毛玻璃效果

package com.android.systemui.statusbar.phone;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Path;
import android.graphics.Path.Direction;
import android.graphics.Region.Op;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Surface;
import android.view.View;
import android.view.WindowManager;

import com.android.systemui.R;
import com.android.systemui.screenshot.GlobalScreenshot;

public class BlurView extends View{

    public static final String TAG = "BlurView";
    private static final float BITMAP_SCALE = 0.125f;
    private static final boolean DEBUG = false;
    private  GlobalScreenshot mScreenshot;
    private Context mContext;
    private WindowManager mWindowManager;
    private int mBackgroud;
    private int mBottomLeftRadius;
    private int mBottomRightRadius;
    private boolean mFullScreen;
    private Bitmap mMasterBitmap = null;

    public BlurView(Context context) {
        this(context, null);
    }

    public BlurView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public BlurView(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public BlurView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        mContext = context;
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.blur);
        mBackgroud = a.getColor(R.styleable.blur_backgroud,
                mContext.getResources().getColor(R.color.status_bar_expanded_blur_masked));
        mBottomLeftRadius = a.getDimensionPixelSize(R.styleable.blur_bottomLeftRadius, 0);
        mBottomRightRadius = a.getDimensionPixelSize(R.styleable.blur_bottomRightRadius, 0);
        mFullScreen = a.getBoolean(R.styleable.blur_fullScreen, false);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (DEBUG)
            Log.d(TAG, "onDraw -->"+System.currentTimeMillis());
        Bitmap initBitmap = null;
        if (mMasterBitmap == null || mMasterBitmap.isRecycled()) {
            if(mScreenshot == null){
                mScreenshot = new GlobalScreenshot(getContext());
            }
            initBitmap = mScreenshot.takeScreenshot();//获取到当前屏幕的图片
        } else {
            initBitmap = mMasterBitmap;
        }
        if(initBitmap == null) {
           //modify for GMOS-6570
           Bitmap blackBitmap = Bitmap.createBitmap(1080, 1920, Bitmap.Config.ARGB_8888);
           initBitmap = blackBitmap;
          // return;
        }
        if (DEBUG)
            Log.d(TAG, "onDraw ---->"+System.currentTimeMillis());
        if (!mFullScreen && (getHeight() != initBitmap.getHeight()
                || getWidth() != initBitmap.getWidth())) {
            initBitmap = cropBitmap(initBitmap);//如果使用blurview的不是占满整个屏幕的，则截取图片
        }

        if (mWindowManager == null) {
            mWindowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
        }
        int orientation = mWindowManager.getDefaultDisplay().getRotation();
        Bitmap rotateBitmap = null;
        Bitmap blurBitmap = null;
        int screenWidth;
        int screenHeight;
        if (Surface.ROTATION_90 == orientation) {
            rotateBitmap = rotateBitmap(initBitmap, -90);//如果屏幕是旋转的
        } else if (Surface.ROTATION_270 == orientation) {
            rotateBitmap = rotateBitmap(initBitmap, -270);
        }
        if (rotateBitmap == null) {
            screenWidth = initBitmap.getWidth();
            screenHeight = initBitmap.getHeight();
            if (DEBUG)
                Log.d(TAG, "onDraw ------>"+System.currentTimeMillis());
            blurBitmap = blurBitmap(getContext(), initBitmap, 18f);//模糊效果实现
            if (DEBUG)
                Log.d(TAG, "onDraw -------->"+System.currentTimeMillis());
            initBitmap.recycle();
        } else {
            screenWidth = rotateBitmap.getWidth();
            screenHeight = rotateBitmap.getHeight();
            if (DEBUG)
                Log.d(TAG, "onDraw ------>"+System.currentTimeMillis());
            blurBitmap = blurBitmap(getContext(), rotateBitmap, 18f);
            if (DEBUG)
                Log.d(TAG, "onDraw -------->"+System.currentTimeMillis());
            rotateBitmap.recycle();
        }

