QmlDesigner: Remove triangle icons

Change-Id: I32e0cb8a2d1b406c464ada33685def1149626a72
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/libs/qmleditorwidgets/resources.qrc

@@ -18,8 +18,6 @@
         <file>images/checkbox_tr_unchecked_pressed@2x.png</file>
         <file>images/lock.png</file>
         <file>images/hole.png</file>
-        <file>images/triangle_horz.png</file>
-        <file>images/triangle_vert.png</file>
         <file>images/scrollbar-borderimage-horizontal.png</file>
         <file>images/scrollbar-borderimage-vertical.png</file>
         <file>images/aspectlockset.png</file>

src/plugins/qmldesigner/components/navigator/navigatorwidget.cpp

@@ -36,6 +36,8 @@
 #include <QtDebug>
 #include <utils/fileutils.h>
 
+#include <QStyleFactory>
+
 namespace QmlDesigner {
 
 NavigatorWidget::NavigatorWidget(NavigatorView *view) :
@@ -51,6 +53,9 @@ NavigatorWidget::NavigatorWidget(NavigatorView *view) :
     m_treeView->setDefaultDropAction(Qt::LinkAction);
     m_treeView->setHeaderHidden(true);
 
+    QStyle *style = QStyleFactory::create("fusion");
+    m_treeView->setStyle(style);
+
     QVBoxLayout *layout = new QVBoxLayout;
     layout->setSpacing(0);
     layout->setMargin(0);

src/plugins/qmldesigner/components/resources/stylesheet.css

@@ -80,18 +80,6 @@ QTreeView::branch:has-siblings:!adjoins-item {
      image:none;
  }
 
- QTreeView::branch:has-children:!has-siblings:closed,
- QTreeView::branch:closed:has-children:has-siblings {
-         border-image: none;
-         image: url(:/qmldesigner/images/triangle_horz.png);
- }
-
- QTreeView::branch:open:has-children:!has-siblings,
- QTreeView::branch:open:has-children:has-siblings  {
-         border-image: none;
-         image: url(:/qmldesigner/images/triangle_vert.png);
- }
-
  QListView {
     color:creatorTheme.PanelTextColorLight;
     selection-color: creatorTheme.PanelTextColorLight;