[gnome-shell] workspaceThumnails: Add :should-show property

[Marge Bot <marge-bot src gnome org>]

commit f2391796825b7966501e158efaf3b80a00a076b0
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Feb 16 20:40:43 2021 +0100

    workspaceThumnails: Add :should-show property
    
    We currently have two components that show or hide the minimap:
    
     - the thumbnails hide themselves in case of a single static workspace
     - overview controls show the minimap when no search is active
    
    That obviously doesn't work correctly.
    
    To fix this, change thumbnails to set a new :should-show property instead
    of the visibility, and let the overview controls take it into account
    when changing the visibility.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3739
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1696>

 js/ui/overviewControls.js   |  6 +++++-
 js/ui/workspaceThumbnail.js | 30 ++++++++++++++++++++++--------
 2 files changed, 27 insertions(+), 9 deletions(-)
---
diff --git a/js/ui/overviewControls.js b/js/ui/overviewControls.js
index 96d99403f4..5a7f4aa24e 100644
--- a/js/ui/overviewControls.js
+++ b/js/ui/overviewControls.js
@@ -303,6 +303,9 @@ class ControlsManager extends St.Widget {
 
         this._thumbnailsBox =
             new WorkspaceThumbnail.ThumbnailsBox(this._workspaceAdjustment);
+        this._thumbnailsBox.connect('notify::should-show',
+            () => this._updateThumbnailsBox());
+
         this._workspacesDisplay = new WorkspacesView.WorkspacesDisplay(
             this,
             this._workspaceAdjustment,
@@ -426,10 +429,11 @@ class ControlsManager extends St.Widget {
     }
 
     _updateThumbnailsBox(animate = false) {
+        const { shouldShow } = this._thumbnailsBox;
         const { searchActive } = this._searchController;
         const [opacity, scale, translationY] = this._getThumbnailsBoxParams();
 
-        const thumbnailsBoxVisible = !searchActive && opacity !== 0;
+        const thumbnailsBoxVisible = shouldShow && !searchActive && opacity !== 0;
         if (thumbnailsBoxVisible) {
             this._thumbnailsBox.opacity = 0;
             this._thumbnailsBox.visible = thumbnailsBoxVisible;
diff --git a/js/ui/workspaceThumbnail.js b/js/ui/workspaceThumbnail.js
index ad8dfbf539..3c9b7ed0ad 100644
--- a/js/ui/workspaceThumbnail.js
+++ b/js/ui/workspaceThumbnail.js
@@ -607,6 +607,10 @@ var ThumbnailsBox = GObject.registerClass({
             'scale', 'scale', 'scale',
             GObject.ParamFlags.READWRITE,
             0, Infinity, 0),
+        'should-show': GObject.ParamSpec.boolean(
+            'should-show', 'should-show', 'should-show',
+            GObject.ParamFlags.READABLE,
+            true),
     },
 }, class ThumbnailsBox extends St.Widget {
     _init(scrollAdjustment) {
@@ -643,6 +647,8 @@ var ThumbnailsBox = GObject.registerClass({
         this._stateUpdateQueued = false;
         this._animatingIndicator = false;
 
+        this._shouldShow = true;
+
         this._stateCounts = {};
         for (let key in ThumbnailState)
             this._stateCounts[ThumbnailState[key]] = 0;
@@ -669,7 +675,7 @@ var ThumbnailsBox = GObject.registerClass({
 
         this._settings = new Gio.Settings({ schema_id: MUTTER_SCHEMA });
         this._settings.connect('changed::dynamic-workspaces',
-            this._updateSwitcherVisibility.bind(this));
+            () => this._updateShouldShow());
 
         Main.layoutManager.connect('monitors-changed', () => {
             this._destroyThumbnails();
@@ -700,12 +706,16 @@ var ThumbnailsBox = GObject.registerClass({
         });
     }
 
-    _updateSwitcherVisibility() {
-        let workspaceManager = global.workspace_manager;
+    _updateShouldShow() {
+        const { nWorkspaces } = global.workspace_manager;
+        const shouldShow =
+            this._settings.get_boolean('dynamic-workspaces') || nWorkspaces > 1;
+
+        if (this._shouldShow === shouldShow)
+            return;
 
-        this.visible =
-            this._settings.get_boolean('dynamic-workspaces') ||
-                workspaceManager.n_workspaces > 1;
+        this._shouldShow = shouldShow;
+        this.notify('should-show');
     }
 
     _activateThumbnailAtPoint(stageX, stageY, time) {
@@ -960,7 +970,7 @@ var ThumbnailsBox = GObject.registerClass({
 
         this.addThumbnails(0, workspaceManager.n_workspaces);
 
-        this._updateSwitcherVisibility();
+        this._updateShouldShow();
     }
 
     _destroyThumbnails() {
@@ -1011,7 +1021,7 @@ var ThumbnailsBox = GObject.registerClass({
             this.removeThumbnails(removedIndex, removedNum);
         }
 
-        this._updateSwitcherVisibility();
+        this._updateShouldShow();
     }
 
     addThumbnails(start, count) {
@@ -1408,4 +1418,8 @@ var ThumbnailsBox = GObject.registerClass({
         childBox.y2 += indicatorBottomFullBorder;
         this._indicator.allocate(childBox);
     }
+
+    get shouldShow() {
+        return this._shouldShow;
+    }
 });