        if (mBottomLeftRadius != 0 || mBottomRightRadius !=0) {
            Path path = new Path();
            path.addRoundRect(0, 0, getWidth(), getHeight(),
                    new float[]{0, 0, 0, 0, mBottomLeftRadius, mBottomLeftRadius, mBottomRightRadius, mBottomRightRadius},
                    Direction.CCW);
            canvas.clipPath(path, Op.INTERSECT);
        }
        if (DEBUG)
            Log.d(TAG, "onDraw ---------->"+System.currentTimeMillis());
        Bitmap expandBitmap = Bitmap.createScaledBitmap(blurBitmap, screenWidth, screenHeight, true);
        if (DEBUG)
            Log.d(TAG, "onDraw ------------>"+System.currentTimeMillis());
        if (! expandBitmap.equals(blurBitmap)) {
            blurBitmap.recycle();
        }

        canvas.drawBitmap(expandBitmap, 0, 0, null);
        Bitmap blackBitmap = Bitmap.createBitmap(screenWidth, screenHeight, Bitmap.Config.ARGB_8888);
        blackBitmap.eraseColor(mBackgroud);
        canvas.drawBitmap(blackBitmap,0,0,null);
        if (DEBUG)
            Log.d(TAG, "onDraw ------------>"+System.currentTimeMillis());
    }

    private Bitmap cropBitmap(Bitmap bitmap) {
        if (null == bitmap) {
            return null;
        }
        final int[] location = new int[2];
        getLocationOnScreen(location);
        Bitmap cache = null;
        if (location[0] >= 0 && location[1] >= 0 && bitmap.getWidth() >= location[0]+getWidth()
                && bitmap.getHeight() >= location[1]+getHeight()) {
            cache = Bitmap.createBitmap(bitmap, location[0], location[1], getWidth(), getHeight());
        } else {
            Log.e(TAG, "cropBitmap error location[0]:"+location[0]+",location[1]:"+location[1]
                    + ",width:"+getWidth()+",height:"+getHeight());
            return bitmap;
        }
        bitmap.recycle();
        return cache;
    }

    private Bitmap rotateBitmap(Bitmap origin, float degrees) {
        if (origin == null) {
            return null;
        }
        int width = origin.getWidth();
        int height = origin.getHeight();
        Matrix matrix = new Matrix();
        matrix.setRotate(degrees);
        Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false);
        if (newBM.equals(origin)) {
            return newBM;
        }
        origin.recycle();
        return newBM;
    }

    public static Bitmap blurBitmap(Context context, Bitmap image, float blurRadius) {
        if (null == image) {
            return null;
        }
        boolean isRgb8888=false;
        if (image.getConfig() != Bitmap.Config.ARGB_8888) {
            image = RGB565toARGB888(image);
            isRgb8888 = true;
        }
        int width = Math.round(image.getWidth() * BITMAP_SCALE);
        int height = Math.round(image.getHeight() * BITMAP_SCALE);

        Bitmap inputBitmap = Bitmap.createScaledBitmap(image, width, height, false);
        Bitmap outputBitmap = Bitmap.createBitmap(inputBitmap);
        if(isRgb8888){
            image.recycle();
            isRgb8888 = false;
        }
        RenderScript rs = null;
        try {
            rs = RenderScript.create(context);
        } catch (Exception e) {
            e.printStackTrace();

            inputBitmap.recycle();
            outputBitmap.recycle();
            Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            bitmap.eraseColor(Color.parseColor("#D9454545"));
            return bitmap;
        }
        ScriptIntrinsicBlur blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));

        Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
        Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);

        blurScript.setRadius(blurRadius);
        blurScript.setInput(tmpIn);
        blurScript.forEach(tmpOut);

        tmpOut.copyTo(outputBitmap);

        blurScript.destroy();
        tmpIn.destroy();
        tmpOut.destroy();
        rs.destroy();
        inputBitmap.recycle();

        return outputBitmap;
    }

    //mengran.wang add for bug PRODUCTION-7098
    private static Bitmap RGB565toARGB888(Bitmap img) {
        int numPixels = img.getWidth()* img.getHeight();
        int[] pixels = new int[numPixels];

        img.getPixels(pixels, 0, img.getWidth(), 0, 0, img.getWidth(), img.getHeight());
        Bitmap result = Bitmap.createBitmap(img.getWidth(), img.getHeight(), Bitmap.Config.ARGB_8888);
        result.setPixels(pixels, 0, result.getWidth(), 0, 0, result.getWidth(), result.getHeight());
        //img.recycle();

        return result;
    }

    public void setMasterBitmap(Bitmap bitmap) {
        mMasterBitmap = bitmap;
    }
}