Display shortcut badges while holding Super

Summary:
Use `KModifierKeyInfo` to display shortcut badges while holding Super

BUG: 401768

Test Plan:
Just playing with it.
I still don't understand the `GlobalShortcut` class very well, correct me if I make any mistake.

Reviewers: #latte_dock, mvourlakos

Reviewed By: #latte_dock, mvourlakos

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D18620

CMakeLists.txt

@@ -19,7 +19,7 @@ set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR})
 
 find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED NO_MODULE COMPONENTS DBus Gui Qml Quick)
 find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
-    Activities Archive CoreAddons Crash DBusAddons Declarative GlobalAccel I18n
+    Activities Archive CoreAddons GuiAddons Crash DBusAddons Declarative GlobalAccel I18n 
     IconThemes NewStuff Notifications Plasma PlasmaQuick Wayland WindowSystem XmlGui)
 
 find_package(X11 REQUIRED)

README.md

@@ -28,6 +28,7 @@ We recommend that you use at least **Plasma 5.12.0**
  KF5PlasmaQuick >= 5.38.0
  KF5Activities >= 5.38.0
  KF5CoreAddons >= 5.38.0
+ KF5GuiAddons >= 5.38.0
  KF5DBusAddons >= 5.38.0
  KF5Declarative >= 5.38.0
  KF5Wayland >= 5.38.0

app/CMakeLists.txt

@@ -54,6 +54,7 @@ target_link_libraries(latte-dock
     KF5::DBusAddons
     KF5::Declarative
     KF5::CoreAddons
+    KF5::GuiAddons
     KF5::GlobalAccel
     KF5::Archive
     KF5::Crash

app/globalshortcuts.cpp

@@ -273,6 +273,19 @@ void GlobalShortcuts::init()
 
     m_singleMetaAction = new QAction(this);
     m_singleMetaAction->setShortcut(QKeySequence(Qt::META));
+
+    //display shortcut badges while holding Meta
+    m_mKeyInfoTimer.setInterval(1000);
+    connect(&m_mKeyInfoTimer, &QTimer::timeout, this, [&]() {
+                showDocks();
+            });
+    connect(&m_keyInfo, &KModifierKeyInfo::keyPressed, this, [&](Qt::Key key, bool state) {
+                if (key == Qt::Key_Super_L && state) {
+                    m_mKeyInfoTimer.start();
+                } else if (key == Qt::Key_Super_L && !state) {
+                    m_mKeyInfoTimer.stop();
+                }
+            });
 }
 
 //! Activate launcher menu through dbus interface
@@ -563,6 +576,10 @@ int GlobalShortcuts::applicationLauncherId(const Plasma::Containment *c)
 void GlobalShortcuts::showDocks()
 {
     m_lastInvokedAction = dynamic_cast<QAction *>(sender());
+    if (!m_lastInvokedAction) {
+        // when holding Meta
+        m_lastInvokedAction = m_singleMetaAction;
+    }
 
     auto invokeShowNumbers = [this](const Plasma::Containment * c) {
         if (QQuickItem *containmentInterface = c->property("_plasma_graphicObject").value<QQuickItem *>()) {

app/globalshortcuts.h

@@ -29,6 +29,9 @@
 #include <QQuickItem>
 #include <QTimer>
 
+// KDE
+#include <kmodifierkeyinfo.h>
+
 namespace Plasma {
 class Containment;
 }
@@ -82,6 +85,9 @@ private:
     QList<QMetaMethod> m_methodsShowNumbers;
 
     Latte::Corona *m_corona{nullptr};
+
+    KModifierKeyInfo m_keyInfo;
+    QTimer m_mKeyInfoTimer;
 };
 
 }