Add workspaces on non-primary monitors

We create a Workspace with a null metaWorkspace for each
non-primary monitor, showing the windows on these monitors.
These are saved in WorkspaceView.extraWorkspaces.

https://bugzilla.gnome.org/show_bug.cgi?id=609258

js/ui/workspace.js

@@ -541,7 +541,7 @@ const WindowPositionFlags = {
 };
 
 /**
- * @metaWorkspace: a #Meta.Workspace
+ * @metaWorkspace: a #Meta.Workspace, or null
  */
 function Workspace(metaWorkspace, monitorIndex) {
     this._init(metaWorkspace, monitorIndex);
@@ -587,10 +587,12 @@ Workspace.prototype = {
         }
 
         // Track window changes
-        this._windowAddedId = this.metaWorkspace.connect('window-added',
+        if (this.metaWorkspace) {
-                                                          Lang.bind(this, this._windowAdded));
+            this._windowAddedId = this.metaWorkspace.connect('window-added',
-        this._windowRemovedId = this.metaWorkspace.connect('window-removed',
+                                                             Lang.bind(this, this._windowAdded));
-                                                            Lang.bind(this, this._windowRemoved));
+            this._windowRemovedId = this.metaWorkspace.connect('window-removed',
+                                                               Lang.bind(this, this._windowRemoved));
+        }
         this._windowEnteredMonitorId = global.screen.connect('window-entered-monitor',
                                                            Lang.bind(this, this._windowEnteredMonitor));
         this._windowLeftMonitorId = global.screen.connect('window-left-monitor',
@@ -902,7 +904,7 @@ Workspace.prototype = {
         clones = this._orderWindowsByMotionAndStartup(clones, slots);
 
         let currentWorkspace = global.screen.get_active_workspace();
-        let isOnCurrentWorkspace = this.metaWorkspace == currentWorkspace;
+        let isOnCurrentWorkspace = this.metaWorkspace == null || this.metaWorkspace == currentWorkspace;
 
         for (let i = 0; i < clones.length; i++) {
             let slot = slots[i];
@@ -1005,7 +1007,8 @@ Workspace.prototype = {
         for (let i = 0; i < this._windows.length; i++) {
             let clone = this._windows[i];
             let overlay = this._windowOverlays[i];
-            this._showWindowOverlay(clone, overlay, this.metaWorkspace == currentWorkspace);
+            this._showWindowOverlay(clone, overlay,
+                                    this.metaWorkspace == null || this.metaWorkspace == currentWorkspace);
         }
     },
 
@@ -1202,7 +1205,7 @@ Workspace.prototype = {
         this._overviewHiddenId = Main.overview.connect('hidden', Lang.bind(this,
                                                                            this._doneLeavingOverview));
 
-        if (this.metaWorkspace != currentWorkspace)
+        if (this.metaWorkspace != null && this.metaWorkspace != currentWorkspace)
             return;
 
         // Position and scale the windows.
@@ -1246,8 +1249,10 @@ Workspace.prototype = {
         }
         Tweener.removeTweens(actor);
 
-        this.metaWorkspace.disconnect(this._windowAddedId);
+        if (this.metaWorkspace) {
-        this.metaWorkspace.disconnect(this._windowRemovedId);
+            this.metaWorkspace.disconnect(this._windowAddedId);
+            this.metaWorkspace.disconnect(this._windowRemovedId);
+        }
         global.screen.disconnect(this._windowEnteredMonitorId);
         global.screen.disconnect(this._windowLeftMonitorId);
 
@@ -1270,7 +1275,7 @@ Workspace.prototype = {
 
     // Tests if @win belongs to this workspaces and monitor
     _isMyWindow : function (win) {
-        return Main.isWindowActorDisplayedOnWorkspace(win, this.metaWorkspace.index()) &&
+        return (this.metaWorkspace == null || Main.isWindowActorDisplayedOnWorkspace(win, this.metaWorkspace.index())) &&
             (!win.get_meta_window() || win.get_meta_window().get_monitor() == this.monitorIndex);
     },
 
