core/jni/android/graphics/AnimatedImageDrawable.cpp

/*
 * Copyright (C) 2018 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.
 */

#include "GraphicsJNI.h"
#include "ImageDecoder.h"
#include "Utils.h"
#include "core_jni_helpers.h"

#include <SkAndroidCodec.h>
#include <SkAnimatedImage.h>
#include <SkColorFilter.h>
#include <SkPicture.h>
#include <SkPictureRecorder.h>
#include <hwui/AnimatedImageDrawable.h>
#include <hwui/Canvas.h>
#include <utils/Looper.h>

using namespace android;

static jmethodID gAnimatedImageDrawable_onAnimationEndMethodID;

// Note: jpostProcess holds a handle to the ImageDecoder.
static jlong AnimatedImageDrawable_nCreate(JNIEnv* env, jobject /*clazz*/,
                                           jlong nativeImageDecoder, jobject jpostProcess,
                                           jint width, jint height, jobject jsubset) {
    if (nativeImageDecoder == 0) {
        doThrowIOE(env, "Cannot create AnimatedImageDrawable from null!");
        return 0;
    }

    auto* imageDecoder = reinterpret_cast<ImageDecoder*>(nativeImageDecoder);
    const SkISize scaledSize = SkISize::Make(width, height);
    SkIRect subset;
    if (jsubset) {
        GraphicsJNI::jrect_to_irect(env, jsubset, &subset);
    } else {
        subset = SkIRect::MakeWH(width, height);
    }

    auto info = imageDecoder->mCodec->getInfo();
    bool hasRestoreFrame = false;
    if (imageDecoder->mCodec->getEncodedFormat() == SkEncodedImageFormat::kWEBP) {
        if (width < info.width() && height < info.height()) {
            // WebP will scale its SkBitmap to the scaled size.
            // FIXME: b/73529447 GIF should do the same.
            info = info.makeWH(width, height);
        }
    } else {
        const int frameCount = imageDecoder->mCodec->codec()->getFrameCount();
        for (int i = 0; i < frameCount; ++i) {
            SkCodec::FrameInfo frameInfo;
            if (!imageDecoder->mCodec->codec()->getFrameInfo(i, &frameInfo)) {
                doThrowIOE(env, "Failed to read frame info!");
                return 0;
            }
            if (frameInfo.fDisposalMethod == SkCodecAnimation::DisposalMethod::kRestorePrevious) {
                hasRestoreFrame = true;
                break;
            }
        }
    }

    size_t bytesUsed = info.computeMinByteSize();
    // SkAnimatedImage has one SkBitmap for decoding, plus an extra one if there is a
    // kRestorePrevious frame. AnimatedImageDrawable has two SkPictures storing the current
    // frame and the next frame. (The former assumes that the image is animated, and the
    // latter assumes that it is drawn to a hardware canvas.)
    bytesUsed *= hasRestoreFrame ? 4 : 3;
    sk_sp<SkPicture> picture;
    if (jpostProcess) {
        SkRect bounds = SkRect::MakeWH(subset.width(), subset.height());

        SkPictureRecorder recorder;
        SkCanvas* skcanvas = recorder.beginRecording(bounds);
        std::unique_ptr<Canvas> canvas(Canvas::create_canvas(skcanvas));
        postProcessAndRelease(env, jpostProcess, std::move(canvas));
        if (env->ExceptionCheck()) {
            return 0;
        }
        picture = recorder.finishRecordingAsPicture();
        bytesUsed += picture->approximateBytesUsed();
    }


    sk_sp<SkAnimatedImage> animatedImg = SkAnimatedImage::Make(std::move(imageDecoder->mCodec),
                                                               scaledSize, subset,
                                                               std::move(picture));
    if (!animatedImg) {
        doThrowIOE(env, "Failed to create drawable");
        return 0;
    }

    bytesUsed += sizeof(animatedImg.get());

    sk_sp<AnimatedImageDrawable> drawable(new AnimatedImageDrawable(std::move(animatedImg),
                                                                    bytesUsed));
    return reinterpret_cast<jlong>(drawable.release());
}

static void AnimatedImageDrawable_destruct(AnimatedImageDrawable* drawable) {
    SkSafeUnref(drawable);
}

static jlong AnimatedImageDrawable_nGetNativeFinalizer(JNIEnv* /*env*/, jobject /*clazz*/) {
    return static_cast<jlong>(reinterpret_cast<uintptr_t>(&AnimatedImageDrawable_destruct));
}

// Java's FINISHED relies on this being -1
static_assert(SkAnimatedImage::kFinished == -1);

static jlong AnimatedImageDrawable_nDraw(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                         jlong canvasPtr) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    auto* canvas = reinterpret_cast<Canvas*>(canvasPtr);
    return (jlong) canvas->drawAnimatedImage(drawable);
}

static void AnimatedImageDrawable_nSetAlpha(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                            jint alpha) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    drawable->setStagingAlpha(alpha);
}

static jlong AnimatedImageDrawable_nGetAlpha(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    return drawable->getStagingAlpha();
}

static void AnimatedImageDrawable_nSetColorFilter(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                                  jlong nativeFilter) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    auto* filter = reinterpret_cast<SkColorFilter*>(nativeFilter);
    drawable->setStagingColorFilter(sk_ref_sp(filter));
}

static jboolean AnimatedImageDrawable_nIsRunning(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    return drawable->isRunning();
}

static jboolean AnimatedImageDrawable_nStart(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    return drawable->start();
}

static jboolean AnimatedImageDrawable_nStop(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    return drawable->stop();
}

