Reenable workspace switcher wrapping

These changes have been accidentally removed. The previously used
handler has been added to the code again, which connects to the scroll
event of the WnckPager widget.

port of 9b8f9e8147e27e19eb08a262a140b937051545b9 + fix from 9705869fdcf0f31bc05b8454cd7ec60b7b489234

1 files changed, 112 insertions, 0 deletions

diff --git a/applets/wncklet/workspace-switcher.c b/applets/wncklet/workspace-switcher.c
index e88839dd..17fbd651 100644
--- a/applets/wncklet/workspace-switcher.c
+++ b/applets/wncklet/workspace-switcher.c
@@ -210,6 +210,115 @@ static void applet_change_background(MatePanelApplet* applet, MatePanelAppletBac
                 type == PANEL_NO_BACKGROUND ? GTK_SHADOW_NONE : GTK_SHADOW_IN);
 }
 
+/* Replacement for the default scroll handler that also cares about the wrapping property.
+ * Alternative: Add behaviour to libwnck (to the WnckPager widget).
+ */
+static gboolean applet_scroll(MatePanelApplet* applet, GdkEventScroll* event, PagerData* pager)
+{
+	GdkScrollDirection absolute_direction;
+	int index;
+	int n_workspaces;
+	int n_columns;
+	int in_last_row;
+
+	if (event->type != GDK_SCROLL)
+		return FALSE;
+
+	if (event->direction == GDK_SCROLL_SMOOTH)
+		return FALSE;
+
+	index = wnck_workspace_get_number(wnck_screen_get_active_workspace(pager->screen));
+	n_workspaces = wnck_screen_get_workspace_count(pager->screen);
+	n_columns = n_workspaces / pager->n_rows;
+
+	if (n_workspaces % pager->n_rows != 0)
+		n_columns++;
+
+	in_last_row    = n_workspaces % n_columns;
+
+	absolute_direction = event->direction;
+
+	if (gtk_widget_get_direction(GTK_WIDGET(applet)) == GTK_TEXT_DIR_RTL)
+	{
+		switch (event->direction)
+		{
+			case GDK_SCROLL_RIGHT:
+				absolute_direction = GDK_SCROLL_LEFT;
+				break;
+			case GDK_SCROLL_LEFT:
+				absolute_direction = GDK_SCROLL_RIGHT;
+				break;
+			default:
+				break;
+		}
+	}
+
+	switch (absolute_direction)
+	{
+		case GDK_SCROLL_DOWN:
+			if (index + n_columns < n_workspaces)
+			{
+				index += n_columns;
+			}
+			else if (pager->wrap_workspaces && index == n_workspaces - 1)
+			{
+				index = 0;
+			}
+			else if ((index < n_workspaces - 1 && index + in_last_row != n_workspaces - 1) || (index == n_workspaces - 1 && in_last_row != 0))
+			{
+				index = (index % n_columns) + 1;
+			}
+			break;
+
+		case GDK_SCROLL_RIGHT:
+			if (index < n_workspaces - 1)
+			{
+				index++;
+			}
+			else if (pager->wrap_workspaces)
+			{
+			        index = 0;
+			}
+			break;
+
+		case GDK_SCROLL_UP:
+			if (index - n_columns >= 0)
+			{
+				index -= n_columns;
+			}
+			else if (index > 0)
+			{
+				index = ((pager->n_rows - 1) * n_columns) + (index % n_columns) - 1;
+			}
+			else if (pager->wrap_workspaces)
+			{
+				index = n_workspaces - 1;
+			}
+
+			if (index >= n_workspaces)
+				index -= n_columns;
+			break;
+
+		case GDK_SCROLL_LEFT:
+			if (index > 0)
+			{
+				index--;
+			}
+			else if (pager->wrap_workspaces)
+			{
+				index = n_workspaces - 1;
+			}
+			break;
+		default:
+			g_assert_not_reached();
+			break;
+	}
+
+	wnck_workspace_activate(wnck_screen_get_workspace(pager->screen, index), event->time);
+
+	return TRUE;
+}
+
 static void destroy_pager(GtkWidget* widget, PagerData* pager)
 {
 	g_object_unref (pager->settings);
@@ -422,6 +531,9 @@ gboolean workspace_switcher_applet_fill(MatePanelApplet* applet)
 
 	g_signal_connect(G_OBJECT(pager->pager), "destroy", G_CALLBACK(destroy_pager), pager);
 
+	/* overwrite default WnckPager widget scroll-event */
+	g_signal_connect(G_OBJECT(pager->pager), "scroll-event", G_CALLBACK(applet_scroll), pager);
+
 	gtk_container_add(GTK_CONTAINER(pager->applet), pager->pager);
 	gtk_widget_show(pager->pager);