From d109e7d69bb34fb9d5b32005ea2589ca53a406ca Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Wed, 26 May 2021 12:27:27 +0300
Subject: [PATCH] Introduce Item visible property

This property can be used to control the visibility of an item and its
child subtree.
---
 src/item.cpp                | 44 +++++++++++++++++++++++++++++++++++++
 src/item.h                  |  9 ++++++++
 src/surfaceitem_wayland.cpp |  4 ----
 src/surfaceitem_x11.cpp     |  4 ----
 src/windowitem.cpp          |  7 ++++++
 src/windowitem.h            |  1 +
 6 files changed, 61 insertions(+), 8 deletions(-)

diff --git a/src/item.cpp b/src/item.cpp
index 013c7f8579..a27f3c13f0 100644
--- a/src/item.cpp
+++ b/src/item.cpp
@@ -126,6 +126,7 @@ void Item::setParentItem(Item *item)
     if (m_parentItem) {
         m_parentItem->addChild(this);
     }
+    updateEffectiveVisibility();
 }
 
 void Item::addChild(Item *item)
@@ -343,6 +344,13 @@ void Item::stackChildren(const QList<Item *> &children)
 }
 
 void Item::scheduleRepaint(const QRegion &region)
+{
+    if (isVisible()) {
+        scheduleRepaintInternal(region);
+    }
+}
+
+void Item::scheduleRepaintInternal(const QRegion &region)
 {
     const QRegion globalRegion = mapToGlobal(region);
     if (kwinApp()->platform()->isPerScreenRenderingEnabled()) {
@@ -366,6 +374,9 @@ void Item::scheduleRepaint(const QRegion &region)
 
 void Item::scheduleFrame()
 {
+    if (!isVisible()) {
+        return;
+    }
     if (kwinApp()->platform()->isPerScreenRenderingEnabled()) {
         const QRect geometry = mapToGlobal(rect());
         const QVector<AbstractOutput *> outputs = kwinApp()->platform()->enabledOutputs();
@@ -416,4 +427,37 @@ void Item::reallocRepaints()
     m_repaints.fill(infiniteRegion());
 }
 
+bool Item::isVisible() const
+{
+    return m_effectiveVisible;
+}
+
+void Item::setVisible(bool visible)
+{
+    if (m_visible != visible) {
+        m_visible = visible;
+        updateEffectiveVisibility();
+    }
+}
+
+bool Item::computeEffectiveVisibility() const
+{
+    return m_visible && (!m_parentItem || m_parentItem->isVisible());
+}
+
+void Item::updateEffectiveVisibility()
+{
+    const bool effectiveVisible = computeEffectiveVisibility();
+    if (m_effectiveVisible == effectiveVisible) {
+        return;
+    }
+
+    m_effectiveVisible = effectiveVisible;
+    scheduleRepaintInternal(boundingRect());
+
+    for (Item *childItem : qAsConst(m_childItems)) {
+        childItem->updateEffectiveVisibility();
+    }
+}
+
 } // namespace KWin
diff --git a/src/item.h b/src/item.h
index 74db62f0e4..3e50a68f61 100644
--- a/src/item.h
+++ b/src/item.h
@@ -91,6 +91,9 @@ public:
      */
     void stackChildren(const QList<Item *> &children);
 
+    bool isVisible() const;
+    void setVisible(bool visible);
+
     void scheduleRepaint(const QRegion &region);
     void scheduleFrame();
     QRegion repaints(int screen) const;
@@ -128,8 +131,12 @@ private:
     void addChild(Item *item);
     void removeChild(Item *item);
     void updateBoundingRect();
+    void scheduleRepaintInternal(const QRegion &region);
     void reallocRepaints();
 
+    bool computeEffectiveVisibility() const;
+    void updateEffectiveVisibility();
+
     Scene::Window *m_window;
     QPointer<Item> m_parentItem;
     QList<Item *> m_childItems;
@@ -138,6 +145,8 @@ private:
     int m_y = 0;
     int m_width = 0;
     int m_height = 0;
+    bool m_visible = true;
+    bool m_effectiveVisible = true;
     QVector<QRegion> m_repaints;
 
     friend class Scene::Window;
diff --git a/src/surfaceitem_wayland.cpp b/src/surfaceitem_wayland.cpp
index 9689d85a4f..d5ea9346a9 100644
--- a/src/surfaceitem_wayland.cpp
+++ b/src/surfaceitem_wayland.cpp
@@ -206,10 +206,6 @@ SurfaceItemXwayland::SurfaceItemXwayland(Scene::Window *window, Item *parent)
 QRegion SurfaceItemXwayland::shape() const
 {
     const Toplevel *toplevel = window()->window();
-    if (window()->isShaded()) {
-        return QRegion();
-    }
-
     const QRect clipRect = toplevel->clientGeometry().translated(-toplevel->bufferGeometry().topLeft());
     const QRegion shape = toplevel->shapeRegion();
 
diff --git a/src/surfaceitem_x11.cpp b/src/surfaceitem_x11.cpp
index 280aa6b944..bce26234d5 100644
--- a/src/surfaceitem_x11.cpp
+++ b/src/surfaceitem_x11.cpp
@@ -122,10 +122,6 @@ QPointF SurfaceItemX11::mapToBuffer(const QPointF &point) const
 QRegion SurfaceItemX11::shape() const
 {
     const Toplevel *toplevel = window()->window();
-    if (window()->isShaded()) {
-        return QRegion();
-    }
-
     const QRect clipRect = toplevel->clientGeometry().translated(-toplevel->bufferGeometry().topLeft());
     const QRegion shape = toplevel->shapeRegion();
 
diff --git a/src/windowitem.cpp b/src/windowitem.cpp
index 8db229ff60..1bd86f2a80 100644
--- a/src/windowitem.cpp
+++ b/src/windowitem.cpp
@@ -46,10 +46,12 @@ void WindowItem::updateSurfaceItem(SurfaceItem *surfaceItem)
 
     m_surfaceItem.reset(surfaceItem);
 
+    connect(toplevel, &Toplevel::shadeChanged, this, &WindowItem::updateSurfaceVisibility);
     connect(toplevel, &Toplevel::bufferGeometryChanged, this, &WindowItem::updateSurfacePosition);
     connect(toplevel, &Toplevel::frameGeometryChanged, this, &WindowItem::updateSurfacePosition);
 
     updateSurfacePosition();
+    updateSurfaceVisibility();
 }
 
 void WindowItem::updateSurfacePosition()
@@ -62,6 +64,11 @@ void WindowItem::updateSurfacePosition()
     m_surfaceItem->setPosition(bufferGeometry.topLeft() - frameGeometry.topLeft());
 }
 
+void WindowItem::updateSurfaceVisibility()
+{
+    m_surfaceItem->setVisible(!window()->window()->isShade());
+}
+
 void WindowItem::setShadow(Shadow *shadow)
 {
     if (shadow) {
diff --git a/src/windowitem.h b/src/windowitem.h
index 5e98f204f0..3d9a506c7e 100644
--- a/src/windowitem.h
+++ b/src/windowitem.h
@@ -41,6 +41,7 @@ protected:
 private Q_SLOTS:
     void updateDecorationItem();
     void updateSurfacePosition();
+    void updateSurfaceVisibility();
 
 private:
     QScopedPointer<SurfaceItem> m_surfaceItem;