Rely on overview allocation, enough with the ghosts

overview.js

@@ -41,7 +41,11 @@ const WorkspaceThumbnail = imports.ui.workspaceThumbnail;
 const Meta = imports.gi.Meta;
 
 const GS_HOTKEYS_KEY = 'switch-to-application-';
-const DASH_MARGIN = 60;
+
+// When the dash is shown, workspace window preview bottom labels go over it (default
+// gnome-shell behavior), but when the extension hides the dash, leave some space
+// so those labels don't go over a bottom panel
+const LABEL_MARGIN = 60;
 
 //timeout names
 const T1 = 'swipeEndTimeout';
@@ -64,7 +68,9 @@ var Overview = class {
         this._optionalHotKeys();
         this._optionalNumberOverlay();
         this._optionalClickToExit();
+
         this._toggleDash();
+        this._adaptAlloc(true);
 
         this._signalsHandler.add([
             Me.settings,
@@ -81,6 +87,7 @@ var Overview = class {
         this._injectionsHandler.destroy();
         
         this._toggleDash(true);
+        this._adaptAlloc();
 
         // Remove key bindings
         this._disableHotKeys();
@@ -94,16 +101,34 @@ var Overview = class {
         }
 
         let visibilityFunc = visible ? 'show' : 'hide';
-        let height = -1;
+        let height = visible ? -1 : LABEL_MARGIN;
         let overviewControls = Main.overview._overview._controls;
 
-        if (!visible && this._panel.geom.position == St.Side.BOTTOM)
-            height = this._panel.geom.h + DASH_MARGIN
-
         overviewControls.dash.actor[visibilityFunc]();
         overviewControls.dash.actor.set_height(height);
     }
 
+    _adaptAlloc(enable) {
+        let overviewControls = Main.overview._overview._controls
+        let proto = Object.getPrototypeOf(overviewControls)
+        let allocFunc = null
+
+        if (enable)
+            allocFunc = (box) => {
+                // The default overview allocation is very good and takes into account external 
+                // struts, everywhere but the bottom where the dash is usually fixed anyway.
+                // If there is a bottom panel under the dash location, give it some space here
+                let focusedPanel = this._panel.panelManager.focusedMonitorPanel
+
+                if (focusedPanel?.geom.position == St.Side.BOTTOM)
+                    box.y2 -= focusedPanel.geom.h
+                
+                proto.vfunc_allocate.call(overviewControls, box)
+            }
+
+        Utils.hookVfunc(proto, 'allocate', allocFunc)
+    }
+
     /**
      * Isolate overview to open new windows for inactive apps
      */

panel.js

@@ -184,28 +184,11 @@ var Panel = GObject.registerClass({
 
         this.geom = this.getGeometry();
         
-        // The overview uses the panel height as a margin by way of a "ghost" transparent Clone
-        // This pushes everything down, which isn't desired when the panel is moved to the bottom
-        // I'm adding a 2nd ghost panel and will resize the top or bottom ghost depending on the panel position
-        this._myPanelGhost = new Clutter.Actor({ 
-            x: this.geom.x,
-            y: this.geom.y ,
-            reactive: false, 
-            opacity: 0
-        });
-
         let isTop = this.geom.position == St.Side.TOP;
 
-        if (isTop) {
-            if (Config.PACKAGE_VERSION < '42') {
-                this.panel._leftCorner = this.panel._leftCorner || new GSPanel.PanelCorner(St.Side.LEFT);
-                this.panel._rightCorner = this.panel._rightCorner || new GSPanel.PanelCorner(St.Side.RIGHT);
-            }
-
-            Main.overview._overview.insert_child_at_index(this._myPanelGhost, 0);
-        } else {
-            let overviewControls = Main.overview._overview._controls || Main.overview._controls;
-            Main.overview._overview.add_actor(this._myPanelGhost);
+        if (isTop && Config.PACKAGE_VERSION < '42') {
+            this.panel._leftCorner = this.panel._leftCorner || new GSPanel.PanelCorner(St.Side.LEFT);
+            this.panel._rightCorner = this.panel._rightCorner || new GSPanel.PanelCorner(St.Side.RIGHT);
         }
 
         if (Config.PACKAGE_VERSION < '42' && this.panel._leftCorner) {
@@ -280,8 +263,6 @@ var Panel = GObject.registerClass({
 
         this.panel.actor.add_style_class_name('dashtopanelMainPanel ' + this.getOrientation());
 
