Implement drag-and-drop from Assets View to Texture Editor

The asset (i.e. image) can now be dragged to the "Source" property of
the Texture Editor.

Task-number: QDS-8341
Change-Id: I2d30bdf245a8328a864c116c727d3faaaad347cc
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/components/textureeditor/textureeditorcontextobject.cpp

@@ -103,6 +103,19 @@ void TextureEditorContextObject::setMajorVersion(int majorVersion)
     emit majorVersionChanged();
 }
 
+QString TextureEditorContextObject::activeDragSuffix() const
+{
+    return m_activeDragSuffix;
+}
+
+void TextureEditorContextObject::setActiveDragSuffix(const QString &suffix)
+{
+    if (m_activeDragSuffix != suffix) {
+        m_activeDragSuffix = suffix;
+        emit activeDragSuffixChanged();
+    }
+}
+
 bool TextureEditorContextObject::hasActiveTimeline() const
 {
     return m_hasActiveTimeline;

src/plugins/qmldesigner/components/textureeditor/textureeditorcontextobject.h

@@ -42,6 +42,8 @@ class TextureEditorContextObject : public QObject
 
     Q_PROPERTY(QQmlPropertyMap *backendValues READ backendValues WRITE setBackendValues NOTIFY backendValuesChanged)
 
+    Q_PROPERTY(QString activeDragSuffix READ activeDragSuffix NOTIFY activeDragSuffixChanged)
+
 public:
     TextureEditorContextObject(QQmlContext *context, QObject *parent = nullptr);
 
@@ -95,6 +97,9 @@ public:
     bool hasSingleModelSelection() const;
     void setHasSingleModelSelection(bool b);
 
+    QString activeDragSuffix() const;
+    void setActiveDragSuffix(const QString &suffix);
+
     bool hasAliasExport() const { return m_aliasExport; }
 
     void setSelectedMaterial(const ModelNode &matNode);
@@ -126,6 +131,7 @@ signals:
     void hasQuick3DImportChanged();
     void hasMaterialLibraryChanged();
     void hasSingleModelSelectionChanged();
+    void activeDragSuffixChanged();
 
 private:
     QUrl m_specificsUrl;
@@ -152,6 +158,8 @@ private:
     bool m_hasSingleModelSelection = false;
 
     ModelNode m_selectedTexture;
+
+    QString m_activeDragSuffix;
 };
 
 } // QmlDesigner

src/plugins/qmldesigner/components/textureeditor/textureeditorview.cpp

@@ -821,10 +821,15 @@ void QmlDesigner::TextureEditorView::highlightSupportedProperties(bool highlight
     QTC_ASSERT(metaInfo.isValid(), return);
 
     for (const QString &propName : propNames) {
-        if (metaInfo.property(propName.toUtf8()).propertyType().isQtQuick3DTexture()) { // TODO: support dropping to texture source
+        if (metaInfo.property(propName.toUtf8()).propertyType().isQtQuick3DTexture()) {
             QObject *propEditorValObj = propMap.value(propName).value<QObject *>();
             PropertyEditorValue *propEditorVal = qobject_cast<PropertyEditorValue *>(propEditorValObj);
             propEditorVal->setHasActiveDrag(highlight);
+        } else if (metaInfo.property(propName.toUtf8()).propertyType().isUrl()) {
+            QObject *propEditorValObj = propMap.value(propName).value<QObject *>();
+            PropertyEditorValue *propEditorVal = qobject_cast<PropertyEditorValue *>(propEditorValObj);
+            if (propEditorVal)
+                propEditorVal->setHasActiveDrag(highlight);
         }
     }
 }
@@ -841,6 +846,9 @@ void TextureEditorView::dragStarted(QMimeData *mimeData)
         return;
 
     highlightSupportedProperties();
+
+    const QString suffix = "*." + assetPath.split('.').last().toLower();
+    m_qmlBackEnd->contextObject()->setActiveDragSuffix(suffix);
 }
 
 void TextureEditorView::dragEnded()