implementation of dynamic constraints reorganized

src/controls/QskBox.cpp

@@ -16,9 +16,9 @@ QskBox::~QskBox()
 {
 }
 
-QRectF QskBox::layoutRect() const
+QRectF QskBox::layoutRectForSize( const QSizeF& size ) const
 {
-    return innerBox( Panel, subControlRect( Panel ) );
+    return innerBox( Panel, subControlRect( size, Panel ) );
 }
 
 QSizeF QskBox::contentsSizeHint() const

src/controls/QskBox.h

@@ -20,7 +20,7 @@ class QSK_EXPORT QskBox : public QskControl
     QskBox( QQuickItem* parent = nullptr );
     ~QskBox() override;
 
-    QRectF layoutRect() const override;
+    QRectF layoutRectForSize( const QSizeF& ) const override;
     QSizeF contentsSizeHint() const override;
 };
 

src/controls/QskControl.cpp

@@ -13,6 +13,7 @@
 #include "QskSkin.h"
 #include "QskSkinlet.h"
 #include "QskSkinHintTable.h"
+#include "QskLayoutConstraint.h"
 
 #include <qglobalstatic.h>
 #include <qlocale.h>
@@ -1013,6 +1014,15 @@ QRectF QskControl::subControlRect( QskAspect::Subcontrol subControl ) const
     return effectiveSkinlet()->subControlRect( this, contentsRect(), subControl );
 }
 
+QRectF QskControl::subControlRect(
+    const QSizeF& size, QskAspect::Subcontrol subControl ) const
+{
+    QRectF rect( 0.0, 0.0, size.width(), size.height() );
+    rect = qskValidOrEmptyInnerRect( rect, margins() );
+
+    return effectiveSkinlet()->subControlRect( this, rect, subControl );
+}
+
 bool QskControl::layoutMirroring() const
 {
     return d_func()->effectiveLayoutMirror;
@@ -1379,58 +1389,24 @@ void QskControl::resetImplicitSize()
 
 qreal QskControl::heightForWidth( qreal width ) const
 {
-    qreal h = -1;
+    if ( !d_func()->autoLayoutChildren )
+        return -1.0;
 
-    if ( d_func()->autoLayoutChildren )
-    {
-        const auto innerSize = layoutRect().size();
-        const auto outerSize = size();
+    using namespace QskLayoutConstraint;
 
-        width -= outerSize.width() - innerSize.width();
-
-        const auto children = childItems();
-        for ( auto child : children )
-        {
-            if ( auto control = qobject_cast< const QskControl* >( child ) )
-            {
-                if ( !control->isTransparentForPositioner() )
-                    h = qMax( h, control->heightForWidth( width ) );
-            }
-        }
-
-        if ( h >= 0 )
-            h += outerSize.height() - innerSize.height();
-    }
-
-    return h;
+    return constrainedMetric(
+        HeightForWidth, this, width, constrainedChildrenMetric );
 }
 
 qreal QskControl::widthForHeight( qreal height ) const
 {
-    qreal w = -1;
+    if ( !d_func()->autoLayoutChildren )
+        return -1.0;
 
-    if ( d_func()->autoLayoutChildren )
-    {
-        const auto innerSize = layoutRect().size();
-        const auto outerSize = size();
+    using namespace QskLayoutConstraint;
 
-        height -= outerSize.height() - innerSize.height();
-
-        const auto children = childItems();
-        for ( auto child : children )
-        {
-            if ( auto control = qobject_cast< const QskControl* >( child ) )
-            {
-                if ( !control->isTransparentForPositioner() )
-                    w = qMax( w, control->widthForHeight( height ) );
-            }
-        }
-
-        if ( w >= 0 )
-            w += outerSize.width() - innerSize.width();
-    }
-
-    return w;
+    return constrainedMetric(
+        WidthForHeight, this, height, constrainedChildrenMetric );
 }
 
 bool QskControl::event( QEvent* event )
@@ -1932,9 +1908,10 @@ QskControl* QskControl::owningControl() const
     return const_cast< QskControl* >( this );
 }
 
