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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright (C) 2013 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.view;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.os.Parcel;
import android.os.Parcelable;
/**
* Simple wrapper for the native GraphicBuffer class.
*
* @hide
*/
@SuppressWarnings("UnusedDeclaration")
public class GraphicBuffer implements Parcelable {
// Note: keep usage flags in sync with GraphicBuffer.h and gralloc.h
public static final int USAGE_SW_READ_NEVER = 0x0;
public static final int USAGE_SW_READ_RARELY = 0x2;
public static final int USAGE_SW_READ_OFTEN = 0x3;
public static final int USAGE_SW_READ_MASK = 0xF;
public static final int USAGE_SW_WRITE_NEVER = 0x0;
public static final int USAGE_SW_WRITE_RARELY = 0x20;
public static final int USAGE_SW_WRITE_OFTEN = 0x30;
public static final int USAGE_SW_WRITE_MASK = 0xF0;
public static final int USAGE_SOFTWARE_MASK = USAGE_SW_READ_MASK | USAGE_SW_WRITE_MASK;
public static final int USAGE_PROTECTED = 0x4000;
public static final int USAGE_HW_TEXTURE = 0x100;
public static final int USAGE_HW_RENDER = 0x200;
public static final int USAGE_HW_2D = 0x400;
public static final int USAGE_HW_COMPOSER = 0x800;
public static final int USAGE_HW_VIDEO_ENCODER = 0x10000;
public static final int USAGE_HW_MASK = 0x71F00;
private final int mWidth;
private final int mHeight;
private final int mFormat;
private final int mUsage;
// Note: do not rename, this field is used by native code
private final int mNativeObject;
// These two fields are only used by lock/unlockCanvas()
private Canvas mCanvas;
private int mSaveCount;
// If set to true, this GraphicBuffer instance cannot be used anymore
private boolean mDestroyed;
/**
* Creates new GraphicBuffer instance. This method will return null
* if the buffer cannot be created.
*
* @param width The width in pixels of the buffer
* @param height The height in pixels of the buffer
* @param format The format of each pixel as specified in {@link PixelFormat}
* @param usage Hint indicating how the buffer will be used
*
* @return A GraphicBuffer instance or null
*/
public static GraphicBuffer create(int width, int height, int format, int usage) {
int nativeObject = nCreateGraphicBuffer(width, height, format, usage);
if (nativeObject != 0) {
return new GraphicBuffer(width, height, format, usage, nativeObject);
}
return null;
}
/**
* Private use only. See {@link #create(int, int, int, int)}.
*/
private GraphicBuffer(int width, int height, int format, int usage, int nativeObject) {
mWidth = width;
mHeight = height;
mFormat = format;
mUsage = usage;
mNativeObject = nativeObject;
}
/**
* Returns the width of this buffer in pixels.
*/
public int getWidth() {
return mWidth;
}
/**
* Returns the height of this buffer in pixels.
*/
public int getHeight() {
return mHeight;
}
/**
* Returns the pixel format of this buffer. The pixel format must be one of
* the formats defined in {@link PixelFormat}.
*/
public int getFormat() {
return mFormat;
}
/**
* Returns the usage hint set on this buffer.
*/
public int getUsage() {
return mUsage;
}
/**
* Start editing the pixels in the buffer. A null is returned if the buffer
* cannot be locked for editing.
*
* The content of the buffer is preserved between unlockCanvas()
* and lockCanvas().
*
* If this method is called after {@link #destroy()}, the return value will
* always be null.
*
* @return A Canvas used to draw into the buffer, or null.
*
* @see #lockCanvas(android.graphics.Rect)
* @see #unlockCanvasAndPost(android.graphics.Canvas)
* @see #isDestroyed()
*/
public Canvas lockCanvas() {
return lockCanvas(null);
}
/**
* Just like {@link #lockCanvas()} but allows specification of a dirty
* rectangle.
*
* If this method is called after {@link #destroy()}, the return value will
* always be null.
