plugins/fadingpopups: don't block direct scanout

The effect only modifies the opacity of individual windows that
WorkspaceScene::scanoutCandidate will reject anyways, so there's no reason
for it to block direct scanout.
Once a more proper solution for blocking direct scanout on individual items
is in place, this can be removed again

BUG: 487780

autotests/integration/dont_crash_cancel_animation.cpp

@@ -71,7 +71,7 @@ void DontCrashCancelAnimationFromAnimationEndedTest::cleanup()
 void DontCrashCancelAnimationFromAnimationEndedTest::testScript()
 {
     // load a scripted effect which deletes animation data
-    ScriptedEffect *effect = ScriptedEffect::create(QStringLiteral("crashy"), QFINDTESTDATA("data/anim-data-delete-effect/effect.js"), 10, QString());
+    ScriptedEffect *effect = ScriptedEffect::create(QStringLiteral("crashy"), QFINDTESTDATA("data/anim-data-delete-effect/effect.js"), 10, QString(), true);
     QVERIFY(effect);
 
     const auto children = effects->children();

src/plugins/fadingpopups/package/metadata.json

@@ -103,5 +103,6 @@
         "Name[zh_TW]": "淡化彈出視窗"
     },
     "X-KDE-Ordering": 60,
+    "X-KDE-BlocksDirectScanout": false,
     "X-Plasma-API": "javascript"
 }

src/scripting/scriptedeffect.cpp

@@ -165,10 +165,10 @@ ScriptedEffect *ScriptedEffect::create(const KPluginMetaData &effect)
         return nullptr;
     }
 
-    return ScriptedEffect::create(name, scriptFile, effect.value(QStringLiteral("X-KDE-Ordering"), 0), effect.value(QStringLiteral("X-KWin-Exclusive-Category")));
+    return ScriptedEffect::create(name, scriptFile, effect.value(QStringLiteral("X-KDE-Ordering"), 0), effect.value(QStringLiteral("X-KWin-Exclusive-Category")), effect.value(QStringLiteral("X-KDE-BlocksDirectScanout"), true));
 }
 
-ScriptedEffect *ScriptedEffect::create(const QString &effectName, const QString &pathToScript, int chainPosition, const QString &exclusiveCategory)
+ScriptedEffect *ScriptedEffect::create(const QString &effectName, const QString &pathToScript, int chainPosition, const QString &exclusiveCategory, bool blocksDirectScanout)
 {
     ScriptedEffect *effect = new ScriptedEffect();
     effect->m_exclusiveCategory = exclusiveCategory;
@@ -177,6 +177,7 @@ ScriptedEffect *ScriptedEffect::create(const QString &effectName, const QString
         return nullptr;
     }
     effect->m_chainPosition = chainPosition;
+    effect->m_blocksDirectScanout = blocksDirectScanout;
 
     return effect;
 }
@@ -306,6 +307,11 @@ bool ScriptedEffect::isActiveFullScreenEffect() const
     return effects->activeFullScreenEffect() == this;
 }
 
+bool ScriptedEffect::blocksDirectScanout() const
+{
+    return m_blocksDirectScanout;
+}
+
 QList<int> ScriptedEffect::touchEdgesForAction(const QString &action) const
 {
     QList<int> ret;

src/scripting/scriptedeffect.h

@@ -80,7 +80,7 @@ public:
     }
     QString activeConfig() const;
     void setActiveConfig(const QString &name);
-    static ScriptedEffect *create(const QString &effectName, const QString &pathToScript, int chainPosition, const QString &exclusiveCategory);
+    static ScriptedEffect *create(const QString &effectName, const QString &pathToScript, int chainPosition, const QString &exclusiveCategory, bool blocksDirectScanout);
     static ScriptedEffect *create(const KPluginMetaData &effect);
     static bool supported();
     ~ScriptedEffect() override;
@@ -182,6 +182,7 @@ public:
 
     QString pluginId() const;
     bool isActiveFullScreenEffect() const;
+    bool blocksDirectScanout() const override;
 
 public Q_SLOTS:
     bool borderActivated(ElectricBorder border) override;
@@ -222,5 +223,6 @@ private:
     Effect *m_activeFullScreenEffect = nullptr;
     std::map<uint, std::unique_ptr<GLShader>> m_shaders;
     uint m_nextShaderId{1u};
+    bool m_blocksDirectScanout = true;
 };
 }