Android BlurMaskFilter has no effect in canvas.drawOval while text is blurred

Question

I've been trying to create a custom view which has blurred shapes under text. The problem is that the BlurMaskFilter has no effect on any shape that I draw on the canvas. Here is how I'm initialising the Paint objects in the constructor:

paint = new Paint(0); paint.setColor(0xffffffff); paint.setMaskFilter(new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL));  mShadowPaint = new Paint(0); mShadowPaint.setColor(0xff333333); mShadowPaint.setMaskFilter(new BlurMaskFilter(10, BlurMaskFilter.Blur.NORMAL)); 

And I'm calling the functions like this in onDraw():

canvas.drawOval(mShadowBounds,mShadowPaint); canvas.drawText("hello", x, y, paint); 

But this is what I see.

Using android 4.0 sdk and testing on a 4.0.4 galaxy nexus device (UK). I'm wondering if this is a bug in 4.0.4 as I did test it on the emulator with 4.0 and 4.0.3 and it did blur perfectly well on them, unless I'm doing something completely wrong?

EDIT: Here is the extended View code to test it on other platforms.

import android.content.Context; import android.graphics.BlurMaskFilter; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.RectF; import android.util.AttributeSet; import android.view.View;  public class BlurTestView extends View{      private Paint paint;     private Paint mShadowPaint;     private int size = 100;     private RectF mShadowBounds = new RectF();      public BlurTestView(Context context) {         this(context, null, 0);     }      public BlurTestView(Context context, AttributeSet attrs) {         this(context, attrs, 0);     }      public BlurTestView(Context context, AttributeSet attrs, int defStyle) {         super(context, attrs, defStyle);         paint = new Paint(0);         paint.setColor(0xff333333);         paint.setTextSize(size);         paint.setMaskFilter(new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL));          mShadowPaint = new Paint(0);         mShadowPaint.setColor(0xff333333);         mShadowPaint.setMaskFilter(new BlurMaskFilter(10, BlurMaskFilter.Blur.NORMAL));          mShadowBounds.top = size;         mShadowBounds.bottom = mShadowBounds.top+(size /2);         mShadowBounds.left = 0;         mShadowBounds.right = (int)paint.measureText("hello");     }      @Override     public void onDraw(Canvas canvas)     {         canvas.drawOval(mShadowBounds,mShadowPaint);         canvas.drawText("hello", 0, size, paint);     }  } 

Answer 1

Looks like a bug to me. I reported it to the Android team; we'll see what they say.

It renders correctly if you set android:hardwareAccelerated="false" on your Activity in AndroidManifest.xml.

Here is the official word from the Android graphics team: "BlurMaskFilter is not supported with hardware acceleration." (As of July 10, 2012)