[gnome-shell] layout: Don't always extend struts to the screen edge

[Florian Müllner <fmuellner src gnome org>]

commit 76c4ec8ee4fa7e712eb9e88d636b43e44ff4d797
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Apr 15 17:24:07 2014 +0200

    layout: Don't always extend struts to the screen edge
    
    NetWM struts are defined in terms of screen edges (rather than monitor
    edges), which works poorly with vertical monitor layouts (as it renders
    entire monitors unusable). Don't extend struts in those cases.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=663690

 js/ui/layout.js |   30 +++++++++++++++++++++++++-----
 1 files changed, 25 insertions(+), 5 deletions(-)
---
diff --git a/js/ui/layout.js b/js/ui/layout.js
index 80428a5..c1fdc74 100644
--- a/js/ui/layout.js
+++ b/js/ui/layout.js
@@ -1018,19 +1018,39 @@ const LayoutManager = new Lang.Class({
                     continue;
 
                 // Ensure that the strut rects goes all the way to the screen edge,
-                // as this really what mutter expects.
+                // as this really what mutter expects. However skip this step
+                // in cases where this would render an entire monitor unusable.
                 switch (side) {
                 case Meta.Side.TOP:
-                    y1 = 0;
+                    let hasMonitorsAbove = this.monitors.some(Lang.bind(this,
+                        function(mon) {
+                            return this._isAboveOrBelowPrimary(mon) &&
+                                   mon.y < primary.y;
+                        }));
+                    if (!hasMonitorsAbove)
+                        y1 = 0;
                     break;
                 case Meta.Side.BOTTOM:
-                    y2 = global.screen_height;
+                    if (this.primaryIndex == this.bottomIndex)
+                        y2 = global.screen_height;
                     break;
                 case Meta.Side.LEFT:
-                    x1 = 0;
+                    let hasMonitorsLeft = this.monitors.some(Lang.bind(this,
+                        function(mon) {
+                            return !this._isAboveOrBelowPrimary(mon) &&
+                                   mon.x < primary.x;
+                        }));
+                    if (!hasMonitorsLeft)
+                        x1 = 0;
                     break;
                 case Meta.Side.RIGHT:
-                    x2 = global.screen_width;
+                    let hasMonitorsRight = this.monitors.some(Lang.bind(this,
+                        function(mon) {
+                            return !this._isAboveOrBelowPrimary(mon) &&
+                                   mon.x > primary.x;
+                        }));
+                    if (!hasMonitorsRight)
+                        x2 = global.screen_width;
                     break;
                 }