Android Launcher3獲取桌布作為左屏背景 並實現毛玻璃效果
在Launcher.java中（實現左屏的方法詳見https://mp.csdn.net/postedit/80192206）
在oncreate()中
/*wanchengguo 負一屏載入佈局 20180424 begin*/
WallpaperManager mWallpaperManager = WallpaperManager.getInstance(getApplicationContext());
/*wanchengguo 負一屏載入佈局 20180424 end*/
新建方法
private void setBackgroundScreen() {
//setBackNegative(int x, int y, int width, int height)DisplayMetrics dm = this.getResources().getDisplayMetrics();
int width = dm.widthPixels;
int height = dm.heightPixels;//獲取螢幕的高寬
//ll_main 是左屏的主控制元件
ll_main.setBackgroundDrawable(setBackNegative(0,0,width,height));// //起始的X Y 要截的圖的寬度 要截的圖的高度
}
public Drawable setBackNegative(int x,int y,int width,int height) {
WallpaperInfo wallpaperInfo = mWallpaperManager.getWallpaperInfo();
Bitmap mBackground = null;
if(wallpaperInfo != null) {//判斷是靜態還是動態桌布
}else {
mBackground = mWallpaperManager.getBitmap();//獲取當前桌面處理後的桌布 ~靜態桌布
}
Bitmap result = Bitmap.createBitmap(mBackground, x,y,width,height, null, false);//根據螢幕大小，以及view長寬，裁剪當前桌面桌布 起始的X Y 要截的圖的寬度 要截的圖的高度
Drawable drawable = FastBlur.doBlur(result);//高斯模糊 FastBlur 自己新建的類 在文章後面貼出
return drawable ;
}
桌布變化更新背景
private BroadcastReceiver WallpaperIntentReceiver = new BroadcastReceiver() {
//監聽桌布更換的廣播
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
//Intent.ACTION_WALLPAPER_CHANGED
android.util.Log.i("wcg","更換了桌布");
setBackgroundScreen();
}
};
在oncreate（）中
//註冊桌布切換的廣播 wanchengguo 20180427 begin
IntentFilter intentFilter_wallpaper = new IntentFilter(Intent.ACTION_WALLPAPER_CHANGED);
registerReceiver(WallpaperIntentReceiver, intentFilter_wallpaper);
//註冊桌布切換的廣播 wanchengguo 20180427 end
/*毛玻璃模糊效果類：*/
public class FastBlur {
private static final float BLUR_RADIUS = 10.0f;
public static Drawable doBlur(Bitmap sentBitmap) {
int radius = (int)BLUR_RADIUS ;
Bitmap bitmap = sentBitmap;
if (radius < 1) {
return (null);
}
int w = bitmap.getWidth();
int h = bitmap.getHeight();
int[] pix = new int[w * h];
bitmap.getPixels(pix, 0, w, 0, 0, w, h);
int wm = w - 1;
int hm = h - 1;
int wh = w * h;
int div = radius + radius + 1;
int r[] = new int[wh];
int g[] = new int[wh];
int b[] = new int[wh];
int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
int vmin[] = new int[Math.max(w, h)];
int divsum = (div + 1) >> 1;
divsum *= divsum;
int dv[] = new int[256 * divsum];
for (i = 0; i < 256 * divsum; i++) {
dv[i] = (i / divsum);
}
yw = yi = 0;
int[][] stack = new int[div][3];
int stackpointer;
int stackstart;
int[] sir;
int rbs;
int r1 = radius + 1;
int routsum, goutsum, boutsum;
int rinsum, ginsum, binsum;
for (y = 0; y < h; y++) {
rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
for (i = -radius; i <= radius; i++) {
p = pix[yi + Math.min(wm, Math.max(i, 0))];
sir = stack[i + radius];
sir[0] = (p & 0xff0000) >> 16;
sir[1] = (p & 0x00ff00) >> 8;
sir[2] = (p & 0x0000ff);
rbs = r1 - Math.abs(i);
rsum += sir[0] * rbs;
gsum += sir[1] * rbs;
bsum += sir[2] * rbs;
if (i > 0) {
rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];
} else {
routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];
}
}
stackpointer = radius;
for (x = 0; x < w; x++) {
r[yi] = dv[rsum];
g[yi] = dv[gsum];
b[yi] = dv[bsum];
rsum -= routsum;
gsum -= goutsum;
bsum -= boutsum;
