scene: Decouple SurfaceItem from Window

The main motivation is to allow SurfaceItem used to be to present non
window contents.

src/item.cpp

@@ -91,6 +91,8 @@ void Item::addChild(Item *item)
 
     updateBoundingRect();
     scheduleRepaint(item->boundingRect().translated(item->position()));
+
+    Q_EMIT childAdded(item);
 }
 
 void Item::removeChild(Item *item)

src/item.h

@@ -108,6 +108,7 @@ public:
     virtual void preprocess();
 
 Q_SIGNALS:
+    void childAdded(Item *item);
     /**
      * This signal is emitted when the position of this item has changed.
      */

src/surfaceitem.cpp

@@ -5,26 +5,13 @@
 */
 
 #include "surfaceitem.h"
-#include "deleted.h"
 
 namespace KWin
 {
 
-SurfaceItem::SurfaceItem(Window *window, Item *parent)
+SurfaceItem::SurfaceItem(Item *parent)
     : Item(parent)
-    , m_window(window)
 {
-    connect(window, &Window::windowClosed, this, &SurfaceItem::handleWindowClosed);
-}
-
-Window *SurfaceItem::window() const
-{
-    return m_window;
-}
-
-void SurfaceItem::handleWindowClosed(Window *original, Deleted *deleted)
-{
-    m_window = deleted;
 }
 
 QMatrix4x4 SurfaceItem::surfaceToBufferMatrix() const
@@ -41,8 +28,7 @@ void SurfaceItem::addDamage(const QRegion &region)
 {
     m_damage += region;
     scheduleRepaint(region);
-
+    Q_EMIT damaged();
-    Q_EMIT m_window->damaged(m_window);
 }
 
 void SurfaceItem::resetDamage()

src/surfaceitem.h

@@ -12,7 +12,6 @@
 namespace KWin
 {
 
-class Deleted;
 class SurfacePixmap;
 class Window;
 
@@ -27,8 +26,6 @@ public:
     QMatrix4x4 surfaceToBufferMatrix() const;
     void setSurfaceToBufferMatrix(const QMatrix4x4 &matrix);
 
-    Window *window() const;
-
     void addDamage(const QRegion &region);
     void resetDamage();
     QRegion damage() const;
@@ -44,16 +41,16 @@ public:
 
     virtual ContentType contentType() const;
 
+Q_SIGNALS:
+    void damaged();
+
 protected:
-    explicit SurfaceItem(Window *window, Item *parent = nullptr);
+    explicit SurfaceItem(Item *parent = nullptr);
 
     virtual std::unique_ptr<SurfacePixmap> createPixmap() = 0;
     void preprocess() override;
     WindowQuadList buildQuads() const override;
 
-    void handleWindowClosed(Window *original, Deleted *deleted);
-
-    Window *m_window;
     QRegion m_damage;
     std::unique_ptr<SurfacePixmap> m_pixmap;
     std::unique_ptr<SurfacePixmap> m_previousPixmap;

src/surfaceitem_internal.cpp

@@ -6,6 +6,7 @@
 
 #include "surfaceitem_internal.h"
 #include "composite.h"
+#include "deleted.h"
 #include "internalwindow.h"
 #include "scene.h"
 
@@ -15,10 +16,13 @@ namespace KWin
 {
 
 SurfaceItemInternal::SurfaceItemInternal(InternalWindow *window, Item *parent)
-    : SurfaceItem(window, parent)
+    : SurfaceItem(parent)
+    , m_window(window)
 {
     connect(window, &Window::bufferGeometryChanged,
             this, &SurfaceItemInternal::handleBufferGeometryChanged);
+    connect(window, &Window::windowClosed,
+            this, &SurfaceItemInternal::handleWindowClosed);
 
     setSize(window->bufferGeometry().size());
 
@@ -28,6 +32,11 @@ SurfaceItemInternal::SurfaceItemInternal(InternalWindow *window, Item *parent)
     setSurfaceToBufferMatrix(surfaceToBufferMatrix);
 }
 
+Window *SurfaceItemInternal::window() const
+{
+    return m_window;
+}
+
 QVector<QRectF> SurfaceItemInternal::shape() const
 {
     return {rect()};
@@ -46,6 +55,11 @@ void SurfaceItemInternal::handleBufferGeometryChanged(Window *window, const QRec
     setSize(window->bufferGeometry().size());
 }
 
+void SurfaceItemInternal::handleWindowClosed(Window *original, Deleted *deleted)
+{
+    m_window = deleted;
+}
+
 SurfacePixmapInternal::SurfacePixmapInternal(SurfaceItemInternal *item, QObject *parent)
     : SurfacePixmap(Compositor::self()->scene()->createSurfaceTextureInternal(this), parent)
     , m_item(item)

src/surfaceitem_internal.h

@@ -13,6 +13,7 @@ class QOpenGLFramebufferObject;
 namespace KWin
 {
 
+class Deleted;
 class InternalWindow;
 
