CircleShader.java

package com.marshalchen.common.uimodule.shapeimageview.shader;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;

public class CircleShader extends ShaderHelper {
    private float center;
    private float bitmapCenterX;
    private float bitmapCenterY;
    private float borderRadius;
    private int bitmapRadius;

    public CircleShader() {
    }

    @Override
    public void init(Context context, AttributeSet attrs, int defStyle) {
        super.init(context, attrs, defStyle);
        square = true;
    }

    @Override
    public void draw(Canvas canvas, Paint imagePaint, Paint borderPaint) {
        canvas.drawCircle(center, center, borderRadius, borderPaint);
        canvas.save();
        canvas.concat(matrix);
        canvas.drawCircle(bitmapCenterX, bitmapCenterY, bitmapRadius, imagePaint);
        canvas.restore();
    }

    @Override
    public void onSizeChanged(int width, int height) {
        super.onSizeChanged(width, height);
        center = Math.round(viewWidth / 2f);
        borderRadius = Math.round((viewWidth - borderWidth) / 2f);
    }

    @Override
    public void calculate(int bitmapWidth, int bitmapHeight,
                          float width, float height,
                          float scale,
                          float translateX, float translateY) {
        bitmapCenterX = Math.round(bitmapWidth / 2f);
        bitmapCenterY = Math.round(bitmapHeight / 2f);
        bitmapRadius = Math.round(width / scale / 2f + 0.5f);
    }

    @Override
    public void reset() {
        bitmapRadius = 0;
        bitmapCenterX = 0;
        bitmapCenterY = 0;
    }
}