Add ForwardingDelegate for use in RD extended widgets.

* This item delegate will forward on either to a specified other
  delegate or to the base implementation. This allows chaining delegates
  (i.e. having one built-in to the widget, which forwards to a user-set
  delegate).

qrenderdoc/Code/QRDUtils.h

@@ -32,6 +32,7 @@
 #include <QProcess>
 #include <QSemaphore>
 #include <QSortFilterProxyModel>
+#include <QStyledItemDelegate>
 #include "Code/Interface/QRDInterface.h"
 
 template <typename T>
@@ -258,6 +259,113 @@ private:
   QDir::Filters m_requireMask, m_excludeMask;
 };
 
+// Simple QStyledItemDelegate child that will either forward to an external delegate (allowing
+// chaining) or to the base implementation. Delegates can derive from this and specialise a couple
+// of functions to still be able to chain
+class ForwardingDelegate : public QStyledItemDelegate
+{
+  Q_OBJECT
+public:
+  explicit ForwardingDelegate(QObject *parent = NULL) : QStyledItemDelegate(parent) {}
+  ~ForwardingDelegate() {}
+  void setForwardDelegate(QAbstractItemDelegate *real) { m_delegate = real; }
+  void paint(QPainter *painter, const QStyleOptionViewItem &option,
+             const QModelIndex &index) const override
+  {
+    if(m_delegate)
+      return m_delegate->paint(painter, option, index);
+
+    return QStyledItemDelegate::paint(painter, option, index);
+  }
+
+  QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const override
+  {
+    if(m_delegate)
+      return m_delegate->sizeHint(option, index);
+
+    return QStyledItemDelegate::sizeHint(option, index);
+  }
+
+  QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
+                        const QModelIndex &index) const override
+  {
+    if(m_delegate)
+      return m_delegate->createEditor(parent, option, index);
+
+    return QStyledItemDelegate::createEditor(parent, option, index);
+  }
+
+  void destroyEditor(QWidget *editor, const QModelIndex &index) const override
+  {
+    if(m_delegate)
+      return m_delegate->destroyEditor(editor, index);
+
+    return QStyledItemDelegate::destroyEditor(editor, index);
+  }
+
+  void setEditorData(QWidget *editor, const QModelIndex &index) const override
+  {
+    if(m_delegate)
+      return m_delegate->setEditorData(editor, index);
+
+    return QStyledItemDelegate::setEditorData(editor, index);
+  }
+
+  void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const override
+  {
+    if(m_delegate)
+      return m_delegate->setModelData(editor, model, index);
+
+    return QStyledItemDelegate::setModelData(editor, model, index);
+  }
+
+  void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option,
+                            const QModelIndex &index) const override
+  {
+    if(m_delegate)
+      return m_delegate->updateEditorGeometry(editor, option, index);
+
+    return QStyledItemDelegate::updateEditorGeometry(editor, option, index);
+  }
+
+  bool eventFilter(QObject *watched, QEvent *event) override
+  {
+    if(m_delegate)
+      return m_delegate->eventFilter(watched, event);
+
+    return QStyledItemDelegate::eventFilter(watched, event);
+  }
+
+  bool editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option,
+                   const QModelIndex &index) override
+  {
+    if(m_delegate)
+      return m_delegate->editorEvent(event, model, option, index);
+
+    return QStyledItemDelegate::editorEvent(event, model, option, index);
+  }
+
+  bool helpEvent(QHelpEvent *event, QAbstractItemView *view, const QStyleOptionViewItem &option,
+                 const QModelIndex &index) override
+  {
+    if(m_delegate)
+      return m_delegate->helpEvent(event, view, option, index);
+
+    return QStyledItemDelegate::helpEvent(event, view, option, index);
+  }
+
+  QVector<int> paintingRoles() const override
+  {
+    if(m_delegate)
+      return m_delegate->paintingRoles();
+
+    return QStyledItemDelegate::paintingRoles();
+  }
+
+private:
+  QAbstractItemDelegate *m_delegate = NULL;
+};
+
 class QMenu;
 
 // helper for doing a manual blocking invoke of a dialog

qrenderdoc/Widgets/Extended/RDTreeView.cpp

@@ -31,33 +31,15 @@
 #include <QToolTip>
 #include <QWheelEvent>
 
-RDTreeViewDelegate::RDTreeViewDelegate(RDTreeView *view) : QStyledItemDelegate(view), m_View(view)
+RDTreeViewDelegate::RDTreeViewDelegate(RDTreeView *view) : ForwardingDelegate(view), m_View(view)
 {
 }
 
