From bf200fc948d89e1a735a8bcca879654028f944d2 Mon Sep 17 00:00:00 2001
From: Jan Arve Saether <jan-arve.saether@theqtcompany.com>
Date: Mon, 20 Oct 2014 15:40:18 +0200
Subject: Adjust the layout if a QGraphicsWidget is explicitly hidden

Since layout items can now be hidden, this also makes sure we respect
the QSizePolicy::retainSizeWhenHidden

Task-number: QTBUG-20132
Change-Id: Iab59fc9b61d4ca1bb2208c479a027da6eb0283a9
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>
---
 .../graphicsview/qgraphicsgridlayoutengine.cpp       | 20 ++++++++++++++++++++
 .../graphicsview/qgraphicsgridlayoutengine_p.h       |  4 ++++
 src/widgets/graphicsview/qgraphicswidget.cpp         |  4 ++++
 3 files changed, 28 insertions(+)

(limited to 'src/widgets/graphicsview')

diff --git a/src/widgets/graphicsview/qgraphicsgridlayoutengine.cpp b/src/widgets/graphicsview/qgraphicsgridlayoutengine.cpp
index 3d9c5d6de5..c9b2ecd62c 100644
--- a/src/widgets/graphicsview/qgraphicsgridlayoutengine.cpp
+++ b/src/widgets/graphicsview/qgraphicsgridlayoutengine.cpp
@@ -38,9 +38,29 @@
 #include "qgraphicslayoutitem_p.h"
 #include "qgraphicslayout_p.h"
 #include "qgraphicswidget.h"
+#include <private/qgraphicswidget_p.h>
 
 QT_BEGIN_NAMESPACE
 
+bool QGraphicsGridLayoutEngineItem::isHidden() const
+{
+    if (QGraphicsItem *item = q_layoutItem->graphicsItem())
+        return QGraphicsItemPrivate::get(item)->explicitlyHidden;
+    return false;
+}
+
+/*!
+  \internal
+
+  If this returns true, the layout will arrange just as if the item was never added to the layout.
+  (Note that this shouldn't lead to a "double spacing" where the item was hidden)
+  ### Qt6: Move to QGraphicsLayoutItem and make virtual
+*/
+bool QGraphicsGridLayoutEngineItem::isIgnored() const
+{
+    return isHidden() && !q_layoutItem->sizePolicy().retainSizeWhenHidden();
+}
+
 /*
   returns \c true if the size policy returns \c true for either hasHeightForWidth()
   or hasWidthForHeight()
diff --git a/src/widgets/graphicsview/qgraphicsgridlayoutengine_p.h b/src/widgets/graphicsview/qgraphicsgridlayoutengine_p.h
index 4d6bdfce0a..07486514f8 100644
--- a/src/widgets/graphicsview/qgraphicsgridlayoutengine_p.h
+++ b/src/widgets/graphicsview/qgraphicsgridlayoutengine_p.h
@@ -82,6 +82,10 @@ public:
         return q_layoutItem->effectiveSizeHint(which, constraint);
     }
 
+    bool isHidden() const;
+
+    virtual bool isIgnored() const Q_DECL_OVERRIDE;
+
     virtual void setGeometry(const QRectF &rect) Q_DECL_OVERRIDE
     {
          q_layoutItem->setGeometry(rect);
diff --git a/src/widgets/graphicsview/qgraphicswidget.cpp b/src/widgets/graphicsview/qgraphicswidget.cpp
index 4a9c3b098e..5bd563e535 100644
--- a/src/widgets/graphicsview/qgraphicswidget.cpp
+++ b/src/widgets/graphicsview/qgraphicswidget.cpp
@@ -1137,6 +1137,10 @@ QVariant QGraphicsWidget::itemChange(GraphicsItemChange change, const QVariant &
                 setAttribute(Qt::WA_Resized, false);
             }
         }
+
+        // layout size hint only changes if an item changes from/to explicitly hidden state
+        if (value.toBool() || d->explicitlyHidden)
+            updateGeometry();
         break;
     case ItemVisibleHasChanged:
         if (!value.toBool()) {
-- 
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