core/jni/android/graphics/GraphicsJNI.h

#ifndef GraphicsJNI_DEFINED
#define GraphicsJNI_DEFINED

#include "SkBitmap.h"
#include "SkDevice.h"
#include "SkPixelRef.h"
#include "SkMallocPixelRef.h"
#include "SkPoint.h"
#include "SkRect.h"
#include "SkImageDecoder.h"
#include <jni.h>

class SkBitmapRegionDecoder;
class SkCanvas;
class SkPaint;
class SkPicture;

class GraphicsJNI {
public:
    enum BitmapCreateFlags {
        kBitmapCreateFlag_None = 0x0,
        kBitmapCreateFlag_Mutable = 0x1,
        kBitmapCreateFlag_Premultiplied = 0x2,
    };

    // returns true if an exception is set (and dumps it out to the Log)
    static bool hasException(JNIEnv*);

    static void get_jrect(JNIEnv*, jobject jrect, int* L, int* T, int* R, int* B);
    static void set_jrect(JNIEnv*, jobject jrect, int L, int T, int R, int B);

    static SkIRect* jrect_to_irect(JNIEnv*, jobject jrect, SkIRect*);
    static void irect_to_jrect(const SkIRect&, JNIEnv*, jobject jrect);

    static SkRect* jrectf_to_rect(JNIEnv*, jobject jrectf, SkRect*);
    static SkRect* jrect_to_rect(JNIEnv*, jobject jrect, SkRect*);
    static void rect_to_jrectf(const SkRect&, JNIEnv*, jobject jrectf);

    static void set_jpoint(JNIEnv*, jobject jrect, int x, int y);

    static SkIPoint* jpoint_to_ipoint(JNIEnv*, jobject jpoint, SkIPoint* point);
    static void ipoint_to_jpoint(const SkIPoint& point, JNIEnv*, jobject jpoint);

    static SkPoint* jpointf_to_point(JNIEnv*, jobject jpointf, SkPoint* point);
    static void point_to_jpointf(const SkPoint& point, JNIEnv*, jobject jpointf);

    static SkCanvas* getNativeCanvas(JNIEnv*, jobject canvas);
    static SkPaint*  getNativePaint(JNIEnv*, jobject paint);
    static SkBitmap* getNativeBitmap(JNIEnv*, jobject bitmap);
    static SkPicture* getNativePicture(JNIEnv*, jobject picture);
    static SkRegion* getNativeRegion(JNIEnv*, jobject region);

    /** Return the corresponding native config from the java Config enum,
        or kNo_Config if the java object is null.
    */
    static SkBitmap::Config getNativeBitmapConfig(JNIEnv*, jobject jconfig);

    /** Create a java Bitmap object given the native bitmap (required) and optional
        storage array (may be null).
    */
    static jobject createBitmap(JNIEnv* env, SkBitmap* bitmap, jbyteArray buffer,
            int bitmapCreateFlags, jbyteArray ninepatch, jintArray layoutbounds, int density = -1);

    static jobject createBitmap(JNIEnv* env, SkBitmap* bitmap, int bitmapCreateFlags,
            jbyteArray ninepatch, int density = -1);

    static void reinitBitmap(JNIEnv* env, jobject javaBitmap, SkBitmap* bitmap,
            bool isPremultiplied);

    static int getBitmapAllocationByteCount(JNIEnv* env, jobject javaBitmap);

    static jobject createRegion(JNIEnv* env, SkRegion* region);

    static jobject createBitmapRegionDecoder(JNIEnv* env, SkBitmapRegionDecoder* bitmap);

    static jbyteArray allocateJavaPixelRef(JNIEnv* env, SkBitmap* bitmap,
            SkColorTable* ctable);

    /** Copy the colors in colors[] to the bitmap, convert to the correct
        format along the way.
    */
    static bool SetPixels(JNIEnv* env, jintArray colors, int srcOffset,
            int srcStride, int x, int y, int width, int height,
            const SkBitmap& dstBitmap, bool isPremultiplied);

    static jbyteArray getBitmapStorageObj(SkPixelRef *pixref);
};

class AndroidPixelRef : public SkMallocPixelRef {
public:
    AndroidPixelRef(JNIEnv* env, void* storage, size_t size, jbyteArray storageObj,
                    SkColorTable* ctable);

    /**
     * Creates an AndroidPixelRef that wraps (and refs) another to reuse/share
     * the same storage and java byte array refcounting, yet have a different
     * color table.
     */
    AndroidPixelRef(AndroidPixelRef& wrappedPixelRef, SkColorTable* ctable);

    virtual ~AndroidPixelRef();

    jbyteArray getStorageObj();

    void setLocalJNIRef(jbyteArray arr);

    /** Used to hold a ref to the pixels when the Java bitmap may be collected.
     *  If specified, 'localref' is a valid JNI local reference to the byte array
     *  containing the pixel data.
     *
     *  'localref' may only be NULL if setLocalJNIRef() was already called with
     *  a JNI local ref that is still valid.
     */
    virtual void globalRef(void* localref=NULL);

