android.graphics.drawable
Class LayerDrawable

java.lang.Object
  android.graphics.drawable.Drawable
      android.graphics.drawable.LayerDrawable

All Implemented Interfaces:

Drawable.Callback

Direct Known Subclasses:

TransitionDrawable

public class LayerDrawable
extends Drawable
implements Drawable.Callback

Drawable that manages an array of other drawables. These are drawn in array order, so the element with the largest index will be drawn on top.

Nested Class Summary

(package private) static class	LayerDrawable.LayerState
(package private) static class	LayerDrawable.Rec

Nested classes/interfaces inherited from class android.graphics.drawable.Drawable

Drawable.Callback, Drawable.ConstantState

Field Summary

(package private) LayerDrawable.LayerState

mLayerState

Fields inherited from class android.graphics.drawable.Drawable

mCallback

Constructor Summary

LayerDrawable()

LayerDrawable(Drawable[] array)

LayerDrawable(LayerDrawable.LayerState state)

Method Summary

(package private) LayerDrawable.LayerState	createConstantState(LayerDrawable.LayerState state)
void	draw(Canvas canvas) Draw in its bounds (set via setBounds) respecting optional effects such as alpha (set via setAlpha) and color filter (set via setColorFilter).
Drawable	findDrawableByLayerId(int id) Look for a layer with the given id, and returns its Drawable.
int	getChangingConfigurations() Return a mask of the configuration parameters for which this drawable mau change, requiring that it be re-created.
Drawable.ConstantState	getConstantState()
Drawable	getDrawable(int index)
int	getId(int index)
int	getIntrinsicHeight() Return the intrinsic height of the underlying drawable object.
int	getIntrinsicWidth() Return the intrinsic width of the underlying drawable object.
int	getNumberOfLayers() Returns the number of layers contained within this.
int	getOpacity() Return the opacity/transparency of this Drawable.
boolean	getPadding(Rect padding) Return in padding the insets suggested by this Drawable for placing content inside the drawable's bounds.
void	inflate(Resources r, XmlPullParser parser, AttributeSet attrs)
void	invalidateDrawable(Drawable who) Called when the drawable needs to be redrawn.
boolean	isStateful() Indicates whether this view will change its appearance based on state.
protected void	onBoundsChange(Rect bounds) Override this in your subclass to change appearance if you recognize the specified state.
protected boolean	onLevelChange(int level) Override this in your subclass to change appearance if you vary based on level.
protected boolean	onStateChange(int[] state) Override this in your subclass to change appearance if you recognize the specified state.
void	scheduleDrawable(Drawable who, Runnable what, long when) A Drawable can call this to schedule the next frame of its animation.
void	setAlpha(int alpha) Specify an alpha value for the drawable.
void	setColorFilter(ColorFilter cf) Specify an optional colorFilter for the drawable.
void	setDither(boolean dither) Set to true to have the drawable dither its colors when drawn to a device with fewer than 8-bits per color component.
boolean	setDrawableByLayerId(int id, Drawable drawable) Sets (or replaces) the Drawable for the layer with the given id.
void	setId(int index, int id) Sets the ID of a layer.
void	setLayerInset(int index, int l, int t, int r, int b) Specify modifiers to the bounds for the drawable[index].
boolean	setVisible(boolean visible, boolean restart) Set whether this Drawable is visible.
void	unscheduleDrawable(Drawable who, Runnable what) A Drawable can call this to unschedule an action previously scheduled with Drawable.Callback.scheduleDrawable(android.graphics.drawable.Drawable, java.lang.Runnable, long).

Methods inherited from class android.graphics.drawable.Drawable

clearColorFilter, copyBounds, copyBounds, createFromPath, createFromStream, createFromXml, createFromXmlInner, getBounds, getCurrent, getLevel, getMinimumHeight, getMinimumWidth, getState, getTransparentRegion, inflateWithAttributes, invalidateSelf, isVisible, resolveOpacity, scheduleSelf, setBounds, setBounds, setCallback, setChangingConfigurations, setColorFilter, setFilterBitmap, setLevel, setState, unscheduleSelf

Methods inherited from class java.lang.Object

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

Field Detail

mLayerState

LayerDrawable.LayerState mLayerState

Constructor Detail

LayerDrawable

public LayerDrawable(Drawable[] array)

