GifView实现笔记，真正的成功实现Gif播放

GifView实现笔记，真正的成功实现Gif播放

本文属于记录学习实现GifView播放gif图片，由于时间久，已经忘记了是向哪个大神写的文章学习的了，现将源码贴出来，一作个人笔记用，二作为技术共享，供学习交流用。源码如下：

GIFView.java

package com.sage.org.view;

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.sage.org.R;
/**

• 用来显示Gif图片的
  */
  public class GifView extends View {

  private static final int DEFAULT_MOVIE_DURATION = 1000;

  private int mMovieResourceId;

  private Movie mMovie;

  private long mMovieStart;

  private int mCurrentAnimationTime = 0;

  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);
  }

  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) {
  setLayerType(View.LAYER_TYPE_SOFTWARE, null);
  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));
  }
  }

  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();
  }

  public void setPaused(boolean paused) {
  this.mPaused = paused;
  if (!paused) {
  mMovieStart = android.os.SystemClock.uptimeMillis()
  - mCurrentAnimationTime;
  }
  invalidate();
  }

  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();
  if (mMovieStart == 0) {
  mMovieStart = now;
  }
  int dur = mMovie.duration();
  if (dur == 0) {
  dur = DEFAULT_MOVIE_DURATION;
  }
  mCurrentAnimationTime = (int) ((now - mMovieStart) % dur);
  }

  private void drawMovieFrame(Canvas canvas) {
  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();
  }
  }

还需要attrs.xml里面添加：

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

界面引用：
//注意： 替换inputstream为实际的gif，引用即时的context，将GifView添加到容器组件
Movie movie = Movie.decodeStream(inpustream);
GifView gifView = new GifView(context);
gifView.setPaused(false);
gifView.setMovie(movie);

布局引用：
// 将gif_1替换为实际的gif图片
<com.vogtec.sdk.ui.view.GifView
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
app:gif="@raw/gif_1"
app:paused=“false”
/>