[gnome-shell/workspace-thumbnails: 5/13] Use a single "zoomed out" view for both workspace controls hover and DND

[Owen Taylor <otaylor src gnome org>]

commit a48053383b9927d323121f4772219db17a524514
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Sun Jan 30 20:35:58 2011 -0500

    Use a single "zoomed out" view for both workspace controls hover and DND
    
    Instead of having a separation between popping the controls out on hover
    and zooming out for DND, always do both at once. This is necessary because
    when we added workspace thumbnails the controls will get bigger, so we need
    to make sure we zoom out far enough so that the windows don't overlap the
    controls.

 js/ui/workspacesView.js |  234 ++++++++++++++++++++++++++++-------------------
 1 files changed, 140 insertions(+), 94 deletions(-)
---
diff --git a/js/ui/workspacesView.js b/js/ui/workspacesView.js
index c21d10b..39c30c8 100644
--- a/js/ui/workspacesView.js
+++ b/js/ui/workspacesView.js
@@ -19,22 +19,23 @@ const WORKSPACE_SWITCH_TIME = 0.25;
 // Note that mutter has a compile-time limit of 36
 const MAX_WORKSPACES = 16;
 
-const WORKSPACE_DRAGGING_SCALE = 0.85;
-
 
 const CONTROLS_POP_IN_FRACTION = 0.8;
 const CONTROLS_POP_IN_TIME = 0.1;
 
 
-function WorkspacesView(width, height, x, y, workspaces) {
-    this._init(width, height, x, y, workspaces);
+function WorkspacesView(width, height, x, y, zoomScale, workspaces) {
+    this._init(width, height, x, y, zoomScale, workspaces);
 }
 
 WorkspacesView.prototype = {
-    _init: function(width, height, x, y, workspaces) {
+    _init: function(width, height, x, y, zoomScale, workspaces) {
         this.actor = new St.Group({ style_class: 'workspaces-view' });
         this.actor.set_clip(x, y, width, height);
 
+        // The actor itself isn't a drop target, so we don't want to pick on its aea
+        this.actor.set_size(0, 0);
+
         this.actor.connect('destroy', Lang.bind(this, this._onDestroy));
 
         this.actor.connect('style-changed', Lang.bind(this,
@@ -50,6 +51,7 @@ WorkspacesView.prototype = {
         this._height = height;
         this._x = x;
         this._y = y;
+        this._zoomScale = zoomScale;
         this._spacing = 0;
         this._activeWorkspaceX = 0; // x offset of active ws while dragging
         this._activeWorkspaceY = 0; // y offset of active ws while dragging
@@ -57,6 +59,7 @@ WorkspacesView.prototype = {
         this._animating = false; // tweening
         this._scrolling = false; // swipe-scrolling
         this._animatingScroll = false; // programatically updating the adjustment
+        this._zoomOut = false; // zoom to a larger area
         this._inDrag = false; // dragging a window
 
         let activeWorkspaceIndex = global.screen.get_active_workspace_index();
@@ -263,6 +266,24 @@ WorkspacesView.prototype = {
                                        global.get_current_time());
     },
 
+    zoomOut: function() {
+        if (this._zoomOut)
+            return;
+
+        this._zoomOut = true;
+        this._computeWorkspacePositions();
+        this._updateWorkspaceActors(true);
+    },
+
+    zoomIn: function() {
+        if (!this._zoomOut)
+            return;
+
+        this._zoomOut = false;
+        this._computeWorkspacePositions();
+        this._updateWorkspaceActors(true);
+    },
+
     _handleDragOverNewWorkspace: function(source, dropActor, x, y, time) {
         if (source.realWindow)
             return DND.DragMotionResult.MOVE_DROP;
@@ -282,10 +303,8 @@ WorkspacesView.prototype = {
     // actually change the actors to match
     _computeWorkspacePositions: function() {
         let active = global.screen.get_active_workspace_index();
-
-        let scale = this._width / global.screen_width;
-        if (this._inDrag)
-            scale *= WORKSPACE_DRAGGING_SCALE;
+        let zoomScale = this._zoomOut ? this._zoomScale : 1;
+        let scale = zoomScale * this._width / global.screen_width;
 