-        this._setPanelGhostSize();
-
         this._timeoutsHandler.add([T2, Me.settings.get_int('intellihide-enable-start-delay'), () => this.intellihide = new Intellihide.Intellihide(this)]);
 
         this._signalsHandler.add(
@@ -404,8 +385,6 @@ var Panel = GObject.registerClass({
 
         this.menuManager._changeMenu = this.menuManager._oldChangeMenu;
 
-        this._myPanelGhost.get_parent().remove_actor(this._myPanelGhost);
-        
         panelBoxes.forEach(b => delete this[b].allocate);
         this._unmappedButtons.forEach(a => this._disconnectVisibleId(a));
 
@@ -700,10 +679,6 @@ var Panel = GObject.registerClass({
         return Me.persistentStorage[propName].pop();
     }
 
-    _setPanelGhostSize() {
-        this._myPanelGhost.set_size(this.width, this.checkIfVertical() ? 1 : this.height); 
-    }
-
     _adjustForOverview() {
         let isFocusedMonitor = this.panelManager.checkIfFocusedMonitor(this.monitor);
         let isOverview = !!Main.overview.visibleTarget;
@@ -711,19 +686,10 @@ var Panel = GObject.registerClass({
         let isShown = !isOverview || isOverviewFocusedMonitor;
 
         this.panelBox[isShown ? 'show' : 'hide']();
-
-        if (isOverview) {
-            this._myPanelGhost[isOverviewFocusedMonitor ? 'show' : 'hide']();
-
-            if (isOverviewFocusedMonitor) {
-                Utils.getPanelGhost().set_size(1, this.geom.position == St.Side.TOP ? 0 : 32);
-            }
-        }
     }
 
     _resetGeometry() {
         this.geom = this.getGeometry();
-        this._setPanelGhostSize();
         this._setPanelPosition();
         this.taskbar.resetAppIcons(true);
         this.dynamicTransparency.updateExternalStyle();

panelManager.js

@@ -272,8 +272,6 @@ var PanelManager = class {
 
         Main.overview._overview._controls._workspacesDisplay._updateWorkspacesViews = this._oldUpdateWorkspacesViews;
 
-        Utils.getPanelGhost().set_size(-1, -1);
-
         LookingGlass.LookingGlass.prototype._resize = LookingGlass.LookingGlass.prototype._oldResize;
         delete LookingGlass.LookingGlass.prototype._oldResize;
 
@@ -284,6 +282,8 @@ var PanelManager = class {
     }
 
     setFocusedMonitor(monitor) {
+        this.focusedMonitorPanel = this.allPanels.find(p => p.monitor == monitor)
+
         if (!this.checkIfFocusedMonitor(monitor)) {
             Main.overview._overview.clear_constraints();
             Main.overview._overview.add_constraint(new Layout.MonitorConstraint({ index: monitor.index }));

utils.js

@@ -526,14 +526,6 @@ var getPoint = function(coords) {
     return new Clutter.Point(coords);
 }
 
-var getPanelGhost = function() {
-    if (!Main.overview._panelGhost) {
-        return Main.overview._overview.get_first_child();
-    }
-
-    return Main.overview._panelGhost;
-}
-
 var notify = function(text, iconName, action, isTransient) {
     let source = new MessageTray.SystemNotificationSource();
     let notification = new MessageTray.Notification(source, 'Dash to Panel', text);