kcm/tabbox: Make the preview show desktop if the option is selected

The thumbnail that represents the "desktop" in the switcher preview
is taken from the default wallpaper, and it will update automatically
as it changes in future versions of Plasma.

The current one is also added along the other thumbnails as a fallback.

BUG: 309401
FIXED-IN: 5.24

src/kcmkwin/kwintabbox/CMakeLists.txt

@@ -38,5 +38,10 @@ install(TARGETS kcm_kwintabbox DESTINATION ${KDE_INSTALL_PLUGINDIR} )
 
 ########### install files ###############
 install(FILES kwintabbox.desktop DESTINATION ${KDE_INSTALL_KSERVICES5DIR})
-install(FILES thumbnails/konqueror.png thumbnails/kmail.png thumbnails/systemsettings.png thumbnails/dolphin.png DESTINATION ${KDE_INSTALL_DATADIR}/kwin/kcm_kwintabbox)
+install(FILES thumbnails/konqueror.png
+              thumbnails/kmail.png
+              thumbnails/systemsettings.png
+              thumbnails/dolphin.png
+              thumbnails/desktop.png
+        DESTINATION ${KDE_INSTALL_DATADIR}/kwin/kcm_kwintabbox)
 install(FILES kwinswitcher.knsrc DESTINATION ${KDE_INSTALL_KNSRCDIR})

src/kcmkwin/kwintabbox/layoutpreview.cpp

@@ -8,7 +8,7 @@
 */
 // own
 #include "layoutpreview.h"
-#include "thumbnailitem.h"
+
 #include <QApplication>
 #include <QDebug>
 #include <QQmlEngine>
@@ -25,7 +25,7 @@ namespace KWin
 namespace TabBox
 {
 
-LayoutPreview::LayoutPreview(const QString &path, QObject *parent)
+LayoutPreview::LayoutPreview(const QString &path, bool showDesktopThumbnail, QObject *parent)
     : QObject(parent)
     , m_item(nullptr)
 {
@@ -52,6 +52,7 @@ LayoutPreview::LayoutPreview(const QString &path, QObject *parent)
     };
     if (SwitcherItem *switcher = findSwitcher()) {
         m_item = switcher;
+        static_cast<ExampleClientModel *>(switcher->model())->showDesktopThumbnail(showDesktopThumbnail);
         switcher->setVisible(true);
     }
     auto findWindow = [item]() -> QQuickWindow* {
@@ -115,50 +116,56 @@ ExampleClientModel::~ExampleClientModel()
 void ExampleClientModel::init()
 {
     if (const auto s = KApplicationTrader::preferredService(QStringLiteral("inode/directory"))) {
-        m_services << s;
-        m_fileManager = s;
+        m_thumbnails << ThumbnailInfo{ WindowThumbnailItem::Dolphin, s->name(), s->icon() };
     }
     if (const auto s = KApplicationTrader::preferredService(QStringLiteral("text/html"))) {
-        m_services << s;
-        m_browser = s;
+        m_thumbnails << ThumbnailInfo{ WindowThumbnailItem::Konqueror, s->name(), s->icon() };
     }
     if (const auto s = KApplicationTrader::preferredService(QStringLiteral("message/rfc822"))) {
-        m_services << s;
-        m_email = s;
+        m_thumbnails << ThumbnailInfo{ WindowThumbnailItem::KMail, s->name(), s->icon() };
     }
     if (const auto s = KService::serviceByDesktopName(QStringLiteral("kdesystemsettings"))) {
-        m_services << s;
-        m_systemSettings = s;
+        m_thumbnails << ThumbnailInfo{ WindowThumbnailItem::Systemsettings, s->name(), s->icon() };
     }
 }
 
