Display Animated GIF

2018-12-31 04:58发布

I want to display animated GIF images in my aplication. As I found out the hard way Android doesn't support animated GIF natively.

However it can display animations using AnimationDrawable:

Develop > Guides > Images & Graphics > Drawables Overview

The example uses animation saved as frames in application resources but what I need is to display animated gif directly.

My plan is to break animated GIF to frames and add each frame as drawable to AnimationDrawable.

Does anyone know how to extract frames from animated GIF and convert each of them into Drawable?

29条回答
永恒的永恒
2楼-- · 2018-12-31 05:30

Android actually can decode and display animated GIFs, using android.graphics.Movie class.

This is not too much documented, but is in SDK Reference. Moreover, it is used in Samples in ApiDemos in BitmapDecode example with some animated flag.

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有味是清欢
3楼-- · 2018-12-31 05:30
public class Test extends GraphicsActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new SampleView(this));
  }

  private static class SampleView extends View {
    private Bitmap mBitmap;
    private Bitmap mBitmap2;
    private Bitmap mBitmap3;
    private Bitmap mBitmap4;
    private Drawable mDrawable;

    private Movie mMovie;
    private long mMovieStart;

    // Set to false to use decodeByteArray
    private static final boolean DECODE_STREAM = true;

    private static byte[] streamToBytes(InputStream is) {
      ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
      byte[] buffer = new byte[1024];
      int len;
      try {
        while ((len = is.read(buffer)) >= 0) {
          os.write(buffer, 0, len);
        }
      } catch (java.io.IOException e) {
      }
      return os.toByteArray();
    }

    public SampleView(Context context) {
      super(context);
      setFocusable(true);

      java.io.InputStream is;
      is = context.getResources().openRawResource(R.drawable.icon);

      BitmapFactory.Options opts = new BitmapFactory.Options();
      Bitmap bm;

      opts.inJustDecodeBounds = true;
      bm = BitmapFactory.decodeStream(is, null, opts);

      // now opts.outWidth and opts.outHeight are the dimension of the
      // bitmap, even though bm is null

      opts.inJustDecodeBounds = false; // this will request the bm
      opts.inSampleSize = 4; // scaled down by 4
      bm = BitmapFactory.decodeStream(is, null, opts);

      mBitmap = bm;

      // decode an image with transparency
      is = context.getResources().openRawResource(R.drawable.icon);
      mBitmap2 = BitmapFactory.decodeStream(is);

      // create a deep copy of it using getPixels() into different configs
      int w = mBitmap2.getWidth();
      int h = mBitmap2.getHeight();
      int[] pixels = new int[w * h];
      mBitmap2.getPixels(pixels, 0, w, 0, 0, w, h);
      mBitmap3 = Bitmap.createBitmap(pixels, 0, w, w, h,
          Bitmap.Config.ARGB_8888);
      mBitmap4 = Bitmap.createBitmap(pixels, 0, w, w, h,
          Bitmap.Config.ARGB_4444);

      mDrawable = context.getResources().getDrawable(R.drawable.icon);
      mDrawable.setBounds(150, 20, 300, 100);

      is = context.getResources().openRawResource(R.drawable.animated_gif);

      if (DECODE_STREAM) {
        mMovie = Movie.decodeStream(is);
      } else {
        byte[] array = streamToBytes(is);
        mMovie = Movie.decodeByteArray(array, 0, array.length);
      }
    }

    @Override
    protected void onDraw(Canvas canvas) {
      canvas.drawColor(0xFFCCCCCC);

      Paint p = new Paint();
      p.setAntiAlias(true);

      canvas.drawBitmap(mBitmap, 10, 10, null);
      canvas.drawBitmap(mBitmap2, 10, 170, null);
      canvas.drawBitmap(mBitmap3, 110, 170, null);
      canvas.drawBitmap(mBitmap4, 210, 170, null);

      mDrawable.draw(canvas);

      long now = android.os.SystemClock.uptimeMillis();
      if (mMovieStart == 0) { // first time
        mMovieStart = now;
      }
      if (mMovie != null) {
        int dur = mMovie.duration();
        if (dur == 0) {
          dur = 1000;
        }
        int relTime = (int) ((now - mMovieStart) % dur);
        mMovie.setTime(relTime);
        mMovie.draw(canvas, getWidth() - mMovie.width(), getHeight()
            - mMovie.height());
        invalidate();
      }
    }
  }
}

class GraphicsActivity extends Activity {
  // set to true to test Picture
  private static final boolean TEST_PICTURE = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  }

  @Override
  public void setContentView(View view) {
    if (TEST_PICTURE) {
      ViewGroup vg = new PictureLayout(this);
      vg.addView(view);
      view = vg;
    }

    super.setContentView(view);
  }
}

class PictureLayout extends ViewGroup {
  private final Picture mPicture = new Picture();

  public PictureLayout(Context context) {
    super(context);
  }

  public PictureLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  @Override
  public void addView(View child) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child);
  }

  @Override
  public void addView(View child, int index) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index);
  }

  @Override
  public void addView(View child, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, params);
  }

  @Override
  public void addView(View child, int index, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index, params);
  }

