < allocation->height || old.height < app->allocation.height)
+		gtk_widget_queue_draw (widget);
+	}
+
+	region = gdk_region_rectangle (&old);
+
+	gdk_window_move_region (widget->window, region, dx, dy);
+
+	gdk_region_destroy (region);
+    }
+    
+    app->allocation = *allocation;
 }
 
 static void
@@ -347,6 +415,7 @@ connect_signals (Application *app)
 	{ "menu_checkerboard", "activate", G_CALLBACK (on_various) },
 	{ "drawing_area", "expose_event", G_CALLBACK (on_expose) },
 	{ "drawing_area", "scroll_event", G_CALLBACK (on_scroll) },
+	{ "drawing_area", "size_allocate", G_CALLBACK (on_size_allocate) },
     };
 
     for (i = 0; i < G_N_ELEMENTS (connections); ++i)
@@ -385,7 +454,9 @@ build_gui (Application *app)
     app->xml = glade_xml_new (GLADE_FILE, NULL, NULL);
 
     gtk_widget_add_events (GET_WIDGET (app, "drawing_area"), GDK_SCROLL_MASK);
-
+    gtk_widget_set_redraw_on_allocate (
+	GET_WIDGET (app, "drawing_area"), FALSE);
+    
     /* Connect signals */
     connect_signals (app);