Refactor Window Manager interaction (#2041)

* TaskBar: forward declare

* TaskBar: new ILXQtTaskbarAbstractBackend

This is an abstract interface to operate windows
and workspaces

* ILXQtTaskbarAbstractBackend: add supportsAction() method

- Move WindowProperty enum to lxqttaskbartypes.h

* TaskBar: add X11 backend

* TaskBar: new LXQtTaskBarProxyModel

This model will manage the tasks shown

* TaskBar: use backend in LXQtTaskBar

* TaskBar: initial use of backend in LXQtTaskButton

* TaskBar: use backend for urgency hint

* TaskBar: use backend to set window layer

* TaskBar: use backend to close and raise window

Also use it to get window icon

* TaskBar: use backend to roll up (shade) windows

* TaskBar: use backend to minimize window

* TaskBar: use backend to de-maximize window

* TaskBar: use backend to get window state

* TaskBar: use backend to set window state

* TaskBar: port workspace usage to backend

* TaskBar: remove X11 specific includes in lxqttaskbutton.cpp

* TaskBar: remove X11 code from LXQtTaskBar and LXQtTaskGroup

* TaskBar: LXQtTaskButton remove X11 specific code

* TaskBar: set context menu parent

* LXQtPanel: rework calculatePopupWindowPos()

- Don't rely on global screen coordinates

- This will be needed for future Wayland port,
  Where we don't have global screen coordinates

- Keep compatible behavior on X11

* LXQtPanel: avoid QCursor::pos() usage

* ILXQtTaskbarAbstractBackend: new Geometry window property

This new window propery flag is needed to notify geometry changes

* Move ILXQtTaskbarAbstractBackend to panel directory

- It is now a global instance

* ILXQtTaskbarAbstractBackend: new isAreaOverlapped() method

* LXQtPanel: use less KX11Extras and more ILXQtTaskbarAbstractBackend

* ILXQtTaskbarAbstractBackend: add dummy implementation

This will be used to avoid crashing panel in case no backend could be
created.
A warning message will be printed in this case.

* LXQtMainMenu: indent header include

* ILXQtTaskbarAbstractBackend: new showDesktop() function

* ShowDesktop: use ILXQtTaskbarAbstractBackend

* DesktopSwitch: port to ILXQtTaskbarAbstractBackend

- Clarify desktop index range

* LXQtTaskbarConfiguration: port to ILXQtTaskBarAbstractBackend

* DesktopSwitchConfiguration: port to ILXQtTaskBarAbstractBackend TODO

TODO: this will disable changing desktop names

* TaskBar: consider initial windows

* DesktopSwitch: remove unused isWindowHighlightable()

* DesktopSwitch: show unsupported widget if backend does not have switch
capability

* ILXQtTaskbarAbstractBackend: add setDesktopLayout() function

- Use it in DesktopSwitch::settingsChanged()

* LXQtTaskbarX11Backend: fix re-add window after property changes

* LXQtTaskBarDummyBackend: fix compilation

* LXQtTaskBarPlugin: fix headers path

* Revert "LXQtPanel: rework calculatePopupWindowPos()"

This reverts commit b0e54b8.

* Removed `mDesktops` after rebasing

* Reverted X11 codes of `DesktopSwitchConfiguration::loadDesktopsNames`

---------

Co-authored-by: Tsu Jan <[email protected]>

panel/CMakeLists.txt

@@ -1,5 +1,8 @@
 set(PROJECT lxqt-panel)
 
+# TODO
+add_subdirectory(backends)
+
 set(PRIV_HEADERS
     panelpluginsmodel.h
     windownotifier.h
@@ -18,6 +21,12 @@ set(PRIV_HEADERS
     config/configstyling.h
     config/configpluginswidget.h
     config/addplugindialog.h
+
+    backends/ilxqttaskbarabstractbackend.h
+    backends/lxqttaskbartypes.h
+
+    backends/lxqttaskbardummybackend.h
+    backends/xcb/lxqttaskbarbackend_x11.h
 )
 
