QtGui.QGraphicsLinearLayout Class Reference

The QGraphicsLinearLayout class provides a horizontal or vertical layout for managing widgets in Graphics View. More...

Inheritance diagram for QtGui.QGraphicsLinearLayout:

Collaboration diagram for QtGui.QGraphicsLinearLayout:

Public Member Functions
	QGraphicsLinearLayout (IQGraphicsLayoutItem parent=null)
	QGraphicsLinearLayout (Qt.Orientation orientation, IQGraphicsLayoutItem parent=null)
override void	CreateProxy ()
new void	AddItem (IQGraphicsLayoutItem item)
new void	AddStretch (int stretch=1)
new Qt.AlignmentFlag	Alignment (IQGraphicsLayoutItem item)
override int	Count ()
new void	Dump (int indent=0)
new void	InsertItem (int index, IQGraphicsLayoutItem item)
new void	InsertStretch (int index, int stretch=1)
override void	Invalidate ()
override IQGraphicsLayoutItem	ItemAt (int index)
new double	ItemSpacing (int index)
override void	RemoveAt (int index)
new void	RemoveItem (IQGraphicsLayoutItem item)
new void	SetAlignment (IQGraphicsLayoutItem item, Qt.AlignmentFlag alignment)
new void	SetItemSpacing (int index, double spacing)
new void	SetStretchFactor (IQGraphicsLayoutItem item, int stretch)
new QSizeF	SizeHint (Qt.SizeHint which)
new int	StretchFactor (IQGraphicsLayoutItem item)
new void	Dispose ()
Public Member Functions inherited from QtGui.QGraphicsLayout
	QGraphicsLayout (IQGraphicsLayoutItem parent=null)
new void	Activate ()
override void	GetContentsMargins (ref double left, ref double top, ref double right, ref double bottom)
new bool	IsActivated ()
new void	SetContentsMargins (double left, double top, double right, double bottom)
override void	UpdateGeometry ()
virtual void	OnWidgetEvent (QEvent e)
new void	Dispose ()
Public Member Functions inherited from QtGui.QGraphicsLayoutItem
	QGraphicsLayoutItem (IQGraphicsLayoutItem parent=null, bool isLayout=false)
new QRectF	ContentsRect ()
new QSizeF	EffectiveSizeHint (Qt.SizeHint which)
new QSizeF	EffectiveSizeHint (Qt.SizeHint which, QSizeF constraint)
new IQGraphicsItem	GraphicsItem ()
new bool	IsLayout ()
new bool	OwnedByLayout ()
new void	SetMaximumSize (double w, double h)
new void	SetMinimumSize (double w, double h)
new void	SetPreferredSize (double w, double h)
new void	SetSizePolicy (QSizePolicy.Policy hPolicy, QSizePolicy.Policy vPolicy, QSizePolicy.ControlType controlType=QSizePolicy.ControlType.DefaultType)
new void	Dispose ()
Public Member Functions inherited from QtGui.IQGraphicsLayoutItem
new QRectF	ContentsRect ()
new QSizeF	EffectiveSizeHint (Qt.SizeHint which)
new QSizeF	EffectiveSizeHint (Qt.SizeHint which, QSizeF constraint)
void	GetContentsMargins (ref double left, ref double top, ref double right, ref double bottom)
new IQGraphicsItem	GraphicsItem ()
new bool	IsLayout ()
new bool	OwnedByLayout ()
new void	SetMaximumSize (double w, double h)
new void	SetMinimumSize (double w, double h)
new void	SetPreferredSize (double w, double h)
new void	SetSizePolicy (QSizePolicy.Policy hPolicy, QSizePolicy.Policy vPolicy, QSizePolicy.ControlType controlType=QSizePolicy.ControlType.DefaultType)
void	UpdateGeometry ()

Protected Member Functions
	QGraphicsLinearLayout (System.Type dummy)
override QSizeF	SizeHint (Qt.SizeHint which, QSizeF constraint)
Protected Member Functions inherited from QtGui.QGraphicsLayout
	QGraphicsLayout (System.Type dummy)
new void	AddChildLayoutItem (IQGraphicsLayoutItem layoutItem)
Protected Member Functions inherited from QtGui.QGraphicsLayoutItem
	QGraphicsLayoutItem (System.Type dummy)
new void	SetGraphicsItem (IQGraphicsItem item)
new void	SetOwnedByLayout (bool ownedByLayout)
new QSizeF	SizeHint (Qt.SizeHint which)