stackstart = stackpointer - radius + div;
sir = stack[stackstart % div];
routsum -= sir[0];
goutsum -= sir[1];
boutsum -= sir[2];
if (y == 0) {
vmin[x] = Math.min(x + radius + 1, wm);
}
p = pix[yw + vmin[x]];
sir[0] = (p & 0xff0000) >> 16;
sir[1] = (p & 0x00ff00) >> 8;
sir[2] = (p & 0x0000ff);
rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];
rsum += rinsum;
gsum += ginsum;
bsum += binsum;
stackpointer = (stackpointer + 1) % div;
sir = stack[(stackpointer) % div];
routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];
rinsum -= sir[0];
ginsum -= sir[1];
binsum -= sir[2];
yi++;
}
yw += w;
}
for (x = 0; x < w; x++) {
rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
yp = -radius * w;
for (i = -radius; i <= radius; i++) {
yi = Math.max(0, yp) + x;
sir = stack[i + radius];
sir[0] = r[yi];
sir[1] = g[yi];
sir[2] = b[yi];
rbs = r1 - Math.abs(i);
rsum += r[yi] * rbs;
gsum += g[yi] * rbs;
bsum += b[yi] * rbs;
if (i > 0) {
rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];
} else {
routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];
}
if (i < hm) {
yp += w;
}
}
yi = x;
stackpointer = radius;
for (y = 0; y < h; y++) {
// Preserve alpha channel: ( 0xff000000 & pix[yi] )
pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] << 16)
| (dv[gsum] << 8) | dv[bsum];
rsum -= routsum;
gsum -= goutsum;
bsum -= boutsum;
stackstart = stackpointer - radius + div;
sir = stack[stackstart % div];
routsum -= sir[0];
goutsum -= sir[1];
boutsum -= sir[2];
if (x == 0) {
vmin[y] = Math.min(y + r1, hm) * w;
}
p = x + vmin[y];
sir[0] = r[p];
sir[1] = g[p];
sir[2] = b[p];
rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];
rsum += rinsum;
gsum += ginsum;
bsum += binsum;
stackpointer = (stackpointer + 1) % div;
sir = stack[stackpointer];
routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];
rinsum -= sir[0];
ginsum -= sir[1];
binsum -= sir[2];
yi += w;
}
}
bitmap.setPixels(pix, 0, w, 0, 0, w, h);
//Bitmap cc = roundBitmapByShader(bitmap,bitmap.getWidth(),bitmap.getWidth(),25);
Drawable drawable = new BitmapDrawable(bitmap);
return (drawable);
}
/**
* 利用BitmapShader繪製圓角圖片
*
* @param bitmap
* 待處理圖片
* @param outWidth
* 結果圖片寬度，一般為控制元件的寬度
* @param outHeight
* 結果圖片高度，一般為控制元件的高度
* @param radius
* 圓角半徑大小
* @return
* 結果圖片
*/
private static Bitmap roundBitmapByShader(Bitmap bitmap, int outWidth, int outHeight, int radius) {
if(bitmap == null) {
throw new NullPointerException("Bitmap can't be null");
}
android.util.Log.i("wanchengguo","587bitmap.getWidth()="+bitmap.getWidth());
// 初始化縮放比
float widthScale = outWidth * 1.0f / bitmap.getWidth();
float heightScale = outHeight * 1.0f / bitmap.getHeight();
Matrix matrix = new Matrix();
matrix.setScale(widthScale, heightScale);
// 初始化繪製紋理圖
BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
// 根據控制元件大小對紋理圖進行拉伸縮放處理
bitmapShader.setLocalMatrix(matrix);
// 初始化目標bitmap
Bitmap targetBitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);
// 初始化目標畫布
Canvas targetCanvas = new Canvas(targetBitmap);
// 初始化畫筆
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShader(bitmapShader);
// 利用畫筆將紋理圖繪製到畫布上面
targetCanvas.drawRoundRect(new RectF(0, 0, outWidth, outWidth), radius, radius, paint);
return targetBitmap;
}
}