-QRectF QskControl::layoutRect() const
+QRectF QskControl::layoutRectForSize( const QSizeF& size ) const
 {
-    return contentsRect();
+    const QRectF r( 0.0, 0.0, size.width(), size.height() );
+    return qskValidOrEmptyInnerRect( r, margins() );
 }
 
 QRectF QskControl::gestureRect() const

src/controls/QskControl.h

@@ -110,12 +110,14 @@ class QSK_EXPORT QskControl : public QQuickItem, public QskSkinnable
 
     QRectF rect() const;
     QRectF contentsRect() const;
+    QRectF layoutRect() const;
 
-    virtual QRectF layoutRect() const;
+    virtual QRectF layoutRectForSize( const QSizeF& ) const;
     virtual QRectF gestureRect() const;
     virtual QRectF focusIndicatorRect() const;
 
     QRectF subControlRect( QskAspect::Subcontrol ) const;
+    QRectF subControlRect( const QSizeF&, QskAspect::Subcontrol ) const;
 
     void setAutoFillBackground( bool );
     bool autoFillBackground() const;
@@ -313,6 +315,11 @@ inline QSizeF QskControl::preferredSize() const
     return explicitSizeHint( Qt::PreferredSize );
 }
 
+inline QRectF QskControl::layoutRect() const
+{
+    return layoutRectForSize( size() );
+}
+
 inline QskControl* qskControlCast( QObject* object )
 {
     return qobject_cast< QskControl* >( object );

src/controls/QskPushButton.cpp

@@ -245,9 +245,9 @@ void QskPushButton::updateLayout()
     }
 }
 
-QRectF QskPushButton::layoutRect() const
+QRectF QskPushButton::layoutRectForSize( const QSizeF& size ) const
 {
-    return innerBox( Panel, subControlRect( Panel ) );
+    return innerBox( Panel, subControlRect( size, Panel ) );
 }
 
 QSizeF QskPushButton::contentsSizeHint() const

src/controls/QskPushButton.h

@@ -65,7 +65,7 @@ class QSK_EXPORT QskPushButton : public QskAbstractButton
     QFont font() const;
 
     QSizeF contentsSizeHint() const override;
-    QRectF layoutRect() const override;
+    QRectF layoutRectForSize( const QSizeF& ) const override;
 
   public Q_SLOTS:
     void setText( const QString& );

src/controls/QskSubWindow.cpp

@@ -231,11 +231,11 @@ void QskSubWindow::updateLayout()
     Inherited::updateLayout();
 }
 
-QRectF QskSubWindow::layoutRect() const
+QRectF QskSubWindow::layoutRectForSize( const QSizeF& size ) const
 {
     QRectF rect = contentsRect();
 
-    const qreal top = rect.top() + subControlRect( TitleBar ).height();
+    const qreal top = rect.top() + subControlRect( size, TitleBar ).height();
     rect.setTop( top );
 
     return innerBox( Panel, rect );

src/controls/QskSubWindow.h

@@ -79,7 +79,7 @@ class QSK_EXPORT QskSubWindow : public QskPopup
     QRectF titleBarRect() const;
 
     QSizeF contentsSizeHint() const override;
-    QRectF layoutRect() const override;
+    QRectF layoutRectForSize( const QSizeF& ) const override;
 
   Q_SIGNALS:
     void decoratedChanged();

src/controls/QskTabButton.cpp

@@ -101,9 +101,9 @@ QSizeF QskTabButton::contentsSizeHint() const
     return size;
 }
 
-QRectF QskTabButton::layoutRect() const
+QRectF QskTabButton::layoutRectForSize( const QSizeF& size ) const
 {
-    return innerBox( Panel, subControlRect( Panel ) );
+    return innerBox( Panel, subControlRect( size, Panel ) );
 }
 
 QskAspect::Placement QskTabButton::effectivePlacement() const

src/controls/QskTabButton.h

@@ -37,7 +37,7 @@ class QSK_EXPORT QskTabButton : public QskAbstractButton
     QskTextOptions textOptions() const;
 
     QSizeF contentsSizeHint() const override;
-    QRectF layoutRect() const override;
+    QRectF layoutRectForSize( const QSizeF& ) const override;
 
