[nautilus] desktop-canvas: set margins according to the primary workarea

[Cosimo Cecchi <cosimoc src gnome org>]

commit 1292610b87be44fcd5a7d5a09738cd7f3287325f
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Thu Oct 4 16:16:25 2012 -0400

    desktop-canvas: set margins according to the primary workarea
    
    This ensures desktop icons are pinned to the primary monitor, instead of
    moving around when plugging in a new display.
    There's also a slight change in behavior introduced by this patch - that
    is for multihead configurations where the first monitor in visible order
    is not the primary one, it won't be possible to move desktop icons to
    monitors to the left, or to the top, of the primary monitor - in other
    words, desktop icons layout starts from the primary monitor and expands
    rightwards/downwards.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=420624

 src/nautilus-desktop-canvas-view.c |   26 +++++++++++++-------------
 1 files changed, 13 insertions(+), 13 deletions(-)
---
diff --git a/src/nautilus-desktop-canvas-view.c b/src/nautilus-desktop-canvas-view.c
index e0c9ca5..7162055 100644
--- a/src/nautilus-desktop-canvas-view.c
+++ b/src/nautilus-desktop-canvas-view.c
@@ -102,27 +102,27 @@ canvas_container_set_workarea (NautilusCanvasContainer *canvas_container,
 			     int                    n_items)
 {
 	int left, right, top, bottom;
-	int screen_width, screen_height;
 	int i;
+	GdkRectangle geometry;
 
 	left = right = top = bottom = 0;
-
-	screen_width  = gdk_screen_get_width (screen);
-	screen_height = gdk_screen_get_height (screen);
+	gdk_screen_get_monitor_geometry (screen, gdk_screen_get_primary_monitor (screen), &geometry);
 
 	for (i = 0; i < n_items; i += 4) {
-		int x      = workareas [i];
-		int y      = workareas [i + 1];
-		int width  = workareas [i + 2];
-		int height = workareas [i + 3];
+		GdkRectangle workarea;
+
+		workarea.x = workareas[i];
+		workarea.y = workareas[i + 1];
+		workarea.width = workareas[i + 2];
+		workarea.height = workareas[i + 3];
 
-		if ((x + width) > screen_width || (y + height) > screen_height)
+		if (!gdk_rectangle_intersect (&geometry, &workarea, &workarea))
 			continue;
 
-		left   = MAX (left, x);
-		right  = MAX (right, screen_width - width - x);
-		top    = MAX (top, y);
-		bottom = MAX (bottom, screen_height - height - y);
+		left   = MAX (left, workarea.x);
+		right  = MAX (right, (geometry.x + geometry.width) - (workarea.x + workarea.width));
+		top    = MAX (top, workarea.y);
+		bottom = MAX (bottom, (geometry.y + geometry.height) - (workarea.y + workarea.height));
 	}
 
 	nautilus_canvas_container_set_margins (canvas_container,