// Java's LOOP_INFINITE relies on this being the same.
static_assert(SkCodec::kRepetitionCountInfinite == -1);

static jint AnimatedImageDrawable_nGetRepeatCount(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    return drawable->getRepetitionCount();
}

static void AnimatedImageDrawable_nSetRepeatCount(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                                  jint loopCount) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    drawable->setRepetitionCount(loopCount);
}

class InvokeListener : public MessageHandler {
public:
    InvokeListener(JNIEnv* env, jobject javaObject) {
        LOG_ALWAYS_FATAL_IF(env->GetJavaVM(&mJvm) != JNI_OK);
        // Hold a weak reference to break a cycle that would prevent GC.
        mWeakRef = env->NewWeakGlobalRef(javaObject);
    }

    ~InvokeListener() override {
        auto* env = get_env_or_die(mJvm);
        env->DeleteWeakGlobalRef(mWeakRef);
    }

    virtual void handleMessage(const Message&) override {
        auto* env = get_env_or_die(mJvm);
        jobject localRef = env->NewLocalRef(mWeakRef);
        if (localRef) {
            env->CallVoidMethod(localRef, gAnimatedImageDrawable_onAnimationEndMethodID);
        }
    }

private:
    JavaVM* mJvm;
    jweak mWeakRef;
};

class JniAnimationEndListener : public OnAnimationEndListener {
public:
    JniAnimationEndListener(sp<Looper>&& looper, JNIEnv* env, jobject javaObject) {
        mListener = new InvokeListener(env, javaObject);
        mLooper = std::move(looper);
    }

    void onAnimationEnd() override { mLooper->sendMessage(mListener, 0); }

private:
    sp<InvokeListener> mListener;
    sp<Looper> mLooper;
};

static void AnimatedImageDrawable_nSetOnAnimationEndListener(JNIEnv* env, jobject /*clazz*/,
                                                             jlong nativePtr, jobject jdrawable) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    if (!jdrawable) {
        drawable->setOnAnimationEndListener(nullptr);
    } else {
        sp<Looper> looper = Looper::getForThread();
        if (!looper.get()) {
            doThrowISE(env,
                       "Must set AnimatedImageDrawable's AnimationCallback on a thread with a "
                       "looper!");
            return;
        }

        drawable->setOnAnimationEndListener(
                std::make_unique<JniAnimationEndListener>(std::move(looper), env, jdrawable));
    }
}

static jlong AnimatedImageDrawable_nNativeByteSize(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    return drawable->byteSize();
}

static void AnimatedImageDrawable_nSetMirrored(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                               jboolean mirrored) {
    auto* drawable = reinterpret_cast<AnimatedImageDrawable*>(nativePtr);
    drawable->setStagingMirrored(mirrored);
}

static const JNINativeMethod gAnimatedImageDrawableMethods[] = {
    { "nCreate",             "(JLandroid/graphics/ImageDecoder;IILandroid/graphics/Rect;)J", (void*) AnimatedImageDrawable_nCreate },
    { "nGetNativeFinalizer", "()J",                                                          (void*) AnimatedImageDrawable_nGetNativeFinalizer },
    { "nDraw",               "(JJ)J",                                                        (void*) AnimatedImageDrawable_nDraw },
    { "nSetAlpha",           "(JI)V",                                                        (void*) AnimatedImageDrawable_nSetAlpha },
    { "nGetAlpha",           "(J)I",                                                         (void*) AnimatedImageDrawable_nGetAlpha },
    { "nSetColorFilter",     "(JJ)V",                                                        (void*) AnimatedImageDrawable_nSetColorFilter },
    { "nIsRunning",          "(J)Z",                                                         (void*) AnimatedImageDrawable_nIsRunning },
    { "nStart",              "(J)Z",                                                         (void*) AnimatedImageDrawable_nStart },
    { "nStop",               "(J)Z",                                                         (void*) AnimatedImageDrawable_nStop },
    { "nGetRepeatCount",     "(J)I",                                                         (void*) AnimatedImageDrawable_nGetRepeatCount },
    { "nSetRepeatCount",     "(JI)V",                                                        (void*) AnimatedImageDrawable_nSetRepeatCount },
    { "nSetOnAnimationEndListener", "(JLandroid/graphics/drawable/AnimatedImageDrawable;)V", (void*) AnimatedImageDrawable_nSetOnAnimationEndListener },
    { "nNativeByteSize",     "(J)J",                                                         (void*) AnimatedImageDrawable_nNativeByteSize },
    { "nSetMirrored",        "(JZ)V",                                                        (void*) AnimatedImageDrawable_nSetMirrored },
};

int register_android_graphics_drawable_AnimatedImageDrawable(JNIEnv* env) {
    jclass animatedImageDrawable_class = FindClassOrDie(env, "android/graphics/drawable/AnimatedImageDrawable");
    gAnimatedImageDrawable_onAnimationEndMethodID = GetMethodIDOrDie(env, animatedImageDrawable_class, "onAnimationEnd", "()V");

    return android::RegisterMethodsOrDie(env, "android/graphics/drawable/AnimatedImageDrawable",
            gAnimatedImageDrawableMethods, NELEM(gAnimatedImageDrawableMethods));
}