/**
* 播放动画的主类
*/
@SuppressLint("AppCompatCustomView")
public class GifImageViewextends ImageViewimplements View.OnClickListener {
private MoviemMovie;//播放动画需要用到的，系统类
private int mImageWidth;//动画的imageview的宽度
private int mImageHeight;//动画imageview的高度
private long mMovieStart =0;// 播放开始
private boolean isAutoPlay;//是否自动播放
private BitmapmStartPlay;//开始按钮
private boolean isPlaying =false;//记录是否正在播放
/**
* Scaling factor to fit the animation within view bounds.
*/
private float mScale;
/**
* Scaled movie frames width and height.
*/
private int mMeasuredGifWidth;
private int mMeasuredGifHeight;
public GifImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context, attrs);
}
public GifImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public GifImageView(Context context) {
super(context);
}
private void init(Context context, AttributeSet attrs) {
TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.GifImageView);
// 通过反射拿布局中src的资源id,所以gif文件需要放在布局的src中
int resourceId = getResourceId(attributes, context, attrs);
if (resourceId !=0) {
// 说明是gif动画
// 1.将resourcesId变成流
// 2.用Move来decode解析流
// 3.获得bitmap的长宽
InputStream is = getResources().openRawResource(resourceId);
mMovie = Movie.decodeStream(is);
if (mMovie !=null) {
Bitmap bitmap = BitmapFactory.decodeStream(is);
mImageWidth = bitmap.getWidth();
mImageHeight = bitmap.getHeight();
// 用完释放
bitmap.recycle();
// 获得是否允许自动播放，如果不允许自动播放，则初始化播放按钮
isAutoPlay = attributes.getBoolean(R.styleable.GifImageView_auto_play, false);
if (!isAutoPlay) {
mStartPlay = BitmapFactory.decodeResource(getResources(), R.drawable.play);
setOnClickListener(this);
}
}
}
//回收资源
if (attributes !=null) {
attributes.recycle();
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mMovie !=null) {
/*
* Calculate horizontal scaling
*/
float scaleW =1f;
int measureModeWidth = MeasureSpec.getMode(widthMeasureSpec);
if (measureModeWidth != MeasureSpec.UNSPECIFIED) {
int maximumWidth = MeasureSpec.getSize(widthMeasureSpec);
scaleW = (float)mImageWidth / (float) maximumWidth;
}
/*
* calculate vertical scaling
*/
float scaleH =1f;
int measureModeHeight = MeasureSpec.getMode(heightMeasureSpec);
if (measureModeHeight != MeasureSpec.UNSPECIFIED) {
int maximumHeight = MeasureSpec.getSize(heightMeasureSpec);
scaleH = (float)mImageHeight / (float) maximumHeight;
}
/*
* calculate overall scale
*/
mScale =1f / Math.max(scaleH, scaleW);
mMeasuredGifWidth = (int) (mImageWidth *mScale);
mMeasuredGifHeight = (int) (mImageHeight *mScale);
setMeasuredDimension(mMeasuredGifWidth, mMeasuredGifHeight);
}
}
@SuppressLint("WrongConstant")
@Override
protected void onDraw(Canvas canvas) {
if (mMovie ==null) {
// mMovie等于null，说明是张普通的图片，则直接调用父类的onDraw()方法
super.onDraw(canvas);
}else {
// mMovie不等于null，说明是张GIF图片
if (isAutoPlay) {
// 如果允许自动播放，就播放
playMovie(canvas);
invalidate();
}else {
// 不允许自动播放的话
// 1.判断是否正在播放
// 2.获得第一帧的图像
// 3.然后添加播放按钮
if (isPlaying) {
// 如果正在播放就playmoive继续播放
if (playMovie(canvas)) {
isPlaying =false;
}
invalidate();
}else {
// 第一帧
mMovie.setTime(0);
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(mScale, mScale);
mMovie.draw(canvas, 0, 0);// 画
canvas.restore();
// 绘制开始按钮
int offsetW = (mMeasuredGifWidth -mStartPlay.getWidth()) /2;
int offsetH = (mMeasuredGifHeight -mStartPlay.getHeight()) /2;
canvas.drawBitmap(mStartPlay, offsetW, offsetH, null);
}
}
}
}
/**
* 播放gif动画
*
* @param canvas
*/
@SuppressLint("WrongConstant")
private boolean playMovie(Canvas canvas) {
// 1.获取播放的时间
// 2.如果开始start=0，则认为是开始
// 3.记录播放的时间
// 4.设置进度
// 5.画动画
// 6.如果时间大于了播放的时间，则证明结束
long now = SystemClock.uptimeMillis();
if (mMovieStart ==0) {
mMovieStart = now;
}
int duration =mMovie.duration();
if (duration ==0) {
duration =1000;
}
//记录gif播放了多少时间
int relTime = (int) ((now -mMovieStart) % duration);
mMovie.setTime(relTime);// 设置时间
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(mScale, mScale);
mMovie.draw(canvas, 0, 0);// 画
canvas.restore();
if ((now -mMovieStart) >= duration) {
// 结束
mMovieStart =0;
return true;
}
return false;
}
/**
* 通过反射拿布局中src的资源id
*
* @param attrs
* @param context
* @param attributes
*/
private int getResourceId(TypedArray attributes, Context context, AttributeSet attrs) {
try {
Field filed = TypedArray.class.getDeclaredField("mValue");
filed.setAccessible(true);
TypedValue typeValue = (TypedValue) filed.get(attributes);
return typeValue.resourceId;
}catch (Exception e) {
e.printStackTrace();
}
return 0;
}
@Override
public void onClick(View v) {
if (v.getId() == getId()) {
isPlaying =true;
invalidate();
}
}
}