LayerDrawable

LayerDrawable()

LayerDrawable

LayerDrawable(LayerDrawable.LayerState state)

Method Detail

createConstantState

LayerDrawable.LayerState createConstantState(LayerDrawable.LayerState state)

inflate

public void inflate(Resources r,
                    XmlPullParser parser,
                    AttributeSet attrs)
             throws XmlPullParserException,
                    IOException

Overrides:

inflate in class Drawable

Throws:

XmlPullParserException

IOException

findDrawableByLayerId

public Drawable findDrawableByLayerId(int id)

Look for a layer with the given id, and returns its Drawable.

Parameters:

id - The layer ID to search for.

Returns:

The Drawable of the layer that has the given id in the hierarchy or null.

setId

public void setId(int index,
                  int id)

Sets the ID of a layer.

Parameters:

index - The index of the layer which will received the ID.

id - The ID to assign to the layer.

getNumberOfLayers

public int getNumberOfLayers()

Returns the number of layers contained within this.

Returns:

The number of layers.

getDrawable

public Drawable getDrawable(int index)

getId

public int getId(int index)

setDrawableByLayerId

public boolean setDrawableByLayerId(int id,
                                    Drawable drawable)

Sets (or replaces) the Drawable for the layer with the given id.

Parameters:

id - The layer ID to search for.

drawable - The replacement Drawable.

Returns:

Whether the Drawable was replaced (could return false if the id was not found).

setLayerInset

public void setLayerInset(int index,
                          int l,
                          int t,
                          int r,
                          int b)

Specify modifiers to the bounds for the drawable[index]. left += l top += t; right -= r; bottom -= b;

invalidateDrawable

public void invalidateDrawable(Drawable who)

Description copied from interface: Drawable.Callback

Called when the drawable needs to be redrawn. A view at this point should invalidate itself (or at least the part of itself where the drawable appears).

Specified by:

invalidateDrawable in interface Drawable.Callback

Parameters:

who - The drawable that is requesting the update.

scheduleDrawable

public void scheduleDrawable(Drawable who,
                             Runnable what,
                             long when)

Description copied from interface: Drawable.Callback

A Drawable can call this to schedule the next frame of its animation. An implementation can generally simply call Handler.postAtTime(Runnable, Object, long) with the parameters (what, who, when) to perform the scheduling.

Specified by:

scheduleDrawable in interface Drawable.Callback

Parameters:

who - The drawable being scheduled.

what - The action to execute.

when - The time (in milliseconds) to run. The timebase is SystemClock.uptimeMillis()

unscheduleDrawable

public void unscheduleDrawable(Drawable who,
                               Runnable what)

Description copied from interface: Drawable.Callback

A Drawable can call this to unschedule an action previously scheduled with Drawable.Callback.scheduleDrawable(android.graphics.drawable.Drawable, java.lang.Runnable, long). An implementation can generally simply call Handler.removeCallbacks(Runnable, Object) with the parameters (what, who) to unschedule the drawable.

Specified by:

unscheduleDrawable in interface Drawable.Callback

Parameters:

who - The drawable being unscheduled.

what - The action being unscheduled.

draw

public void draw(Canvas canvas)

Description copied from class: Drawable

Draw in its bounds (set via setBounds) respecting optional effects such as alpha (set via setAlpha) and color filter (set via setColorFilter).

Specified by:

draw in class Drawable

Parameters:

canvas - The canvas to draw into

getChangingConfigurations

public int getChangingConfigurations()

Description copied from class: Drawable

Return a mask of the configuration parameters for which this drawable mau change, requiring that it be re-created. The default implementation returns whatever was provided through Drawable.setChangingConfigurations(int) or 0 by default. Subclasses may extend this to or in the changing configurations of any other drawables they hold.

Overrides:

getChangingConfigurations in class Drawable

Returns:

Returns a mask of the changing configuration parameters, as defined by Configuration.

See Also:

Configuration

getPadding

public boolean getPadding(Rect padding)

Description copied from class: Drawable

Return in padding the insets suggested by this Drawable for placing content inside the drawable's bounds. Positive values move toward the center of the Drawable (set Rect.inset). Returns true if this drawable actually has a padding, else false. When false is returned, the padding is always set to 0.