     QskAspect::Placement effectivePlacement() const override;
 

src/layouts/QskLayoutBox.cpp

@@ -7,6 +7,7 @@
 #include "QskEvent.h"
 #include "QskLayoutEngine.h"
 #include "QskLayoutItem.h"
+#include "QskLayoutConstraint.h"
 
 class QskLayoutBox::PrivateData
 {
@@ -266,24 +267,26 @@ QSizeF QskLayoutBox::layoutItemsSizeHint() const
 
 qreal QskLayoutBox::heightForWidth( qreal width ) const
 {
-    const auto m = margins();
-    width -= m.left() + m.right();
+    auto constrainedHeight =
+        [this]( QskLayoutConstraint::Type, const QskControl*, qreal width )
+    {
+        return engine().heightForWidth( width );
+    };
 
-    qreal height = engine().heightForWidth( width );
-    
-    height += m.top() + m.bottom();
-    return height;
+    return QskLayoutConstraint::constrainedMetric(
+        QskLayoutConstraint::HeightForWidth, this, width, constrainedHeight );
 }   
 
 qreal QskLayoutBox::widthForHeight( qreal height ) const
 {
-    const auto m = margins();
-    height -= m.top() + m.bottom();
+    auto constrainedWidth =
+        [this]( QskLayoutConstraint::Type, const QskControl*, qreal height )
+    {
+        return engine().widthForHeight( height );
+    };
 
-    qreal width = engine().widthForHeight( height );
-    
-    width += m.left() + m.right();
-    return width;
+    return QskLayoutConstraint::constrainedMetric(
+        QskLayoutConstraint::WidthForHeight, this, height, constrainedWidth );
 }   
 
 void QskLayoutBox::geometryChangeEvent( QskGeometryChangeEvent* event )

src/layouts/QskLayoutConstraint.cpp

@@ -7,6 +7,8 @@
 #include "QskControl.h"
 #include "QskSizePolicy.h"
 
+#include <functional>
+
 static inline qreal qskHintFor(
     const QQuickItem* item, const char* method, qreal widthOrHeight )
 {
@@ -85,6 +87,71 @@ qreal QskLayoutConstraint::widthForHeight( const QQuickItem* item, qreal height
     return qskHintFor( item, "widthForHeight", height );
 }
 
+qreal QskLayoutConstraint::constrainedMetric(
+    Type type, const QskControl* control, qreal widthOrHeight,
+    std::function< qreal( Type, const QskControl*, qreal ) > constrainFunction )
+{
+#if 1
+    /*
+        In case of having a corner radius of Qt::RelativeSize the margins
+        we might have a wrong result when using QskLayoutConstraint::unlimited.
+        No idea how to solve this in a generic way: TODO ...
+     */
+#endif
+
+    const qreal upperLimit = 10e6;
+
+    if ( type == WidthForHeight )
+    {
+        const QSizeF outer( upperLimit, widthOrHeight );
+        const QSizeF inner = control->layoutRectForSize( outer ).size();
+
+        qreal width = constrainFunction( type, control, inner.height() );
+
+        if ( width >= 0.0 )
+            width += outer.width() - inner.width();
+
+        return width;
+    }
+    else
+    {
+        const QSizeF outer( widthOrHeight, upperLimit );
+        const QSizeF inner = control->layoutRectForSize( outer ).size();
+    
+        qreal height = constrainFunction( type, control, inner.width() );
+        
+        if ( height >= 0.0 )
+            height += outer.height() - inner.height();
+    
+        return height;
+    }
+}
+
+qreal QskLayoutConstraint::constrainedChildrenMetric(
+    Type type, const QskControl* control, qreal widthOrHeight )
+{
+    auto constrainFunction =
+        ( type == WidthForHeight ) ? widthForHeight : heightForWidth;
+
+    qreal constrainedValue = -1.0;
+
+    const auto children = control->childItems();
+    for ( auto child : children )
+    {
+        if ( auto control = qskControlCast( child ) )
+        {
+            if ( !control->isTransparentForPositioner() )
+            {
+                const auto v = constrainFunction( control, widthOrHeight );
+                if ( v > constrainedValue )
+                    constrainedValue = v;
+            }
+        }
+    }
+
+    return constrainedValue;
+}
+
 QSizeF QskLayoutConstraint::effectiveConstraint(
     const QQuickItem* item, Qt::SizeHint whichHint )
 {

src/layouts/QskLayoutConstraint.h

@@ -12,15 +12,30 @@
 #include <limits>
 
 class QskSizePolicy;
+class QskControl;
 class QQuickItem;
 class QSizeF;
 
