Delay window previews on hover for #26

Settings.ui

@@ -364,6 +364,11 @@
     <property name="step_increment">0.01</property>
     <property name="page_increment">0.10000000000000001</property>
   </object>
+  <object class="GtkAdjustment" id="preview_timeout_adjustment">
+    <property name="upper">9999</property>
+    <property name="step_increment">25</property>
+    <property name="page_increment">100</property>
+  </object>
   <object class="GtkAdjustment" id="statusicon_padding_adjustment">
     <property name="lower">0.33000000000000002</property>
     <property name="upper">1</property>
@@ -957,6 +962,34 @@
                             <property name="top_attach">0</property>
                           </packing>
                         </child>
+                        <child>
+                          <object class="GtkSpinButton" id="preview_timeout_spinbutton">
+                            <property name="visible">True</property>
+                            <property name="can_focus">True</property>
+                            <property name="width_chars">4</property>
+                            <property name="text" translatable="yes">0</property>
+                            <property name="adjustment">preview_timeout_adjustment</property>
+                            <property name="numeric">True</property>
+                          </object>
+                          <packing>
+                            <property name="left_attach">1</property>
+                            <property name="top_attach">1</property>
+                          </packing>
+                        </child>
+                        <child>
+                          <object class="GtkLabel" id="preview_timeout_label">
+                            <property name="visible">True</property>
+                            <property name="can_focus">False</property>
+                            <property name="hexpand">True</property>
+                            <property name="label" translatable="yes">Time before showing (ms)</property>
+                            <property name="use_markup">True</property>
+                            <property name="xalign">0</property>
+                          </object>
+                          <packing>
+                            <property name="left_attach">0</property>
+                            <property name="top_attach">1</property>
+                          </packing>
+                        </child>
                       </object>
                     </child>
                   </object>

prefs.js

@@ -155,6 +155,16 @@ const Settings = new Lang.Class({
                             this._builder.get_object('show_window_previews_switch'),
                             'active',
                             Gio.SettingsBindFlags.DEFAULT);
+        this._settings.bind('show-window-previews',
+                this._builder.get_object('preview_timeout_spinbutton'),
+                'sensitive',
+                Gio.SettingsBindFlags.DEFAULT);
+
+        this._builder.get_object('preview_timeout_spinbutton').set_value(this._settings.get_int('show-window-previews-timeout'));
+        this._builder.get_object('preview_timeout_spinbutton').connect('value-changed', Lang.bind (this, function(widget) {
+            this._settings.set_int('show-window-previews-timeout', widget.get_value());
+        }));
+       
         this._settings.bind('isolate-workspaces',
                             this._builder.get_object('isolate_workspaces_switch'),
                             'active',
@@ -249,7 +259,7 @@ const Settings = new Lang.Class({
 
             this._builder.get_object('leave_timeout_spinbutton').set_value(this._settings.get_int('leave-timeout'));
 
-            this._builder.get_object('leave_timeout_spinbutton').connect('changed', Lang.bind (this, function(widget) {
+            this._builder.get_object('leave_timeout_spinbutton').connect('value-changed', Lang.bind (this, function(widget) {
                 this._settings.set_int('leave-timeout', widget.get_value());
             }));
 

schemas/org.gnome.shell.extensions.dash-to-panel.gschema.xml

@@ -69,6 +69,11 @@
       <summary>Show window preview</summary>
       <description>Show preview of running window on hover of app icon</description>
     </key>
+    <key type="i" name="show-window-previews-timeout">
+      <default>100</default>
+      <summary>Icon enter display time</summary>
+      <description>Amount of time after entering icon to wait before displaying window preview if icon is not clicked or mouse has not left.</description>
+    </key>
     <key type="b" name="isolate-workspaces">
       <default>false</default>
       <summary>Provide workspace isolation</summary>

taskbar.js

@@ -1226,14 +1226,37 @@ const taskbarAppIcon = new Lang.Class({
         // Creating a new menu manager for window previews as adding it to the
         // using the secondary menu's menu manager (which uses the "ignoreRelease"
         // function) caused the extension to crash.
-        this._menuManagerWindowPreview = new PopupMenu.PopupMenuManager(this);
+        this.menuManagerWindowPreview = new PopupMenu.PopupMenuManager(this);
+
+        this.windowPreview = new WindowPreview.thumbnailPreviewMenu(this, this._dtpSettings, this.menuManagerWindowPreview);
 
-        this.windowPreview = new WindowPreview.thumbnailPreviewMenu(this, this._dtpSettings);
         this.windowPreview.connect('open-state-changed', Lang.bind(this, function (menu, isPoppedUp) {
             if (!isPoppedUp)
                 this._onMenuPoppedDown();
         }));
-        this._menuManagerWindowPreview.addMenu(this.windowPreview);
+        this.menuManagerWindowPreview.addMenu(this.windowPreview);
+
+        // grabHelper.grab() is usually called when the menu is opened. However, there seems to be a bug in the 
+        // underlying gnome-shell that causes all window contents to freeze if the grab and ungrab occur
+        // in quick succession (for example, clicking the icon as the preview window is opening)
+        // So, instead I'll issue the grab when the preview menu is actually entered.
+        // Alternatively, I was able to solve this by waiting a 100ms timeout to ensure the menu was
+        // still open, but this waiting until the menu is entered seems a bit safer if it doesn't cause other issues
+        let windowPreviewMenuData = this.menuManagerWindowPreview._menus[this.menuManagerWindowPreview._findMenu(this.windowPreview)];
+        this.windowPreview.disconnect(windowPreviewMenuData.openStateChangeId);
+        windowPreviewMenuData.openStateChangeId = this.windowPreview.connect('open-state-changed', Lang.bind(this.menuManagerWindowPreview, function(menu, open) {
+            if (open) {
+                if (this.activeMenu)
+                    this.activeMenu.close(BoxPointer.PopupAnimation.FADE);
+
+                // Mainloop.timeout_add(100, Lang.bind(this, function() {
+                //     if(menu.isOpen)
+                //         this._grabHelper.grab({ actor: menu.actor, focus: menu.sourceActor, onUngrab: Lang.bind(this, this._closeMenu, menu) });
+                // }));
+            } else {
+                this._grabHelper.ungrab({ actor: menu.actor });
+            }
+        }));
         
         this.forcedOverview = false;
     },

windowPreview.js

@@ -110,6 +110,13 @@ const thumbnailPreviewMenu = new Lang.Class({
         this.shouldOpen = true;
         this.shouldClose = false;
 
+        // This grab is usually called when the menu is opened. However, there seems to be a bug in the 
+        // underlying gnome-shell that causes the window contents to freeze if the grab and ungrab occur
+        // in quick succession (for example, clicking the icon as the preview window is opening)
+        // So, instead I'll issue the grab when the preview menu is actually entered.
+        this._source.menuManagerWindowPreview._grabHelper.grab({ actor: this.actor, focus: this.sourceActor, 
+                                                                onUngrab: Lang.bind(this, this.requestCloseMenu) });
+
         this.hoverOpen();
     },
 
@@ -123,7 +130,7 @@ const thumbnailPreviewMenu = new Lang.Class({
         this.shouldOpen = true;
         this.shouldClose = false;
 
-        this.hoverOpen();
+        Mainloop.timeout_add(this._dtpSettings.get_int('show-window-previews-timeout'), Lang.bind(this, this.hoverOpen));
     },
 
     _onLeave: function () {