[gnome-shell] overview: Restore previous workspace switcher policy

[Florian Müllner <fmuellner src gnome org>]

commit 764fbbe0524e89eb25cad8894fa4091f3fa47ac7
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Jul 20 20:35:54 2018 +0200

    overview: Restore previous workspace switcher policy
    
    We used to keep the workspace switcher slid out when the user made use
    of workspaces. This was changed in commit 2d84975 to give more space
    to window previews, but it turned out to make the switcher quite a lot
    more difficult to interact with (rather than only being a question of
    discoverability). So go back to the previous behavior.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/161

 js/ui/overviewControls.js | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/overviewControls.js b/js/ui/overviewControls.js
index 1b1c9cf10..4cd161374 100644
--- a/js/ui/overviewControls.js
+++ b/js/ui/overviewControls.js
@@ -253,13 +253,23 @@ var ThumbnailsSlider = new Lang.Class({
         this.actor.add_actor(this._thumbnailsBox.actor);
 
         Main.layoutManager.connect('monitors-changed', this._updateSlide.bind(this));
+        global.workspace_manager.connect('active-workspace-changed',
+                                         this._updateSlide.bind(this));
+        global.workspace_manager.connect('notify::n-workspaces',
+                                         this._updateSlide.bind(this));
         this.actor.connect('notify::hover', this._updateSlide.bind(this));
         this._thumbnailsBox.actor.bind_property('visible', this.actor, 'visible', 
GObject.BindingFlags.SYNC_CREATE);
     },
 
     _getAlwaysZoomOut() {
-        // Always show the pager on hover or during a drag
-        let alwaysZoomOut = this.actor.hover || this._inDrag;
+        // Always show the pager on hover, during a drag, or if workspaces are
+        // actually used, e.g. there are windows on any non-active workspace
+        let workspaceManager = global.workspace_manager;
+        let alwaysZoomOut = this.actor.hover ||
+                            this._inDrag ||
+                            !Meta.prefs_get_dynamic_workspaces() ||
+                            workspaceManager.n_workspaces > 2 ||
+                            workspaceManager.get_active_workspace_index() != 0;
 
         if (!alwaysZoomOut) {
             let monitors = Main.layoutManager.monitors;