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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.graphics;
/**
* 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.
*
*/
public class NinePatch {
/**
* Struct of inset information attached to a 9 patch bitmap.
*
* Present on a 9 patch bitmap if it optical insets were manually included,
* or if outline insets were automatically included by aapt.
*
* @hide
*/
public static class InsetStruct {
@SuppressWarnings({"UnusedDeclaration"}) // called from JNI
InsetStruct(int opticalLeft, int opticalTop, int opticalRight, int opticalBottom,
int outlineLeft, int outlineTop, int outlineRight, int outlineBottom,
float outlineRadius, int outlineAlpha, float decodeScale) {
opticalRect = new Rect(opticalLeft, opticalTop, opticalRight, opticalBottom);
opticalRect.scale(decodeScale);
outlineRect = scaleInsets(outlineLeft, outlineTop,
outlineRight, outlineBottom, decodeScale);
this.outlineRadius = outlineRadius * decodeScale;
this.outlineAlpha = outlineAlpha / 255.0f;
}
public final Rect opticalRect;
public final Rect outlineRect;
public final float outlineRadius;
public final float outlineAlpha;
/**
* Scales up the rect by the given scale, ceiling values, so actual outline Rect
* grows toward the inside.
*/
public static Rect scaleInsets(int left, int top, int right, int bottom, float scale) {
if (scale == 1.0f) {
return new Rect(left, top, right, bottom);
}
Rect result = new Rect();
result.left = (int) Math.ceil(left * scale);
result.top = (int) Math.ceil(top * scale);
result.right = (int) Math.ceil(right * scale);
result.bottom = (int) Math.ceil(bottom * scale);
return result;
}
}
private final Bitmap mBitmap;
/**
* Used by native code. This pointer is an instance of Res_png_9patch*.
*
* @hide
*/
public long mNativeChunk;
private Paint mPaint;
private String mSrcName;
/**
* Create a drawable projection from a bitmap to nine patches.
*
* @param bitmap The bitmap describing the patches.
* @param chunk The 9-patch data chunk describing how the underlying bitmap
* is split apart and drawn.
*/
public NinePatch(Bitmap bitmap, byte[] chunk) {
this(bitmap, chunk, null);
}
/**
* Create a drawable projection from a bitmap to nine patches.
*
* @param bitmap The bitmap describing the patches.
* @param chunk The 9-patch data chunk describing how the underlying
* bitmap is split apart and drawn.
* @param srcName The name of the source for the bitmap. Might be null.
*/
public NinePatch(Bitmap bitmap, byte[] chunk, String srcName) {
mBitmap = bitmap;
mSrcName = srcName;
mNativeChunk = validateNinePatchChunk(chunk);
}
/**
* @hide
*/
public NinePatch(NinePatch patch) {
mBitmap = patch.mBitmap;
mSrcName = patch.mSrcName;
if (patch.mPaint != null) {
mPaint = new Paint(patch.mPaint);
}
// No need to validate the 9patch chunk again, it was done by
// the instance we're copying from
mNativeChunk = patch.mNativeChunk;
}
@Override
protected void finalize() throws Throwable {
try {
if (mNativeChunk != 0) {
// only attempt to destroy correctly initilized chunks
nativeFinalize(mNativeChunk);
mNativeChunk = 0;
}
} finally {
super.finalize();
}
}
/**
* Returns the name of this NinePatch object if one was specified
* when calling the constructor.
*/
public String getName() {
return mSrcName;
}
/**
* Returns the paint used to draw this NinePatch. The paint can be null.
*
* @see #setPaint(Paint)
* @see #draw(Canvas, Rect)
* @see #draw(Canvas, RectF)
*/
public Paint getPaint() {
return mPaint;
}
/**
* Sets the paint to use when drawing the NinePatch.
*
* @param p The paint that will be used to draw this NinePatch.
*
* @see #getPaint()
* @see #draw(Canvas, Rect)
* @see #draw(Canvas, RectF)
*/
public void setPaint(Paint p) {
mPaint = p;
}
/**
* Returns the bitmap used to draw this NinePatch.
*/
public Bitmap getBitmap() {
return mBitmap;
}
/**
* Draws the NinePatch. This method will use the paint returned by {@link #getPaint()}.
*
* @param canvas A container for the current matrix and clip used to draw the NinePatch.
* @param location Where to draw the NinePatch.
*/
public void draw(Canvas canvas, RectF location) {
canvas.drawPatch(this, location, mPaint);
}
/**
* Draws the NinePatch. This method will use the paint returned by {@link #getPaint()}.
*
* @param canvas A container for the current matrix and clip used to draw the NinePatch.
* @param location Where to draw the NinePatch.
*/
public void draw(Canvas canvas, Rect location) {
canvas.drawPatch(this, location, mPaint);
}
/**
* Draws the NinePatch. This method will ignore the paint returned
* by {@link #getPaint()} and use the specified paint instead.
*
* @param canvas A container for the current matrix and clip used to draw the NinePatch.
* @param location Where to draw the NinePatch.
* @param paint The Paint to draw through.
*/
public void draw(Canvas canvas, Rect location, Paint paint) {
canvas.drawPatch(this, location, paint);
}
/**
* Return the underlying bitmap's density, as per
* {@link Bitmap#getDensity() Bitmap.getDensity()}.
*/
public int getDensity() {
return mBitmap.mDensity;
}
/**
* Returns the intrinsic width, in pixels, of this NinePatch. This is equivalent
* to querying the width of the underlying bitmap returned by {@link #getBitmap()}.
*/
public int getWidth() {
return mBitmap.getWidth();
}
/**
* Returns the intrinsic height, in pixels, of this NinePatch. This is equivalent
* to querying the height of the underlying bitmap returned by {@link #getBitmap()}.
*/
public int getHeight() {
return mBitmap.getHeight();
}
/**
* Indicates whether this NinePatch contains transparent or translucent pixels.
* This is equivalent to calling getBitmap().hasAlpha()
on this
* NinePatch.
*/
public final boolean hasAlpha() {
return mBitmap.hasAlpha();
}
/**
* Returns a {@link Region} representing the parts of the NinePatch that are
* completely transparent.
*
* @param bounds The location and size of the NinePatch.
*
* @return null if the NinePatch has no transparent region to
* report, else a {@link Region} holding the parts of the specified bounds
* that are transparent.
*/
public final Region getTransparentRegion(Rect bounds) {
long r = nativeGetTransparentRegion(mBitmap, mNativeChunk, bounds);
return r != 0 ? new Region(r) : null;
}
/**
* Verifies that the specified byte array is a valid 9-patch data chunk.
*
* @param chunk A byte array representing a 9-patch data chunk.
*
* @return True if the specified byte array represents a 9-patch data chunk,
* false otherwise.
*/
public native static boolean isNinePatchChunk(byte[] chunk);
/**
* Validates the 9-patch chunk and throws an exception if the chunk is invalid.
* If validation is successful, this method returns a native Res_png_9patch*
* object used by the renderers.
*/
private static native long validateNinePatchChunk(byte[] chunk);
private static native void nativeFinalize(long chunk);
private static native long nativeGetTransparentRegion(Bitmap bitmap, long chunk, Rect location);
}