workspaceOsd.js: destroy and recreate the label on each display

This forces the switcher to allocate the proper amount of space for the
workspace name. Fixes and issue with the text getting ellipsized.

data/theme/cinnamon-sass/widgets/_osd.scss

@@ -58,6 +58,7 @@ $ws_dot_inactive: $ws_indicator_height / 6;
   @extend %osd_base;
   @extend %title_4;
 
+  min-width: 140px;
   margin-bottom: 4em;
   border-radius: 9999px;
   font-weight: bold;

js/ui/workspaceOsd.js

@@ -41,11 +41,14 @@ class WorkspaceOsd extends Clutter.Actor {
         });
         this.add_child(this._vbox);
 
-        this._label = new St.Label();
-        this._vbox.add_child(this._label);
+        this._labelBin = new St.Bin();
+        this._activeWorkspaceName = null;
+        this._label = null;
+        this._vbox.add_child(this._labelBin);
 
         this._list = new St.BoxLayout({
             style_class: 'workspace-switch-osd-indicator-box',
+            x_align: Clutter.ActorAlign.CENTER,
         });
         this._vbox.add_child(this._list);
 
@@ -64,6 +67,18 @@ class WorkspaceOsd extends Clutter.Actor {
     }
 
     _redisplay() {
+        if (!this._activeWorkspaceName)
+            return;
+
+        if (this._label !== null)
+            this._label.destroy();
+
+        this._label = new St.Label ({
+            text: this._activeWorkspaceName,
+        });
+
+        this._labelBin.set_child(this._label);
+
         let workspaceManager = global.workspace_manager;
 
         this._list.destroy_all_children();
@@ -82,7 +97,7 @@ class WorkspaceOsd extends Clutter.Actor {
 
     display(activeWorkspaceIndex, workspaceName) {
         this._activeWorkspaceIndex = activeWorkspaceIndex;
-        this._label.text = workspaceName;
+        this._activeWorkspaceName = workspaceName;
 
         this._redisplay();
         if (this._timeoutId != 0)