Zoom center the canvas.

diff --git a/src/gtkmapserver.c b/src/gtkmapserver.c
index 97413a4224f96b46edd4adc5ad535841b4335518..16348b4e00e965184ba09160b366463c4c607bb2 100644 (file)
--- a/src/gtkmapserver.c
+++ b/src/gtkmapserver.c
@@ -461,6 +461,36 @@ gtk_mapserver_on_size_allocate (GtkWidget *widget,
        g_source_attach (priv->sresize, NULL);
 }
 
+static void
+gtk_mapserver_center_map (GtkMapserver *gtkm)
+{
+       GtkAllocation allocation;
+       GooCanvasBounds bounds;
+
+       gdouble x;
+       gdouble y;
+       gdouble scale;
+       gdouble rotation;
+
+       GtkMapserverPrivate *priv = GTK_MAPSERVER_GET_PRIVATE (gtkm);
+
+       gtk_widget_get_allocation (GTK_WIDGET (gtkm), &allocation);
+
+       goo_canvas_item_get_bounds (priv->img, &bounds);
+
+       goo_canvas_item_get_simple_transform (priv->img,
+                                                                                 &x,
+                                                                                 &y,
+                                                                                 &scale,
+                                                                                 &rotation);
+
+       goo_canvas_item_set_simple_transform (priv->img,
+                                                                                 ((gdouble)allocation.width - (bounds.x2 - bounds.x1)) / 2,
+                                                                                 ((gdouble)allocation.height - (bounds.y2 - bounds.y1)) / 2,
+                                                                                 scale,
+                                                                                 rotation);
+}
+
 static gboolean
 gtk_mapserver_on_key_release_event (GooCanvasItem *item,
                                                                        GooCanvasItem *target_item,
@@ -472,7 +502,8 @@ gtk_mapserver_on_key_release_event (GooCanvasItem *item,
                        case GDK_KEY_0:
                        case GDK_KEY_KP_0:
                                {
-                                       GtkMapserverPrivate *priv = GTK_MAPSERVER_GET_PRIVATE ((GtkMapserver *)user_data);
+                                       GtkMapserver *gtkm = (GtkMapserver *)user_data;
+                                       GtkMapserverPrivate *priv = GTK_MAPSERVER_GET_PRIVATE (gtkm);
 
                                        gdouble x;
                                        gdouble y;
@@ -489,6 +520,7 @@ gtk_mapserver_on_key_release_event (GooCanvasItem *item,
                                                                                                                  y,
                                                                                                                  1,
                                                                                                                  rotation);
+                                       gtk_mapserver_center_map (gtkm);
 
                                        return TRUE;
                                }
@@ -496,7 +528,8 @@ gtk_mapserver_on_key_release_event (GooCanvasItem *item,
                        case GDK_KEY_plus:
                        case GDK_KEY_KP_Add:
                                {
-                                       GtkMapserverPrivate *priv = GTK_MAPSERVER_GET_PRIVATE ((GtkMapserver *)user_data);
+                                       GtkMapserver *gtkm = (GtkMapserver *)user_data;
+                                       GtkMapserverPrivate *priv = GTK_MAPSERVER_GET_PRIVATE (gtkm);
 
                                        gdouble x;
                                        gdouble y;
@@ -513,6 +546,7 @@ gtk_mapserver_on_key_release_event (GooCanvasItem *item,
                                                                                                                  y,
                                                                                                                  scale + 0.1,
                                                                                                                  rotation);
+                                       gtk_mapserver_center_map (gtkm);
 
                                        return TRUE;
                                }
@@ -520,7 +554,8 @@ gtk_mapserver_on_key_release_event (GooCanvasItem *item,
                        case GDK_KEY_minus:
                        case GDK_KEY_KP_Subtract:
                                {
-                                       GtkMapserverPrivate *priv = GTK_MAPSERVER_GET_PRIVATE ((GtkMapserver *)user_data);
+                                       GtkMapserver *gtkm = (GtkMapserver *)user_data;
+                                       GtkMapserverPrivate *priv = GTK_MAPSERVER_GET_PRIVATE (gtkm);
 
                                        gdouble x;
                                        gdouble y;
@@ -537,6 +572,7 @@ gtk_mapserver_on_key_release_event (GooCanvasItem *item,
                                                                                                                  y,
                                                                                                                  scale - 0.1,
                                                                                                                  rotation);
+                                       gtk_mapserver_center_map (gtkm);
 
                                        return TRUE;
                                }