ReactShadowNode (ReactAndroid 0.20.1 API)

java.lang.Object
- com.facebook.csslayout.CSSNode
- - com.facebook.react.uimanager.ReactShadowNode

Direct Known Subclasses:

ARTVirtualNode, LayoutShadowNode
```
public class ReactShadowNode
extends CSSNode
```
Base node class for representing virtual tree of React nodes. Shadow nodes are used primarily for layouting therefore it extends CSSNode to allow that. They also help with handling Common base subclass of CSSNode for all layout nodes for react-based view. It extends CSSNode by adding additional capabilities. Instances of this class receive property updates from JS via @{link UIManagerModule}. Subclasses may use #updateShadowNode to persist some of the updated fields in the node instance that corresponds to a particular view type. Subclasses of ReactShadowNode should be created only from ViewManager that corresponds to a certain type of native view. They will be updated and accessed only from JS thread. Subclasses of ViewManager may choose to use base class ReactShadowNode or custom subclass of it if necessary. The primary use-case for ReactShadowNode nodes is to calculate layouting. Although this might be extended. For some examples please refer to ARTGroupCSSNode or ReactTextCSSNode. This class allows for the native view hierarchy to not be an exact copy of the hierarchy received from JS by keeping track of both JS children (e.g. CSSNode.getChildCount() and separately native children (e.g. getNativeChildCount()). See NativeViewHierarchyOptimizer for more information.

Nested Class Summary
- Nested classes/interfaces inherited from class com.facebook.csslayout.CSSNode
  CSSNode.MeasureFunction

Field Summary
- Fields inherited from class com.facebook.csslayout.CSSNode
  lineIndex

Constructor Summary

Constructors
Constructor and Description

ReactShadowNode()

Constructors
Constructor and Description
`ReactShadowNode()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addChildAt(CSSNode child, int i)`
`void`	`addNativeChildAt(ReactShadowNode child, int nativeIndex)` Adds a child that the native view hierarchy will have at this index in the native view corresponding to this node.
`protected void`	`dirty()`
`ReactShadowNode`	`getChildAt(int i)`
`int`	`getNativeChildCount()`
`int`	`getNativeOffsetForChild(ReactShadowNode child)` Returns the offset within the native children owned by all layout-only nodes in the subtree rooted at this node for the given child.
`ReactShadowNode`	`getNativeParent()`
`ReactShadowNode`	`getParent()`
`int`	`getReactTag()`
`ReactShadowNode`	`getRootNode()`
`int`	`getScreenHeight()`
`int`	`getScreenWidth()`
`int`	`getScreenX()`
`int`	`getScreenY()`
`ThemedReactContext`	`getThemedContext()` Get the `ThemedReactContext` associated with this `ReactShadowNode`.
`int`	`getTotalNativeChildren()`
`java.lang.String`	`getViewClass()`
`boolean`	`hasUpdates()`
`int`	`indexOfNativeChild(ReactShadowNode nativeChild)`
`boolean`	`isLayoutOnly()`
`boolean`	`isVirtual()` Nodes that return `true` will be treated as "virtual" nodes.
`boolean`	`isVirtualAnchor()` Nodes that return `true` will be treated as a root view for the virtual nodes tree.
`protected void`	`markUpdated()`
`void`	`markUpdateSeen()`
`void`	`onAfterUpdateTransaction()`
`void`	`onBeforeLayout()` This method will be called by `UIManagerModule` once per batch, before calculating layout.
`void`	`onCollectExtraUpdates(UIViewOperationQueue uiViewOperationQueue)` Called after layout step at the end of the UI batch from `UIManagerModule`.
`void`	`removeAllChildren()`
`void`	`removeAllNativeChildren()`
`ReactShadowNode`	`removeChildAt(int i)`
`ReactShadowNode`	`removeNativeChildAt(int i)`
`void`	`setIsLayoutOnly(boolean isLayoutOnly)` Sets whether this node only contributes to the layout of its children without doing any drawing or functionality itself.
`void`	`setShouldNotifyOnLayout(boolean shouldNotifyOnLayout)`
`void`	`setThemedContext(ThemedReactContext themedContext)`
`boolean`	`shouldNotifyOnLayout()`
`void`	`updateProperties(ReactStylesDiffMap props)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - ReactShadowNode
```
public ReactShadowNode()
```
- Method Detail
  - isVirtual
```
public boolean isVirtual()
```
    Nodes that return true will be treated as "virtual" nodes. That is, nodes that are not mapped into native views (e.g. nested text node). By default this method returns false.
  - isVirtualAnchor
```
public boolean isVirtualAnchor()
```
    Nodes that return true will be treated as a root view for the virtual nodes tree. It means that NativeViewHierarchyManager will not try to perform manageChildren operation on such views. Good example is InputText view that may have children Text nodes but this whole hierarchy will be mapped to a single android EditText view.
  - getViewClass
```
public final java.lang.String getViewClass()
```
  - hasUpdates
```
public final boolean hasUpdates()
```
  - markUpdateSeen
```
public final void markUpdateSeen()
```
  - markUpdated
```
protected void markUpdated()
```
  - dirty
```
protected void dirty()
```
    Overrides:
    
    dirty in class CSSNode
  - addChildAt
```
public void addChildAt(CSSNode child,
              int i)
```
    Overrides:
    
    addChildAt in class CSSNode
  - removeChildAt
```
public ReactShadowNode removeChildAt(int i)
```
    Overrides:
    
    removeChildAt in class CSSNode
  - removeAllChildren
```
public void removeAllChildren()
```
  - onBeforeLayout
```
public void onBeforeLayout()
```
    This method will be called by UIManagerModule once per batch, before calculating layout. Will be only called for nodes that are marked as updated with markUpdated() or require layouting (marked with dirty()).
  - updateProperties
```
public final void updateProperties(ReactStylesDiffMap props)
```
  - onAfterUpdateTransaction
```
public void onAfterUpdateTransaction()
```
  - onCollectExtraUpdates
```
public void onCollectExtraUpdates(UIViewOperationQueue uiViewOperationQueue)
```
    Called after layout step at the end of the UI batch from UIManagerModule. May be used to enqueue additional ui operations for the native view. Will only be called on nodes marked as updated either with dirty() or markUpdated().
    