@@ -1359,8 +1364,10 @@ Workspace.prototype = {
     },
 
     _onCloneSelected : function (clone, time) {
-        Main.activateWindow(clone.metaWindow, time,
+        let wsIndex = undefined;
-                            this.metaWorkspace.index());
+        if (this.metaWorkspace)
+            wsIndex = this.metaWorkspace.index();
+        Main.activateWindow(clone.metaWindow, time, wsIndex);
     },
 
     // Draggable target interface
@@ -1388,7 +1395,15 @@ Workspace.prototype = {
             };
 
             let metaWindow = win.get_meta_window();
-            metaWindow.change_workspace_by_index(this.metaWorkspace.index(),
+
+            // We need to move the window before changing the workspace, because
+            // the move itself could cause a workspace change if the window enters
+            // the primary monitor
+            if (metaWindow.get_monitor() != this.monitorIndex)
+                metaWindow.move_frame(true, this._x, this._y);
+
+            let index = this.metaWorkspace ? this.metaWorkspace.index() : global.screen.get_active_workspace_index();
+            metaWindow.change_workspace_by_index(index,
                                                  false, // don't create workspace
                                                  time);
             return true;

js/ui/workspacesView.js

@@ -67,6 +67,18 @@ WorkspacesView.prototype = {
             this._workspaces[w].actor.reparent(this.actor);
         this._workspaces[activeWorkspaceIndex].actor.raise_top();
 
+        this._extraWorkspaces = [];
+        let monitors = global.get_monitors();
+        let m = 0;
+        for (let i = 0; i < monitors.length; i++) {
+            if (i == global.get_primary_monitor_index())
+                continue;
+            let ws = new Workspace.Workspace(null, i);
+            this._extraWorkspaces[m++] = ws;
+            ws.setGeometry(monitors[i].x, monitors[i].y, monitors[i].width, monitors[i].height);
+            global.overlay_group.add_actor(ws.actor);
+        }
+
         // Position/scale the desktop windows and their children after the
         // workspaces have been created. This cannot be done first because
         // window movement depends on the Workspaces object being accessible
@@ -76,6 +88,8 @@ WorkspacesView.prototype = {
                                  Lang.bind(this, function() {
                 for (let w = 0; w < this._workspaces.length; w++)
                     this._workspaces[w].zoomToOverview();
+                for (let w = 0; w < this._extraWorkspaces.length; w++)
+                    this._extraWorkspaces[w].zoomToOverview();
         }));
         this._overviewShownId =
             Main.overview.connect('shown',
@@ -146,6 +160,8 @@ WorkspacesView.prototype = {
 
         for (let w = 0; w < this._workspaces.length; w++)
             this._workspaces[w].zoomFromOverview();
+        for (let w = 0; w < this._extraWorkspaces.length; w++)
+            this._extraWorkspaces[w].zoomFromOverview();
     },
 
     destroy: function() {
@@ -155,6 +171,8 @@ WorkspacesView.prototype = {
     syncStacking: function(stackIndices) {
         for (let i = 0; i < this._workspaces.length; i++)
             this._workspaces[i].syncStacking(stackIndices);
+        for (let i = 0; i < this._extraWorkspaces.length; i++)
+            this._extraWorkspaces[i].syncStacking(stackIndices);
     },
 
     updateWindowPositions: function() {
@@ -315,6 +333,8 @@ WorkspacesView.prototype = {
     },
 
     _onDestroy: function() {
+        for (let i = 0; i < this._extraWorkspaces.length; i++)
+            this._extraWorkspaces[i].destroy();
         this._scrollAdjustment.run_dispose();
         Main.overview.disconnect(this._overviewShowingId);
         Main.overview.disconnect(this._overviewShownId);