package com.example.m_evolution;

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.Rect;

import android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;

import android.support.annotation.Nullable;

import android.util.AttributeSet;

import android.widget.ImageView;

public class CircleImageView extends ImageView {

    private Paint paint;

    public CircleImageView(Context context) {

        super(context);

        paint = new Paint();

    }

    public CircleImageView(Context context, @Nullable AttributeSet attrs) {

        super(context, attrs);

        paint = new Paint();

    }

    public CircleImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {

        super(context, attrs, defStyleAttr);

        paint = new Paint();

    }

    //显示时调用的函数

    @Override

    protected void onDraw(Canvas canvas) {

        Drawable drawable = getDrawable();  //获取drawable

        if (drawable != null) {

            Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();//转换成bitmap

            Bitmap bitmap_circle = getCircleBitmap(bitmap);  //将bitmap图片剪切成圆形

            final Rect rectSrc = new Rect(0, 0, bitmap_circle.getWidth(), bitmap_circle.getHeight());

            final Rect rectDest = new Rect(0,0,getWidth(),getHeight());

            paint.reset();

            canvas.drawBitmap(bitmap_circle, rectSrc, rectDest, paint);

        }

        else{

            super.onDraw(canvas);

        }

    }

    //将bitmap图片剪切成圆形

    private Bitmap getCircleBitmap(Bitmap bitmap) {

        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),bitmap.getHeight(), Bitmap.Config.ARGB_8888);

        Canvas canvas = new Canvas(output);

        final int color = 0xff424242;

        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

        paint.setAntiAlias(true);

        canvas.drawARGB(0, 0, 0, 0);

        paint.setColor(color);

        int x = bitmap.getWidth();

        canvas.drawCircle(x / 2, x / 2, x / 2, paint);

        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));

        canvas.drawBitmap(bitmap, rect, rect, paint);

        return output;

    }

}