blurry background of activity, without knowing what avtivity is behind

Question

I have an activity that jumps every time i open the phone.

i want it's background to be blurry, so whatever activity should open after mine, would be blurry. But i can't know what activity should be behind,

cause it's not an activity from my app, could be from any app.

So i can't use the method that blurs the last activity i used from here

Android, how to blur/glass/frost current activity

I created a blur builder is stated here

Create blurry transparent background effect

like this

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.view.View;
public class BlurBuilder {
    private static final float BITMAP_SCALE = 0.4f;
    private static final float BLUR_RADIUS = 7.5f;

    public static Bitmap blur(View v) {
        return blur(v.getContext(), getScreenshot(v));
    }

    public static Bitmap blur(Context ctx, Bitmap image) {
        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);

        RenderScript rs = RenderScript.create(ctx);
        ScriptIntrinsicBlur theIntrinsic = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
        Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
        Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);
        theIntrinsic.setRadius(BLUR_RADIUS);
        theIntrinsic.setInput(tmpIn);
        theIntrinsic.forEach(tmpOut);
        tmpOut.copyTo(outputBitmap);

        return outputBitmap;
    }

    private static Bitmap getScreenshot(View v) {
        Bitmap b = Bitmap.createBitmap(v.getWidth(), v.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b);
        v.draw(c);
        return b;
    }
}

but I'm not sure how to use it on the onCreate of my activity.

Thanks!

Michele Lacorte · Answer 1 · 2015-11-21T15:41:39.533

1

Use this in your onCreate():

For Fragment:

final Activity activity = getActivity();
final View content = activity.findViewById(android.R.id.content).getRootView();
    if (content.getWidth() > 0) {
        Bitmap image = BlurBuilder.blur(content);
        content.setBackground(new BitmapDrawable(activity.getResources(), image));
}

For Activity:

final View content = findViewById(android.R.id.content).getRootView();
if (content.getWidth() > 0) {
        Bitmap image = BlurBuilder.blur(content);
        content.setBackground(new BitmapDrawable(getResources(), image));
}

EDIT:

Solution for Blur in onCreate(), add this:

new CountDownTimer(1, 1) {
public void onTick(long millisUntilFinished) {
        }

public void onFinish() {
            final View content = findViewById(android.R.id.content).getRootView();
            if (content.getWidth() > 0) {
                Bitmap image = BlurBuilder.blur(content);
                content.setBackground(new BitmapDrawable(getResources(), image));
            }

        }
}.start();

edited Nov 21 '15 at 15:41

answered Nov 21 '15 at 14:29

Michele Lacorte

5,323
7
32
54

trust me, it works, how you use the code ? @Mumfordwiz – Michele Lacorte Nov 21 '15 at 15:05
I added it in the onCreate of my activity that jumps – Mumfordwiz Nov 21 '15 at 15:09
and now everytime it's supposed to jump it crashes – Mumfordwiz Nov 21 '15 at 15:10
I used it exactly the way you said. – Mumfordwiz Nov 21 '15 at 15:16
If you use a Fragment for Blur it works perfectly, now I try it on Activty, and it does not work the way you prefer – Michele Lacorte Nov 21 '15 at 15:20
that's what i said, i didn't try the fragment – Mumfordwiz Nov 21 '15 at 15:31
ok , I found the solution , I know it is not very nice but I do not understand why invalidate() does not redraw the View in onCreate() @Mumfordwiz, now works :D – Michele Lacorte Nov 21 '15 at 15:42
without addding what u said to the activity? – Mumfordwiz Nov 21 '15 at 15:51
I've been edit the post with code which you have to add in onCreate() – Michele Lacorte Nov 21 '15 at 15:53
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/95801/discussion-between-mumfordwiz-and-michele-lacorte). – Mumfordwiz Nov 21 '15 at 15:54

blurry background of activity, without knowing what avtivity is behind

1 Answers1