*
* @param dirty Area of the buffer that may be modified.
* @return A Canvas used to draw into the surface, or null.
*
* @see #lockCanvas()
* @see #unlockCanvasAndPost(android.graphics.Canvas)
* @see #isDestroyed()
*/
public Canvas lockCanvas(Rect dirty) {
if (mDestroyed) {
return null;
}
if (mCanvas == null) {
mCanvas = new Canvas();
}
if (nLockCanvas(mNativeObject, mCanvas, dirty)) {
mSaveCount = mCanvas.save();
return mCanvas;
}
return null;
}
/**
* Finish editing pixels in the buffer.
*
* This method doesn't do anything if {@link #destroy()} was
* previously called.
*
* @param canvas The Canvas previously returned by lockCanvas()
*
* @see #lockCanvas()
* @see #lockCanvas(android.graphics.Rect)
* @see #isDestroyed()
*/
public void unlockCanvasAndPost(Canvas canvas) {
if (!mDestroyed && mCanvas != null && canvas == mCanvas) {
canvas.restoreToCount(mSaveCount);
mSaveCount = 0;
nUnlockCanvasAndPost(mNativeObject, mCanvas);
}
}
/**
* Destroyes this buffer immediately. Calling this method frees up any
* underlying native resources. After calling this method, this buffer
* must not be used in any way ({@link #lockCanvas()} must not be called,
* etc.)
*
* @see #isDestroyed()
*/
public void destroy() {
if (!mDestroyed) {
mDestroyed = true;
nDestroyGraphicBuffer(mNativeObject);
}
}
/**
* Indicates whether this buffer has been destroyed. A destroyed buffer
* cannot be used in any way: locking a Canvas will return null, the buffer
* cannot be written to a parcel, etc.
*
* @return True if this GraphicBuffer is in a destroyed state,
* false otherwise.
*
* @see #destroy()
*/
public boolean isDestroyed() {
return mDestroyed;
}
@Override
protected void finalize() throws Throwable {
try {
if (!mDestroyed) nDestroyGraphicBuffer(mNativeObject);
} finally {
super.finalize();
}
}
@Override
public int describeContents() {
return 0;
}
/**
* Flatten this object in to a Parcel.
*
* Calling this method will throw an IllegalStateException if
* {@link #destroy()} has been previously called.
*
* @param dest The Parcel in which the object should be written.
* @param flags Additional flags about how the object should be written.
* May be 0 or {@link #PARCELABLE_WRITE_RETURN_VALUE}.
*/
@Override
public void writeToParcel(Parcel dest, int flags) {
if (mDestroyed) {
throw new IllegalStateException("This GraphicBuffer has been destroyed and cannot be "
+ "written to a parcel.");
}
dest.writeInt(mWidth);
dest.writeInt(mHeight);
dest.writeInt(mFormat);
dest.writeInt(mUsage);
nWriteGraphicBufferToParcel(mNativeObject, dest);
}
public static final Parcelable.Creator CREATOR =
new Parcelable.Creator() {
public GraphicBuffer createFromParcel(Parcel in) {
int width = in.readInt();
int height = in.readInt();
int format = in.readInt();
int usage = in.readInt();
int nativeObject = nReadGraphicBufferFromParcel(in);
if (nativeObject != 0) {
return new GraphicBuffer(width, height, format, usage, nativeObject);
}
return null;
}
public GraphicBuffer[] newArray(int size) {
return new GraphicBuffer[size];
}
};
private static native int nCreateGraphicBuffer(int width, int height, int format, int usage);
private static native void nDestroyGraphicBuffer(int nativeObject);
private static native void nWriteGraphicBufferToParcel(int nativeObject, Parcel dest);
private static native int nReadGraphicBufferFromParcel(Parcel in);
private static native boolean nLockCanvas(int nativeObject, Canvas canvas, Rect dirty);
private static native boolean nUnlockCanvasAndPost(int nativeObject, Canvas canvas);
}