MaskImageView.java

package com.marshalchen.common.ui;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.StateListDrawable;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ImageView;

/**
 * Created by cym on 14-5-9.
 * Do not try the effect now!!!!
 */
public class MaskImageView extends ImageView{
    public MaskImageView(Context context) {
        super(context);
    }

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

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

    @Override
    public void setImageBitmap(Bitmap bm) {
        Drawable d = createStateDrawable(getContext(), new BitmapDrawable(getContext().getResources(), bm));
        setImageDrawable(d);
    }

    public StateListDrawable createStateDrawable(Context context, Drawable normal) {
        StateListDrawable drawable = new StateListDrawable();
        drawable.addState(View.PRESSED_ENABLED_STATE_SET, createPressDrawable(normal));
        drawable.addState(View.ENABLED_STATE_SET, normal);
        drawable.addState(View.EMPTY_STATE_SET, normal);
        return drawable;
    }

    public Drawable createPressDrawable(Drawable d) {
        Bitmap bitmap = ((BitmapDrawable) d).getBitmap().copy(Bitmap.Config.ARGB_8888, true);
        Paint paint = new Paint();
        paint.setColor(0x60000000);
        RectF rect = new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight());
        new Canvas(bitmap).drawRoundRect(rect, 4, 4, paint);
        return new BitmapDrawable(getContext().getResources(), bitmap);
    }
}