Properties
override QRectF	Geometry [get, set]
new Qt.Orientation	Orientation [get, set]
new double	Spacing [get, set]
Properties inherited from QtGui.QGraphicsLayout
static bool	InstantInvalidatePropagation [get, set]
Properties inherited from QtGui.QGraphicsLayoutItem
virtual QRectF	Geometry [get, set]
new double	MaximumHeight [get, set]
new QSizeF	MaximumSize [get, set]
new double	MaximumWidth [get, set]
new double	MinimumHeight [get, set]
new QSizeF	MinimumSize [get, set]
new double	MinimumWidth [get, set]
new IQGraphicsLayoutItem	ParentLayoutItem [get, set]
new double	PreferredHeight [get, set]
new QSizeF	PreferredSize [get, set]
new double	PreferredWidth [get, set]
new QSizePolicy	SizePolicy [get, set]
virtual System.IntPtr	SmokeObject [get, set]
Properties inherited from QtGui.IQGraphicsLayoutItem
QRectF	Geometry [get, set]
System.Double	MaximumHeight [get, set]
QSizeF	MaximumSize [get, set]
System.Double	MaximumWidth [get, set]
System.Double	MinimumHeight [get, set]
QSizeF	MinimumSize [get, set]
System.Double	MinimumWidth [get, set]
IQGraphicsLayoutItem	ParentLayoutItem [get, set]
System.Double	PreferredHeight [get, set]
QSizeF	PreferredSize [get, set]
System.Double	PreferredWidth [get, set]
QSizePolicy	SizePolicy [get, set]

Additional Inherited Members
Protected Attributes inherited from QtGui.QGraphicsLayoutItem
SmokeInvocation	interceptor

Detailed Description

The QGraphicsLinearLayout class provides a horizontal or vertical layout for managing widgets in Graphics View.

The default orientation for a linear layout is Qt::Horizontal. You can choose a vertical orientation either by calling setOrientation(), or by passing Qt::Vertical to QGraphicsLinearLayout's constructor.

The most common way to use QGraphicsLinearLayout is to construct an object on the heap with no parent, add widgets and layouts by calling addItem(), and finally assign the layout to a widget by calling QGraphicsWidget::setLayout().

QGraphicsScene scene;

QGraphicsWidget *textEdit = scene.addWidget(new QTextEdit);

QGraphicsWidget *pushButton = scene.addWidget(new QPushButton);

QGraphicsLinearLayout *layout = new QGraphicsLinearLayout;

layout->addItem(textEdit);

layout->addItem(pushButton);

QGraphicsWidget *form = new QGraphicsWidget;

form->setLayout(layout);

scene.addItem(form);

You can add widgets, layouts, stretches (addStretch(), insertStretch() or setStretchFactor()), and spacings (setItemSpacing()) to a linear layout. The layout takes ownership of the items. In some cases when the layout item also inherits from QGraphicsItem (such as QGraphicsWidget) there will be a ambiguity in ownership because the layout item belongs to two ownership hierarchies. See the documentation of QGraphicsLayoutItem::setOwnedByLayout() how to handle this. You can access each item in the layout by calling count() and itemAt(). Calling removeAt() or removeItem() will remove an item from the layout, without destroying it.

Size Hints and Size Policies in QGraphicsLinearLayout

QGraphicsLinearLayout respects each item's size hints and size policies, and when the layout contains more space than the items can fill, each item is arranged according to the layout's alignment for that item. You can set an alignment for each item by calling setAlignment(), and check the alignment for any item by calling alignment(). By default, items are aligned to the top left.

Spacing within QGraphicsLinearLayout

Between the items, the layout distributes some space. The actual amount of space depends on the managed widget's current style, but the common spacing is 4. You can also set your own spacing by calling setSpacing(), and get the current spacing value by calling spacing(). If you want to configure individual spacing for your items, you can call setItemSpacing().

Stretch Factor in QGraphicsLinearLayout

You can assign a stretch factor to each item to control how much space it will get compared to the other items. By default, two identical widgets arranged in a linear layout will have the same size, but if the first widget has a stretch factor of 1 and the second widget has a stretch factor of 2, the first widget will get 1/3 of the available space, and the second will get 2/3.

QGraphicsLinearLayout calculates the distribution of sizes by adding up the stretch factors of all items, and then dividing the available space accordingly. The default stretch factor is 0 for all items; a factor of 0 means the item does not have any defined stretch factor; effectively this is the same as setting the stretch factor to 1. The stretch factor only applies to the available space in the lengthwise direction of the layout (following its orientation). If you want to control both the item's horizontal and vertical stretch, you can use QGraphicsGridLayout instead.

QGraphicsLinearLayout Compared to Other Layouts

QGraphicsLinearLayout is very similar to QVBoxLayout and QHBoxLayout, but in contrast to these classes, it is used to manage QGraphicsWidget and QGraphicsLayout instead of QWidget and QLayout.

See also QGraphicsGridLayout and QGraphicsWidget.

Constructor & Destructor Documentation

QtGui.QGraphicsLinearLayout.QGraphicsLinearLayout ( System.Type  dummy )

protected

QtGui.QGraphicsLinearLayout.QGraphicsLinearLayout

(

IQGraphicsLayoutItem

parent = null

)

Constructs a QGraphicsLinearLayout instance using Qt::Horizontal orientation. parent is passed to QGraphicsLayout's constructor.

QtGui.QGraphicsLinearLayout.QGraphicsLinearLayout	(	Qt.Orientation	orientation,
		IQGraphicsLayoutItem	parent = null
	)

Constructs a QGraphicsLinearLayout instance. You can pass the orientation for the layout, either horizontal or vertical, and parent is passed to QGraphicsLayout's constructor.

