QmlDesigner.NodeInstanceView: introducing delay in setPathToQt()

We have to delayed the restart, because when creating a
new project we switch to that project before we open
the new file. This means the user can get an error about
a missing puppet, because the new project is based on another Qt version.

This is a hotfix for Qt Creator 2.7.

Task-number: QTCREATORBUG-8756
Change-Id: I8c74c6334dca35ad29771339855e777d307b9e43
Reviewed-by: Marco Bubke <marco.bubke@digia.com>

src/plugins/qmldesigner/designercore/include/nodeinstanceview.h

@@ -44,6 +44,7 @@
 #include <QWeakPointer>
 #include <QRectF>
 #include <QTime>
+#include <QTimer>
 
 QT_BEGIN_NAMESPACE
 class QDeclarativeEngine;
@@ -193,9 +194,11 @@ private: // functions
     void resetVerticalAnchors(const ModelNode &node);
 
     void restartProcess();
+    void restartProcessDelayed();
 
 private slots:
     void handleChrash();
+    void restartProcessDelayedTimeOut();
 
 private: //variables
     NodeInstance m_rootNodeInstance;
@@ -210,6 +213,8 @@ private: //variables
     QTime m_lastCrashTime;
     NodeInstanceServerInterface::RunModus m_runModus;
     QString m_pathToQt;
+    bool m_puppetRestarted;
+    QTimer m_singleShotTimerRestartProcessDelayed;
 };
 
 } // namespace ProxyNodeInstanceView

src/plugins/qmldesigner/designercore/instances/nodeinstanceview.cpp

@@ -35,6 +35,7 @@
 #include <QGraphicsObject>
 #include <QFileSystemWatcher>
 #include <QMultiHash>
+#include <QTimer>
 
 #include <model.h>
 #include <modelnode.h>
@@ -110,9 +111,13 @@ d too.
 NodeInstanceView::NodeInstanceView(QObject *parent, NodeInstanceServerInterface::RunModus runModus)
         : AbstractView(parent),
           m_baseStatePreviewImage(QSize(100, 100), QImage::Format_ARGB32),
-          m_runModus(runModus)
+          m_runModus(runModus),
+          m_puppetRestarted(false)
 {
     m_baseStatePreviewImage.fill(0xFFFFFF);
+    m_singleShotTimerRestartProcessDelayed.setSingleShot(true);
+    m_singleShotTimerRestartProcessDelayed.setInterval(400);
+    connect(&m_singleShotTimerRestartProcessDelayed, SIGNAL(timeout()), this, SLOT(restartProcessDelayedTimeOut()));
 }
 
 
@@ -197,10 +202,15 @@ void NodeInstanceView::handleChrash()
         emit  qmlPuppetCrashed();
 }
 
-
+void NodeInstanceView::restartProcessDelayedTimeOut()
+{
+    if (!m_puppetRestarted)
+        restartProcess();
+}
 
 void NodeInstanceView::restartProcess()
 {
+    m_puppetRestarted = true;
     if (model()) {
         delete nodeInstanceServer();
 
@@ -218,6 +228,12 @@ void NodeInstanceView::restartProcess()
     }
 }
 
+void NodeInstanceView::restartProcessDelayed()
+{
+    m_puppetRestarted = false;
+    m_singleShotTimerRestartProcessDelayed.start();
+}
+
 void NodeInstanceView::nodeCreated(const ModelNode &createdNode)
 {
     NodeInstance instance = loadNode(createdNode);
@@ -1123,7 +1139,16 @@ void NodeInstanceView::setPathToQt(const QString &pathToQt)
 {
     if (m_pathToQt != pathToQt) {
         m_pathToQt = pathToQt;
-        restartProcess();
+
+        /* The restart is done delayed, because when creating a new project we switch to that project
+         * before we open the new file. This means the user can get an error about a missing puppet,
+         * because the new project is based on another Qt version.
+         *
+         * See QTCREATORBUG-8756 for more details.
+         *
+         */
+
+        restartProcessDelayed();
     }
 }