Overrides:

getPadding in class Drawable

setVisible

public boolean setVisible(boolean visible,
                          boolean restart)

Description copied from class: Drawable

Set whether this Drawable is visible. This generally does not impact the Drawable's behavior, but is a hint that can be used by some Drawables, for example, to decide whether run animations.

Overrides:

setVisible in class Drawable

Parameters:

visible - Set to true if visible, false if not.

restart - You can supply true here to force the drawable to behave as if it has just become visible, even if it had last been set visible. Used for example to force animations to restart.

Returns:

boolean Returns true if the new visibility is different than its previous state.

setDither

public void setDither(boolean dither)

Description copied from class: Drawable

Set to true to have the drawable dither its colors when drawn to a device with fewer than 8-bits per color component. This can improve the look on those devices, but can also slow down the drawing a little.

Overrides:

setDither in class Drawable

setAlpha

public void setAlpha(int alpha)

Description copied from class: Drawable

Specify an alpha value for the drawable. 0 means fully transparent, and 255 means fully opaque.

Specified by:

setAlpha in class Drawable

setColorFilter

public void setColorFilter(ColorFilter cf)

Description copied from class: Drawable

Specify an optional colorFilter for the drawable. Pass null to remove any filters.

Specified by:

setColorFilter in class Drawable

getOpacity

public int getOpacity()

Description copied from class: Drawable

Return the opacity/transparency of this Drawable. The returned value is one of the abstract format constants in PixelFormat: PixelFormat.UNKNOWN, PixelFormat.TRANSLUCENT, PixelFormat.TRANSPARENT, or PixelFormat.OPAQUE.

Generally a Drawable should be as conservative as possible with the value it returns. For example, if it contains multiple child drawables and only shows one of them at a time, if only one of the children is TRANSLUCENT and the others are OPAQUE then TRANSLUCENT should be returned. You can use the method Drawable.resolveOpacity(int, int) to perform a standard reduction of two opacities to the appropriate single output.

Note that the returned value does not take into account a custom alpha or color filter that has been applied by the client through the Drawable.setAlpha(int) or Drawable.setColorFilter(android.graphics.ColorFilter) methods.

Specified by:

getOpacity in class Drawable

Returns:

int The opacity class of the Drawable.

See Also:

PixelFormat

isStateful

public boolean isStateful()

Description copied from class: Drawable

Indicates whether this view will change its appearance based on state. Clients can use this to determine whether it is necessary to calculate their state and call setState.

Overrides:

isStateful in class Drawable

Returns:

True if this view changes its appearance based on state, false otherwise.

See Also:

Drawable.setState(int[])

onStateChange

protected boolean onStateChange(int[] state)

Description copied from class: Drawable

Override this in your subclass to change appearance if you recognize the specified state.

Overrides:

onStateChange in class Drawable

Returns:

Returns true if the state change has caused the appearance of the Drawable to change (that is, it needs to be drawn), else false if it looks the same and there is no need to redraw it since its last state.

onLevelChange

protected boolean onLevelChange(int level)

Description copied from class: Drawable

Override this in your subclass to change appearance if you vary based on level.

Overrides:

onLevelChange in class Drawable

Returns:

Returns true if the level change has caused the appearance of the Drawable to change (that is, it needs to be drawn), else false if it looks the same and there is no need to redraw it since its last level.

onBoundsChange

protected void onBoundsChange(Rect bounds)

Description copied from class: Drawable

Override this in your subclass to change appearance if you recognize the specified state.

Overrides:

onBoundsChange in class Drawable

getIntrinsicWidth

public int getIntrinsicWidth()

Description copied from class: Drawable

Return the intrinsic width of the underlying drawable object. Returns -1 if it has no intrinsic width, such as with a solid color.

Overrides:

getIntrinsicWidth in class Drawable

getIntrinsicHeight

public int getIntrinsicHeight()

Description copied from class: Drawable

Return the intrinsic height of the underlying drawable object. Returns -1 if it has no intrinsic height, such as with a solid color.

Overrides:

getIntrinsicHeight in class Drawable

getConstantState

public Drawable.ConstantState getConstantState()

Overrides:

getConstantState in class Drawable