Group (libGDX Core 1.9.14 API)

java.lang.Object
- com.badlogic.gdx.scenes.scene2d.Actor
- - com.badlogic.gdx.scenes.scene2d.Group

All Implemented Interfaces:

Cullable

Direct Known Subclasses:

WidgetGroup
```
public class Group
extends Actor
implements Cullable
```
2D scene graph node that may contain other actors.
Actors have a z-order equal to the order they were inserted into the group. Actors inserted later will be drawn on top of actors added earlier. Touch events that hit more than one actor are distributed to topmost actors first.

Author:

mzechner, Nathan Sweet

Constructor Summary

Constructors
Constructor and Description

Group()

Constructors
Constructor and Description
`Group()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`act(float delta)` Updates the actor based on time.
`void`	`addActor(Actor actor)` Adds an actor as a child of this group, removing it from its previous parent.
`void`	`addActorAfter(Actor actorAfter, Actor actor)` Adds an actor as a child of this group immediately after another child actor, removing it from its previous parent.
`void`	`addActorAt(int index, Actor actor)` Adds an actor as a child of this group at a specific index, removing it from its previous parent.
`void`	`addActorBefore(Actor actorBefore, Actor actor)` Adds an actor as a child of this group immediately before another child actor, removing it from its previous parent.
`void`	`clear()` Removes all children, actions, and listeners from this group.
`void`	`clearChildren()` Removes all actors from this group.
`Group`	`debugAll()` Calls `setDebug(boolean, boolean)` with `true, true`.
`void`	`draw(Batch batch, float parentAlpha)` Draws the group and its children.
`void`	`drawDebug(ShapeRenderer shapes)` Draws this actor's debug lines if `Actor.getDebug()` is true and, regardless of `Actor.getDebug()`, calls `Actor.drawDebug(ShapeRenderer)` on each child.
`<T extends Actor> T`	`findActor(String name)` Returns the first actor found with the specified name.
`Actor`	`getChild(int index)` Returns the child at the specified index.
`SnapshotArray<Actor>`	`getChildren()` Returns an ordered list of child actors in this group.
`Rectangle`	`getCullingArea()`
`boolean`	`hasChildren()`
`Actor`	`hit(float x, float y, boolean touchable)` Returns the deepest `visible` (and optionally, `touchable`) actor that contains the specified point, or null if no actor was hit.
`boolean`	`isTransform()`
`Vector2`	`localToDescendantCoordinates(Actor descendant, Vector2 localCoords)` Converts coordinates for this group to those of a descendant actor.
`boolean`	`removeActor(Actor actor)` Removes an actor from this group and unfocuses it.
`boolean`	`removeActor(Actor actor, boolean unfocus)` Removes an actor from this group.
`Actor`	`removeActorAt(int index, boolean unfocus)` Removes an actor from this group.
`void`	`setCullingArea(Rectangle cullingArea)` Children completely outside of this rectangle will not be drawn.
`void`	`setDebug(boolean enabled, boolean recursively)` If true, `drawDebug(ShapeRenderer)` will be called for this group and, optionally, all children recursively.
`void`	`setTransform(boolean transform)` When true (the default), the Batch is transformed so children are drawn in their parent's coordinate system.
`boolean`	`swapActor(Actor first, Actor second)` Swaps two actors.
`boolean`	`swapActor(int first, int second)` Swaps two actors by index.
`String`	`toString()` Returns a description of the actor hierarchy, recursively.

