com.facebook.litho

Class ComponentTree

java.lang.Object

com.facebook.litho.ComponentTree

public class ComponentTree
extends Object

Represents a tree of components and controls their life cycle. ComponentTree takes in a single root component and recursively invokes its OnCreateLayout to create a tree of components. ComponentTree is responsible for refreshing the mounted state of a component with new props.

The usual use case for ComponentTree is: ComponentTree component = ComponentTree.create(context, MyComponent.create()); myHostView.setRoot(component);

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ComponentTree.Builder A builder class that can be used to create a ComponentTree.
static interface	ComponentTree.MeasureListener
static interface	ComponentTree.NewLayoutStateReadyListener Listener that will be notified when a new LayoutState is computed and ready to be committed to this ComponentTree.
static interface	ComponentTree.RecyclingMode

Field Summary

Fields

Modifier and Type	Field and Description
static int	INVALID_ID
protected int	mId
static int	STATE_UPDATES_IN_LOOP_THRESHOLD

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ComponentTree(ComponentTree.Builder builder)

Method Summary

Modifier and Type	Method and Description
HooksHandler	acquireHooksHandlerIfNecessary()
StateHandler	acquireStateHandler() Provides a new instance from the StateHandler pool that is initialized with the information from the StateHandler currently held by the ComponentTree.
void	addMeasureListener(ComponentTree.MeasureListener measureListener) The provided measureListener will be called when a valid layout is commited.
void	cancelLayoutAndReleaseTree()
void	checkWorkingRangeAndDispatch(int position, int firstVisibleIndex, int lastVisibleIndex, int firstFullyVisibleIndex, int lastFullyVisibleIndex) Check if the any child components stored in LayoutState have entered/exited the working range, and dispatch the event to trigger the corresponding registered methods.
void	clearMeasureListener(ComponentTree.MeasureListener measureListener)
RenderState	consumePreviousRenderState() Takes ownership of the RenderState object from this ComponentTree - this allows the RenderState to be persisted somewhere and then set back on another ComponentTree using the ComponentTree.Builder.
static ComponentTree.Builder	create(ComponentContext context)
static ComponentTree.Builder	create(ComponentContext context, Component.Builder<?> root)
static ComponentTree.Builder	create(ComponentContext context, Component root)
static int	generateComponentTreeId()
LayoutState	getCommittedLayoutState()
ComponentContext	getContext()
LithoHandler	getLayoutThreadHandler()
LithoView	getLithoView()
ComponentsLogger	getLogger()
String	getLogTag()
ComponentTree.NewLayoutStateReadyListener	getNewLayoutStateReadyListener()
int	getRecyclingMode() Returns the recycling mode.
String	getSimpleName()
boolean	hasCompatibleLayout(int widthSpec, int heightSpec)
boolean	hasMounted() Whether this ComponentTree has been mounted at least once.
boolean	isFirstMount()
boolean	isIncrementalMountEnabled() Returns whether incremental mount is enabled or not in this component.
boolean	isReconciliationEnabled()
boolean	isReleased()
void	release() The contract is that in order to release a ComponentTree, you must do so from the main thread, or guarantee that it will never be accessed from the main thread again.
void	setIsFirstMount(boolean isFirstMount)
void	setNewLayoutStateReadyListener(ComponentTree.NewLayoutStateReadyListener listener)
void	setRoot(Component root) Update the root component.
void	setRootAndSizeSpec(Component root, int widthSpec, int heightSpec) Compute a new layout with the given component root and sizes
void	setRootAndSizeSpec(Component root, int widthSpec, int heightSpec, Size output)
void	setRootAndSizeSpec(Component root, int widthSpec, int heightSpec, Size output, TreeProps treeProps)
void	setRootAndSizeSpecAsync(Component root, int widthSpec, int heightSpec) Compute asynchronously a new layout with the given component root and sizes
void	setRootAndSizeSpecAsync(Component root, int widthSpec, int heightSpec, TreeProps treeProps) Compute asynchronously a new layout with the given component root, sizes and stored TreeProps.
void	setRootAsync(Component root)
void	setSizeSpec(int widthSpec, int heightSpec) Update the width/height spec.
void	setSizeSpec(int widthSpec, int heightSpec, Size output) Same as setSizeSpec(int, int) but fetches the resulting width/height in the given Size.
void	setSizeSpecAsync(int widthSpec, int heightSpec)
void	setVersionedRootAndSizeSpec(Component root, int widthSpec, int heightSpec, Size output, TreeProps treeProps, int externalRootVersion)
void	updateLayoutThreadHandler(LithoHandler layoutThreadHandler) Provide custom LithoHandler.

Methods inherited from class java.lang.Object

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

Field Detail

INVALID_ID

public static final int INVALID_ID

See Also:

Constant Field Values

STATE_UPDATES_IN_LOOP_THRESHOLD

public static final int STATE_UPDATES_IN_LOOP_THRESHOLD

See Also:

Constant Field Values

mId

protected final int mId

Constructor Detail

ComponentTree

protected ComponentTree(ComponentTree.Builder builder)

Method Detail

create

public static ComponentTree.Builder create(ComponentContext context)

create

public static ComponentTree.Builder create(ComponentContext context,
                                           Component.Builder<?> root)

create

public static ComponentTree.Builder create(ComponentContext context,
                                           Component root)

addMeasureListener

public void addMeasureListener(ComponentTree.MeasureListener measureListener)

The provided measureListener will be called when a valid layout is commited.

