ImageButton and Button in FrameLayout won't change z-index

Question

When you switch the order of the elements, place Button after ImageButton, the z-index is not affected. I tried with other types of Views and they are positioned correctly on top of one another depending on their order in the parent FrameLayout. I tried programmatically with View.bringToFront() without success.

<FrameLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Suzi"
        android:textSize="22sp" />

    <ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@mipmap/ic_launcher" />

</FrameLayout>

The buttons don't have an ID, how do you call bringToFront()? Post the code — MikeKeepsOnShine, Feb 08 '17 at 09:03
The point is to have one Button placed aside, with some offset, but on top of the other. — speirs23, Feb 08 '17 at 09:03
Where I tried bringToFront() they have ID, the point here is I think they should change stack position when changed order in the Frame — speirs23, Feb 08 '17 at 09:10
Post the code, without it we can help you ... maybe you used bringToFront() in the wrong way or something else, now we can only trust in your word — MikeKeepsOnShine, Feb 08 '17 at 09:21
Just tried findViewById(R.id.b2).bringToFront(); in the sample. Doesn't work. And when I change Buttons to TextView for example, it does. — speirs23, Feb 08 '17 at 09:22
The issue is 100% reproduced in the sample, I don't see any need to post the snippet from the project — speirs23, Feb 08 '17 at 09:24
Weirdly, it works with two Buttons and two ImageButtons, but not with Button and ImageButton — speirs23, Feb 08 '17 at 09:37
The main thing that should. Tested on an emulator and the real device. — speirs23, Feb 08 '17 at 09:57

score 2 · Accepted Answer · answered Feb 10 '17 at 13:45

I tried to reproduce the issue: it is reproduced for me on Lollipop+ devices and isn't reproduced on pre-Lollipop. Could you please check this?

If it is exactly the case, then the solution might be to use android:translationZ attribute (which is available since Lollipop)

Something like:

<FrameLayout android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Suzi"
        android:textSize="22sp"
        android:translationZ="1dp"/>

    <ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"
        android:translationZ="2dp"/>

</FrameLayout>

And that fact that translationZ isn't available on pre-Lollipop would not matter (and attribute would be ignored), as there is no such issue.

Hope it helps

ImageButton and Button in FrameLayout won't change z-index

1 Answers1