QmlDesigner: fix shutdown crash via Q_GLOBAL_STATIC singleton

- Ensures proper lazy initialization and destruction order
- Prevents null accesses during shutdown
  (triggered by missing null-checks in qtddeclarative QQuickShaderEffect)

Change-Id: Ibcce41441b7472e483a3f36c27cf8acfbf45b0c8
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

share/qtcreator/qmldesigner/effectComposerQmlSources/BlurHelper.qml

@@ -4,6 +4,7 @@
 // This file should match the BlurHelper.qml in qtquickdesigner repository, except for shader paths
 
 import QtQuick
+import EffectComposerPropertyData
 
 Item {
     id: rootItem
@@ -20,8 +21,8 @@ Item {
         visible: false
         layer.enabled: true
         layer.smooth: true
-        vertexShader: g_propertyData?.blur_vs_path ?? ""
+        vertexShader: GlobalPropertyData?.blur_vs_path ?? ""
-        fragmentShader: g_propertyData?.blur_fs_path ?? ""
+        fragmentShader: GlobalPropertyData?.blur_fs_path ?? ""
     }
 
     QtObject {

share/qtcreator/qmldesigner/effectComposerQmlSources/EffectComposerPreview.qml

@@ -7,6 +7,7 @@ import HelperWidgets as HelperWidgets
 import StudioControls as StudioControls
 import StudioTheme as StudioTheme
 import EffectComposerBackend
+import EffectComposerPropertyData
 
 Column {
     id: root
@@ -298,8 +299,8 @@ Column {
             BlurHelper {
                 id: blurHelper
                 source: source
-                property int blurMax: g_propertyData?.blur_helper_max_level ?? 64
+                property int blurMax: GlobalPropertyData?.blur_helper_max_level ?? 64
-                property real blurMultiplier: g_propertyData?.blurMultiplier ?? 0
+                property real blurMultiplier: GlobalPropertyData?.blurMultiplier ?? 0
             }
 
             Item {

src/plugins/effectcomposer/compositionnode.cpp

@@ -210,7 +210,7 @@ void CompositionNode::parse(const QString &effectName, const QString &qenPath, c
     for (const QJsonValueConstRef &prop : jsonProps) {
         const auto uniform = new Uniform(effectName, prop.toObject(), qenPath);
         m_uniformsModel.addUniform(uniform);
-        g_propertyData.insert(uniform->name(), uniform->value());
+        g_propertyData()->insert(uniform->name(), uniform->value());
         if (uniform->type() == Uniform::Type::Define) {
             // Changing defines requires rebaking the shaders
             connect(uniform, &Uniform::uniformValueChanged, this, &CompositionNode::rebakeRequested);
@@ -335,7 +335,7 @@ void CompositionNode::openCodeEditor()
 void CompositionNode::addUniform(const QVariantMap &data)
 {
     const auto uniform = new Uniform({}, QJsonObject::fromVariantMap(data), {});
-    g_propertyData.insert(uniform->name(), uniform->value());
+    g_propertyData()->insert(uniform->name(), uniform->value());
     m_uniformsModel.addUniform(uniform);
     updateAreUniformsInUse(true);
 }
@@ -346,7 +346,7 @@ void CompositionNode::updateUniform(int index, const QVariantMap &data)
 
     const auto uniform = new Uniform({}, QJsonObject::fromVariantMap(data), {});
 
-    g_propertyData.insert(uniform->name(), uniform->value());
+    g_propertyData()->insert(uniform->name(), uniform->value());
     m_uniformsModel.updateUniform(index, uniform);
     updateAreUniformsInUse(true);
 }

src/plugins/effectcomposer/effectcomposermodel.cpp

@@ -2547,8 +2547,8 @@ QString EffectComposerModel::getQmlComponentString(bool localFiles)
         s += l3 + "id: blurHelper\n";
         s += l3 + "source: rootItem.source\n";
         int blurMax = 32;
-        if (g_propertyData.contains("BLUR_HELPER_MAX_LEVEL"))
+        if (g_propertyData()->contains("BLUR_HELPER_MAX_LEVEL"))
-            blurMax = g_propertyData["BLUR_HELPER_MAX_LEVEL"].toInt();
+            blurMax = g_propertyData()->value("BLUR_HELPER_MAX_LEVEL").toInt();
         s += l3 + QString("property int blurMax: %1\n").arg(blurMax);
         s += l3 + "property real blurMultiplier: rootItem.blurMultiplier\n";
         s += l2 + "}\n";

