com.facebook.rendercore

Class Node

java.lang.Object

com.facebook.rendercore.Node

All Implemented Interfaces:

Copyable, Cloneable

Direct Known Subclasses:

DefaultInternalNode

public abstract class Node
extends Object
implements Copyable

Represents a single node in a RenderCore Tree. A Node has children, base layout information, and whether it needs to be rendered.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Node.Container<T extends Node> Interface to be implemented by a Node with children.
static interface	Node.LayoutResult<T> Represents the result of a Layout pass.

Constructor Summary

Constructors

Constructor and Description
Node()

Method Summary

Modifier and Type	Method and Description
abstract Node.LayoutResult	calculateLayout(RenderState.LayoutContext context, int widthSpec, int heightSpec) Implementations of Node are responsible to calculate a layout based on the width/height constraints provided.
Copyable	getLayoutParams()
RenderUnit	getRenderUnit()
Node	makeCopy()
void	setLayoutParams(Copyable layoutParams)
void	setRenderUnit(RenderUnit content)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Node

public Node()

Method Detail

getRenderUnit

public final RenderUnit getRenderUnit()

Returns:

a RenderUnit that represents the rendering content of this Node.

setRenderUnit

public final void setRenderUnit(RenderUnit content)

calculateLayout

public abstract Node.LayoutResult calculateLayout(RenderState.LayoutContext context,
                                                  int widthSpec,
                                                  int heightSpec)

Implementations of Node are responsible to calculate a layout based on the width/height constraints provided. A Node could decide to implement its own layout function or to delegate to its RenderUnit measure.

The general contract is:
• - A Node must call calculateLayout on each child (if it has any) at least once, even if the Node is going to assign that child an exact size -- this gives a chance for children to lay out their own children and produce artifacts like text layouts.
• - If a Node calls layout on a child with flexible specs (UNSPECIFIED or AT_MOST) to get sizing information, but ultimately decides to assign that child a different size than the child returned, the Node must call calculateLayout again on that child with a mode of EXACTLY to enforce the assigned size.

Parameters:

context - The LayoutContext associated with this layout calculation RenderState.LayoutContext

widthSpec - a measure spec for the width in the format of View.MeasureSpec

heightSpec - a measure spec for the height in the format of View.MeasureSpec

getLayoutParams

public Copyable getLayoutParams()

setLayoutParams

public void setLayoutParams(Copyable layoutParams)

makeCopy

public Node makeCopy()

Specified by:

makeCopy in interface Copyable