From 1941fbc8476c55cbf1524ecc99a8c65618645cab Mon Sep 17 00:00:00 2001
From: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date: Tue, 10 Mar 2020 10:30:44 +0100
Subject: [PATCH] QskControl::LayoutOutWhenHidden flag added

---
 src/controls/QskControl.h             |  9 ++++++++-
 src/layouts/QskGridLayoutEngine.cpp   |  2 +-
 src/layouts/QskLayoutEngine2D.cpp     | 17 +++++++++++++++++
 src/layouts/QskLayoutEngine2D.h       |  1 +
 src/layouts/QskLinearLayoutEngine.cpp |  2 +-
 src/layouts/QskStackBox.cpp           |  4 ++++
 6 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/src/controls/QskControl.h b/src/controls/QskControl.h
index 752ee031..69eb3d79 100644
--- a/src/controls/QskControl.h
+++ b/src/controls/QskControl.h
@@ -59,7 +59,14 @@ class QSK_EXPORT QskControl : public QskQuickItem, public QskSkinnable
     enum LayoutHint
     {
         // How to be treated by layouts
-        RetainSizeWhenHidden = 1 << 0
+        RetainSizeWhenHidden = 1 << 0,
+
+        /*
+            Adjust the item even, even when being hidden
+            Depending on the type of layout the value only works
+            in combination with RetainSizeWhenHidden
+         */
+        LayoutOutWhenHidden = 1 << 1
     };
 
     Q_ENUM( LayoutHint )
diff --git a/src/layouts/QskGridLayoutEngine.cpp b/src/layouts/QskGridLayoutEngine.cpp
index dad083eb..1fa47bef 100644
--- a/src/layouts/QskGridLayoutEngine.cpp
+++ b/src/layouts/QskGridLayoutEngine.cpp
@@ -581,7 +581,7 @@ void QskGridLayoutEngine::layoutItems()
     {
         auto item = element.item();
 
-        if ( item && qskIsVisibleToParent( item ) )
+        if ( requiresAdjustment( item ) )
         {
             const auto grid = m_data->effectiveGrid( element );
             layoutItem( item, grid );
diff --git a/src/layouts/QskLayoutEngine2D.cpp b/src/layouts/QskLayoutEngine2D.cpp
index a60d10dd..f324bc7c 100644
--- a/src/layouts/QskLayoutEngine2D.cpp
+++ b/src/layouts/QskLayoutEngine2D.cpp
@@ -6,6 +6,7 @@
 #include "QskLayoutEngine2D.h"
 #include "QskLayoutChain.h"
 #include "QskLayoutHint.h"
+#include "QskControl.h"
 #include "QskQuick.h"
 
 #include <qguiapplication.h>
@@ -652,3 +653,19 @@ QskSizePolicy::ConstraintType QskLayoutEngine2D::constraintType() const
     return static_cast< QskSizePolicy::ConstraintType >( m_data->constraintType );
 }
 
+bool QskLayoutEngine2D::requiresAdjustment( const QQuickItem* item ) const
+{
+    if ( qskIsVisibleToParent( item ) )
+        return true;
+
+    if ( auto control = qskControlCast( item ) )
+    {
+        constexpr auto mask =
+            QskControl::RetainSizeWhenHidden | QskControl::LayoutOutWhenHidden;
+
+        if ( control->layoutHints() & mask )
+            return true;
+    }
+
+    return false;
+}
diff --git a/src/layouts/QskLayoutEngine2D.h b/src/layouts/QskLayoutEngine2D.h
index c5b4abe8..9231c1a2 100644
--- a/src/layouts/QskLayoutEngine2D.h
+++ b/src/layouts/QskLayoutEngine2D.h
@@ -67,6 +67,7 @@ class QskLayoutEngine2D
     };
 
     void invalidate( int what );
+    bool requiresAdjustment( const QQuickItem* ) const;
 
   private:
     Q_DISABLE_COPY( QskLayoutEngine2D )
diff --git a/src/layouts/QskLinearLayoutEngine.cpp b/src/layouts/QskLinearLayoutEngine.cpp
index 446686dd..363ba65b 100644
--- a/src/layouts/QskLinearLayoutEngine.cpp
+++ b/src/layouts/QskLinearLayoutEngine.cpp
@@ -348,7 +348,7 @@ void QskLinearLayoutEngine::layoutItems()
 
         if ( auto item = element.item() )
         {
-            if ( qskIsVisibleToParent( item ) )
+            if ( requiresAdjustment( item ) )
             {
                 const QRect grid( col, row, 1, 1 );
                 layoutItem( item, grid );
diff --git a/src/layouts/QskStackBox.cpp b/src/layouts/QskStackBox.cpp
index 76ffdcec..3d85d709 100644
--- a/src/layouts/QskStackBox.cpp
+++ b/src/layouts/QskStackBox.cpp
@@ -331,6 +331,10 @@ void QskStackBox::updateLayout()
     if ( maybeUnresized() )
         return;
 
+#if 1
+    // what about QskControl::LayoutOutWhenHidden
+#endif
+
     const auto index = m_data->currentIndex;
 
     if ( index >= 0 )