Methods inherited from class com.badlogic.gdx.scenes.scene2d.Actor
addAction, addCaptureListener, addListener, ancestorsVisible, ascendantsVisible, clearActions, clearListeners, clipBegin, clipBegin, clipEnd, debug, fire, firstAscendant, getActions, getCaptureListeners, getColor, getDebug, getHeight, getListeners, getName, getOriginX, getOriginY, getParent, getRight, getRotation, getScaleX, getScaleY, getStage, getTop, getTouchable, getUserObject, getWidth, getX, getX, getY, getY, getZIndex, hasActions, hasKeyboardFocus, hasParent, hasScrollFocus, isAscendantOf, isDescendantOf, isTouchable, isTouchFocusListener, isTouchFocusTarget, isVisible, localToActorCoordinates, localToAscendantCoordinates, localToParentCoordinates, localToScreenCoordinates, localToStageCoordinates, moveBy, notify, parentToLocalCoordinates, remove, removeAction, removeCaptureListener, removeListener, rotateBy, scaleBy, scaleBy, screenToLocalCoordinates, setBounds, setColor, setColor, setDebug, setHeight, setName, setOrigin, setOrigin, setOriginX, setOriginY, setPosition, setPosition, setRotation, setScale, setScale, setScaleX, setScaleY, setSize, setTouchable, setUserObject, setVisible, setWidth, setX, setX, setY, setY, setZIndex, sizeBy, sizeBy, stageToLocalCoordinates, toBack, toFront

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

- Constructor Detail
  - Group
```
public Group()
```
- Method Detail
  - act
```
public void act(float delta)
```
    Description copied from class: Actor
    
    Updates the actor based on time. Typically this is called each frame by Stage.act(float).
    The default implementation calls Action.act(float) on each action and removes actions that are complete.
    
    Overrides:
    
    act in class Actor
    
    Parameters:
    
    delta - Time in seconds since the last frame.
  - draw
```
public void draw(Batch batch,
                 float parentAlpha)
```
    Draws the group and its children. The default implementation calls applyTransform(Batch, Matrix4) if needed, then drawChildren(Batch, float), then resetTransform(Batch) if needed.
    
    Overrides:
    
    draw in class Actor
    
    parentAlpha - The parent alpha, to be multiplied with this actor's alpha, allowing the parent's alpha to affect all children.
  - drawDebug
```
public void drawDebug(ShapeRenderer shapes)
```
    Draws this actor's debug lines if Actor.getDebug() is true and, regardless of Actor.getDebug(), calls Actor.drawDebug(ShapeRenderer) on each child.
    
    Overrides:
    
    drawDebug in class Actor
  - setCullingArea
```
public void setCullingArea(@Null
                           Rectangle cullingArea)
```
    Children completely outside of this rectangle will not be drawn. This is only valid for use with unrotated and unscaled actors.
    
    Specified by:
    
    setCullingArea in interface Cullable
    
    Parameters:
    
    cullingArea - May be null.
  - getCullingArea
```
@Null
public Rectangle getCullingArea()
```
    Returns:
    
    May be null.
    
    See Also:
    
    setCullingArea(Rectangle)
  - hit
```
@Null
public Actor hit(float x,
                        float y,
                        boolean touchable)
```
    Description copied from class: Actor
    
    Returns the deepest visible (and optionally, touchable) actor that contains the specified point, or null if no actor was hit. The point is specified in the actor's local coordinate system (0,0 is the bottom left of the actor and width,height is the upper right).
    This method is used to delegate touchDown, mouse, and enter/exit events. If this method returns null, those events will not occur on this Actor.
    The default implementation returns this actor if the point is within this actor's bounds and this actor is visible.
    
    Overrides:
    
    hit in class Actor
    
    touchable - If true, hit detection will respect the touchability.
    
    See Also:
    
    Touchable
  - addActor
```
public void addActor(Actor actor)
```
    Adds an actor as a child of this group, removing it from its previous parent. If the actor is already a child of this group, no changes are made.
  - addActorAt
```
public void addActorAt(int index,
                       Actor actor)
```
    Adds an actor as a child of this group at a specific index, removing it from its previous parent. If the actor is already a child of this group, no changes are made.
    
