QmlDesigner: Clean up unused imports after effect node deletion

Import removal is done asynchronously as false node deletions can be
triggered by node reorganization that happens sometimes e.g. when
undo/redo is done.

Fixes: QDS-11741
Change-Id: I1d33e43ee205408c6a0fb2a45347ede13c02c4ed
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

src/plugins/effectcomposer/effectcomposerview.cpp

@@ -9,6 +9,7 @@
 
 #include <designermcumanager.h>
 #include <documentmanager.h>
+#include <import.h>
 #include <modelnodeoperations.h>
 #include <qmlchangeset.h>
 #include <qmldesignerconstants.h>
@@ -16,6 +17,8 @@
 
 #include <coreplugin/icore.h>
 
+#include <QTimer>
+
 namespace EffectComposer {
 
 EffectComposerContext::EffectComposerContext(QWidget *widget)
@@ -183,4 +186,48 @@ void EffectComposerView::selectedNodesChanged(const QList<QmlDesigner::ModelNode
     m_widget->effectComposerModel()->setHasValidTarget(hasValidTarget);
 }
 
+void EffectComposerView::nodeAboutToBeRemoved(const QmlDesigner::ModelNode &removedNode)
+{
+    QList<QmlDesigner::ModelNode> nodes = removedNode.allSubModelNodesAndThisNode();
+    bool effectRemoved = false;
+    for (const QmlDesigner::ModelNode &node : nodes) {
+        QmlDesigner::QmlItemNode qmlNode(node);
+        if (qmlNode.isEffectItem()) {
+            effectRemoved = true;
+            break;
+        }
+    }
+    if (effectRemoved)
+        QTimer::singleShot(0, this, &EffectComposerView::removeUnusedEffectImports);
+}
+
+void EffectComposerView::removeUnusedEffectImports()
+{
+    QTC_ASSERT(model(), return);
+
+    const QString effectPrefix = m_componentUtils.composedEffectsTypePrefix();
+
+    const QmlDesigner::Imports &imports = model()->imports();
+    QHash<QString, QmlDesigner::Import> effectImports;
+    for (const QmlDesigner::Import &import : imports) {
+        if (import.url().startsWith(effectPrefix)) {
+            QString type = import.url().split('.').last();
+            effectImports.insert(type, import);
+        }
+    }
+
+    const QList<QmlDesigner::ModelNode> allNodes = allModelNodes();
+    for (const QmlDesigner::ModelNode &node : allNodes) {
+        if (QmlDesigner::QmlItemNode(node).isEffectItem())
+            effectImports.remove(node.simplifiedTypeName());
+    }
+
+    if (!effectImports.isEmpty()) {
+        QmlDesigner::Imports removeImports;
+        for (const QmlDesigner::Import &import : effectImports)
+            removeImports.append(import);
+        model()->changeImports({}, removeImports);
+    }
+}
+
 } // namespace EffectComposer

src/plugins/effectcomposer/effectcomposerview.h

@@ -39,10 +39,12 @@ public:
     void modelAboutToBeDetached(QmlDesigner::Model *model) override;
     void selectedNodesChanged(const QList<QmlDesigner::ModelNode> &selectedNodeList,
                               const QList<QmlDesigner::ModelNode> &lastSelectedNodeList) override;
+    void nodeAboutToBeRemoved(const QmlDesigner::ModelNode &removedNode) override;
 
 private:
     void customNotification(const AbstractView *view, const QString &identifier,
                             const QList<QmlDesigner::ModelNode> &nodeList, const QList<QVariant> &data) override;
+    void removeUnusedEffectImports();
 
     QPointer<EffectComposerWidget> m_widget;
     QString m_currProjectPath;