Fixed crash when opening ui files in design mode

QML Designer now listens to contextChanged signal instead of
modeChanged and checks that the context is same as that of qmldesigner.

Reviewed-by: con

src/plugins/coreplugin/designmode.cpp

@@ -174,6 +174,11 @@ QStringList DesignMode::registeredMimeTypes() const
     return rc;
 }
 
+/**
+  * Registers a widget to be displayed when an editor with a file specified in
+  * mimeTypes is opened. This also appends the additionalContext in ICore to
+  * the context, specified here.
+  */
 void DesignMode::registerDesignWidget(QWidget *widget,
                                       const QStringList &mimeTypes,
                                       const QList<int> &context,

src/plugins/qmldesigner/designmodewidget.cpp

@@ -159,7 +159,8 @@ void DesignModeWidget::showEditor(Core::IEditor *editor)
         fileName = editor->file()->fileName();
         textEdit = qobject_cast<QPlainTextEdit*>(editor->widget());
         textEditor = qobject_cast<TextEditor::ITextEditor*>(editor);
-        m_fakeToolBar->addEditor(textEditor);
+        if (textEditor)
+            m_fakeToolBar->addEditor(textEditor);
     }
 
     if (debug)

src/plugins/qmldesigner/qmldesignerplugin.cpp

@@ -43,6 +43,7 @@
 #include <coreplugin/actionmanager/actioncontainer.h>
 #include <coreplugin/actionmanager/command.h>
 #include <coreplugin/icore.h>
+#include <coreplugin/icontext.h>
 #include <coreplugin/dialogs/iwizard.h>
 #include <coreplugin/editormanager/ieditorfactory.h>
 #include <coreplugin/editormanager/editormanager.h>
@@ -227,8 +228,9 @@ void BauhausPlugin::createDesignModeWidget()
     connect(m_editorManager, SIGNAL(editorsClosed(QList<Core::IEditor*>)),
             this, SLOT(textEditorsClosed(QList<Core::IEditor*>)));
 
-    connect(Core::ModeManager::instance(), SIGNAL(currentModeChanged(Core::IMode*)),
+    connect(creatorCore, SIGNAL(contextChanged(Core::IContext*,QList<int>)),
-            this, SLOT(modeChanged(Core::IMode*)));
+            this, SLOT(contextChanged(Core::IContext*,QList<int>)));
+
 }
 
 void BauhausPlugin::updateEditor(Core::IEditor *editor)
@@ -241,17 +243,22 @@ void BauhausPlugin::updateEditor(Core::IEditor *editor)
     }
 }
 
-void BauhausPlugin::modeChanged(Core::IMode *mode)
+void BauhausPlugin::contextChanged(Core::IContext *context, const QList<int> &additionalContexts)
 {
-    if (mode == m_designMode) {
+    Q_UNUSED(context)
-        m_isActive = true;
+
-        m_mainWidget->showEditor(m_editorManager->currentEditor());
+    foreach(int additionalContext, additionalContexts) {
-    } else {
+        if (m_context->context().contains(additionalContext)) {
-        if (m_isActive) {
+            m_isActive = true;
-            m_isActive = false;
+            m_mainWidget->showEditor(m_editorManager->currentEditor());
-            m_mainWidget->showEditor(0);
+            return;
         }
     }
+
+    if (m_isActive) {
+        m_isActive = false;
+        m_mainWidget->showEditor(0);
+    }
 }
 
 void BauhausPlugin::textEditorsClosed(QList<Core::IEditor*> editors)

src/plugins/qmldesigner/qmldesignerplugin.h

@@ -42,6 +42,7 @@ class QAction;
 QT_END_NAMESPACE
 
 namespace Core {
+    class IContext;
     class IWizard;
     class ICore;
     class IEditorFactory;
@@ -84,7 +85,7 @@ private slots:
     void textEditorsClosed(QList<Core::IEditor *> editors);
     void updateActions(Core::IEditor* editor);
     void updateEditor(Core::IEditor *editor);
-    void modeChanged(Core::IMode *mode);
+    void contextChanged(Core::IContext *context, const QList<int> &additionalContexts);
 
 private:
     void createDesignModeWidget();