Android 自定义Drawable

public class CornerDrawable extends Drawable {
    private Paint mPaint;
    private Bitmap bmp;
    private RectF rectF;

    public CornerDrawable(Bitmap bmp) {
        this.bmp = bmp;
        BitmapShader shader = new BitmapShader(bmp, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
//        CLAMP 拉伸
//        REPEAT 重复
//        MIRROR 镜像
//        BitmapShader是从画布的左上角开始绘制的
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setShader(shader);
    }

    @Override
    public void draw(Canvas canvas) {
        Rect rect = getBounds();
        // Log.e(getClass().getSimpleName(), rect.left + ":" + rect.width() + ":" + rect.height());
        // Log.e(getClass().getSimpleName(), rectF.left + ":" + rectF.width() + ":" + rectF.height());
        canvas.drawRoundRect(rectF, 20, 20, mPaint);
    }

    @Override
    public void setAlpha(int alpha) {
        mPaint.setAlpha(alpha);
    }

    @Override
    public void setColorFilter(ColorFilter cf) {
        mPaint.setColorFilter(cf);
    }

    @Override
    public int getOpacity() {
        return PixelFormat.TRANSLUCENT;
    }

    // getIntrinsicWidth、getIntrinsicHeight主要是为了在View使用wrap_content的时候，提供一下尺寸
    @Override
    public int getIntrinsicHeight() {
        return bmp.getHeight();
    }

    @Override
    public int getIntrinsicWidth() {
        return bmp.getWidth();
    }

    @Override
    public void setBounds(int left, int top, int right, int bottom) {
        super.setBounds(left, top, right, bottom);
        rectF = new RectF(left, top, right, bottom);
    }
}

RectF rf = new RectF(-100, -130, 160, 130);
canvas.drawArc(rf, 0, 120, true, paint);

    @Override
    public void draw(Canvas canvas) {
        PorterDuffXfermode pdf = new PorterDuffXfermode(PorterDuff.Mode.SRC_IN);
        paint.setXfermode(pdf);
        paint.setColor(0xffff4400);
        canvas.drawBitmap(bmp, 0, 0, paint);
        paint.setXfermode(null);
    }

    public static Drawable getPrimaryDrawable(int resId) {
        Drawable icon = context.getResources().getDrawable(resId);
        int baseColor = context.getResources().getColor(R.color._secondary_color);
        icon.setColorFilter(baseColor, PorterDuff.Mode.SRC_IN);
        return icon;
    }

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <solid android:color="#ff80cbc4" />
        </shape>
    </item>
    <item android:top="48dp">
        <bitmap
            android:gravity="center"
            android:src="@drawable/app_background_png"
            android:tileMode="disabled" />
    </item>
</layer-list>

    <declare-styleable name="CustomStateDrawableButton">
        <attr name="state_readed" format="boolean" />
    </declare-styleable>

public class CustomStateDrawableButton extends ImageButton {
    public static final int[] MessageReaded = {R.attr.state_readed};
    private boolean isReaded = false;

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

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

    public CustomStateDrawableButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setReaded(boolean isReaded) {
        if (this.isReaded != isReaded) {
            this.isReaded = isReaded;
            //
            refreshDrawableState();
        }
    }

    @Override
    public int[] onCreateDrawableState(int extraSpace) {
        if (!isReaded) {
            int[] ds = super.onCreateDrawableState(extraSpace + 1);
            mergeDrawableStates(ds, MessageReaded);
            return ds;
        }
        return super.onCreateDrawableState(extraSpace);
    }
}