Class LayoutItem

Definition

Namespace:

Tizen.NUI

Assembly:

Tizen.NUI.dll

Base class for layouts. It is used to layout a View It can be laid out by a LayoutGroup.

public class LayoutItem : IDisposable

Inheritance

object

LayoutItem

Derived

LayoutGroup

LayoutGroup

Implements

System.IDisposable

Constructors

LayoutItem()

Default constructor of LayoutItem class.

Declaration

public LayoutItem()

Properties

Margin

Margin for this LayoutItem

Declaration

public Extents Margin { get; set; }

Property Value

Type	Description
Extents

MeasuredHeight

Get the measured height (without any measurement flags).
This method should be used only during measurement and layout calculations.

Declaration

public MeasuredSize MeasuredHeight { get; set; }

Property Value

Type	Description
MeasuredSize

MeasuredWidth

Get the measured width (without any measurement flags).
This method should be used only during measurement and layout calculations.

Declaration

public MeasuredSize MeasuredWidth { get; set; }

Property Value

Type	Description
MeasuredSize

Owner

The View that this Layout has been assigned to.

Declaration

public View Owner { get; set; }

Property Value

Type	Description
View

Padding

Padding for this LayoutItem

Declaration

public Extents Padding { get; set; }

Property Value

Type	Description
Extents

SuggestedMinimumHeight

Returns the suggested minimum height that the layout should use.
This returns the maximum of the layout's minimum height and the owner's natural height.

Declaration

public LayoutLength SuggestedMinimumHeight { get; }

Property Value

Type	Description
LayoutLength

SuggestedMinimumWidth

Returns the suggested minimum width that the layout should use.
This returns the maximum of the layout's minimum width and the owner's natural width.

Declaration

public LayoutLength SuggestedMinimumWidth { get; }

Property Value

Type	Description
LayoutLength

Methods

GetDefaultSize(LayoutLength, MeasureSpecification)

Utility to return a default size.
Uses the supplied size if the MeasureSpecification imposed no constraints. Will get larger if allowed by the MeasureSpecification.

Declaration

public static LayoutLength GetDefaultSize(LayoutLength size, MeasureSpecification measureSpecification)

Parameters

Type	Name	Description
LayoutLength	size	Default size for this layout.
MeasureSpecification	measureSpecification	Constraints imposed by the parent.

Returns

Type	Description
LayoutLength	The size this layout should be.

GetParent()

Get the Layouts parent

Declaration

public ILayoutParent GetParent()

Returns

Type	Description
ILayoutParent	Layout parent with an LayoutParent interface

Layout(LayoutLength, LayoutLength, LayoutLength, LayoutLength)

Assign a size and position to a layout and all of its descendants.
This is the second phase of the layout mechanism. (The first is measuring). In this phase, each parent calls layout on all of its children to position them. This is typically done using the child
measurements that were stored in the measure pass.

Declaration

public void Layout(LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)

Parameters

Type	Name	Description
LayoutLength	left	Left position, relative to parent.
LayoutLength	top	Top position, relative to parent.
LayoutLength	right	Right position, relative to parent.
LayoutLength	bottom	Bottom position, relative to parent.

Measure(MeasureSpecification, MeasureSpecification)

This is called to find out how big a layout should be.
The parent supplies constraint information in the width and height parameters.
The actual measurement work of a layout is performed in OnMeasure called by this method. Therefore, only OnMeasure can and must be overridden by subclasses.

Declaration

public void Measure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)

Parameters

Type	Name	Description
MeasureSpecification	widthMeasureSpec	Horizontal space requirements as imposed by the parent.
MeasureSpecification	heightMeasureSpec	Vertical space requirements as imposed by the parent.

OnAttachedToOwner()

Virtual method called when this Layout is attached to it's owner. Allows derived layouts to take ownership of child Views and connect to any Owner signals required.

Declaration

protected virtual void OnAttachedToOwner()

OnLayout(bool, LayoutLength, LayoutLength, LayoutLength, LayoutLength)

Called from Layout() when this layout should assign a size and position to each of its children.
Derived classes with children should override this method and call Layout() on each of their children.

Declaration

protected virtual void OnLayout(bool changed, LayoutLength left, LayoutLength top, LayoutLength right, LayoutLength bottom)

Parameters

Type	Name	Description
bool	changed	This is a new size or position for this layout.
LayoutLength	left	Left position, relative to parent.
LayoutLength	top	Top position, relative to parent.
LayoutLength	right	Right position, relative to parent.
LayoutLength	bottom	Bottom position, relative to parent.

OnMeasure(MeasureSpecification, MeasureSpecification)

Measure the layout and its content to determine the measured width and the measured height.
The base class implementation of measure defaults to the background size, unless a larger size is allowed by the MeasureSpec. Subclasses should override to provide better measurements of their content.
If this method is overridden, it is the subclass's responsibility to make sure the measured height and width are at least the layout's minimum height and width.

Declaration

protected virtual void OnMeasure(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)

Parameters

Type	Name	Description
MeasureSpecification	widthMeasureSpec	horizontal space requirements as imposed by the parent.
MeasureSpecification	heightMeasureSpec	vertical space requirements as imposed by the parent.

OnUnparent()

Virtual method to allow derived classes to remove any children before it is removed from its parent.

Declaration

protected virtual void OnUnparent()

RequestLayout()

Request that this layout is re-laid out.
This will make this layout and all it's parent layouts dirty.

Declaration

public void RequestLayout()

ResolveSizeAndState(LayoutLength, MeasureSpecification, StateType)

Utility to reconcile a desired size and state, with constraints imposed by a MeasureSpecification.

Declaration

protected MeasuredSize ResolveSizeAndState(LayoutLength size, MeasureSpecification measureSpecification, MeasuredSize.StateType childMeasuredState)

Parameters

Type	Name	Description
LayoutLength	size	How big the layout wants to be.
MeasureSpecification	measureSpecification	Constraints imposed by the parent.
MeasuredSize.StateType	childMeasuredState	Size information bit mask for the layout's children.

Returns

Type	Description
MeasuredSize	A measured size, which may indicate that it is too small.

SetMeasuredDimensions(MeasuredSize, MeasuredSize)

This method must be called by OnMeasure(MeasureSpec,MeasureSpec) to store the measured width and measured height.

Declaration

protected void SetMeasuredDimensions(MeasuredSize measuredWidth, MeasuredSize measuredHeight)

Parameters

Type	Name	Description
MeasuredSize	measuredWidth	The measured width of this layout.
MeasuredSize	measuredHeight	The measured height of this layout.

Implements

System.IDisposable