src/plugins/effectcomposer/effectcomposeruniformsmodel.cpp

@@ -68,10 +68,10 @@ bool EffectComposerUniformsModel::setData(const QModelIndex &index, const QVaria
             updatedValue = QUrl::fromLocalFile(path).toString();
 
         uniform->setValue(updatedValue);
-        g_propertyData.insert(uniform->name(), updatedValue);
+        g_propertyData()->insert(uniform->name(), updatedValue);
     } else {
         uniform->setValue(value);
-        g_propertyData.insert(uniform->name(), value);
+        g_propertyData()->insert(uniform->name(), value);
     }
 
     emit dataChanged(index, index, {role});

src/plugins/effectcomposer/effectcomposerwidget.cpp

@@ -100,11 +100,12 @@ EffectComposerWidget::EffectComposerWidget(EffectComposerView *view)
 
     QmlDesigner::QmlDesignerPlugin::trackWidgetFocusTime(this, QmlDesigner::Constants::EVENT_EFFECTCOMPOSER_TIME);
 
-    m_quickWidget->rootContext()->setContextProperty("g_propertyData", &g_propertyData);
+    qmlRegisterSingletonInstance<QQmlPropertyMap>(
+        "EffectComposerPropertyData", 1, 0, "GlobalPropertyData", g_propertyData());
 
     QString blurPath = "file:" + EffectUtils::nodesSourcesPath() + "/common/";
-    g_propertyData.insert(QString("blur_vs_path"), QString(blurPath + "bluritems.vert.qsb"));
+    g_propertyData()->insert("blur_vs_path", QString(blurPath + "bluritems.vert.qsb"));
-    g_propertyData.insert(QString("blur_fs_path"), QString(blurPath + "bluritems.frag.qsb"));
+    g_propertyData()->insert("blur_fs_path", QString(blurPath + "bluritems.frag.qsb"));
 
     auto map = m_quickWidget->registerPropertyMap("EffectComposerBackend");
     map->setProperties({{"effectComposerNodesModel", QVariant::fromValue(effectComposerNodesModel().data())},

src/plugins/effectcomposer/propertyhandler.cpp

@@ -3,8 +3,14 @@
 
 #include "propertyhandler.h"
 
+#include <QQmlPropertyMap>
+
 namespace EffectComposer {
 
-QQmlPropertyMap g_propertyData;
+Q_GLOBAL_STATIC(QQmlPropertyMap, globalEffectComposerPropertyData)
 
+QQmlPropertyMap *g_propertyData()
+{
+    return globalEffectComposerPropertyData();
+}
 }

src/plugins/effectcomposer/propertyhandler.h

@@ -3,13 +3,16 @@
 
 #pragma once
 
-#include <QQmlPropertyMap>
+#include <QtCore/qglobal.h>
+
+QT_BEGIN_NAMESPACE
+class QQmlPropertyMap;
+QT_END_NAMESPACE
 
 namespace EffectComposer {
 
 // This will be used for binding dynamic properties
 // changes between C++ and QML.
-extern QQmlPropertyMap g_propertyData;
+QQmlPropertyMap *g_propertyData();
-
 }
 

src/plugins/effectcomposer/uniform.cpp

@@ -47,7 +47,7 @@ Uniform::Uniform(const QString &effectName, const QJsonObject &propObj, const QS
             m_enableMipmap = getBoolValue(propObj.value("enableMipmap"), false);
         // Update the mipmap property
         QString mipmapProperty = mipmapPropertyName(m_name);
-        g_propertyData[mipmapProperty] = m_enableMipmap;
+        g_propertyData()->insert(mipmapProperty, m_enableMipmap);
     }
 
     QString controlType = propObj.value("controlType").toString();