  @Override
  protected LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(LayoutParams.MATCH_PARENT,
        LayoutParams.MATCH_PARENT);
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int count = getChildCount();

    int maxHeight = 0;
    int maxWidth = 0;

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        measureChild(child, widthMeasureSpec, heightMeasureSpec);
      }
    }

    maxWidth += getPaddingLeft() + getPaddingRight();
    maxHeight += getPaddingTop() + getPaddingBottom();

    Drawable drawable = getBackground();
    if (drawable != null) {
      maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
      maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
    }

    setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
        resolveSize(maxHeight, heightMeasureSpec));
  }

  private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx,
      float sy) {
    canvas.save();
    canvas.translate(x, y);
    canvas.clipRect(0, 0, w, h);
    canvas.scale(0.5f, 0.5f);
    canvas.scale(sx, sy, w, h);
    canvas.drawPicture(mPicture);
    canvas.restore();
  }

  @Override
  protected void dispatchDraw(Canvas canvas) {
    super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
    mPicture.endRecording();

    int x = getWidth() / 2;
    int y = getHeight() / 2;

    if (false) {
      canvas.drawPicture(mPicture);
    } else {
      drawPict(canvas, 0, 0, x, y, 1, 1);
      drawPict(canvas, x, 0, x, y, -1, 1);
      drawPict(canvas, 0, y, x, y, 1, -1);
      drawPict(canvas, x, y, x, y, -1, -1);
    }
  }

  @Override
  public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
    location[0] = getLeft();
    location[1] = getTop();
    dirty.set(0, 0, getWidth(), getHeight());
    return getParent();
  }

  @Override
  protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = super.getChildCount();

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        final int childLeft = getPaddingLeft();
        final int childTop = getPaddingTop();
        child.layout(childLeft, childTop,
            childLeft + child.getMeasuredWidth(),
            childTop + child.getMeasuredHeight());

      }
    }
  }
}
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旧时光的记忆
4楼-- · 2018-12-31 05:31

Easiest way - Can be consider the below code

We can take advantage of Imageview setImageResource , refer below code for the same.

The below code can be used to show the image like gif incase if you have the multiple split image of gif. Just split the gif into individual png from a online tool and put image in the drawable like the below order

image_1.png, image_2.png, etc.

Have the handler to change the image dynamically.

int imagePosition = 1;
    Handler handler = new Handler();
        Runnable runnable = new Runnable() {
            public void run() {
                updateImage();
            }
        };




    public void updateImage() {

                appInstance.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        int resId = getResources().getIdentifier("image_" + imagePosition, "drawable", appInstance.getPackageName());
                        gifImageViewDummy.setImageResource(resId);
                        imagePosition++;
    //Consider you have 30 image for the anim
                        if (imagePosition == 30) {
//this make animation play only once
                            handler.removeCallbacks(runnable);

                        } else {
    //You can define your own time based on the animation
                            handler.postDelayed(runnable, 50);
                        }

//to make animation to continue use below code and remove above if else
// if (imagePosition == 30)
//imagePosition = 1;
// handler.postDelayed(runnable, 50);
// 
                    }
                });
              }
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人气声优
5楼-- · 2018-12-31 05:31

The easy way to display animated GIF directly from URL to your app layout is to use WebView class.

Step 1: In your layout XML

<WebView
android:id="@+id/webView"
android:layout_width="50dp"
android:layout_height="50dp"
/>

Step 2: In your Activity

WebView wb;
wb = (WebView) findViewById(R.id.webView);
wb.loadUrl("https://.......);

Step 3: In your Manifest.XML make Internet permission

<uses-permission android:name="android.permission.INTERNET" />

Step 4: In case you want to make your GIF background transparent and make GIF fit to your Layout

wb.setBackgroundColor(Color.TRANSPARENT);
wb.getSettings().setLoadWithOverviewMode(true);
wb.getSettings().setUseWideViewPort(true);

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与君花间醉酒
6楼-- · 2018-12-31 05:32

Some thoughts on the BitmapDecode example... Basically it uses the ancient, but rather featureless Movie class from android.graphics. On recent API versions you need to turn off hardware acceleration, as described here. It was segfaulting for me otherwise.

<activity
            android:hardwareAccelerated="false"
            android:name="foo.GifActivity"
            android:label="The state of computer animation 2014">
</activity>

Here is the BitmapDecode example shortened with only the GIF part. You have to make your own Widget (View) and draw it by yourself. Not quite as powerful as an ImageView.

import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.os.*;
import android.view.View;

public class GifActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new GifView(this));
    }

    static class GifView extends View {
        Movie movie;

        GifView(Context context) {
            super(context);
            movie = Movie.decodeStream(
                    context.getResources().openRawResource(
                            R.drawable.some_gif));
        }
        @Override
        protected void onDraw(Canvas canvas) {   
            if (movie != null) {
                movie.setTime(
                    (int) SystemClock.uptimeMillis() % movie.duration());
                movie.draw(canvas, 0, 0);
                invalidate();
            }
        }
    }
}

2 other methods, one with ImageView another with WebView can be found in this fine tutorial. The ImageView method uses the Apache licensed android-gifview from Google Code.

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