Question

I have a code that changes the tint of an image button when clicked.

Here’s the java code

 button.setOnTouchListener(new OnTouchListener() {

        public boolean onTouch(View v, MotionEvent me) 
        {
            if (me.getAction() == MotionEvent.ACTION_DOWN) 
            {

                button.setColorFilter(Color.argb(150, 155, 155, 155));

            } 

            else if (me.getAction() == MotionEvent.ACTION_UP) 

            {
                button.setColorFilter(Color.argb(0, 155, 155, 155)); 
                }
            return false;
        }

    });

The code is working fine on this xml, the button dims when clicked.

  <ImageButton
    android:id="@+id/schedule"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_x="138dp"
    android:layout_y="169dp"
    android:src="@drawable/schedule"
    />

But it is not working on this xml, the button doesn’t dim when clicked.

  <ImageButton
    android:id="@+id/schedule"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_x="138dp"
    android:layout_y="169dp"
    android:background="@drawable/schedule"
    />

Why does if I use android:background the setColorFilter doesn’t work? but if I use android:src it is working fine.

Answer 1

The simple answer is that:

• the android:background attribute refers to a method of the View class,
• android:src refers to a methods of ImageView,

and each class maintains their own background resources. So when you call the ImageView method setColorFilter(), it applies the filter to its local background resource (the one set by src) and setColorFilter() has no knowledge of the View resource set by background.