Class View

Namespace

Xui.Core.UI

Assembly

Core.dll

Base class for all UI elements in the Xui layout engine. A view participates in layout, rendering, and input hit testing, and may contain child views.

public abstract class View

Inheritance

object

View

Derived

Border

Label

ViewCollection

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Properties

Count

Returns the number of child views. Used by layout containers and traversal logic. Leaf views should return 0.

public virtual int Count { get; }

Property Value

int

Direction

The writing direction of this view, which determines the block or inline flow direction. Inherited from the parent flow context if set to Inherit.

public Direction Direction { get; set; }

Property Value

Direction

Flow

Controls how the layout system treats this view's children. Can be inherited or explicitly overridden for advanced layout containers.

public Flow Flow { get; set; }

Property Value

Flow

Frame

The border edge of this view in global coordinates relative to the top-left of the window.

public Rect Frame { get; protected set; }

Property Value

Rect

HorizontalAlignment

The horizontal alignment of this view inside its layout anchor region. Used during layout when the view has remaining space within its container.

public HorizontalAlignment HorizontalAlignment { get; set; }

Property Value

HorizontalAlignment

this[int]

Indexer to access child views by index. Layout containers should implement this to expose their children.

public virtual View this[int index] { get; }

Parameters

index int

Property Value

View

Margin

The margin around this view. Margins participate in collapsed margin logic during layout, and are external spacing relative to the parent or surrounding siblings.

public Frame Margin { get; set; }

Property Value

Frame

MaximumHeight

The maximum height of the border edge box.

public NFloat MaximumHeight { get; set; }

Property Value

NFloat

MaximumWidth

The maximum width of the border edge box.

public NFloat MaximumWidth { get; set; }

Property Value

NFloat

MinimumHeight

The minimum height of the border edge box.

public NFloat MinimumHeight { get; set; }

Property Value

NFloat

MinimumWidth

The minimum width of the border edge box.

public NFloat MinimumWidth { get; set; }

Property Value

NFloat

Parent

The parent view in the visual hierarchy. This is set automatically when the view is added to a container.

public View? Parent { get; }

Property Value

View

VerticalAlignment

The vertical alignment of this view inside its layout anchor region. Used during layout when the view has remaining space within its container.

public VerticalAlignment VerticalAlignment { get; set; }

Property Value

VerticalAlignment

WritingMode

The writing mode of this view (e.g. horizontal top-to-bottom or vertical right-to-left). Inherited from the parent if set to Inherit.

public WritingMode WritingMode { get; set; }

Property Value

WritingMode

Methods

Arrange(Rect, IMeasureContext)

Arranges the view within the specified rectangle, finalizing its layout position and size.

public Rect Arrange(Rect rect, IMeasureContext context)

Parameters

rect Rect

The rectangle defining the position and exact size for the view.

context IMeasureContext

Returns

Rect

The rectangle occupied by the arranged view.

ArrangeCore(Rect, IMeasureContext)

Performs the layout pass by arranging content and children within the view's border edge box, using the provided rectangle.

protected virtual void ArrangeCore(Rect rect, IMeasureContext context)

Parameters

rect Rect

The final rectangle (position and size) allocated to this view's border edge box.

context IMeasureContext

The layout metrics context providing access to platform-specific measurements, text sizing, and pixel snapping utilities.

HitTest(Point)

Determines whether the given point (in local coordinates) hits this view’s visual bounds. Used for input dispatch and hit testing.

public virtual bool HitTest(Point point)

Parameters

point Point

The point to test, relative to this view’s coordinate space.

Returns

bool

true if the point is inside the view’s frame; otherwise false.

Measure(Size, IMeasureContext)

Measures the view using the specified available size, returning the desired size calculated during the layout pass.

public Size Measure(Size availableSize, IMeasureContext context)

Parameters

availableSize Size

The maximum space available for the view to occupy.

context IMeasureContext

Returns

Size

The size that the view desires to occupy within the constraints.

MeasureCore(Size, IMeasureContext)

Determines the minimum size that this view's border edge box requires, given the maximum available size. Margin is not part of this size.

protected virtual Size MeasureCore(Size availableBorderEdgeSize, IMeasureContext context)

Parameters

availableBorderEdgeSize Size

The maximum size available for the view’s border edge box. This size excludes margins, which are handled by the parent layout.

context IMeasureContext

The layout metrics context providing access to platform-specific measurements, text sizing, and pixel snapping utilities.

Returns

Size

The desired size of the border edge box based on content and layout logic.

RaisePointerEvent(ref PointerEventRef, EventPhase)

Called during event dispatch to handle a pointer event in a specific event phase.

public virtual void RaisePointerEvent(ref PointerEventRef e, EventPhase phase)

Parameters

e PointerEventRef

phase EventPhase

Render(IContext)

Renders the view using the given rendering context. This should be called after layout is complete.

public void Render(IContext context)

Parameters

context IContext

The rendering context used to draw the view.

RenderCore(IContext)

Renders the content and children of this view using the provided rendering context.

protected virtual void RenderCore(IContext context)

Parameters

context IContext

The drawing context used for rendering visual content to the output surface.

Update(LayoutGuide)

Performs a full layout pass for a view - measure, arrange and render.

Flags can limit to a subset of the layout passes, in case a container needs to measure children multiple times, or in case a container can rush forward without forking the layout pass into multiple sub-passes.

The layout method will delegate parts of the execution to MeasureCore(Size, IMeasureContext), ArrangeCore(Rect, IMeasureContext) and RenderCore(IContext).

If a container needs to call multiple times methods for a child, either call the Measure(Size, IMeasureContext), Arrange(Rect, IMeasureContext) and Render(IContext), or construct a LayoutGuide with the specific flags and pass it to Update(LayoutGuide).

Some containers may override and implement a Layout in a way, that it compacts the flow and avoids fork, like a VerticalStack that is placed on fullscreen (with fixed width), can arrange children top to bottom calling their Layout directly - eventually going foreach-layout without splitting into foreach-measure, foreach-arrange cycles. VerticalStack however, when centered, while it can layout children vertically in a single pass, it can't render, because it needs its height to figure out its position, so in these cases it may foreach-layout (measure and arrange) resolve the stack Y position and then foreach-layout (for render).

public virtual LayoutGuide Update(LayoutGuide guide)

Parameters

guide LayoutGuide

Returns

LayoutGuide