com.facebook.react.uimanager

Class ViewManager<T extends android.view.View,C extends ReactShadowNode>

java.lang.Object

com.facebook.react.uimanager.ViewManager<T,C>

Direct Known Subclasses:

ReactProgressBarViewManager, ReactTextInputManager, ReactTextViewManager, SimpleViewManager, ViewGroupManager

public abstract class ViewManager<T extends android.view.View,C extends ReactShadowNode>
extends java.lang.Object

Class responsible for knowing how to create and update catalyst Views of a given type. It is also responsible for creating and updating CSSNode subclasses used for calculating position and size for the corresponding native view.

Constructor Summary

Constructors

Constructor and Description
ViewManager()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	addEventEmitters(ThemedReactContext reactContext, T view) Subclasses can override this method to install custom event emitters on the given View.
abstract C	createCSSNodeInstance() This method should return a subclass of CSSNode which will be then used for measuring position and size of the view.
T	createView(ThemedReactContext reactContext, JSResponderHandler jsResponderHandler) Creates a view and installs event emitters on it.
protected abstract T	createViewInstance(ThemedReactContext reactContext) Subclasses should return a new View instance of the proper type.
java.util.Map<java.lang.String,java.lang.Integer>	getCommandsMap() Subclasses of ViewManager that expect to receive commands through UIManagerModule.dispatchViewManagerCommand(int, int, com.facebook.react.bridge.ReadableArray) should override this method returning the map between names of the commands and IDs that are then used in receiveCommand(T, int, com.facebook.react.bridge.ReadableArray) method whenever the command is dispatched for this particular ViewManager.
java.util.Map<java.lang.String,java.lang.Object>	getExportedCustomBubblingEventTypeConstants() Returns a map of config data passed to JS that defines eligible events that can be placed on native views.
java.util.Map<java.lang.String,java.lang.Object>	getExportedCustomDirectEventTypeConstants() Returns a map of config data passed to JS that defines eligible events that can be placed on native views.
java.util.Map<java.lang.String,java.lang.Object>	getExportedViewConstants() Returns a map of view-specific constants that are injected to JavaScript.
abstract java.lang.String	getName()
java.util.Map<java.lang.String,UIProp.Type>	getNativeProps()
void	onDropViewInstance(ThemedReactContext reactContext, T view) Called when view is detached from view hierarchy and allows for some additional cleanup by the ViewManager subclass.
void	receiveCommand(T root, int commandId, ReadableArray args) Subclasses may use this method to receive events/commands directly from JS through the UIManager.
abstract void	updateExtraData(T root, java.lang.Object extraData) Subclasses can implement this method to receive an optional extra data enqueued from the corresponding instance of ReactShadowNode in ReactShadowNode.onCollectExtraUpdates(com.facebook.react.uimanager.UIViewOperationQueue).
abstract void	updateView(T root, CatalystStylesDiffMap props) Subclass should use this method to populate native view with updated style properties.

Methods inherited from class java.lang.Object

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

Constructor Detail

ViewManager

public ViewManager()

Method Detail

createView

public final T createView(ThemedReactContext reactContext,
           JSResponderHandler jsResponderHandler)

Creates a view and installs event emitters on it.

getName

public abstract java.lang.String getName()

Returns:

the name of this view manager. This will be the name used to reference this view manager from JavaScript in createReactIOSNativeComponentClass.

createCSSNodeInstance

public abstract C createCSSNodeInstance()

This method should return a subclass of CSSNode which will be then used for measuring position and size of the view. In mose of the cases this should just return an instance of CSSNode

createViewInstance

protected abstract T createViewInstance(ThemedReactContext reactContext)

Subclasses should return a new View instance of the proper type.

Parameters:

reactContext -

onDropViewInstance

public void onDropViewInstance(ThemedReactContext reactContext,
                      T view)

Called when view is detached from view hierarchy and allows for some additional cleanup by the ViewManager subclass.

addEventEmitters

protected void addEventEmitters(ThemedReactContext reactContext,
                    T view)

Subclasses can override this method to install custom event emitters on the given View. You might want to override this method if your view needs to emit events besides basic touch events to JS (e.g. scroll events).

updateView

public abstract void updateView(T root,
              CatalystStylesDiffMap props)

Subclass should use this method to populate native view with updated style properties. In case when a certain property is present in map but the value is null, this property should be reset to the default value

updateExtraData

public abstract void updateExtraData(T root,
                   java.lang.Object extraData)

Subclasses can implement this method to receive an optional extra data enqueued from the corresponding instance of ReactShadowNode in ReactShadowNode.onCollectExtraUpdates(com.facebook.react.uimanager.UIViewOperationQueue). Since css layout step and ui updates can be executed in separate thread apart of setting x/y/width/height this is the recommended and thread-safe way of passing extra data from css node to the native view counterpart. TODO(7247021): Replace updateExtraData with generic update props mechanism after D2086999

receiveCommand

public void receiveCommand(T root,
                  int commandId,
                  @Nullable
                  ReadableArray args)

Subclasses may use this method to receive events/commands directly from JS through the UIManager. Good example of such a command would be scrollTo request with coordinates for a ScrollView or goBack request for a WebView instance.

Parameters:

root - View instance that should receive the command

commandId - code of the command

args - optional arguments for the command

getCommandsMap

@Nullable
public java.util.Map<java.lang.String,java.lang.Integer> getCommandsMap()

Subclasses of ViewManager that expect to receive commands through UIManagerModule.dispatchViewManagerCommand(int, int, com.facebook.react.bridge.ReadableArray) should override this method returning the map between names of the commands and IDs that are then used in receiveCommand(T, int, com.facebook.react.bridge.ReadableArray) method whenever the command is dispatched for this particular ViewManager. As an example we may consider ReactWebViewManager that expose the following commands: goBack, goForward, reload. In this case the map returned from getCommandsMap() from ReactWebViewManager will look as follows: { "goBack": 1, "goForward": 2, "reload": 3, } Now assuming that "reload" command is dispatched through UIManagerModule we trigger ReactWebViewManager#receiveCommand passing "3" as commandId argument.

Returns:

map of string to int mapping of the expected commands

getExportedCustomBubblingEventTypeConstants

@Nullable
public java.util.Map<java.lang.String,java.lang.Object> getExportedCustomBubblingEventTypeConstants()

Returns a map of config data passed to JS that defines eligible events that can be placed on native views. This should return bubbling directly-dispatched event types and specify what names should be used to subscribe to either form (bubbling/capturing). Returned map should be of the form: { "onTwirl": { "phasedRegistrationNames": { "bubbled": "onTwirl", "captured": "onTwirlCaptured" } } }

getExportedCustomDirectEventTypeConstants

@Nullable
public java.util.Map<java.lang.String,java.lang.Object> getExportedCustomDirectEventTypeConstants()

Returns a map of config data passed to JS that defines eligible events that can be placed on native views. This should return non-bubbling directly-dispatched event types. Returned map should be of the form: { "onTwirl": { "registrationName": "onTwirl" } }

getExportedViewConstants

@Nullable
public java.util.Map<java.lang.String,java.lang.Object> getExportedViewConstants()

Returns a map of view-specific constants that are injected to JavaScript. These constants are made accessible via UIManager..Constants.

getNativeProps

public java.util.Map<java.lang.String,UIProp.Type> getNativeProps()