Utils::BaseTreeView: Adjust column size by mouse click

Single click on either header or unoccupied part of the
view will toggle the respective column width between
a large value based on contents contents width and a
small fixed one (8ex). Previously it only expanded.

Change-Id: I2c5865a3b0bad7593a47976626d4c516e021c157
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/libs/utils/basetreeview.cpp

@@ -73,7 +73,7 @@ BaseTreeView::BaseTreeView(QWidget *parent)
     connect(this, SIGNAL(clicked(QModelIndex)),
         SLOT(rowClickedHelper(QModelIndex)));
     connect(header(), SIGNAL(sectionClicked(int)),
-        SLOT(headerSectionClicked(int)));
+        SLOT(toggleColumnWidth(int)));
 
     m_adjustColumnsAction = new QAction(tr("Adjust Column Widths to Contents"), this);
     m_alwaysAdjustColumnsAction = 0;
@@ -122,8 +122,9 @@ void BaseTreeView::setModel(QAbstractItemModel *model)
 void BaseTreeView::mousePressEvent(QMouseEvent *ev)
 {
     Utils::TreeView::mousePressEvent(ev);
-    if (!indexAt(ev->pos()).isValid())
-        resizeColumnsToContents();
+    const QModelIndex mi = indexAt(ev->pos());
+    if (!mi.isValid())
+        toggleColumnWidth(columnAt(ev->x()));
 }
 
 void BaseTreeView::resizeColumnsToContents()
@@ -140,8 +141,13 @@ void BaseTreeView::setAlwaysResizeColumnsToContents(bool on)
     header()->setResizeMode(0, mode);
 }
 
-void BaseTreeView::headerSectionClicked(int logicalIndex)
+void BaseTreeView::toggleColumnWidth(int logicalIndex)
 {
+    const int hint = sizeHintForColumn(logicalIndex);
+    const int size = 8 * QFontMetrics(font()).width(QLatin1Char('x'));
+    if (hint == header()->sectionSize(logicalIndex))
+        header()->resizeSection(logicalIndex, size);
+    else
         resizeColumnToContents(logicalIndex);
 }
 

src/libs/utils/basetreeview.h

@@ -64,7 +64,7 @@ protected slots:
 private slots:
     void rowActivatedHelper(const QModelIndex &index) { rowActivated(index); }
     void rowClickedHelper(const QModelIndex &index) { rowClicked(index); }
-    void headerSectionClicked(int logicalIndex);
+    void toggleColumnWidth(int logicalIndex);
 
 private:
     QAction *m_alwaysAdjustColumnsAction;