overviewControls: account for the search entry in each control

Account for the search entry space at the bottom (the former message
tray clone) individually in each side control, instead of packing
another actor in the overview.
This allows us to extend the central view all the way to the bottom,
while still keeping controls centered vertically.

https://bugzilla.gnome.org/show_bug.cgi?id=693987

data/theme/gnome-shell.css

@@ -718,6 +718,7 @@ StScrollBar StButton#vhandle:active {
     -vertical-spacing: 32px;
     padding-left: 32px;
     padding-right: 32px;
+    padding-bottom: 32px;
 }
 
 .window-picker.external-monitor {
@@ -849,13 +850,13 @@ StScrollBar StButton#vhandle:active {
 }
 
 .all-app {
-    padding: 16px 16px 16px 48px;
+    padding: 0px 16px 32px 32px;
     spacing: 20px;
 }
 
 .all-app:rtl {
     padding-left: 16px;
-    padding-right: 48px;
+    padding-right: 32px;
 }
 
 .app-filter {

js/ui/overview.js

@@ -230,7 +230,8 @@ const Overview = new Lang.Class({
         this._thumbnailsBox = new WorkspaceThumbnail.ThumbnailsBox();
         this._controls = new OverviewControls.ControlsManager(this._dash,
                                                               this._thumbnailsBox,
-                                                              this._viewSelector);
+                                                              this._viewSelector,
+                                                              this._searchEntryBin);
 
         // Pack all the actors into the group
         this._group.add_actor(this._controls.dashActor);
@@ -242,14 +243,6 @@ const Overview = new Lang.Class({
         this._overview.add(this._group, { y_fill: true,
                                           expand: true });
 
-        // Then account for message tray
-        this._messageTrayGhost = new St.Bin({ style_class: 'message-tray-summary',
-                                              reactive: false,
-                                              opacity: 0,
-                                              x_fill: true,
-                                              y_fill: true });
-        this._overview.add_actor(this._messageTrayGhost);
-
         // TODO - recalculate everything when desktop size changes
         this.dashIconSize = this._dash.iconSize;
         this._dash.connect('icon-size-changed',

js/ui/overviewControls.js

@@ -294,15 +294,37 @@ const DashSlider = new Lang.Class({
     }
 });
 
+const SlidingControlContainer = new Lang.Class({
+    Name: 'SlidingControlContainer',
+    Extends: St.Widget,
+
+    _init: function(child, entryBin) {
+        this._layout = new Clutter.BoxLayout({ vertical: true });
+        this.parent({ layout_manager: this._layout });
+
+        child.x_expand = true;
+        this.add_actor(child);
+
+        let entryClone = new St.Widget();
+        entryClone.height = entryBin.height;
+        this.add_actor(entryClone);
+
+        entryBin.connect('notify::height', Lang.bind(this,
+            function() {
+                entryClone.height = entryBin.height;
+            }));
+    }
+});
+
 const ControlsManager = new Lang.Class({
     Name: 'ControlsManager',
 
-    _init: function(dash, thumbnails, viewSelector) {
+    _init: function(dash, thumbnails, viewSelector, entryBin) {
         this._dashSlider = new DashSlider(dash);
-        this.dashActor = this._dashSlider.actor;
+        this.dashActor = new SlidingControlContainer(this._dashSlider.actor, entryBin);
 
         this._thumbnailsSlider = new ThumbnailsSlider(thumbnails);
-        this.thumbnailsActor = this._thumbnailsSlider.actor;
+        this.thumbnailsActor = new SlidingControlContainer(this._thumbnailsSlider.actor, entryBin);
 
         this._viewSelector = viewSelector;
         this._viewSelector.connect('page-changed', Lang.bind(this, this._setVisibility));