         let _width = this._workspaces[0].actor.width * scale;
         let _height = this._workspaces[0].actor.height * scale;
@@ -300,9 +319,19 @@ WorkspacesView.prototype = {
 
             workspace.scale = scale;
             workspace.x = this._x + this._activeWorkspaceX;
-            workspace.y = this._y + this._activeWorkspaceY
-                              + (w - active) * (_height + this._spacing);
 
+            // We adjust the center because the zoomScale is to leave space for
+            // the expanded workspace control so we want to zoom to either the
+            // left part of the area or the right part of the area
+            let offset = 0.5 * (1 - this._zoomScale) * this._width;
+            let rtl = (St.Widget.get_default_direction () == St.TextDirection.RTL);
+            if (this._zoomOut)
+                workspace.x += rtl ? offset : - offset;
+
+            // We divide by zoomScale so that adjacent workspaces are always offscreen
+            // except when we are switching between workspaces
+            workspace.y = this._y + this._activeWorkspaceY
+                              + (w - active) * (_height + this._spacing) / zoomScale;
         }
     },
 
@@ -516,8 +545,6 @@ WorkspacesView.prototype = {
             return;
 
         this._inDrag = true;
-        this._computeWorkspacePositions();
-        this._updateWorkspaceActors(true);
 
         this._dragMonitor = {
             dragMotion: Lang.bind(this, this._onDragMotion)
@@ -606,8 +633,6 @@ WorkspacesView.prototype = {
         }
         DND.removeMonitor(this._dragMonitor);
         this._inDrag = false;
-        this._computeWorkspacePositions();
-        this._updateWorkspaceActors(true);
 
         for (let i = 0; i < this._workspaces.length; i++)
             this._workspaces[i].setReservedSlot(null);
@@ -701,50 +726,13 @@ WorkspaceControlsContainer.prototype = {
         this.actor.add_actor(controls);
 
         this._controls = controls;
-        this._controls.reactive = true;
-        this._controls.track_hover = true;
-        this._controls.connect('notify::hover',
-                               Lang.bind(this, this._onHoverChanged));
-
-        this._itemDragBeginId = 0;
-        this._itemDragEndId = 0;
-        this._windowDragBeginId = 0;
-        this._windowDragEndId = 0;
     },
 
     show: function() {
-        if (this._itemDragBeginId == 0)
-            this._itemDragBeginId = Main.overview.connect('item-drag-begin',
-                                                          Lang.bind(this, this.popOut));
-        if (this._itemDragEndId == 0)
-            this._itemDragEndId = Main.overview.connect('item-drag-end',
-                                                        Lang.bind(this, this.popIn));
-        if (this._windowDragBeginId == 0)
-            this._windowDragBeginId = Main.overview.connect('window-drag-begin',
-                                                            Lang.bind(this, this.popOut));
-        if (this._windowDragEndId == 0)
-            this._windowDragEndId = Main.overview.connect('window-drag-end',
-                                                          Lang.bind(this, this.popIn));
         this._controls.x = this._poppedInX();
     },
 
     hide: function() {
-        if (this._itemDragBeginId > 0) {
-            Main.overview.disconnect(this._itemDragBeginId);
-            this._itemDragBeginId = 0;
-        }
-        if (this._itemEndBeginId > 0) {
-            Main.overview.disconnect(this._itemDragEndId);
-            this._itemDragEndId = 0;
-        }
-        if (this._windowDragBeginId > 0) {
-            Main.overview.disconnect(this._windowDragBeginId);
-            this._windowDragBeginId = 0;
-        }
-        if (this._windowDragEndId > 0) {
-            Main.overview.disconnect(this._windowDragEndId);
-            this._windowDragEndId = 0;
-        }
     },
 