    Parameters:
    uiViewOperationQueue - interface for enqueueing UI operations
  - getReactTag
```
public final int getReactTag()
```
  - getRootNode
```
public final ReactShadowNode getRootNode()
```
  - getChildAt
```
public final ReactShadowNode getChildAt(int i)
```
    Overrides:
    
    getChildAt in class CSSNode
  - getParent
```
@Nullable
public final ReactShadowNode getParent()
```
    Overrides:
    
    getParent in class CSSNode
  - getThemedContext
```
public ThemedReactContext getThemedContext()
```
    Get the ThemedReactContext associated with this ReactShadowNode. This will never change during the lifetime of a ReactShadowNode instance, but different instances can have different contexts; don't cache any calculations based on theme values globally.
  - setThemedContext
```
public void setThemedContext(ThemedReactContext themedContext)
```
  - setShouldNotifyOnLayout
```
public void setShouldNotifyOnLayout(boolean shouldNotifyOnLayout)
```
  - shouldNotifyOnLayout
```
public boolean shouldNotifyOnLayout()
```
  - addNativeChildAt
```
public void addNativeChildAt(ReactShadowNode child,
                    int nativeIndex)
```
    Adds a child that the native view hierarchy will have at this index in the native view corresponding to this node.
  - removeNativeChildAt
```
public ReactShadowNode removeNativeChildAt(int i)
```
  - removeAllNativeChildren
```
public void removeAllNativeChildren()
```
  - getNativeChildCount
```
public int getNativeChildCount()
```
  - indexOfNativeChild
```
public int indexOfNativeChild(ReactShadowNode nativeChild)
```
  - getNativeParent
```
@Nullable
public ReactShadowNode getNativeParent()
```
  - setIsLayoutOnly
```
public void setIsLayoutOnly(boolean isLayoutOnly)
```
    Sets whether this node only contributes to the layout of its children without doing any drawing or functionality itself.
  - isLayoutOnly
```
public boolean isLayoutOnly()
```
  - getTotalNativeChildren
```
public int getTotalNativeChildren()
```
  - getNativeOffsetForChild
```
public int getNativeOffsetForChild(ReactShadowNode child)
```
    Returns the offset within the native children owned by all layout-only nodes in the subtree rooted at this node for the given child. Put another way, this returns the number of native nodes (nodes not optimized out of the native tree) that are a) to the left (visited before by a DFS) of the given child in the subtree rooted at this node and b) do not have a native parent in this subtree (which means that the given child will be a sibling of theirs in the final native hierarchy since they'll get attached to the same native parent). Basically, a view might have children that have been optimized away by NativeViewHierarchyOptimizer. Since those children will then add their native children to this view, we now have ranges of native children that correspond to single unoptimized children. The purpose of this method is to return the index within the native children that corresponds to the **start** of the native children that belong to the given child. Also, note that all of the children of a view might be optimized away, so this could return the same value for multiple different children. Example. Native children are represented by (N) where N is the no-opt child they came from. If no children are optimized away it'd look like this: (0) (1) (2) (3) ... (n) In case some children are optimized away, it might look like this: (0) (1) (1) (1) (3) (3) (4) In that case: getNativeOffsetForChild(Node 0) => 0 getNativeOffsetForChild(Node 1) => 1 getNativeOffsetForChild(Node 2) => 4 getNativeOffsetForChild(Node 3) => 4 getNativeOffsetForChild(Node 4) => 6
  - getScreenX
```
public int getScreenX()
```
    Returns:
    the x position of the corresponding view on the screen, rounded to pixels
  - getScreenY
```
public int getScreenY()
```
    Returns:
    the y position of the corresponding view on the screen, rounded to pixels
  - getScreenWidth
```
public int getScreenWidth()
```
    Returns:
    width corrected for rounding to pixels.
  - getScreenHeight
```
public int getScreenHeight()
```
    Returns:
    height corrected for rounding to pixels.

Class ReactShadowNode

Nested Class Summary

Nested classes/interfaces inherited from class com.facebook.csslayout.CSSNode

Field Summary

Fields inherited from class com.facebook.csslayout.CSSNode

Constructor Summary

Method Summary

Methods inherited from class com.facebook.csslayout.CSSNode

Methods inherited from class java.lang.Object

Constructor Detail

ReactShadowNode

Method Detail

isVirtual

isVirtualAnchor

getViewClass

hasUpdates

markUpdateSeen

markUpdated

dirty

addChildAt

removeChildAt

removeAllChildren

onBeforeLayout

updateProperties

onAfterUpdateTransaction

onCollectExtraUpdates

getReactTag

getRootNode

getChildAt

getParent

getThemedContext

setThemedContext

setShouldNotifyOnLayout

shouldNotifyOnLayout

addNativeChildAt

removeNativeChildAt

removeAllNativeChildren

getNativeChildCount

indexOfNativeChild

getNativeParent

setIsLayoutOnly

isLayoutOnly

getTotalNativeChildren

getNativeOffsetForChild

getScreenX

getScreenY

getScreenWidth

getScreenHeight