 /**
@@ -25,13 +26,19 @@ class KWIN_EXPORT SurfaceItemInternal : public SurfaceItem
 public:
     explicit SurfaceItemInternal(InternalWindow *window, Item *parent = nullptr);
 
+    Window *window() const;
+
     QVector<QRectF> shape() const override;
 
 private Q_SLOTS:
     void handleBufferGeometryChanged(Window *window, const QRectF &old);
+    void handleWindowClosed(Window *original, Deleted *deleted);
 
 protected:
     std::unique_ptr<SurfacePixmap> createPixmap() override;
+
+private:
+    Window *m_window;
 };
 
 class KWIN_EXPORT SurfacePixmapInternal final : public SurfacePixmap

src/surfaceitem_wayland.cpp

@@ -6,6 +6,7 @@
 
 #include "surfaceitem_wayland.h"
 #include "composite.h"
+#include "deleted.h"
 #include "scene.h"
 #include "wayland/clientbuffer.h"
 #include "wayland/subcompositor_interface.h"
@@ -14,9 +15,8 @@
 namespace KWin
 {
 
-SurfaceItemWayland::SurfaceItemWayland(KWaylandServer::SurfaceInterface *surface,
+SurfaceItemWayland::SurfaceItemWayland(KWaylandServer::SurfaceInterface *surface, Item *parent)
-                                       Window *window, Item *parent)
+    : SurfaceItem(parent)
-    : SurfaceItem(window, parent)
     , m_surface(surface)
 {
     connect(surface, &KWaylandServer::SurfaceInterface::surfaceToBufferMatrixChanged,
@@ -94,7 +94,7 @@ SurfaceItemWayland *SurfaceItemWayland::getOrCreateSubSurfaceItem(KWaylandServer
 {
     SurfaceItemWayland *&item = m_subsurfaces[child];
     if (!item) {
-        item = new SurfaceItemWayland(child->surface(), window());
+        item = new SurfaceItemWayland(child->surface());
         item->setParent(this);
         item->setParentItem(this);
     }
@@ -203,15 +203,17 @@ void SurfacePixmapWayland::setBuffer(KWaylandServer::ClientBuffer *buffer)
 }
 
 SurfaceItemXwayland::SurfaceItemXwayland(Window *window, Item *parent)
-    : SurfaceItemWayland(window->surface(), window, parent)
+    : SurfaceItemWayland(window->surface(), parent)
+    , m_window(window)
 {
     connect(window, &Window::geometryShapeChanged, this, &SurfaceItemXwayland::discardQuads);
+    connect(window, &Window::windowClosed, this, &SurfaceItemXwayland::handleWindowClosed);
 }
 
 QVector<QRectF> SurfaceItemXwayland::shape() const
 {
-    const QRectF clipRect = rect() & window()->clientGeometry().translated(-window()->bufferGeometry().topLeft());
+    const QRectF clipRect = rect() & m_window->clientGeometry().translated(-m_window->bufferGeometry().topLeft());
-    QVector<QRectF> shape = window()->shapeRegion();
+    QVector<QRectF> shape = m_window->shapeRegion();
 
     // bounded to clipRect
     for (QRectF &shapePart : shape) {
@@ -220,4 +222,9 @@ QVector<QRectF> SurfaceItemXwayland::shape() const
     return shape;
 }
 
+void SurfaceItemXwayland::handleWindowClosed(Window *original, Deleted *deleted)
+{
+    m_window = deleted;
+}
+
 } // namespace KWin

src/surfaceitem_wayland.h

@@ -18,6 +18,8 @@ class SurfaceInterface;
 namespace KWin
 {
 
+class Deleted;
+
 /**
  * The SurfaceItemWayland class represents a Wayland surface in the scene.
  */
@@ -26,8 +28,7 @@ class KWIN_EXPORT SurfaceItemWayland : public SurfaceItem
     Q_OBJECT
 
 public:
-    explicit SurfaceItemWayland(KWaylandServer::SurfaceInterface *surface,
+    explicit SurfaceItemWayland(KWaylandServer::SurfaceInterface *surface, Item *parent = nullptr);
-                                Window *window, Item *parent = nullptr);
 
     QVector<QRectF> shape() const override;
     QRegion opaque() const override;
@@ -89,6 +90,11 @@ public:
     explicit SurfaceItemXwayland(Window *window, Item *parent = nullptr);
 
     QVector<QRectF> shape() const override;
+
+private:
+    void handleWindowClosed(Window *original, Deleted *deleted);
+
+    Window *m_window;
 };
 
 } // namespace KWin

src/surfaceitem_x11.cpp

@@ -6,6 +6,7 @@
 
 #include "surfaceitem_x11.h"
 #include "composite.h"
+#include "deleted.h"
 #include "scene.h"
 #include "x11syncmanager.h"
 