    Parameters:
    
    index - May be greater than the number of children.
  - addActorBefore
```
public void addActorBefore(Actor actorBefore,
                           Actor actor)
```
    Adds an actor as a child of this group immediately before another child actor, removing it from its previous parent. If the actor is already a child of this group, no changes are made.
  - addActorAfter
```
public void addActorAfter(Actor actorAfter,
                          Actor actor)
```
    Adds an actor as a child of this group immediately after another child actor, removing it from its previous parent. If the actor is already a child of this group, no changes are made. If actorAfter is not in this group, the actor is added as the last child.
  - removeActor
```
public boolean removeActor(Actor actor)
```
    Removes an actor from this group and unfocuses it. Calls removeActor(Actor, boolean) with true.
  - removeActor
```
public boolean removeActor(Actor actor,
                           boolean unfocus)
```
    Removes an actor from this group. Calls removeActorAt(int, boolean) with the actor's child index.
  - removeActorAt
```
public Actor removeActorAt(int index,
                           boolean unfocus)
```
    Removes an actor from this group. If the actor will not be used again and has actions, they should be cleared so the actions will be returned to their pool, if any. This is not done automatically.
    
    Parameters:
    
    unfocus - If true, Stage.unfocus(Actor) is called.
    
    Returns:
    
    the actor removed from this group.
  - clearChildren
```
public void clearChildren()
```
    Removes all actors from this group.
  - clear
```
public void clear()
```
    Removes all children, actions, and listeners from this group.
    
    Overrides:
    
    clear in class Actor
  - findActor
```
@Null
public <T extends Actor> T findActor(String name)
```
    Returns the first actor found with the specified name. Note this recursively compares the name of every actor in the group.
  - swapActor
```
public boolean swapActor(int first,
                         int second)
```
    Swaps two actors by index. Returns false if the swap did not occur because the indexes were out of bounds.
  - swapActor
```
public boolean swapActor(Actor first,
                         Actor second)
```
    Swaps two actors. Returns false if the swap did not occur because the actors are not children of this group.
  - getChild
```
public Actor getChild(int index)
```
    Returns the child at the specified index.
  - getChildren
```
public SnapshotArray<Actor> getChildren()
```
    Returns an ordered list of child actors in this group.
  - hasChildren
```
public boolean hasChildren()
```
  - setTransform
```
public void setTransform(boolean transform)
```
    When true (the default), the Batch is transformed so children are drawn in their parent's coordinate system. This has a performance impact because Batch.flush() must be done before and after the transform. If the actors in a group are not rotated or scaled, then the transform for the group can be set to false. In this case, each child's position will be offset by the group's position for drawing, causing the children to appear in the correct location even though the Batch has not been transformed.
  - isTransform
```
public boolean isTransform()
```
  - localToDescendantCoordinates
```
public Vector2 localToDescendantCoordinates(Actor descendant,
                                            Vector2 localCoords)
```
    Converts coordinates for this group to those of a descendant actor. The descendant does not need to be a direct child.
    
    Throws:
    
    IllegalArgumentException - if the specified actor is not a descendant of this group.
  - setDebug
```
public void setDebug(boolean enabled,
                     boolean recursively)
```
    If true, drawDebug(ShapeRenderer) will be called for this group and, optionally, all children recursively.
  - debugAll
```
public Group debugAll()
```
    Calls setDebug(boolean, boolean) with true, true.
  - toString
```
public String toString()
```
    Returns a description of the actor hierarchy, recursively.
    
    Overrides:
    
    toString in class Actor

Class Group

Constructor Summary

Method Summary

Methods inherited from class com.badlogic.gdx.scenes.scene2d.Actor

Methods inherited from class java.lang.Object

Constructor Detail

Group

Method Detail

act

draw

drawDebug

setCullingArea

getCullingArea

hit

addActor

addActorAt

addActorBefore

addActorAfter

removeActor

removeActor

removeActorAt

clearChildren

clear

findActor

swapActor

swapActor

getChild

getChildren

hasChildren

setTransform

isTransform

localToDescendantCoordinates

setDebug

debugAll

toString