 # using LXQt namespace in the public headers.
@@ -26,6 +35,9 @@ set(PUB_HEADERS
     pluginsettings.h
     ilxqtpanelplugin.h
     ilxqtpanel.h
+
+    backends/ilxqttaskbarabstractbackend.h
+    backends/lxqttaskbartypes.h
 )
 
 set(SOURCES
@@ -45,6 +57,11 @@ set(SOURCES
     config/configstyling.cpp
     config/configpluginswidget.cpp
     config/addplugindialog.cpp
+
+    backends/ilxqttaskbarabstractbackend.cpp
+
+    backends/lxqttaskbardummybackend.cpp
+    backends/xcb/lxqttaskbarbackend_x11.cpp
 )
 
 set(UI

panel/backends/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(xcb)

panel/backends/ilxqttaskbarabstractbackend.cpp

@@ -0,0 +1,25 @@
+#include "../panel/backends/ilxqttaskbarabstractbackend.h"
+
+
+ILXQtTaskbarAbstractBackend::ILXQtTaskbarAbstractBackend(QObject *parent)
+    : QObject(parent)
+{
+
+}
+
+void ILXQtTaskbarAbstractBackend::moveApplicationToPrevNextDesktop(WId windowId, bool next)
+{
+    int count = getWorkspacesCount();
+    if (count <= 1)
+        return;
+
+    int targetWorkspace = getWindowWorkspace(windowId) + (next ? 1 : -1);
+
+    // Wrap around
+    if (targetWorkspace > count)
+        targetWorkspace = 1; //Ids are 1-based
+    else if (targetWorkspace < 1)
+        targetWorkspace = count;
+
+    setWindowOnWorkspace(windowId, targetWorkspace);
+}

panel/backends/ilxqttaskbarabstractbackend.h

@@ -0,0 +1,99 @@
+#ifndef ILXQTTASKBARABSTRACTBACKEND_H
+#define ILXQTTASKBARABSTRACTBACKEND_H
+
+#include <QObject>
+
+#include "lxqttaskbartypes.h"
+
+class QIcon;
+class QScreen;
+
+class ILXQtTaskbarAbstractBackend : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit ILXQtTaskbarAbstractBackend(QObject *parent = nullptr);
+
+    // Backend
+    virtual bool supportsAction(WId windowId, LXQtTaskBarBackendAction action) const = 0;
+
+    // Windows
+    virtual bool reloadWindows() = 0;
+
+    virtual QVector<WId> getCurrentWindows() const = 0;
+
+    virtual QString getWindowTitle(WId windowId) const = 0;
+
+    virtual bool applicationDemandsAttention(WId windowId) const = 0;
+
+    virtual QIcon getApplicationIcon(WId windowId, int fallbackDevicePixels) const = 0;
+
+    virtual QString getWindowClass(WId windowId) const = 0;
+
+    virtual LXQtTaskBarWindowLayer getWindowLayer(WId windowId) const = 0;
+    virtual bool setWindowLayer(WId windowId, LXQtTaskBarWindowLayer layer) = 0;
+
+    virtual LXQtTaskBarWindowState getWindowState(WId windowId) const = 0;
+    virtual bool setWindowState(WId windowId, LXQtTaskBarWindowState state, bool set = true) = 0;
+
+    virtual bool isWindowActive(WId windowId) const = 0;
+    virtual bool raiseWindow(WId windowId, bool onCurrentWorkSpace) = 0;
+
+    virtual bool closeWindow(WId windowId) = 0;
+
+    virtual WId getActiveWindow() const = 0;
+
+    // Workspaces
+    // NOTE: indexes are 1-based, 0 means "Show on All desktops"
+    virtual int getWorkspacesCount() const = 0;
+    virtual QString getWorkspaceName(int idx) const = 0;
+
+    virtual int getCurrentWorkspace() const = 0;
+    virtual bool setCurrentWorkspace(int idx) = 0;
+
+    virtual int getWindowWorkspace(WId windowId) const = 0;
+    virtual bool setWindowOnWorkspace(WId windowId, int idx) = 0;
+
+    virtual void moveApplicationToPrevNextDesktop(WId windowId, bool next); // Default implementation
+    virtual void moveApplicationToPrevNextMonitor(WId windowId, bool next, bool raiseOnCurrentDesktop) = 0;
+
+    virtual bool isWindowOnScreen(QScreen *screen, WId windowId) const = 0;
+
+    virtual bool setDesktopLayout(Qt::Orientation orientation, int rows, int columns, bool rightToLeft) = 0;
+
+    // X11 Specific
+    virtual void moveApplication(WId windowId) = 0;
+    virtual void resizeApplication(WId windowId) = 0;
+
+    virtual void refreshIconGeometry(WId windowId, const QRect &geom) = 0;
+
+    // Panel internal
+    virtual bool isAreaOverlapped(const QRect& area) const = 0;
+
+    // Show Destop TODO: split in multiple interfeces, this is becoming big
+    // NOTE: KWindowSystem already has these functions
+    // However on Wayland they are only compatible with KWin
+    // because internally it uses org_kde_plasma_window_management protocol
+    // We make this virtual so it can be implemented also for other compositors
+    virtual bool isShowingDesktop() const = 0;
+    virtual bool showDesktop(bool value) = 0;
+
+signals:
+    void reloaded();
+
+    // Windows
+    void windowAdded(WId windowId);
+    void windowRemoved(WId windowId);
+    void windowPropertyChanged(WId windowId, int prop);
+
+    // Workspaces
+    void workspacesCountChanged();
+    void workspaceNameChanged(int idx);
+    void currentWorkspaceChanged(int idx);
+
+    // TODO: needed?
+    void activeWindowChanged(WId windowId);
+};
+
+#endif // ILXQTTASKBARABSTRACTBACKEND_H