     _getPreferredWidth: function(actor, forHeight, alloc) {
@@ -775,13 +763,6 @@ WorkspaceControlsContainer.prototype = {
         this._controls.allocate(childBox, flags);
     },
 
-    _onHoverChanged: function() {
-        if (this._controls.hover)
-            this.popOut();
-        else
-            this.popIn();
-    },
-
     _poppedInX: function() {
         let x = CONTROLS_POP_IN_FRACTION * this._controls.width;
         if (St.Widget.get_default_direction() == St.TextDirection.RTL)
@@ -796,12 +777,6 @@ WorkspaceControlsContainer.prototype = {
                            transition: 'easeOutQuad' });
     },
 
-    popIn: function() {
-        Tweener.addTween(this._controls,
-                         { x: this._poppedInX(),
-                           time: CONTROLS_POP_IN_TIME,
-                           transition: 'easeOutQuad' });
-    }
 };
 
 function WorkspacesDisplay() {
@@ -810,19 +785,18 @@ function WorkspacesDisplay() {
 
 WorkspacesDisplay.prototype = {
     _init: function() {
-        this.actor = new St.BoxLayout();
-
-        let workspacesBox = new St.BoxLayout({ vertical: true });
-        this.actor.add(workspacesBox, { expand: true });
-
-        // placeholder for window previews
-        this._workspacesBin = new St.Bin();
-        workspacesBox.add(this._workspacesBin, { expand: true });
+        this.actor = new St.Group();
+        this.actor.set_size(0, 0);
 
         let controls = new St.BoxLayout({ vertical: true,
                                           style_class: 'workspace-controls' });
-        this._controlsContainer = new WorkspaceControlsContainer(controls);
-        this.actor.add(this._controlsContainer.actor);
+        this._controls = controls;
+        this.actor.add_actor(controls);
+
+        controls.reactive = true;
+        controls.track_hover = true;
+        controls.connect('notify::hover',
+                         Lang.bind(this, this._onControlsHoverChanged));
 
         // Add/remove workspace buttons
         this._removeButton = new St.Button({ label: '&#8211;', // n-dash
@@ -849,11 +823,21 @@ WorkspacesDisplay.prototype = {
         controls.add(this._addButton, { expand: true });
 
         this.workspacesView = null;
+
+        this._inDrag = false;
+        this._zoomOut = false;
+
         this._nWorkspacesNotifyId = 0;
+        this._switchWorkspaceNotifyId = 0;
+
+        this._itemDragBeginId = 0;
+        this._itemDragEndId = 0;
+        this._windowDragBeginId = 0;
+        this._windowDragEndId = 0;
     },
 
    show: function() {
-        this._controlsContainer.show();
+        this._controls.show();
 
         this._workspaces = [];
         for (let i = 0; i < global.screen.n_workspaces; i++) {
@@ -861,33 +845,44 @@ WorkspacesDisplay.prototype = {
             this._workspaces[i] = new Workspace.Workspace(metaWorkspace);
         }
 
-        this._nWorkspacesNotifyId =
-            global.screen.connect('notify::n-workspaces',
-                                  Lang.bind(this, this._workspacesChanged));
+        let rtl = (St.Widget.get_default_direction () == St.TextDirection.RTL);
 
-        let binAllocation = this._workspacesBin.allocation;
-        let binWidth = binAllocation.x2 - binAllocation.x1;
-        let binHeight = binAllocation.y2 - binAllocation.y1;
+        let totalAllocation = this.actor.allocation;
+        let totalWidth = totalAllocation.x2 - totalAllocation.x1;
+        // XXXX: 50 is just a hack for message tray compensation
+        let totalHeight = totalAllocation.y2 - totalAllocation.y1 - 50;
+
+        let [controlsMin, controlsNatural] = this._controls.get_preferred_width(-1);
+        let controlsReserved = controlsNatural * (1 - CONTROLS_POP_IN_FRACTION);
+
+        totalWidth -= controlsReserved;
 
