From eb3a46fc743b7ca886d30b966af53088176fc884 Mon Sep 17 00:00:00 2001
From: Kaj-Michael Lang <milang@tal.org>
Date: Mon, 5 May 2008 23:59:18 +0300
Subject: [PATCH] Add mouse scroller zoom in/out handling and zoom-changed
 signal

---
 src/gtkmap.c | 64 ++++++++++++++++++++++++++++++++--------------------
 src/gtkmap.h |  1 +
 2 files changed, 40 insertions(+), 25 deletions(-)

diff --git a/src/gtkmap.c b/src/gtkmap.c
index 3fc3948..4022761 100644
--- a/src/gtkmap.c
+++ b/src/gtkmap.c
@@ -137,6 +137,7 @@ struct _GtkMapPriv
 	gint zoom;
 	gint max_zoom;
 	gint min_zoom;
+	gboolean zoom_to_mouse;
 
 	gfloat units_conv;
 	gchar *units_str;
@@ -236,17 +237,16 @@ static void gtk_map_update_size(GtkWidget *widget, gint width, gint height);
 static void gtk_map_set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
 static void gtk_map_get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
 
+static gboolean gtk_map_button_press_cb(GtkWidget *widget, GdkEventButton *event);
+static gboolean gtk_map_button_release_cb(GtkWidget *widget, GdkEventButton *event);
+static gboolean gtk_map_scroll_event_cb(GtkWidget *widget, GdkEventScroll *event); 
+
 /* Signal IDs */
 enum {
 	MAP_LOCATION_CHANGED,
-	
-	MAP_ZOOMED_IN,
-	MAP_ZOOMED_OUT,
-
+	MAP_ZOOM_CHANGED,
 	MAP_PANNED,
-
 	MARKER_CLICK,
-
 	LAST_SIGNAL
 };
 
@@ -276,6 +276,11 @@ widget_class->realize = gtk_map_realize;
 widget_class->size_allocate = gtk_map_size_allocate;
 
 g_type_class_add_private (object_class, sizeof(GtkMapPriv));
+
+gtk_map_signals[MAP_ZOOM_CHANGED]=g_signal_new("zoom-changed", G_OBJECT_CLASS_TYPE(object_class),
+     G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET(GtkMapClass, zoom_changed),
+     NULL, NULL, g_cclosure_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);
+
 }
 
 static inline void 
@@ -350,6 +355,7 @@ priv->draw_width=4;
 priv->zoom=3;
 priv->min_zoom=0;
 priv->max_zoom=17;
+priv->zoom_to_mouse=TRUE;
 
 priv->center_mode=CENTER_LATLON;
 priv->center.unitx=0;
@@ -581,6 +587,13 @@ if (priv->gl_config) {
 }
 #endif
 
+#if 0
+g_signal_connect(G_OBJECT(map), "button_press_event", G_CALLBACK(map_cb_button_press), NULL);
+g_signal_connect(G_OBJECT(map), "button_release_event",G_CALLBACK(map_cb_button_release), NULL);
+#endif
+
+g_signal_connect(G_OBJECT(map), "scroll_event",  G_CALLBACK(gtk_map_scroll_event_cb), NULL);
+
 priv->scale_context=gtk_widget_get_pango_context(widget);
 priv->scale_layout=pango_layout_new(priv->scale_context);
 priv->scale_font=pango_font_description_new();
@@ -614,25 +627,6 @@ g_signal_connect(G_OBJECT(widget), "button_press_event", G_CALLBACK(gtk_map_pres
 
 }
 
-static void
-draw (GtkWidget *clock, cairo_t *cr)
-{
-	double x, y;
-	double radius;
-	int i;
-	
-	x = clock->allocation.x + clock->allocation.width / 2;
-	y = clock->allocation.y + clock->allocation.height / 2;
-	radius = MIN (clock->allocation.width / 2, clock->allocation.height / 2) - 5;
-
-	/* clock back */
-	cairo_arc (cr, x, y, radius, 0, 2 * M_PI);
-	cairo_set_source_rgb (cr, 1, 1, 1);
-	cairo_fill_preserve (cr);
-	cairo_set_source_rgb (cr, 0, 0, 0);
-	cairo_stroke (cr);
-}
-
 static gboolean
 gtk_map_expose(GtkWidget *widget, GdkEventExpose *event)
 {
@@ -1249,6 +1243,7 @@ gtk_map_recalc_focus_base(priv);
 gtk_map_recalc_focus_size(priv);
 
 gtk_map_refresh(widget);
+g_signal_emit(widget, gtk_map_signals[MAP_ZOOM_CHANGED], 0, priv->zoom);
 
 return TRUE;
 }
@@ -1301,3 +1296,22 @@ if (cache_size>512)
 	cache_size=512;
 image_cache_set_size(priv->icache, cache_size);
 }
+
+/**
+ * Mouse scroller zoom in/out callback
+ */
+static gboolean
+gtk_map_scroll_event_cb(GtkWidget *widget, GdkEventScroll *event)
+{
+GtkMap *map;
+GtkMapPriv *priv;
+
+g_return_if_fail(GTK_IS_MAP(widget));
+
+map=GTK_MAP(widget);
+priv=GTK_MAP_GET_PRIVATE(map);
+gtk_map_zoom(widget, event->direction==GDK_SCROLL_UP ? -1 : 1);
+if (priv->zoom_to_mouse)
+	gtk_map_set_center(widget, x2unit((gint) (event->x + 0.5)), y2unit((gint) (event->y + 0.5)));
+return FALSE;
+}
diff --git a/src/gtkmap.h b/src/gtkmap.h
index 47985b4..0504dbf 100644
--- a/src/gtkmap.h
+++ b/src/gtkmap.h
@@ -49,6 +49,7 @@ struct _GtkMap {
 
 struct _GtkMapClass {
 	GtkDrawingAreaClass parent_class;
+	void (* zoom_changed) (GtkWidget *widget, int zoom);
 };
 
 G_BEGIN_DECLS
-- 
2.39.5