    /** Release a ref that was acquired using globalRef(). */
    virtual void globalUnref();

private:
    AndroidPixelRef* const fWrappedPixelRef; // if set, delegate memory management calls to this

    JavaVM* fVM;
    bool fOnJavaHeap; // If true, the memory was allocated on the Java heap

    jbyteArray fStorageObj; // The Java byte[] object used as the bitmap backing store
    bool fHasGlobalRef; // If true, fStorageObj holds a JNI global ref

    mutable int32_t fGlobalRefCnt;
};

/** A helper class for accessing Java-heap-allocated bitmaps.
 *  This should be used when calling into a JNI method that retains a
 *  reference to the bitmap longer than the lifetime of the Java Bitmap.
 *
 *  After creating an instance of this class, a call to
 *  AndroidPixelRef::globalRef() will allocate a JNI global reference
 *  to the backing buffer object.
 */
class JavaHeapBitmapRef {
public:

    JavaHeapBitmapRef(JNIEnv *env, SkBitmap* nativeBitmap, jbyteArray buffer);
    ~JavaHeapBitmapRef();

private:
    JNIEnv* fEnv;
    SkBitmap* fNativeBitmap;
    jbyteArray fBuffer;
};

/** Allocator which allocates the backing buffer in the Java heap.
 *  Instances can only be used to perform a single allocation, which helps
 *  ensure that the allocated buffer is properly accounted for with a
 *  reference in the heap (or a JNI global reference).
 */
class JavaPixelAllocator : public SkBitmap::Allocator {
public:
    JavaPixelAllocator(JNIEnv* env);
    // overrides
    virtual bool allocPixelRef(SkBitmap* bitmap, SkColorTable* ctable);

    /** Return the Java array object created for the last allocation.
     *  This returns a local JNI reference which the caller is responsible
     *  for storing appropriately (usually by passing it to the Bitmap
     *  constructor).
     */
    jbyteArray getStorageObj() { return fStorageObj; }

    /** Same as getStorageObj(), but also resets the allocator so that it
     *  can allocate again.
     */
    jbyteArray getStorageObjAndReset() {
        jbyteArray result = fStorageObj;
        fStorageObj = NULL;
        fAllocCount = 0;
        return result;
    };

private:
    JavaVM* fVM;
    bool fAllocateInJavaHeap;
    jbyteArray fStorageObj;
    int fAllocCount;
};

enum JNIAccess {
    kRO_JNIAccess,
    kRW_JNIAccess
};

class AutoJavaFloatArray {
public:
    AutoJavaFloatArray(JNIEnv* env, jfloatArray array,
                       int minLength = 0, JNIAccess = kRW_JNIAccess);
    ~AutoJavaFloatArray();

    float* ptr() const { return fPtr; }
    int    length() const { return fLen; }

private:
    JNIEnv*     fEnv;
    jfloatArray fArray;
    float*      fPtr;
    int         fLen;
    int         fReleaseMode;
};

class AutoJavaIntArray {
public:
    AutoJavaIntArray(JNIEnv* env, jintArray array, int minLength = 0);
    ~AutoJavaIntArray();

    jint* ptr() const { return fPtr; }
    int    length() const { return fLen; }

private:
    JNIEnv*     fEnv;
    jintArray fArray;
    jint*      fPtr;
    int         fLen;
};

class AutoJavaShortArray {
public:
    AutoJavaShortArray(JNIEnv* env, jshortArray array,
                       int minLength = 0, JNIAccess = kRW_JNIAccess);
    ~AutoJavaShortArray();

    jshort* ptr() const { return fPtr; }
    int    length() const { return fLen; }

private:
    JNIEnv*     fEnv;
    jshortArray fArray;
    jshort*      fPtr;
    int         fLen;
    int         fReleaseMode;
};

class AutoJavaByteArray {
public:
    AutoJavaByteArray(JNIEnv* env, jbyteArray array, int minLength = 0);
    ~AutoJavaByteArray();

    jbyte* ptr() const { return fPtr; }
    int    length() const { return fLen; }

private:
    JNIEnv*     fEnv;
    jbyteArray fArray;
    jbyte*      fPtr;
    int         fLen;
};

void doThrowNPE(JNIEnv* env);
void doThrowAIOOBE(JNIEnv* env); // Array Index Out Of Bounds Exception
void doThrowIAE(JNIEnv* env, const char* msg = NULL);   // Illegal Argument
void doThrowRE(JNIEnv* env, const char* msg = NULL);   // Runtime
void doThrowISE(JNIEnv* env, const char* msg = NULL);   // Illegal State
void doThrowOOME(JNIEnv* env, const char* msg = NULL);   // Out of memory
void doThrowIOE(JNIEnv* env, const char* msg = NULL);   // IO Exception

#define NPE_CHECK_RETURN_ZERO(env, object)    \
    do { if (NULL == (object)) { doThrowNPE(env); return 0; } } while (0)

#define NPE_CHECK_RETURN_VOID(env, object)    \
    do { if (NULL == (object)) { doThrowNPE(env); return; } } while (0)

#endif