Android APIs
public class

NinePatch

extends Object
java.lang.Object
   ↳ android.graphics.NinePatch

Class Overview

The NinePatch class permits drawing a bitmap in nine or more sections. Essentially, it allows the creation of custom graphics that will scale the way that you define, when content added within the image exceeds the normal bounds of the graphic. For a thorough explanation of a NinePatch image, read the discussion in the 2D Graphics document.

The Draw 9-Patch tool offers an extremely handy way to create your NinePatch images, using a WYSIWYG graphics editor.

Summary

Public Constructors
NinePatch(Bitmap bitmap, byte[] chunk)
Create a drawable projection from a bitmap to nine patches.
NinePatch(Bitmap bitmap, byte[] chunk, String srcName)
Create a drawable projection from a bitmap to nine patches.
Public Methods
void draw(Canvas canvas, Rect location)
Draws the NinePatch.
void draw(Canvas canvas, RectF location)
Draws the NinePatch.
void draw(Canvas canvas, Rect location, Paint paint)
Draws the NinePatch.
Bitmap getBitmap()
Returns the bitmap used to draw this NinePatch.
int getDensity()
Return the underlying bitmap's density, as per Bitmap.getDensity().
int getHeight()
Returns the intrinsic height, in pixels, of this NinePatch.
String getName()
Returns the name of this NinePatch object if one was specified when calling the constructor.
Paint getPaint()
Returns the paint used to draw this NinePatch.
final Region getTransparentRegion(Rect bounds)
Returns a Region representing the parts of the NinePatch that are completely transparent.
int getWidth()
Returns the intrinsic width, in pixels, of this NinePatch.
final boolean hasAlpha()
Indicates whether this NinePatch contains transparent or translucent pixels.
static boolean isNinePatchChunk(byte[] chunk)
Verifies that the specified byte array is a valid 9-patch data chunk.
void setPaint(Paint p)
Sets the paint to use when drawing the NinePatch.
Protected Methods
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public NinePatch (Bitmap bitmap, byte[] chunk)

Added in API level 19

Create a drawable projection from a bitmap to nine patches.

Parameters
bitmap Bitmap: The bitmap describing the patches.
chunk byte: The 9-patch data chunk describing how the underlying bitmap is split apart and drawn.

public NinePatch (Bitmap bitmap, byte[] chunk, String srcName)

Added in API level 1

Create a drawable projection from a bitmap to nine patches.

Parameters
bitmap Bitmap: The bitmap describing the patches.
chunk byte: The 9-patch data chunk describing how the underlying bitmap is split apart and drawn.
srcName String: The name of the source for the bitmap. Might be null.

Public Methods

public void draw (Canvas canvas, Rect location)

Added in API level 1

Draws the NinePatch. This method will use the paint returned by getPaint().

Parameters
canvas Canvas: A container for the current matrix and clip used to draw the NinePatch.
location Rect: Where to draw the NinePatch.

public void draw (Canvas canvas, RectF location)

Added in API level 1

Draws the NinePatch. This method will use the paint returned by getPaint().

Parameters
canvas Canvas: A container for the current matrix and clip used to draw the NinePatch.
location RectF: Where to draw the NinePatch.

public void draw (Canvas canvas, Rect location, Paint paint)

Added in API level 1

Draws the NinePatch. This method will ignore the paint returned by getPaint() and use the specified paint instead.

Parameters
canvas Canvas: A container for the current matrix and clip used to draw the NinePatch.
location Rect: Where to draw the NinePatch.
paint Paint: The Paint to draw through.

public Bitmap getBitmap ()

Added in API level 19

Returns the bitmap used to draw this NinePatch.

Returns
Bitmap

public int getDensity ()

Added in API level 4

Return the underlying bitmap's density, as per Bitmap.getDensity().

Returns
int

public int getHeight ()

Added in API level 1

Returns the intrinsic height, in pixels, of this NinePatch. This is equivalent to querying the height of the underlying bitmap returned by getBitmap().

Returns
int

public String getName ()

Added in API level 19

Returns the name of this NinePatch object if one was specified when calling the constructor.

Returns
String

public Paint getPaint ()

Added in API level 19

Returns the paint used to draw this NinePatch. The paint can be null.

Returns
Paint

public final Region getTransparentRegion (Rect bounds)

Added in API level 1

Returns a Region representing the parts of the NinePatch that are completely transparent.

Parameters
bounds Rect: The location and size of the NinePatch.
Returns
Region null if the NinePatch has no transparent region to report, else a Region holding the parts of the specified bounds that are transparent.

public int getWidth ()

Added in API level 1

Returns the intrinsic width, in pixels, of this NinePatch. This is equivalent to querying the width of the underlying bitmap returned by getBitmap().

Returns
int

public final boolean hasAlpha ()

Added in API level 1

Indicates whether this NinePatch contains transparent or translucent pixels. This is equivalent to calling getBitmap().hasAlpha() on this NinePatch.

Returns
boolean

public static boolean isNinePatchChunk (byte[] chunk)

Added in API level 1

Verifies that the specified byte array is a valid 9-patch data chunk.

Parameters
chunk byte: A byte array representing a 9-patch data chunk.
Returns
boolean True if the specified byte array represents a 9-patch data chunk, false otherwise.

public void setPaint (Paint p)

Added in API level 1

Sets the paint to use when drawing the NinePatch.

Parameters
p Paint: The paint that will be used to draw this NinePatch.

Protected Methods

protected void finalize ()

Added in API level 1

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable