[gnome-shell] screenshot: Port to GrabHelper

[Florian Müllner <fmuellner src gnome org>]

commit df08ae79966f0f8fe89954c1e234340dbe1604d0
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Apr 25 18:43:10 2014 +0200

    screenshot: Port to GrabHelper
    
    Taking an area screenshot doesn't work currently when in "grab mode",
    for instance when the message tray or top bar menus are open. Fix
    this by using GrabHelper for selecting the area, so grabs are properly
    stacked for us.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=709126

 js/ui/screenshot.js |   43 ++++++++++++++++++++++---------------------
 1 files changed, 22 insertions(+), 21 deletions(-)
---
diff --git a/js/ui/screenshot.js b/js/ui/screenshot.js
index 432a39d..76d1bcd 100644
--- a/js/ui/screenshot.js
+++ b/js/ui/screenshot.js
@@ -11,6 +11,7 @@ const Shell = imports.gi.Shell;
 const Signals = imports.signals;
 const St = imports.gi.St;
 
+const GrabHelper = imports.ui.grabHelper;
 const Lightbox = imports.ui.lightbox;
 const Main = imports.ui.main;
 const Tweener = imports.ui.tweener;
@@ -139,6 +140,7 @@ const SelectArea = new Lang.Class({
         this._startY = -1;
         this._lastX = 0;
         this._lastY = 0;
+        this._result = null;
 
         this._initRubberbandColors();
 
@@ -148,12 +150,12 @@ const SelectArea = new Lang.Class({
                                       y: 0 });
         Main.uiGroup.add_actor(this._group);
 
+        this._grabHelper = new GrabHelper.GrabHelper(this._group);
+
         this._group.connect('button-press-event',
                             Lang.bind(this, this._onButtonPress));
         this._group.connect('button-release-event',
                             Lang.bind(this, this._onButtonRelease));
-        this._group.connect('key-press-event',
-                            Lang.bind(this, this._onKeyPress));
         this._group.connect('motion-event',
                             Lang.bind(this, this._onMotionEvent));
 
@@ -169,10 +171,12 @@ const SelectArea = new Lang.Class({
     },
 
     show: function() {
-        if (!Main.pushModal(this._group) || this._group.visible)
+        if (!this._grabHelper.grab({ actor: this._group,
+                                     onUngrab: Lang.bind(this, this._onUngrab) }))
             return;
 
         global.screen.set_cursor(Meta.Cursor.CROSSHAIR);
+        Main.uiGroup.set_child_above_sibling(this._group, null);
         this._group.visible = true;
     },
 
@@ -202,13 +206,6 @@ const SelectArea = new Lang.Class({
                  height: Math.abs(this._startY - this._lastY) };
     },
 
-    _onKeyPress: function(actor, event) {
-        if (event.get_key_symbol() == Clutter.Escape)
-            this._destroy(null, false);
-
-        return Clutter.EVENT_PROPAGATE;
-    },
-
     _onMotionEvent: function(actor, event) {
         if (this._startX == -1 || this._startY == -1)
             return Clutter.EVENT_PROPAGATE;
@@ -230,24 +227,28 @@ const SelectArea = new Lang.Class({
     },
 
     _onButtonRelease: function(actor, event) {
-        this._destroy(this._getGeometry(), true);
-        return Clutter.EVENT_PROPAGATE;
-    },
-
-    _destroy: function(geometry, fade) {
+        this._result = this._getGeometry();
         Tweener.addTween(this._group,
                          { opacity: 0,
-                           time: fade ? 0.2 : 0,
+                           time: 0.2,
                            transition: 'easeOutQuad',
                            onComplete: Lang.bind(this,
                                function() {
-                                   Main.popModal(this._group);
-                                   this._group.destroy();
-                                   global.screen.set_cursor(Meta.Cursor.DEFAULT);
-
-                                   this.emit('finished', geometry);
+                                   this._grabHelper.ungrab();
                                })
                          });
+        return Clutter.EVENT_PROPAGATE;
+    },
+
+    _onUngrab: function() {
+        global.screen.set_cursor(Meta.Cursor.DEFAULT);
+        this.emit('finished', this._result);
+
+        GLib.idle_add(GLib.PRIORITY_DEFAULT, Lang.bind(this,
+            function() {
+                this._group.destroy();
+                return GLib.SOURCE_REMOVE;
+            }));
     }
 });
 Signals.addSignalMethods(SelectArea.prototype);