用Movie显示gif(2)GifView

1,类

 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.Canvas;
 import android.graphics.Movie;
 import android.os.Build;
 import android.util.AttributeSet;
 import android.view.View;

 import com.e.weixin.R;

 public class GifView extends View {

     /**
      * 默认为1秒
      */
     private static final int DEFAULT_MOVIE_DURATION = ;

     private int mMovieResourceId;   //要显示的gif的id

     private Movie mMovie;           //用于播放gif等

     private long mMovieStart;       //

     private int mCurrentAnimationTime = ;

     private float mLeft;

     private float mTop;

     private float mScale;

     private int mMeasuredMovieWidth;

     private int mMeasuredMovieHeight;

     private boolean mVisible = true;

     private volatile boolean mPaused = false;

     public GifView(Context context) {
         this(context, null);
     }

     public GifView(Context context, AttributeSet attrs) {
         this(context, attrs, R.styleable.CustomTheme_gifViewStyle);
 //        super(context, attrs);
     }

     public GifView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         setViewAttributes(context, attrs, defStyle);
     }

     @SuppressLint("NewApi")
     private void setViewAttributes(Context context, AttributeSet attrs,int defStyle) {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
             setLayerType(View.LAYER_TYPE_SOFTWARE, null);
         }
         // 从描述文件中读出gif的值，创建出Movie实例
         final TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.GifView, defStyle,
                 R.style.Theme_GifView);
         mMovieResourceId = array.getResourceId(R.styleable.GifView_gif, -);
         mPaused = array.getBoolean(R.styleable.GifView_paused, false);
         array.recycle();
         if (mMovieResourceId != -) {
             mMovie = Movie.decodeStream(getResources().openRawResource(mMovieResourceId));
         }
     }

     /**
      * 设置gif图资源
      *
      * @param movieResId
      */
     public void setMovieResource(int movieResId) {
         this.mMovieResourceId = movieResId;
         mMovie = Movie.decodeStream(getResources().openRawResource(mMovieResourceId));
         requestLayout();
     }

     public void setMovie(Movie movie) {
         this.mMovie = movie;
         requestLayout();
     }

     public Movie getMovie() {
         return mMovie;
     }

     public void setMovieTime(int time) {
         mCurrentAnimationTime = time;
         invalidate();
     }

     /**
      * 设置暂停
      *
      * @param paused
      */
     public void setPaused(boolean paused) {
         this.mPaused = paused;
         if (!paused) {
             mMovieStart = android.os.SystemClock.uptimeMillis() - mCurrentAnimationTime;
         }
         invalidate();
     }

     /**
      * 判断gif图是否停止了
      *
      * @return
      */
     public boolean isPaused() {
         return this.mPaused;
     }

     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         if (mMovie != null) {
             int movieWidth = mMovie.width();
             int movieHeight = mMovie.height();
             int maximumWidth = MeasureSpec.getSize(widthMeasureSpec);
             float scaleW = (float) movieWidth / (float) maximumWidth;
             mScale = 1f / scaleW;
             mMeasuredMovieWidth = maximumWidth;
             mMeasuredMovieHeight = (int) (movieHeight * mScale);
             setMeasuredDimension(mMeasuredMovieWidth, mMeasuredMovieHeight);
         } else {
             setMeasuredDimension(getSuggestedMinimumWidth(),getSuggestedMinimumHeight());
         }
     }

     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
         super.onLayout(changed, l, t, r, b);
         mLeft = (getWidth() - mMeasuredMovieWidth) / 2f;
         mTop = (getHeight() - mMeasuredMovieHeight) / 2f;
         mVisible = getVisibility() == View.VISIBLE;
     }

     @Override
     protected void onDraw(Canvas canvas) {
         if (mMovie != null) {
             if (!mPaused) {
                 updateAnimationTime();
                 drawMovieFrame(canvas);
                 invalidateView();
             } else {
                 drawMovieFrame(canvas);
             }
         }
     }

     @SuppressLint("NewApi")
     private void invalidateView() {
         if (mVisible) {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                 postInvalidateOnAnimation();
             } else {
                 invalidate();
             }
         }
     }

     private void updateAnimationTime() {
         long now = android.os.SystemClock.uptimeMillis();
         // 如果第一帧，记录起始时间
         if (mMovieStart == ) {
             mMovieStart = now;
         }
         // 取出动画的时长
         int dur = mMovie.duration();
         if (dur == ) {
             dur = DEFAULT_MOVIE_DURATION;
         }
         // 算出需要显示第几帧
         mCurrentAnimationTime = (int) ((now - mMovieStart) % dur);
     }

     private void drawMovieFrame(Canvas canvas) {
         // 设置要显示的帧，绘制即可
         mMovie.setTime(mCurrentAnimationTime);
         canvas.save(Canvas.MATRIX_SAVE_FLAG);
         canvas.scale(mScale, mScale);
         mMovie.draw(canvas, mLeft / mScale, mTop / mScale);
         canvas.restore();
     }

     @SuppressLint("NewApi")
     @Override
     public void onScreenStateChanged(int screenState) {
         super.onScreenStateChanged(screenState);
         mVisible = screenState == SCREEN_STATE_ON;
         invalidateView();
     }

     @SuppressLint("NewApi")
     @Override
     protected void onVisibilityChanged(View changedView, int visibility) {
         super.onVisibilityChanged(changedView, visibility);
         mVisible = visibility == View.VISIBLE;
         invalidateView();
     }

     @Override
     protected void onWindowVisibilityChanged(int visibility) {
         super.onWindowVisibilityChanged(visibility);
         mVisible = visibility == View.VISIBLE;
         invalidateView();
     }
 }

2，自定义view的属性

 <resources>

     <declare-styleable name="GifView">
         <attr name="gif" format="reference" />
         <attr name="paused" format="boolean" />
     </declare-styleable>
     <declare-styleable name="CustomTheme">
         <attr name="gifViewStyle" format="reference" />
     </declare-styleable>

 </resources>

3，使用到的主题

     <style name="Theme.GifView" parent="@android:style/Theme.Dialog">
         <!--...-->
     </style>

　　不用非继承 @android:style/Theme.Dialog 不可，其它主题也可以。