Question

I have this Selector defined:

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- PRESSED -->
    <item android:state_pressed="true"
          android:drawable="@drawable/backarrow_blueshiny" />

    <!-- FOCUSED --> 
    <item android:state_focused="true"
          android:drawable="@drawable/backarrow_blackshiny" />

    <!-- DEFAULT -->
    <item android:drawable="@drawable/backarrow_blackshiny" />

</selector>

and it’s used with this button:

    <RelativeLayout
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" 
    android:background="@drawable/bottomborder_glossy">

        <!-- BACK -->
        <ImageButton
        android:id="@+id/filter_button_back"
        android:layout_width="90dip" 
        android:layout_height="wrap_content" 
        android:src="@drawable/selector_back_button"
        android:background="#00000000"
        android:layout_alignParentLeft="true"
        android:layout_alignParentBottom="true"/>

    </RelativeLayout>

and the onTouch event consists of:

public boolean onTouch(View v, MotionEvent event)
{
    final int actionPerformed = event.getAction();
    final int widgetID = v.getId();

    if (actionPerformed == MotionEvent.ACTION_UP)
    {
        switch (widgetID)
        {
            case R.id.filter_button_back:
            {
                this.finish();
                break;
            }

        }

    }

    return false;
}

what this button does is exit the current activity this.finish()
However, in my testing the button doesn’t always switch to “backarrow_blueshiny” – namely when pressing very fast.

So the problem is that the selector fires slower than the onTouch(MotionEvent.ACTION_UP) event.

Is there anything I can do to make sure that the selector isn’t “laggy” ?

Answer 1

Do you mean laggier than the typical Android selector behavior? In my experience, there’s always been a slight delay between a button press, and it being selected — I assume it’s to avoid showing a touch event when you’re just wanting to scroll, but it’s always annoyed me. If it’s more than the typical behavior, try using just a button, with the android:background set to the selector, rather than an ImageButton with the android:src set to the selector.

e.g.

<Button
    android:layout_width="90dip"
    android:layout_height="wrap_content"
    android:background="@drawable/selector_back_button"
    android:layout_alignParentLeft="true"
    android:layout_alignParentBottom="true" 
    />