CppEditor: Fix jump behavior in outline sidebar

Before, we jumped to a symbol as soon as the selection changed, which
was problematic:
 * It was inconsistent to other outlines (e.g. class view, project
   explorer)
 * Using the Up/Down keys in the sidebar immediately jumped to the
   symbol in the editor, thus polluting the editor history.

Now we jump to a symbol if the corresponding item was explicitly
activated (QAbstractItemView::activated() signal).

There was also another strange issue: If "Synchronize with Editor" was
de-activated, nothing happened upon activation/selection of an item. Now
"Synchronize with Editor" means to update the selection in the side bar
if the cursor position changes in the editor (one direction only).

Task-number: QTCREATORBUG-12412
Change-Id: I8d9191d5fa8e229723194dcf30081e144debecbb
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/cppeditor/cppoutline.cpp

@@ -113,10 +113,8 @@ CppOutlineWidget::CppOutlineWidget(CPPEditorWidget *editor) :
 
     connect(m_editor->outline(), SIGNAL(modelIndexChanged(QModelIndex)),
             this, SLOT(updateSelectionInTree(QModelIndex)));
-    connect(m_treeView->selectionModel(), SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
-            this, SLOT(updateSelectionInText(QItemSelection)));
     connect(m_treeView, SIGNAL(activated(QModelIndex)),
-            this, SLOT(focusEditor()));
+            this, SLOT(onItemActivated(QModelIndex)));
 }
 
 QList<QAction*> CppOutlineWidget::filterMenuActions() const
@@ -152,17 +150,6 @@ void CppOutlineWidget::updateSelectionInTree(const QModelIndex &index)
     m_blockCursorSync = false;
 }
 
-void CppOutlineWidget::updateSelectionInText(const QItemSelection &selection)
-{
-    if (!syncCursor())
-        return;
-
-    if (!selection.indexes().isEmpty()) {
-        QModelIndex proxyIndex = selection.indexes().first();
-        updateTextCursor(proxyIndex);
-    }
-}
-
 void CppOutlineWidget::updateTextCursor(const QModelIndex &proxyIndex)
 {
     QModelIndex index = m_proxyModel->mapToSource(proxyIndex);
@@ -182,8 +169,12 @@ void CppOutlineWidget::updateTextCursor(const QModelIndex &proxyIndex)
     }
 }
 
-void CppOutlineWidget::focusEditor()
+void CppOutlineWidget::onItemActivated(const QModelIndex &index)
 {
+    if (!index.isValid())
+        return;
+
+    updateTextCursor(index);
     m_editor->setFocus();
 }
 

src/plugins/cppeditor/cppoutline.h

@@ -77,9 +77,8 @@ public:
 private slots:
     void modelUpdated();
     void updateSelectionInTree(const QModelIndex &index);
-    void updateSelectionInText(const QItemSelection &selection);
     void updateTextCursor(const QModelIndex &index);
-    void focusEditor();
+    void onItemActivated(const QModelIndex &index);
 
 private:
     bool syncCursor();