Android中自定义View播放GIF

参考网址：https://github.com/loonggg/GifViewDemo

res/values下attr.xml

<?xml version="1.0" encoding="utf-8"?>
<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>

res/values下styles.xml

<resources>
    <style name="Widget.GifView" parent="@android:style/Widget"/>
</resources>

自定义View

package com.draw;

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.draw.R;

public class GifView extends View {

    /** gift动态效果总时长，在未设置时长时默认为1秒 */
    private static final int DEFAULT_MOVIE_DURATION = 1000;
    /** gift图片资源ID */
    private int mMovieResourceId;
    /** Movie实例，用来显示gift图片 */
    private Movie mMovie;
    /** 显示gift图片的动态效果的开始时间 */
    private long mMovieStart;
    /** 动态图当前显示第几帧 */
    private int mCurrentAnimationTime = 0;
    /** 图片离屏幕左边的距离 */
    private float mLeft;
    /** 图片离屏幕上边的距离 */
    private float mTop;
    /** 图片的缩放比例 */
    private float mScale;
    /** 图片在屏幕上显示的宽度 */
    private int mMeasuredMovieWidth;
    /** 图片在屏幕上显示的高度 */
    private int mMeasuredMovieHeight;
    /** 是否显示动画,为true表示显示，false表示不显示 */
    private boolean mVisible = true;
    /** 动画效果是否被暂停 */
    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);
    }

    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.Widget_GifView);
        mMovieResourceId = array.getResourceId(R.styleable.GifView_gif, -1);
        mPaused = array.getBoolean(R.styleable.GifView_paused, false);
        array.recycle();
        if (mMovieResourceId != -1) {
            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() {
        //是获取系统从开机启动到现在的时间,期间不包括休眠的时间,
        // 这里获得到的时间是一个相对的时间,而不是通过获取当前的时间(绝对时间)
        long now = android.os.SystemClock.uptimeMillis();
        // 如果第一帧，记录起始时间
        if (mMovieStart == 0) {
            mMovieStart = now;
        }
        // 取出动画的时长
        int dur = mMovie.duration();
        if (dur == 0) {
            dur = DEFAULT_MOVIE_DURATION;
        }
        // 算出需要显示第几帧
        //  /10调整GIF每一帧切换的速度
        mCurrentAnimationTime = (int) ((now - mMovieStart)/10 % 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();
    }

}

代码中使用

public class Gif extends Activity {
	private GifView gif1;
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		gif1 = (GifView) findViewById(R.id.gif1);
		// 设置背景gif图片资源
		gif1.setMovieResource(R.raw.kitty);
		// 设置暂停
		// gif1.setPaused(true);
	}

}

布局中使用

<com.draw.GifView
    android:id="@+id/gif1"
    android:layout_width="50dp"
    android:layout_height="50dp"
    android:layout_marginLeft="35dp"
    android:enabled="false" />