 QSize RDTreeViewDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const
 {
-  QSize ret;
-
-  QVariant var = index.data(Qt::SizeHintRole);
-  if(var.canConvert<QSize>())
-  {
-    ret = var.value<QSize>();
-  }
-  else
-  {
-    QStyleOptionViewItem opt = option;
-    initStyleOption(&opt, index);
-
-    if(m_View->ignoreIconSize())
-    {
-      opt.icon = QIcon();
-      opt.features &= ~QStyleOptionViewItem::HasDecoration;
-      opt.decorationSize = QSize();
-    }
-
-    ret = m_View->style()->sizeFromContents(QStyle::CT_ItemViewItem, &opt, QSize(), m_View);
-  }
+  m_suppressIcon = m_View->ignoreIconSize();
+  QSize ret = ForwardingDelegate::sizeHint(option, index);
+  m_suppressIcon = false;
 
   // expand a pixel for the grid lines
   if(m_View->visibleGridLines())
@@ -73,6 +55,18 @@ QSize RDTreeViewDelegate::sizeHint(const QStyleOptionViewItem &option, const QMo
   return ret;
 }
 
+void RDTreeViewDelegate::initStyleOption(QStyleOptionViewItem *option, const QModelIndex &index) const
+{
+  QStyledItemDelegate::initStyleOption(option, index);
+
+  if(m_suppressIcon)
+  {
+    option->icon = QIcon();
+    option->features &= ~QStyleOptionViewItem::HasDecoration;
+    option->decorationSize = QSize();
+  }
+}
+
 RDTipLabel::RDTipLabel() : QLabel(NULL)
 {
   int margin = style()->pixelMetric(QStyle::PM_ToolTipLabelFrameWidth, NULL, this);
@@ -115,7 +109,8 @@ RDTreeView::RDTreeView(QWidget *parent) : QTreeView(parent)
 {
   setMouseTracking(true);
 
-  setItemDelegate(new RDTreeViewDelegate(this));
+  m_delegate = new RDTreeViewDelegate(this);
+  QTreeView::setItemDelegate(m_delegate);
 
   m_ElidedTooltip = new RDTipLabel();
   m_ElidedTooltip->hide();
@@ -157,7 +152,11 @@ bool RDTreeView::viewportEvent(QEvent *event)
     QHelpEvent *he = (QHelpEvent *)event;
     QModelIndex index = indexAt(he->pos());
 
-    QAbstractItemDelegate *delegate = itemDelegate(index);
+    QAbstractItemDelegate *delegate = m_userDelegate;
+
+    if(!delegate)
+      delegate = QTreeView::itemDelegate(index);
+
     if(delegate)
     {
       QStyleOptionViewItem option;
@@ -190,6 +189,17 @@ bool RDTreeView::viewportEvent(QEvent *event)
   return QTreeView::viewportEvent(event);
 }
 
+void RDTreeView::setItemDelegate(QAbstractItemDelegate *delegate)
+{
+  m_userDelegate = delegate;
+  m_delegate->setForwardDelegate(m_userDelegate);
+}
+
+QAbstractItemDelegate *RDTreeView::itemDelegate() const
+{
+  return m_userDelegate;
+}
+
 void RDTreeView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
 {
   m_currentHoverIndex = QModelIndex();

qrenderdoc/Widgets/Extended/RDTreeView.h

@@ -27,19 +27,28 @@
 #include <QLabel>
 #include <QStyledItemDelegate>
 #include <QTreeView>
+#include "Code/QRDUtils.h"
 
 class RDTreeView;
 
-class RDTreeViewDelegate : public QStyledItemDelegate
+class RDTreeViewDelegate : public ForwardingDelegate
 {
 private:
   Q_OBJECT
 
+  // I hate the mutable keyword, but it's necessary to modify it inside sizeHint to access in
+  // initStyleOption. There's no other way to only remove the icon while in sizeHint, and not in
+  // other places that call initStyleOption. We don't want to try and manually init, since if
+  // there's a forwarded delegate it might do something different.
+  mutable bool m_suppressIcon = false;
   RDTreeView *m_View;
 
 public:
   RDTreeViewDelegate(RDTreeView *view);
   QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const override;
+
+protected:
+  void initStyleOption(QStyleOptionViewItem *option, const QModelIndex &index) const override;
 };
 
 class RDTipLabel : public QLabel
@@ -76,6 +85,9 @@ public:
   int verticalItemMargin() { return m_VertMargin; }
   void setIgnoreIconSize(bool ignore) { m_IgnoreIconSize = ignore; }
   bool ignoreIconSize() { return m_IgnoreIconSize; }
+  void setItemDelegate(QAbstractItemDelegate *delegate);
+  QAbstractItemDelegate *itemDelegate() const;
+
 protected:
   void rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end) override;
   void mouseMoveEvent(QMouseEvent *e) override;
@@ -96,6 +108,9 @@ private:
   bool m_VisibleGridLines = true;
   bool m_TooltipElidedItems = true;
 
+  QAbstractItemDelegate *m_userDelegate = NULL;
+  RDTreeViewDelegate *m_delegate;
+
   RDTipLabel *m_ElidedTooltip;
 
   int m_VertMargin = 6;