From b32592f54e5c229c1656e735a2f21a31302242fc Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Thu, 22 Jul 2021 12:17:26 +0300
Subject: [PATCH] kwineffects: Allow disabling automatic frame scheduling in
 EffectQuickView

---
 src/libkwineffects/kwineffectquickview.cpp | 47 +++++++++++++++++++---
 src/libkwineffects/kwineffectquickview.h   |  8 ++++
 2 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/src/libkwineffects/kwineffectquickview.cpp b/src/libkwineffects/kwineffectquickview.cpp
index ed5cef3987..15830f17c2 100644
--- a/src/libkwineffects/kwineffectquickview.cpp
+++ b/src/libkwineffects/kwineffectquickview.cpp
@@ -38,12 +38,14 @@ public:
     QScopedPointer<QOffscreenSurface> m_offscreenSurface;
     QScopedPointer<QOpenGLFramebufferObject> m_fbo;
 
+    QTimer *m_repaintTimer;
     QImage m_image;
     QScopedPointer<GLTexture> m_textureExport;
     // if we should capture a QImage after rendering into our BO.
     // Used for either software QtQuick rendering and nonGL kwin rendering
     bool m_useBlit = false;
     bool m_visible = true;
+    bool m_automaticRepaint = true;
 
     void releaseResources();
 };
@@ -111,13 +113,13 @@ EffectQuickView::EffectQuickView(QObject *parent, ExportMode exportMode)
     connect(d->m_view, &QWindow::widthChanged, this, updateSize);
     connect(d->m_view, &QWindow::heightChanged, this, updateSize);
 
-    QTimer *t = new QTimer(this);
-    t->setSingleShot(true);
-    t->setInterval(10);
+    d->m_repaintTimer = new QTimer(this);
+    d->m_repaintTimer->setSingleShot(true);
+    d->m_repaintTimer->setInterval(10);
 
-    connect(t, &QTimer::timeout, this, &EffectQuickView::update);
-    connect(d->m_renderControl, &QQuickRenderControl::renderRequested, t, [t]() { t->start(); });
-    connect(d->m_renderControl, &QQuickRenderControl::sceneChanged, t, [t]() { t->start(); });
+    connect(d->m_repaintTimer, &QTimer::timeout, this, &EffectQuickView::update);
+    connect(d->m_renderControl, &QQuickRenderControl::renderRequested, this, &EffectQuickView::handleRenderRequested);
+    connect(d->m_renderControl, &QQuickRenderControl::sceneChanged, this, &EffectQuickView::handleSceneChanged);
 }
 
 EffectQuickView::~EffectQuickView()
@@ -132,6 +134,39 @@ EffectQuickView::~EffectQuickView()
     }
 }
 
+bool EffectQuickView::automaticRepaint() const
+{
+    return d->m_automaticRepaint;
+}
+
+void EffectQuickView::setAutomaticRepaint(bool set)
+{
+    if (d->m_automaticRepaint != set) {
+        d->m_automaticRepaint = set;
+
+        // If there's an in-flight update, disable it.
+        if (!d->m_automaticRepaint) {
+            d->m_repaintTimer->stop();
+        }
+    }
+}
+
+void EffectQuickView::handleSceneChanged()
+{
+    if (d->m_automaticRepaint) {
+        d->m_repaintTimer->start();
+    }
+    Q_EMIT sceneChanged();
+}
+
+void EffectQuickView::handleRenderRequested()
+{
+    if (d->m_automaticRepaint) {
+        d->m_repaintTimer->start();
+    }
+    Q_EMIT renderRequested();
+}
+
 void EffectQuickView::update()
 {
     if (!d->m_visible) {
diff --git a/src/libkwineffects/kwineffectquickview.h b/src/libkwineffects/kwineffectquickview.h
index 9335b69028..f7da758e4e 100644
--- a/src/libkwineffects/kwineffectquickview.h
+++ b/src/libkwineffects/kwineffectquickview.h
@@ -104,6 +104,9 @@ public:
     void show();
     void hide();
 
+    bool automaticRepaint() const;
+    void setAutomaticRepaint(bool set);
+
     /**
      * Returns the current output of the scene graph
      * @note The render context must valid at the time of calling
@@ -133,8 +136,13 @@ Q_SIGNALS:
      */
     void repaintNeeded();
     void geometryChanged(const QRect &oldGeometry, const QRect &newGeometry);
+    void renderRequested();
+    void sceneChanged();
 
 private:
+    void handleRenderRequested();
+    void handleSceneChanged();
+
     class Private;
     QScopedPointer<Private> d;
 };