Debugger: Maintain slider position in watch view

Setting column width seems to reset slider positions, needlessly.
Work around.

Change-Id: Ifa6c6a204dd2fbd7ad3dada0c386b697ae7a4100
Reviewed-by: Christian Stenger <christian.stenger@digia.com>

src/plugins/debugger/watchwindow.cpp

@@ -47,17 +47,18 @@
 #include <utils/savedaction.h>
 #include <utils/fancylineedit.h>
 
-#include <QDebug>
-#include <QMetaProperty>
-#include <QMimeData>
-
 #include <QApplication>
 #include <QClipboard>
+#include <QDebug>
 #include <QHeaderView>
+#include <QInputDialog>
 #include <QItemDelegate>
 #include <QMenu>
-#include <QInputDialog>
 #include <QMessageBox>
+#include <QMetaProperty>
+#include <QMimeData>
+#include <QScrollBar>
+#include <QTimer>
 
 //#define USE_WATCH_MODEL_TEST 1
 
@@ -1055,6 +1056,23 @@ void WatchTreeView::reset()
     resetHelper();
 }
 
+void WatchTreeView::doItemsLayout()
+{
+    if (m_sliderPosition == 0)
+        m_sliderPosition = verticalScrollBar()->sliderPosition();
+    Utils::BaseTreeView::doItemsLayout();
+    if (m_sliderPosition)
+        QTimer::singleShot(0, this, SLOT(adjustSlider()));
+}
+
+void WatchTreeView::adjustSlider()
+{
+    if (m_sliderPosition) {
+        verticalScrollBar()->setSliderPosition(m_sliderPosition);
+        m_sliderPosition = 0;
+    }
+}
+
 void WatchTreeView::watchExpression(const QString &exp)
 {
     watchExpression(exp, QString());

src/plugins/debugger/watchwindow.h

@@ -69,6 +69,7 @@ private slots:
     void resetHelper();
     void expandNode(const QModelIndex &idx);
     void collapseNode(const QModelIndex &idx);
+    void adjustSlider();
 
     void onClearIndividualFormat();
     void onClearTypeFormat();
@@ -78,6 +79,7 @@ private slots:
     void onIndividualFormatChange();
 
 private:
+    void doItemsLayout();
     void keyPressEvent(QKeyEvent *ev);
     void contextMenuEvent(QContextMenuEvent *ev);
     void dragEnterEvent(QDragEnterEvent *ev);
@@ -95,6 +97,7 @@ private:
 
     WatchType m_type;
     bool m_grabbing;
+    int m_sliderPosition;
 };
 
 } // namespace Internal