Member Function Documentation

new void QtGui.QGraphicsLinearLayout.AddItem

(

IQGraphicsLayoutItem

item

)

This convenience function is equivalent to calling insertItem(-1, item).

new void QtGui.QGraphicsLinearLayout.AddStretch

(

int

stretch = 1

)

This convenience function is equivalent to calling insertStretch(-1, stretch).

new Qt.AlignmentFlag QtGui.QGraphicsLinearLayout.Alignment

(

IQGraphicsLayoutItem

item

)

Returns the alignment for item. The default alignment is Qt::AlignTop | Qt::AlignLeft.

The alignment decides how the item is positioned within its assigned space in the case where there's more space available in the layout than the widgets can occupy.

See also setAlignment().

override int QtGui.QGraphicsLinearLayout.Count ( )

virtual

Reimplemented from QGraphicsLayout::count().

Implements QtGui.QGraphicsLayout.

override void QtGui.QGraphicsLinearLayout.CreateProxy ( )

virtual

Reimplemented from QtGui.QGraphicsLayout.

new void QtGui.QGraphicsLinearLayout.Dispose

(

)

new void QtGui.QGraphicsLinearLayout.Dump

(

int

indent = 0

)

new void QtGui.QGraphicsLinearLayout.InsertItem	(	int	index,
		IQGraphicsLayoutItem	item
	)

Inserts item into the layout at index, or before any item that is currently at index.

See also addItem(), itemAt(), insertStretch(), and setItemSpacing().

new void QtGui.QGraphicsLinearLayout.InsertStretch	(	int	index,
		int	stretch = 1
	)

Inserts a stretch of stretch at index, or before any item that is currently at index.

See also addStretch(), setStretchFactor(), setItemSpacing(), and insertItem().

override void QtGui.QGraphicsLinearLayout.Invalidate ( )

virtual

Reimplemented from QGraphicsLayout::invalidate().

Reimplemented from QtGui.QGraphicsLayout.

override IQGraphicsLayoutItem QtGui.QGraphicsLinearLayout.ItemAt ( int  index )

virtual

Reimplemented from QGraphicsLayout::itemAt().

When iterating from 0 and up, it will return the items in the visual arranged order.

Implements QtGui.QGraphicsLayout.

new double QtGui.QGraphicsLinearLayout.ItemSpacing

(

int

index

)

Returns the spacing after item at index.

See also setItemSpacing().

override void QtGui.QGraphicsLinearLayout.RemoveAt ( int  index )

virtual

Reimplemented from QGraphicsLayout::removeAt().

Removes the item at index without destroying it. Ownership of the item is transferred to the caller.

See also removeItem() and insertItem().

Implements QtGui.QGraphicsLayout.

new void QtGui.QGraphicsLinearLayout.RemoveItem

(

IQGraphicsLayoutItem

item

)

Removes item from the layout without destroying it. Ownership of item is transferred to the caller.

See also removeAt() and insertItem().

new void QtGui.QGraphicsLinearLayout.SetAlignment	(	IQGraphicsLayoutItem	item,
		Qt.AlignmentFlag	alignment
	)

Sets the alignment of item to alignment. If item's alignment changes, the layout is automatically invalidated.

See also alignment() and invalidate().

new void QtGui.QGraphicsLinearLayout.SetItemSpacing	(	int	index,
		double	spacing
	)

Sets the spacing after item at index to spacing.

See also itemSpacing().

new void QtGui.QGraphicsLinearLayout.SetStretchFactor	(	IQGraphicsLayoutItem	item,
		int	stretch
	)

Sets the stretch factor for item to stretch. If an item's stretch factor changes, this function will invalidate the layout.

Setting stretch to 0 removes the stretch factor from the item, and is effectively equivalent to setting stretch to 1.

See also stretchFactor().

new QSizeF QtGui.QGraphicsLinearLayout.SizeHint

(

Qt.SizeHint

which

)

Reimplemented from QGraphicsLayoutItem::sizeHint().

override QSizeF QtGui.QGraphicsLinearLayout.SizeHint ( Qt.SizeHint  which, QSizeF  constraint  )

protectedvirtual

Reimplemented from QGraphicsLayoutItem::sizeHint().

Implements QtGui.QGraphicsLayoutItem.

new int QtGui.QGraphicsLinearLayout.StretchFactor

(

IQGraphicsLayoutItem

item

)

Returns the stretch factor for item. The default stretch factor is 0, meaning that the item has no assigned stretch factor.

See also setStretchFactor().

Property Documentation

override QRectF QtGui.QGraphicsLinearLayout.Geometry

getset

Reimplemented from QGraphicsLayoutItem::setGeometry().

new Qt.Orientation QtGui.QGraphicsLinearLayout.Orientation

getset

Returns the layout orientation.

Change the layout orientation to orientation. Changing the layout orientation will automatically invalidate the layout.

new double QtGui.QGraphicsLinearLayout.Spacing

getset

Returns the layout's spacing. Spacing refers to the vertical and horizontal distances between items.

Sets the layout's spacing to spacing. Spacing refers to the vertical and horizontal distances between items.