panel/backends/lxqttaskbardummybackend.cpp

@@ -0,0 +1,171 @@
+#include "lxqttaskbardummybackend.h"
+
+#include <QIcon>
+
+LXQtTaskBarDummyBackend::LXQtTaskBarDummyBackend(QObject *parent)
+    : ILXQtTaskbarAbstractBackend(parent)
+{
+
+}
+
+
+/************************************************
+ *   Windows function
+ ************************************************/
+bool LXQtTaskBarDummyBackend::supportsAction(WId, LXQtTaskBarBackendAction) const
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::reloadWindows()
+{
+    return false;
+}
+
+QVector<WId> LXQtTaskBarDummyBackend::getCurrentWindows() const
+{
+    return {};
+}
+
+QString LXQtTaskBarDummyBackend::getWindowTitle(WId) const
+{
+    return QString();
+}
+
+bool LXQtTaskBarDummyBackend::applicationDemandsAttention(WId) const
+{
+    return false;
+}
+
+QIcon LXQtTaskBarDummyBackend::getApplicationIcon(WId, int) const
+{
+    return QIcon();
+}
+
+QString LXQtTaskBarDummyBackend::getWindowClass(WId) const
+{
+    return QString();
+}
+
+LXQtTaskBarWindowLayer LXQtTaskBarDummyBackend::getWindowLayer(WId) const
+{
+    return LXQtTaskBarWindowLayer::Normal;
+}
+
+bool LXQtTaskBarDummyBackend::setWindowLayer(WId, LXQtTaskBarWindowLayer)
+{
+    return false;
+}
+
+LXQtTaskBarWindowState LXQtTaskBarDummyBackend::getWindowState(WId) const
+{
+    return LXQtTaskBarWindowState::Normal;
+}
+
+bool LXQtTaskBarDummyBackend::setWindowState(WId, LXQtTaskBarWindowState, bool)
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::isWindowActive(WId) const
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::raiseWindow(WId, bool)
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::closeWindow(WId)
+{
+    return false;
+}
+
+WId LXQtTaskBarDummyBackend::getActiveWindow() const
+{
+    return 0;
+}
+
+
+/************************************************
+ *   Workspaces
+ ************************************************/
+int LXQtTaskBarDummyBackend::getWorkspacesCount() const
+{
+    return 1; // Fake 1 workspace
+}
+
+QString LXQtTaskBarDummyBackend::getWorkspaceName(int) const
+{
+    return QString();
+}
+
+int LXQtTaskBarDummyBackend::getCurrentWorkspace() const
+{
+    return 0;
+}
+
+bool LXQtTaskBarDummyBackend::setCurrentWorkspace(int)
+{
+    return false;
+}
+
+int LXQtTaskBarDummyBackend::getWindowWorkspace(WId) const
+{
+    return 0;
+}
+
+bool LXQtTaskBarDummyBackend::setWindowOnWorkspace(WId, int)
+{
+    return false;
+}
+
+void LXQtTaskBarDummyBackend::moveApplicationToPrevNextMonitor(WId, bool, bool)
+{
+    //No-op
+}
+
+bool LXQtTaskBarDummyBackend::isWindowOnScreen(QScreen *, WId) const
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::setDesktopLayout(Qt::Orientation, int, int, bool)
+{
+    return false;
+}
+
+/************************************************
+ *   X11 Specific
+ ************************************************/
+void LXQtTaskBarDummyBackend::moveApplication(WId)
+{
+    //No-op
+}
+
+void LXQtTaskBarDummyBackend::resizeApplication(WId)
+{
+    //No-op
+}
+
+void LXQtTaskBarDummyBackend::refreshIconGeometry(WId, QRect const &)
+{
+    //No-op
+}
+
+bool LXQtTaskBarDummyBackend::isAreaOverlapped(const QRect &) const
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::isShowingDesktop() const
+{
+    return false;
+}
+
+bool LXQtTaskBarDummyBackend::showDesktop(bool)
+{
+    return false;
+}
+