[Notifications] Add visible menu button to thumbnail strip

Makes it more obvious there's a menu with more options.
You can still right-click the thumbnail area as before.

Differential Revision: https://phabricator.kde.org/D9255

applets/notifications/package/contents/ui/ThumbnailStrip.qml

@@ -111,8 +111,22 @@ ListView {
 
         preventStealing: true
         cursorShape: Qt.OpenHandCursor
+        acceptedButtons: Qt.LeftButton | Qt.RightButton
 
-        onClicked: notificationItem.openUrl(modelData)
+        onClicked: {
+            if (mouse.button === Qt.LeftButton) {
+                notificationItem.openUrl(modelData);
+            }
+        }
+
+        onPressed: {
+            if (mouse.button === Qt.RightButton) {
+                // avoid menu button glowing if we didn't actually press it
+                menuButton.checked = false;
+
+                thumbnailer.showContextMenu(mouse.x, mouse.y, modelData, this);
+            }
+        }
 
         // cannot drag itself, hence dragging the Pixmap instead
         drag.target: previewPixmap
@@ -193,11 +207,36 @@ ListView {
             }
         }
 
-        MouseArea {
-            anchors.fill: parent
-            acceptedButtons: Qt.RightButton
-            onPressed: {
-                thumbnailer.showContextMenu(mouse.x, mouse.y, modelData, this)
+        PlasmaComponents.Button {
+            id: menuButton
+            anchors {
+                top: parent.top
+                right: parent.right
+                margins: units.smallSpacing
+            }
+            width: Math.ceil(units.iconSizes.small + 2 * units.smallSpacing)
+            height: width
+            tooltip: i18n("More Options...")
+            Accessible.name: tooltip
+            checkable: true
+
+            // -1 tells it to "align bottom left of item (this)"
+            onClicked: {
+                checked = Qt.binding(function() {
+                    return thumbnailer.menuVisible;
+                });
+
+                thumbnailer.showContextMenu(-1, -1, modelData, this)
+            }
+
+            PlasmaCore.IconItem {
+                anchors.fill: parent
+                anchors.margins: parent.padding
+                source: "application-menu"
+
+                // From Plasma's ToolButtonStyle:
+                active: parent.hovered
+                colorGroup: parent.hovered ? PlasmaCore.Theme.ButtonColorGroup : PlasmaCore.ColorScope.colorGroup
             }
         }
     }

applets/notifications/plugin/thumbnailer.cpp

@@ -107,6 +107,11 @@ QString Thumbnailer::iconName() const
     return m_iconName;
 }
 
+bool Thumbnailer::menuVisible() const
+{
+    return m_menuVisible;
+}
+
 void Thumbnailer::showContextMenu(int x, int y, const QString &path, QQuickItem *ctx)
 {
     if (!ctx || !ctx->window()) {
@@ -123,6 +128,11 @@ void Thumbnailer::showContextMenu(int x, int y, const QString &path, QQuickItem
     QMenu *menu = new QMenu();
     menu->setAttribute(Qt::WA_DeleteOnClose, true);
 
+    connect(menu, &QMenu::aboutToHide, this, [this] {
+        m_menuVisible = false;
+        emit menuVisibleChanged();
+    });
+
     if (KProtocolManager::supportsListing(url)) {
         QAction *openContainingFolderAction = menu->addAction(QIcon::fromTheme("folder-open"), i18n("Open Containing Folder"));
         connect(openContainingFolderAction, &QAction::triggered, [url] {
@@ -172,9 +182,24 @@ void Thumbnailer::showContextMenu(int x, int y, const QString &path, QQuickItem
     QTimer::singleShot(0, ctx, ungrabMouseHack);
     //end workaround
 
+    QPoint pos;
+    if (x == -1 && y == -1) { // align "bottom left of ctx"
+        menu->adjustSize();
+
+        pos = ctx->mapToGlobal(QPointF(0, ctx->height())).toPoint();
+
+        if (!qApp->isRightToLeft()) {
+            pos.rx() += ctx->width();
+            pos.rx() -= menu->width();
+        }
+    } else {
+        pos = ctx->mapToGlobal(QPointF(x, y)).toPoint();
+    }
 
-    const QPoint pos = ctx->mapToGlobal(QPointF(x, y)).toPoint();
     menu->popup(pos);
+
+    m_menuVisible = true;
+    emit menuVisibleChanged();
 }
 
 void Thumbnailer::generatePreview()

applets/notifications/plugin/thumbnailer.h

@@ -41,6 +41,8 @@ class Thumbnailer : public QObject, public QQmlParserStatus
 
     Q_PROPERTY(QString iconName READ iconName NOTIFY iconNameChanged)
 
+    Q_PROPERTY(bool menuVisible READ menuVisible NOTIFY menuVisibleChanged)
+
 public:
     explicit Thumbnailer(QObject *parent = nullptr);
     ~Thumbnailer() override;
@@ -57,12 +59,16 @@ public:
 
     QString iconName() const;
 
+    bool menuVisible() const;
+
     Q_INVOKABLE void showContextMenu(int x, int y, const QString &path, QQuickItem *ctx);
 
     void classBegin() override;
     void componentComplete() override;
 
 signals:
+    void menuVisibleChanged();
+
     void urlChanged();
     void sizeChanged();
     void pixmapChanged();
@@ -73,6 +79,8 @@ private:
 
     bool m_inited = false;
 
+    bool m_menuVisible = false;
+
     QUrl m_url;
     QSize m_size;