kcm & taskswitcher: Add option to toggle application previews

components/mobileshell/mobileshellsettings.cpp

@@ -31,6 +31,7 @@ MobileShellSettings::MobileShellSettings(QObject *parent)
             Q_EMIT vibrationDurationChanged();
             Q_EMIT animationsEnabledChanged();
             Q_EMIT navigationPanelEnabledChanged();
+            Q_EMIT taskSwitcherPreviewsEnabledChanged();
         } else if (group.name() == QUICKSETTINGS_CONFIG_GROUP) {
             Q_EMIT enabledQuickSettingsChanged();
             Q_EMIT disabledQuickSettingsChanged();
@@ -103,6 +104,19 @@ void MobileShellSettings::setNavigationPanelEnabled(bool navigationPanelEnabled)
     m_config->sync();
 }
 
+bool MobileShellSettings::taskSwitcherPreviewsEnabled() const
+{
+    auto group = KConfigGroup{m_config, GENERAL_CONFIG_GROUP};
+    return group.readEntry("taskSwitcherPreviewsEnabled", true);
+}
+
+void MobileShellSettings::setTaskSwitcherPreviewsEnabled(bool taskSwitcherPreviewsEnabled)
+{
+    auto group = KConfigGroup{m_config, GENERAL_CONFIG_GROUP};
+    group.writeEntry("taskSwitcherPreviewsEnabled", taskSwitcherPreviewsEnabled, KConfigGroup::Notify);
+    m_config->sync();
+}
+
 QList<QString> MobileShellSettings::enabledQuickSettings() const
 {
     auto group = KConfigGroup{m_config, QUICKSETTINGS_CONFIG_GROUP};

components/mobileshell/mobileshellsettings.h

@@ -19,12 +19,19 @@
 class MobileShellSettings : public QObject
 {
     Q_OBJECT
+
+    // general
     Q_PROPERTY(bool vibrationsEnabled READ vibrationsEnabled WRITE setVibrationsEnabled NOTIFY vibrationsEnabledChanged)
     Q_PROPERTY(int vibrationDuration READ vibrationDuration WRITE setVibrationDuration NOTIFY vibrationDurationChanged)
     Q_PROPERTY(qreal vibrationIntensity READ vibrationIntensity WRITE setVibrationIntensity NOTIFY vibrationIntensityChanged)
     Q_PROPERTY(bool animationsEnabled READ animationsEnabled WRITE setAnimationsEnabled NOTIFY animationsEnabledChanged)
+
+    // navigation panel
     Q_PROPERTY(bool navigationPanelEnabled READ navigationPanelEnabled WRITE setNavigationPanelEnabled NOTIFY navigationPanelEnabledChanged)
 
+    // task switcher
+    Q_PROPERTY(bool taskSwitcherPreviewsEnabled READ taskSwitcherPreviewsEnabled WRITE setTaskSwitcherPreviewsEnabled NOTIFY taskSwitcherPreviewsEnabledChanged)
+
 public:
     static MobileShellSettings *self();
 
@@ -98,6 +105,18 @@ public:
      */
     void setNavigationPanelEnabled(bool navigationPanelEnabled);
 
+    /**
+     * Whether task switcher application previews are enabled.
+     */
+    bool taskSwitcherPreviewsEnabled() const;
+
+    /**
+     * Set whether task switcher application previews are enabled.
+     *
+     * @param taskSwitcherPreviewsEnabled Whether task switcher previews are enabled.
+     */
+    void setTaskSwitcherPreviewsEnabled(bool taskSwitcherPreviewsEnabled);
+
     /**
      * Get the list of IDs of quick settings that are enabled.
      */
@@ -128,6 +147,7 @@ Q_SIGNALS:
     void vibrationDurationChanged();
     void navigationPanelEnabledChanged();
     void animationsEnabledChanged();
+    void taskSwitcherPreviewsEnabledChanged();
     void enabledQuickSettingsChanged();
     void disabledQuickSettingsChanged();
 

components/mobileshell/qml/taskswitcher/Task.qml

@@ -228,7 +228,7 @@ Item {
                     // attempt to load window preview
                     Loader {
                         id: pipeWireLoader
-                        active: taskSwitcher.visible || taskSwitcher.tasksModel.taskReorderingEnabled
+                        active: (taskSwitcher.visible || taskSwitcher.tasksModel.taskReorderingEnabled) && MobileShell.MobileShellSettings.taskSwitcherPreviewsEnabled
                         anchors.fill: parent
                         source: Qt.resolvedUrl("./Thumbnail.qml")
                         

kcms/mobileshell/package/contents/ui/main.qml

@@ -88,6 +88,30 @@ KCM.SimpleKCM {
             }
         }
         
+        MobileForm.FormCard {
+            Layout.fillWidth: true
+            Layout.topMargin: Kirigami.Units.largeSpacing
+            
+            contentItem: ColumnLayout {
+                spacing: 0
+                
+                MobileForm.FormCardHeader {
+                    title: i18n("Task Switcher")
+                }
+                
+                MobileForm.FormSwitchDelegate {
+                    text: i18n("Show Application Previews")
+                    description: i18n("Turning this off may help improve performance.")
+                    checked: MobileShell.MobileShellSettings.taskSwitcherPreviewsEnabled
+                    onCheckedChanged: {
+                        if (checked != MobileShell.MobileShellSettings.taskSwitcherPreviewsEnabled) {
+                            MobileShell.MobileShellSettings.taskSwitcherPreviewsEnabled = checked;
+                        }
+                    }
+                }
+            }
+        }
+        
         MobileForm.FormCard {
             Layout.fillWidth: true
             Layout.topMargin: Kirigami.Units.largeSpacing