EffectComposer: Fix custom preview issues

- Custom preview saving and loading fixed when file is deleted
- Custom preview not shown in combo when it's opened after file deletion
- Fixed selected highlight on custom preview

Fixes: QDS-13880
Change-Id: I8ef3fed5cfc220e3b37007b302f54fe3bf01899d
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

share/qtcreator/qmldesigner/effectComposerQmlSources/PreviewImagesComboBox.qml

@@ -69,6 +69,7 @@ StudioControls.ComboBox {
         target: root.popup
 
         function onAboutToShow() {
+            EffectComposerBackend.effectComposerModel.previewComboAboutToOpen()
             root.calculateWindowGeometry()
 
             window.show()
@@ -170,7 +171,9 @@ StudioControls.ComboBox {
                                 required property var modelData
 
                                 color: "transparent"
-                                border.color: root.selectedImage === modelData ? StudioTheme.Values.themeInteraction
+                                border.color: root.selectedImage === modelData
+                                              || index == 0 && root.selectedImage == EffectComposerBackend.effectComposerModel.customPreviewImage
+                                              ? StudioTheme.Values.themeInteraction
                                               : "transparent"
 
                                 width: 200

src/plugins/effectcomposer/effectcomposermodel.cpp

@@ -294,6 +294,17 @@ void EffectComposerModel::chooseCustomPreviewImage()
     });
 }
 
+void EffectComposerModel::previewComboAboutToOpen()
+{
+    if (!m_customPreviewImage.isEmpty() && !Utils::FilePath::fromUrl(m_customPreviewImage).exists()) {
+        if (m_currentPreviewImage == m_customPreviewImage) {
+            m_customPreviewImage.clear();
+            emit customPreviewImageChanged();
+            setCurrentPreviewImage({});
+        }
+    }
+}
+
 QString EffectComposerModel::fragmentShader() const
 {
     return m_fragmentShader;
@@ -1067,8 +1078,12 @@ void EffectComposerModel::saveComposition(const QString &name)
     json.insert("tool", "EffectComposer");
 
     Utils::FilePath customPreviewPath = Utils::FilePath::fromUrl(m_customPreviewImage);
-    if (m_customPreviewImage.isLocalFile())
+    if (m_customPreviewImage.isLocalFile()) {
+        if (customPreviewPath.exists())
             customPreviewPath = customPreviewPath.relativePathFrom(compositionDir);
+        else
+            customPreviewPath = {};
+    }
     json.insert("customPreviewImage", customPreviewPath.toUrl().toString());
 
     QUrl previewUrl = m_currentPreviewImage;
@@ -1259,6 +1274,7 @@ void EffectComposerModel::openComposition(const QString &path)
     m_customPreviewImage.clear();
     if (json.contains("customPreviewImage")) {
         QUrl imageUrl{json["customPreviewImage"].toString()};
+        if (!imageUrl.isEmpty()) {
             Utils::FilePath imagePath = Utils::FilePath::fromUrl(imageUrl);
             if (imagePath.isAbsolutePath()) {
                 if (imagePath.exists())
@@ -1269,6 +1285,7 @@ void EffectComposerModel::openComposition(const QString &path)
                     m_customPreviewImage = imagePath.toUrl();
             }
         }
+    }
 
     if (json.contains("nodes") && json["nodes"].isArray()) {
         beginResetModel();

src/plugins/effectcomposer/effectcomposermodel.h

@@ -81,6 +81,7 @@ public:
     Q_INVOKABLE QString getUniqueEffectName() const;
     Q_INVOKABLE bool nameExists(const QString &name) const;
     Q_INVOKABLE void chooseCustomPreviewImage();
+    Q_INVOKABLE void previewComboAboutToOpen();
 
     bool shadersUpToDate() const;
     void setShadersUpToDate(bool newShadersUpToDate);