Support dragging

1 files changed, 101 insertions, 13 deletions

diff --git a/window.c b/window.c
index caaeeca..4bf6bf0 100644
--- a/window.c
+++ b/window.c
@@ -23,6 +23,10 @@ struct Window
 
     int			hadj;
     int			vadj;
+
+    gboolean		dragging;
+    int			drag_x;
+    int			drag_y;
 };
 
 static void *
@@ -57,8 +61,8 @@ compute_size (Window *window, int *w, int *h)
     *h = gdk_pixbuf_get_height (window->original) * scale;
 }
 
-static gboolean
-on_expose (GtkWidget *drawing_area, GdkEventExpose *expose, Window *window)
+static void
+paint_rect (GtkWidget *drawing_area, GdkRectangle *area, Window *window)
 {
     GdkPixbuf *tmp;
     GdkInterpType interp;
@@ -67,12 +71,6 @@ on_expose (GtkWidget *drawing_area, GdkEventExpose *expose, Window *window)
     GdkRectangle image;
     guint32 color1, color2;
 
-    if (!window->original)
-	return TRUE;
-
-    if (!GTK_WIDGET_DRAWABLE (get_widget (window, "drawing_area")))
-	return TRUE;
-
     gdk_window_get_size (drawing_area->window, &window_width, &window_height);
 
     image.x = image.y = 0;
@@ -84,8 +82,8 @@ on_expose (GtkWidget *drawing_area, GdkEventExpose *expose, Window *window)
     if (image.height < window_height)
 	image.y = (window_height - image.height) / 2;
     
-    if (!gdk_rectangle_intersect (&(expose->area), &image, &dest))
-	return TRUE;
+    if (!gdk_rectangle_intersect (area, &image, &dest))
+	return;
 
     tmp = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, dest.width, dest.height);
 
@@ -127,6 +125,18 @@ on_expose (GtkWidget *drawing_area, GdkEventExpose *expose, Window *window)
 		     tmp, 0, 0, dest.x, dest.y, dest.width, dest.height, GDK_RGB_DITHER_NONE, 0, 0);
 	
     g_object_unref (tmp);
+}
+
+static gboolean
+on_expose (GtkWidget *drawing_area, GdkEventExpose *expose, Window *window)
+{
+    if (!window->original)
+	return;
+
+    if (!GTK_WIDGET_DRAWABLE (get_widget (window, "drawing_area")))
+	return;
+
+    paint_rect (drawing_area, &(expose->area), window);
     
     return TRUE;
 }
@@ -360,6 +370,79 @@ on_scroll (GtkWidget *widget, GdkEventScroll *event, Window *window)
     return FALSE;
 }
 
+static gboolean
+on_mouse_press (GtkWidget *widget, GdkEventButton *button, Window *window)
+{
+    if (button->button == 1)
+    {
+	if (gdk_pointer_grab (widget->window, FALSE,
+			      GDK_POINTER_MOTION_HINT_MASK |
+			      GDK_BUTTON1_MOTION_MASK |
+			      GDK_BUTTON_RELEASE_MASK |
+			      GDK_ENTER_NOTIFY_MASK |
+			      GDK_LEAVE_NOTIFY_MASK,
+			      NULL, NULL,
+			      button->time) == GDK_GRAB_SUCCESS)
+	{
+	    g_print ("You clicked\n");
+	    window->dragging = TRUE;
+	    window->drag_x = button->x;
+	    window->drag_y = button->y;
+	}
+	else
+	{
+	    g_print ("grab fail\n");
+	}
+    }
+}
+
+static gboolean
+on_mouse_release (GtkWidget *widget, GdkEventButton *button, Window *window)
+{
+    if (button->button == 1)
+    {
+	g_print ("You released\n");
+	gdk_pointer_ungrab (button->time);
+	window->dragging = FALSE;
+    }
+}
+
+static void
+change_adjustment (GtkAdjustment *adj, int dv)
+{
+    double new = adj->value + dv;
+
+    new = CLAMP (new, adj->lower, adj->upper - adj->page_size);
+    
+    gtk_adjustment_set_value (adj, new);
+
+}
+
+
+static void
+on_mouse_motion (GtkWidget *widget, GdkEventMotion *motion, Window *window)
+{
+    if (window->dragging)
+    {
+	GtkAdjustment *vadj = gtk_scrolled_window_get_vadjustment (get_widget (window, "scrolled_window"));
+	GtkAdjustment *hadj = gtk_scrolled_window_get_hadjustment (get_widget (window, "scrolled_window"));
+	int x, y;
+
+	if (motion->is_hint)
+	    gtk_widget_get_pointer (widget, &x, &y);
+	else
+	{
+	    x = motion->x;
+	    y = motion->y;
+	}
+
+	change_adjustment (hadj, window->drag_x - x);
+	change_adjustment (vadj, window->drag_y - y);
+
+	gdk_window_process_updates (widget->window, TRUE);
+    }
+}
+
 static void
 on_various (GtkWidget *widget, Window *window)
 {
@@ -563,8 +646,8 @@ connect_signals (Window *window)
     
     typedef struct
     {
-	char		widget[28];
-	char		signal[16];
+	char		widget[32];
+	char		signal[32];
 	GCallback	callback;
     } Info;
 
@@ -588,6 +671,9 @@ connect_signals (Window *window)
 	{ "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) },
+	{ "drawing_area", "button_press_event", G_CALLBACK (on_mouse_press) },
+	{ "drawing_area", "button_release_event", G_CALLBACK (on_mouse_release) },
+	{ "drawing_area", "motion_notify_event", G_CALLBACK (on_mouse_motion) },
 	{ "menu_open", "activate", G_CALLBACK (on_open) },
 	{ "menu_about", "activate", G_CALLBACK (on_about) },
     };
@@ -797,7 +883,9 @@ window_new (App *app)
     window->xml = glade_xml_new (GLADE_FILE, NULL, NULL);
     window->app = app;
     
-    gtk_widget_add_events (get_widget (window, "drawing_area"), GDK_SCROLL_MASK);
+    gtk_widget_add_events (get_widget (window, "drawing_area"),
+			   GDK_SCROLL_MASK |
+			   GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
     gtk_widget_set_redraw_on_allocate (get_widget (window, "drawing_area"), FALSE);
 
     gtk_widget_realize (get_widget (window, "main_window"));