Parameters:

measureListener -

clearMeasureListener

public void clearMeasureListener(ComponentTree.MeasureListener measureListener)

getCommittedLayoutState

public LayoutState getCommittedLayoutState()

hasMounted

public boolean hasMounted()

Whether this ComponentTree has been mounted at least once.

isFirstMount

public boolean isFirstMount()

setIsFirstMount

public void setIsFirstMount(boolean isFirstMount)

setNewLayoutStateReadyListener

public void setNewLayoutStateReadyListener(ComponentTree.NewLayoutStateReadyListener listener)

updateLayoutThreadHandler

public void updateLayoutThreadHandler(LithoHandler layoutThreadHandler)

Provide custom LithoHandler. If null is provided default one will be used for layouts.

getLayoutThreadHandler

public LithoHandler getLayoutThreadHandler()

getNewLayoutStateReadyListener

public ComponentTree.NewLayoutStateReadyListener getNewLayoutStateReadyListener()

hasCompatibleLayout

public boolean hasCompatibleLayout(int widthSpec,
                                   int heightSpec)

Returns:

whether this ComponentTree has a computed layout that will work for the given measure specs.

isIncrementalMountEnabled

public boolean isIncrementalMountEnabled()

Returns whether incremental mount is enabled or not in this component.

getRecyclingMode

public int getRecyclingMode()

Returns the recycling mode. Please see for details of different modes

isReconciliationEnabled

public boolean isReconciliationEnabled()

setRoot

public void setRoot(Component root)

Update the root component. This can happen in both attached and detached states. In each case we will run a layout and then proxy a message to the main thread to cause a relayout/invalidate.

setRootAsync

public void setRootAsync(Component root)

checkWorkingRangeAndDispatch

public void checkWorkingRangeAndDispatch(int position,
                                         int firstVisibleIndex,
                                         int lastVisibleIndex,
                                         int firstFullyVisibleIndex,
                                         int lastFullyVisibleIndex)

Check if the any child components stored in LayoutState have entered/exited the working range, and dispatch the event to trigger the corresponding registered methods.

setSizeSpec

public void setSizeSpec(int widthSpec,
                        int heightSpec)

Update the width/height spec. This is useful if you are currently detached and are responding to a configuration change. If you are currently attached then the HostView is the source of truth for width/height, so this call will be ignored.

setSizeSpec

public void setSizeSpec(int widthSpec,
                        int heightSpec,
                        Size output)

Same as setSizeSpec(int, int) but fetches the resulting width/height in the given Size.

setSizeSpecAsync

public void setSizeSpecAsync(int widthSpec,
                             int heightSpec)

setRootAndSizeSpecAsync

public void setRootAndSizeSpecAsync(Component root,
                                    int widthSpec,
                                    int heightSpec)

Compute asynchronously a new layout with the given component root and sizes

setRootAndSizeSpecAsync

public void setRootAndSizeSpecAsync(Component root,
                                    int widthSpec,
                                    int heightSpec,
                                    TreeProps treeProps)

Compute asynchronously a new layout with the given component root, sizes and stored TreeProps.

setRootAndSizeSpec

public void setRootAndSizeSpec(Component root,
                               int widthSpec,
                               int heightSpec)

Compute a new layout with the given component root and sizes

setRootAndSizeSpec

public void setRootAndSizeSpec(Component root,
                               int widthSpec,
                               int heightSpec,
                               Size output)

setRootAndSizeSpec

public void setRootAndSizeSpec(Component root,
                               int widthSpec,
                               int heightSpec,
                               Size output,
                               TreeProps treeProps)

setVersionedRootAndSizeSpec

public void setVersionedRootAndSizeSpec(Component root,
                                        int widthSpec,
                                        int heightSpec,
                                        Size output,
                                        TreeProps treeProps,
                                        int externalRootVersion)

getLithoView

public LithoView getLithoView()

Returns:

the LithoView associated with this ComponentTree if any. Since this is modified on the main thread, it is racy to get the current LithoView off the main thread.

acquireStateHandler

public StateHandler acquireStateHandler()

Provides a new instance from the StateHandler pool that is initialized with the information from the StateHandler currently held by the ComponentTree. Once the state updates have been applied and we are back in the main thread the state handler gets released to the pool.

Returns:

a copy of the state handler instance held by ComponentTree.

acquireHooksHandlerIfNecessary

public HooksHandler acquireHooksHandlerIfNecessary()

consumePreviousRenderState

public RenderState consumePreviousRenderState()

Takes ownership of the RenderState object from this ComponentTree - this allows the RenderState to be persisted somewhere and then set back on another ComponentTree using the ComponentTree.Builder. See RenderState for more information on the purpose of this object.

release

public void release()

The contract is that in order to release a ComponentTree, you must do so from the main thread, or guarantee that it will never be accessed from the main thread again. Usually HostView will handle releasing, but if you never attach to a host view, then you should call release yourself.

getSimpleName

public String getSimpleName()

isReleased

public boolean isReleased()

getContext

public ComponentContext getContext()

getLogger

public ComponentsLogger getLogger()

getLogTag

public String getLogTag()

cancelLayoutAndReleaseTree

public void cancelLayoutAndReleaseTree()

generateComponentTreeId

public static int generateComponentTreeId()