[android] 프레임 내 이미지 마스킹 (자르기)

Picasso 라이브러리와 사용자 지정 변환을 사용하면 훨씬 더 쉽습니다.

MaskTransformation.java :

 * ORIGINAL:
 * Copyright (C) 2015 Wasabeef
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package me.monori.example.utilities;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;

import com.squareup.picasso.Transformation;

public class MaskTransformation implements Transformation {

    private static Paint mMaskingPaint = new Paint();
    private Context mContext;
    private int mMaskId;

    static {
        mMaskingPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
    }

    /**
     * @param maskId If you change the mask file, please also rename the mask file, or Glide will get
     * the cache with the old mask. Because getId() return the same values if using the
     * same make file name. If you have a good idea please tell us, thanks.
     */
    public MaskTransformation(Context context, int maskId) {
        mContext = context.getApplicationContext();
        mMaskId = maskId;
    }

    @Override public Bitmap transform(Bitmap source) {
        int width = source.getWidth();
        int height = source.getHeight();

        Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);

        Drawable mask = getMaskDrawable(mContext, mMaskId);

        Canvas canvas = new Canvas(result);
        mask.setBounds(0, 0, width, height);
        mask.draw(canvas);
        canvas.drawBitmap(source, 0, 0, mMaskingPaint);

        source.recycle();

        return result;
    }

    @Override public String key() {
        return "MaskTransformation(maskId=" + mContext.getResources().getResourceEntryName(mMaskId)
                + ")";
    }

    public Drawable getMaskDrawable(Context context, int maskId) {
        Drawable drawable = ContextCompat.getDrawable(context, maskId);

        if (drawable == null) {
            throw new IllegalArgumentException("maskId is invalid");
        }

        return drawable;
    }
}

그런 다음 간단히 한 줄로 정의합니다.

Picasso.with(context)
                    .load(imageUrl)
                    .transform(new MaskTransformation(context, _maskDrawableId))
                    .placeholder(R.drawable.drawableId)
                    .into(imageView);