Android - Setting wallpaper from file path takes longer than expected

Question

I'm trying to set wallpaper from file path. However it takes more than 10 seconds and causes my app to freeze.

Here's the code I'm using:

public void SET_WALLPAPER_FROM_FILE_PATH (String file_path)
{
    Bitmap image_bitmap;
    File   image_file;
    FileInputStream fis;

    try {
        WallpaperManager wallpaper_manager = WallpaperManager.getInstance(m_context);
        image_file                         = new File(file_path);
        fis                                = new FileInputStream(image_file);
        image_bitmap                       = BitmapFactory.decodeStream(fis);

        wallpaper_manager.setBitmap(image_bitmap);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

I have tried to use:

wallpaper_manager.setStream(fis)

instead of:

wallpaper_manager.setBitmap(image_bitmap);

as suggested in this answer but couldn't load the wallpaper.

Can anyone guide me?

Thanks

Answer 1

Try to use AsyncTask, in doInBackground method write something like this

public static Bitmap decodeFile(File f,int WIDTH,int HIGHT){
    try {
        //Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f),null,o);

        //The new size we want to scale to
        final int REQUIRED_WIDTH=WIDTH;
        final int REQUIRED_HIGHT=HIGHT;
        //Find the correct scale value. It should be the power of 2.
        int scale=1;
        while(o.outWidth/scale/2>=REQUIRED_WIDTH && o.outHeight/scale/2>=REQUIRED_HIGHT)
            scale*=2;

        //Decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize=scale;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    }
        catch (FileNotFoundException e) {}
    return null;
}