         // Workspaces expect to have the same ratio as the screen, so take
-        // this into account when fitting the workspace into the bin
+        // this into account when fitting the workspace into the available space
         let width, height;
-        let binRatio = binWidth / binHeight;
+        let totalRatio = totalWidth / totalHeight;
         let wsRatio = global.screen_width / global.screen_height;
-        if (wsRatio > binRatio) {
-            width = binWidth;
-            height = Math.floor(binWidth / wsRatio);
+        if (wsRatio > totalRatio) {
+            width = totalWidth;
+            height = Math.floor(totalWidth / wsRatio);
         } else {
-            width = Math.floor(binHeight * wsRatio);
-            height = binHeight;
+            width = Math.floor(totalHeight * wsRatio);
+            height = totalHeight;
         }
 
-        // Position workspaces as if they were parented to this._workspacesBin
-        let [x, y] = this._workspacesBin.get_transformed_position();
-        x = Math.floor(x + Math.abs(binWidth - width) / 2);
-        y = Math.floor(y + Math.abs(binHeight - height) / 2);
+        // Position workspaces in the available space
+        let [x, y] = this.actor.get_transformed_position();
+        x = Math.floor(x + Math.abs(totalWidth - width) / 2);
+        y = Math.floor(y + Math.abs(totalHeight - height) / 2);
+
+        if (rtl)
+            x += controlsReserved;
 
-        let newView = new WorkspacesView(width, height, x, y, this._workspaces);
+        this._controls.x = this._getControlsX();
+        this._controls.height = totalHeight;
+
+        let zoomScale = (totalWidth - controlsNatural) / totalWidth;
+        let newView = new WorkspacesView(width, height, x, y, zoomScale, this._workspaces);
 
         if (this.workspacesView)
             this.workspacesView.destroy();
@@ -951,6 +946,57 @@ WorkspacesDisplay.prototype = {
         this.workspacesView.updateWorkspaces(oldNumWorkspaces,
                                              newNumWorkspaces,
                                              lostWorkspaces);
+    },
+
+    _getControlsX: function() {
+        let totalAllocation = this.actor.allocation;
+        let totalWidth = totalAllocation.x2 - totalAllocation.x1;
+        let [controlsMin, controlsNatural] = this._controls.get_preferred_width(-1);
+        let controlsReserved = controlsNatural * (1 - CONTROLS_POP_IN_FRACTION);
+
+        let rtl = (St.Widget.get_default_direction () == St.TextDirection.RTL);
+        let width = this._zoomOut ? controlsNatural : controlsReserved;
+        if (rtl)
+            return width;
+        else
+            return totalWidth - width;
+    },
+
+    _updateZoom : function() {
+        if (Main.overview.animationInProgress)
+            return;
+
+        let shouldZoom = this._controls.hover || this._inDrag;
+        if (shouldZoom != this._zoomOut) {
+            this._zoomOut = shouldZoom;
+
+            if (!this.workspacesView)
+                return;
+
+            Tweener.addTween(this._controls,
+                             { x: this._getControlsX(),
+                               time: WORKSPACE_SWITCH_TIME,
+                               transition: 'easeOutQuad' });
+
+            if (shouldZoom)
+                this.workspacesView.zoomOut();
+            else
+                this.workspacesView.zoomIn();
+        }
+    },
+
+    _onControlsHoverChanged: function() {
+        this._updateZoom();
+    },
+
+    _dragBegin: function() {
+        this._inDrag = true;
+        this._updateZoom();
+    },
+
+    _dragEnd: function() {
+        this._inDrag = false;
+        this._updateZoom();
     }
 };
 Signals.addSignalMethods(WorkspacesDisplay.prototype);