@@ -13,12 +14,15 @@ namespace KWin
 {
 
 SurfaceItemX11::SurfaceItemX11(Window *window, Item *parent)
-    : SurfaceItem(window, parent)
+    : SurfaceItem(parent)
+    , m_window(window)
 {
     connect(window, &Window::bufferGeometryChanged,
             this, &SurfaceItemX11::handleBufferGeometryChanged);
     connect(window, &Window::geometryShapeChanged,
             this, &SurfaceItemX11::handleGeometryShapeChanged);
+    connect(window, &Window::windowClosed,
+            this, &SurfaceItemX11::handleWindowClosed);
 
     m_damageHandle = xcb_generate_id(kwinApp()->x11Connection());
     xcb_damage_create(kwinApp()->x11Connection(), m_damageHandle, window->frameId(),
@@ -40,6 +44,16 @@ SurfaceItemX11::~SurfaceItemX11()
     // destroyDamage() will be called by the associated Window.
 }
 
+Window *SurfaceItemX11::window() const
+{
+    return m_window;
+}
+
+void SurfaceItemX11::handleWindowClosed(Window *original, Deleted *deleted)
+{
+    m_window = deleted;
+}
+
 void SurfaceItemX11::preprocess()
 {
     if (!damage().isEmpty()) {
@@ -140,8 +154,8 @@ void SurfaceItemX11::handleGeometryShapeChanged()
 
 QVector<QRectF> SurfaceItemX11::shape() const
 {
-    const QRectF clipRect = window()->clientGeometry().translated(-window()->bufferGeometry().topLeft());
+    const QRectF clipRect = m_window->clientGeometry().translated(-m_window->bufferGeometry().topLeft());
-    QVector<QRectF> shape = window()->shapeRegion();
+    QVector<QRectF> shape = m_window->shapeRegion();
     // bounded to clipRect
     for (QRectF &shapePart : shape) {
         shapePart = shapePart.intersected(clipRect);
@@ -155,10 +169,10 @@ QRegion SurfaceItemX11::opaque() const
     for (const QRectF &shapePart : shape()) {
         shapeRegion |= shapePart.toRect();
     }
-    if (!window()->hasAlpha()) {
+    if (!m_window->hasAlpha()) {
         return shapeRegion;
     } else {
-        return window()->opaqueRegion() & shapeRegion;
+        return m_window->opaqueRegion() & shapeRegion;
     }
     return QRegion();
 }

src/surfaceitem_x11.h

@@ -14,6 +14,8 @@
 namespace KWin
 {
 
+class Deleted;
+
 /**
  * The SurfaceItemX11 class represents an X11 surface in the scene.
  */
@@ -25,6 +27,8 @@ public:
     explicit SurfaceItemX11(Window *window, Item *parent = nullptr);
     ~SurfaceItemX11() override;
 
+    Window *window() const;
+
     void preprocess() override;
 
     void processDamage();
@@ -38,11 +42,13 @@ public:
 private Q_SLOTS:
     void handleBufferGeometryChanged(Window *window, const QRectF &old);
     void handleGeometryShapeChanged();
+    void handleWindowClosed(Window *original, Deleted *deleted);
 
 protected:
     std::unique_ptr<SurfacePixmap> createPixmap() override;
 
 private:
+    Window *m_window;
     xcb_damage_damage_t m_damageHandle = XCB_NONE;
     xcb_xfixes_fetch_region_cookie_t m_damageCookie;
     bool m_isDamaged = false;

src/windowitem.cpp

@@ -176,6 +176,12 @@ void WindowItem::updateSurfaceItem(SurfaceItem *surfaceItem)
         connect(m_window, &Window::bufferGeometryChanged, this, &WindowItem::updateSurfacePosition);
         connect(m_window, &Window::frameGeometryChanged, this, &WindowItem::updateSurfacePosition);
 
+        connect(surfaceItem, &SurfaceItem::damaged, this, &WindowItem::markDamaged);
+        connect(surfaceItem, &SurfaceItem::childAdded, this, [this](Item *item) {
+            auto surfaceItem = static_cast<SurfaceItem *>(item);
+            connect(surfaceItem, &SurfaceItem::damaged, this, &WindowItem::markDamaged);
+        });
+
         updateSurfacePosition();
         updateSurfaceVisibility();
     } else {
@@ -237,6 +243,11 @@ void WindowItem::updateOpacity()
     setOpacity(m_window->opacity());
 }
 
+void WindowItem::markDamaged()
+{
+    Q_EMIT m_window->damaged(m_window);
+}
+
 WindowItemX11::WindowItemX11(Window *window, Item *parent)
     : WindowItem(window, parent)
 {
@@ -267,7 +278,7 @@ void WindowItemX11::initialize()
 WindowItemWayland::WindowItemWayland(Window *window, Item *parent)
     : WindowItem(window, parent)
 {
-    updateSurfaceItem(new SurfaceItemWayland(window->surface(), window, this));
+    updateSurfaceItem(new SurfaceItemWayland(window->surface(), this));
 }
 
 WindowItemInternal::WindowItemInternal(InternalWindow *window, Item *parent)

src/windowitem.h

@@ -68,6 +68,7 @@ private Q_SLOTS:
 private:
     bool computeVisibility() const;
     void updateVisibility();
+    void markDamaged();
 
     Window *m_window;
     std::unique_ptr<SurfaceItem> m_surfaceItem;