+void ExampleClientModel::showDesktopThumbnail(bool showDesktop)
+{
+    const ThumbnailInfo desktopThumbnail = ThumbnailInfo { WindowThumbnailItem::Desktop, i18n("Show Desktop"), QStringLiteral("desktop") };
+    const int desktopIndex = m_thumbnails.indexOf(desktopThumbnail);
+    if (showDesktop == (desktopIndex >= 0)) {
+        return;
+    }
+
+    Q_EMIT beginResetModel();
+    if (showDesktop) {
+        m_thumbnails << desktopThumbnail;
+    } else {
+        m_thumbnails.removeAt(desktopIndex);
+    }
+    Q_EMIT endResetModel();
+}
+
 QVariant ExampleClientModel::data(const QModelIndex &index, int role) const
 {
-    if (!index.isValid()) {
+    if (!index.isValid() || index.row() >= rowCount()) {
         return QVariant();
     }
+
+    const ThumbnailInfo &item = m_thumbnails.at(index.row());
+
     switch (role) {
     case Qt::DisplayRole:
     case CaptionRole:
-        return m_services.at(index.row())->name();
+        return item.caption;
     case MinimizedRole:
         return false;
     case DesktopNameRole:
         return i18nc("An example Desktop Name", "Desktop 1");
     case IconRole:
-        return m_services.at(index.row())->icon();
+        return item.icon;
     case WindowIdRole:
-        const auto s = m_services.at(index.row());
-        if (s == m_browser) {
-            return WindowThumbnailItem::Konqueror;
-        } else if (s == m_email) {
-            return WindowThumbnailItem::KMail;
-        } else if (s == m_systemSettings) {
-            return WindowThumbnailItem::Systemsettings;
-        } else if (s == m_fileManager) {
-            return WindowThumbnailItem::Dolphin;
-        }
-        return 0;
+        return item.wId;
     }
     return QVariant();
 }
@@ -166,10 +173,9 @@ QVariant ExampleClientModel::data(const QModelIndex &index, int role) const
 QString ExampleClientModel::longestCaption() const
 {
     QString caption;
-    for (const auto &item : m_services) {
-        const QString name = item->name();
-        if (name.size() > caption.size()) {
-            caption = name;
+    for (const auto &item : m_thumbnails) {
+        if (item.caption.size() > caption.size()) {
+            caption = item.caption;
         }
     }
     return caption;
@@ -178,7 +184,7 @@ QString ExampleClientModel::longestCaption() const
 int ExampleClientModel::rowCount(const QModelIndex &parent) const
 {
     Q_UNUSED(parent)
-    return m_services.size();
+    return m_thumbnails.size();
 }
 
 QHash<int, QByteArray> ExampleClientModel::roleNames() const

src/kcmkwin/kwintabbox/layoutpreview.h

@@ -9,11 +9,12 @@
 #ifndef KWIN_TABBOX_LAYOUTPREVIEW_H
 #define KWIN_TABBOX_LAYOUTPREVIEW_H
 
-#include <KService>
 #include <QAbstractListModel>
 #include <QQuickView>
 #include <QRect>
 
+#include "thumbnailitem.h"
+
 namespace KWin
 {
 
@@ -26,7 +27,7 @@ class LayoutPreview : public QObject
 {
     Q_OBJECT
 public:
-    explicit LayoutPreview(const QString &path, QObject *parent = nullptr);
+    explicit LayoutPreview(const QString &path, bool showDesktopThumbnail = false, QObject *parent = nullptr);
     ~LayoutPreview() override;
 
     bool eventFilter(QObject *object, QEvent *event) override;
@@ -54,13 +55,21 @@ public:
     QHash<int, QByteArray> roleNames() const override;
     Q_INVOKABLE QString longestCaption() const;
 
+    void showDesktopThumbnail(bool showDesktop);
+
 private:
+    struct ThumbnailInfo {
+        WindowThumbnailItem::Thumbnail wId;
+        QString caption;
+        QString icon;
+
+        bool operator==(const ThumbnailInfo &other) {
+            return wId == other.wId;
+        }
+    };
+
     void init();
-    QList<KService::Ptr> m_services;
-    KService::Ptr m_fileManager;
-    KService::Ptr m_browser;
-    KService::Ptr m_email;
-    KService::Ptr m_systemSettings;
+    QList<ThumbnailInfo> m_thumbnails;
 };
 
 

src/kcmkwin/kwintabbox/main.cpp

@@ -377,7 +377,9 @@ void KWinTabBoxConfig::configureEffectClicked()
 
     if (form->effectComboCurrentData(KWinTabBoxConfigForm::AddonEffect).toBool()) {
         // Show the preview for addon effect
-        new LayoutPreview(form->effectComboCurrentData(KWinTabBoxConfigForm::LayoutPath).toString(), this);
+        new LayoutPreview(form->effectComboCurrentData(KWinTabBoxConfigForm::LayoutPath).toString(),
+                          form->showDesktopMode(),
+                          this);
     } else {
         // For builtin effect, display a configuration dialog
         QPointer<QDialog> configDialog = new QDialog(this);

src/kcmkwin/kwintabbox/thumbnailitem.cpp

@@ -141,6 +141,12 @@ void WindowThumbnailItem::findImage()
     case Dolphin:
         imagePath = QStandardPaths::locate(QStandardPaths::GenericDataLocation, "kwin/kcm_kwintabbox/dolphin.png");
         break;
+    case Desktop:
+        imagePath = QStandardPaths::locate(QStandardPaths::GenericDataLocation, "wallpapers/Next/contents/screenshot.png");
+        if (imagePath.isNull()) {
+            imagePath = QStandardPaths::locate(QStandardPaths::GenericDataLocation, "kwin/kcm_kwintabbox/desktop.png");
+        }
+        break;
     default:
         // ignore
         break;

src/kcmkwin/kwintabbox/thumbnailitem.h

@@ -79,7 +79,8 @@ public:
         Konqueror = 1,
         KMail,
         Systemsettings,
-        Dolphin
+        Dolphin,
+        Desktop,
     };
 Q_SIGNALS:
     void wIdChanged(qulonglong wid);