QmlDesigner: Allow dropping image assets to User Assets

Also fixes a corner case where a "Content Library is disabled inside a non-visual component." message is displayed under Textures if the materials model is empty.

Fixes: QDS-14443
Fixes: QDS-12825
Change-Id: I9fa37b843534a1a54f08652f7a66915ac30d024d
Reviewed-by: Ali Kianian <ali.kianian@qt.io>
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

share/qtcreator/qmldesigner/contentLibraryQmlSource/ContentLibraryUserView.qml

@@ -104,6 +104,7 @@ Item {
                     bottomPadding: StudioTheme.Values.sectionPadding
 
                     caption: categoryTitle
+                    dropEnabled: true
                     category: "ContentLib_User"
 
                     function expandSection() {
@@ -114,6 +115,24 @@ Item {
 
                     onCountChanged: root.assignMaxCount()
 
+                    onDropEnter: (drag) => {
+                        drag.accepted = categoryTitle === "Textures"
+                                     && drag.formats[0] === "application/vnd.qtdesignstudio.assets"
+
+                        section.highlight = drag.accepted
+                    }
+
+                    onDropExit: {
+                        section.highlight = false
+                    }
+
+                    onDrop: (drag) => {
+                        section.highlight = false
+                        ContentLibraryBackend.rootView.acceptTexturesDrop(drag.urls)
+                        drag.accept()
+                        section.expandSection()
+                    }
+
                     Grid {
                         width: section.width - section.leftPadding - section.rightPadding
                         spacing: StudioTheme.Values.sectionGridSpacing
@@ -182,7 +201,7 @@ Item {
                                 qsTr("<b>Content Library</b> is not supported in Qt5 projects.")
                             else if (!ContentLibraryBackend.rootView.hasQuick3DImport && categoryTitle !== "Textures")
                                 qsTr("To use " +  categoryName + ", first add the QtQuick3D module in the <b>Components</b> view.")
-                            else if (!ContentLibraryBackend.rootView.hasMaterialLibrary)
+                            else if (!ContentLibraryBackend.rootView.hasMaterialLibrary && categoryTitle !== "Textures")
                                 qsTr("<b>Content Library</b> is disabled inside a non-visual component.")
                             else if (categoryEmpty)
                                 qsTr("There are no "+ categoryName + " in the <b>User Assets</b>.")

src/plugins/qmldesigner/components/contentlibrary/contentlibraryview.cpp

@@ -87,6 +87,19 @@ WidgetInfo ContentLibraryView::widgetInfo()
             m_draggedBundleItem = item;
         });
 
+        connect(m_widget, &ContentLibraryWidget::acceptTexturesDrop, this,
+                [this](const QList<QUrl> &urls) {
+            QStringList paths;
+
+            for (const QUrl &url : urls) {
+                QString path = url.toLocalFile();
+
+                if (Asset(path).isImage())
+                    paths.append(path);
+            }
+            addLibAssets(paths);
+        });
+
         connect(m_widget,
                 &ContentLibraryWidget::addTextureRequested,
                 this,

src/plugins/qmldesigner/components/contentlibrary/contentlibrarywidget.h

@@ -124,6 +124,7 @@ signals:
     void hasModelSelectionChanged();
     void importBundle();
     void requestTab(int tabIndex);
+    void acceptTexturesDrop(const QList<QUrl> &urls);
 
 protected:
     bool eventFilter(QObject *obj, QEvent *event) override;