+namespace std { template< typename T > class function; }
+
 namespace QskLayoutConstraint
 {
+    enum Type
+    {
+        WidthForHeight,
+        HeightForWidth
+    };
+
     QSK_EXPORT bool hasDynamicConstraint( const QQuickItem* );
     QSK_EXPORT qreal heightForWidth( const QQuickItem*, qreal width );
     QSK_EXPORT qreal widthForHeight( const QQuickItem*, qreal height );
 
+    QSK_EXPORT qreal constrainedMetric(
+        Type, const QskControl*, qreal value,
+        std::function< qreal( Type, const QskControl*, qreal ) > );
+
+    QSK_EXPORT qreal constrainedChildrenMetric( Type, const QskControl*, qreal width );
+
     QSK_EXPORT QSizeF effectiveConstraint( const QQuickItem*, Qt::SizeHint );
     QSK_EXPORT QskSizePolicy sizePolicy( const QQuickItem* );
 

src/layouts/QskStackBox.cpp

@@ -11,6 +11,30 @@
 
 #include <qpointer.h>
 
+static qreal qskConstrainedValue( QskLayoutConstraint::Type type,
+    const QskControl* control, qreal widthOrHeight )
+{
+    using namespace QskLayoutConstraint;
+
+    auto constrainFunction =
+        ( type == WidthForHeight ) ? widthForHeight : heightForWidth;
+
+    qreal constrainedValue = -1;
+    auto stackBox = static_cast< const QskStackBox* >( control );
+
+    for ( int i = 0; i < stackBox->itemCount(); i++ )
+    {
+        if ( const auto item = stackBox->itemAtIndex( i ) )
+        {
+            const qreal v = constrainFunction( item, widthOrHeight );
+            if ( v > constrainedValue )
+                constrainedValue = v;
+        }
+    }   
+
+    return constrainedValue;
+}
+
 class QskStackBox::PrivateData
 {
   public:
@@ -252,40 +276,14 @@ QSizeF QskStackBox::layoutItemsSizeHint() const
 
 qreal QskStackBox::heightForWidth( qreal width ) const
 {
-    const auto m = margins();
-    width -= m.left() + m.right();
-
-    qreal height = -1;
-
-    const QskLayoutEngine& engine = this->engine();
-    for ( int i = 0; i < engine.itemCount(); i++ )
-    {
-        const QskLayoutItem* layoutItem = engine.layoutItemAt( i );
-        if ( const auto item = layoutItem->item() )
-            height = qMax( height, QskLayoutConstraint::heightForWidth( item, width ) );
-    }
-
-    height += m.top() + m.bottom();
-    return height;
+    return QskLayoutConstraint::constrainedMetric(
+        QskLayoutConstraint::HeightForWidth, this, width, qskConstrainedValue );
 }
 
 qreal QskStackBox::widthForHeight( qreal height ) const
 {
-    const auto m = margins();
-    height -= m.top() + m.bottom();
-
-    qreal width = -1;
-
-    const QskLayoutEngine& engine = this->engine();
-    for ( int i = 0; i < engine.itemCount(); i++ )
-    {
-        const QskLayoutItem* layoutItem = engine.layoutItemAt( i );
-        if ( const auto item = layoutItem->item() )
-            width = qMax( width, QskLayoutConstraint::widthForHeight( item, height ) );
-    }
-
-    width += m.left() + m.right();
-    return width;
+    return QskLayoutConstraint::constrainedMetric(
+        QskLayoutConstraint::WidthForHeight, this, height, qskConstrainedValue );
 }
 
 void QskStackBox::layoutItemInserted( QskLayoutItem* layoutItem, int index )