Button in ActionBarSherlock not vertically centered

Question

I met a problem in device below Android 4.0, the button in the ActionBarSherlock sometimes just can't vertically centered. This happened on devices running Android 2.3.6, and will not affect on any device running 4.0+

I made a pretty easy custom layout on the ActionBarSherlock, whose custom layout structure is shown in the XML below

The layout that can't center button vertically:

<Button
    android:id="@+id/button_action_next"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"
    android:background="@color/people_app_theme_color"
    android:gravity="center"
    android:text="NEXT"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/white" />

<LinearLayout
    android:id="@+id/linearLayout1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:gravity="center"
    android:orientation="horizontal" >

    <ImageButton
        android:id="@+id/button_action_home"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:background="@color/people_app_theme_color"
        android:gravity="center"
        android:maxHeight="30dp"
        android:src="@drawable/android_home"
        android:text="HOME"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:textColor="@android:color/white" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:minHeight="48dp"
        android:text="TextView"
        android:textColor="@android:color/white" />
</LinearLayout>

<Button
    android:id="@+id/button_action_prev"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:background="@color/people_app_theme_color"
    android:gravity="center"
    android:text="PREV"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/white" />

And I simply just can't get the buttons (button_action_next and button_action_prev centered vertically within the action bar)

I got the result like this:

However, in the same app, I have another custom layout for ActionBarSherlock which could strangely make the buttons centered vertically very well. The layout of this custom layout is like this:

The layout that can center buttons vertically:

<Button
    android:id="@+id/button_actionbar_done"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"
    android:background="@color/people_app_theme_color"
    android:gravity="center"
    android:text="DONE"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/white" />

<Button
    android:id="@+id/button_actionbar_skip"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:background="@color/people_app_theme_color"
    android:gravity="center"
    android:text="SKIP"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/white" />

<TextView
    android:id="@+id/text_title"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/button_actionbar_skip"
    android:layout_alignBottom="@+id/button_actionbar_skip"
    android:layout_centerHorizontal="true"
    android:text="ENTER YOUR DETAILS"
    android:textColor="@android:color/white" />

The only difference between the working layout and not working layout, is the one that can't center buttons has a child LinearLayout within it.

So my question is, how can I make sure that the buttons are vertically centered in any circumstances(avoid the result shown in the screenshot)?

UPDATE: what I've tried

Thanks to @nicopico 's comment and this SO post: Gravity and layout_gravity on Android . I've applied layout_gravity="center" to my layout, but the buttons are still not vertically centered.

Answer 1

OK I got the problem.

Here's the solutions

Solution 1

within this layout,

<Button
    android:id="@+id/button_actionbar_done"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"
    android:background="@color/people_app_theme_color"
    android:gravity="center"
    android:text="DONE"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/white" />

<Button
    android:id="@+id/button_actionbar_skip"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:background="@color/people_app_theme_color"
    android:gravity="center"
    android:text="SKIP"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/white" />

<TextView
    android:id="@+id/text_title"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/button_actionbar_skip"
    android:layout_alignBottom="@+id/button_actionbar_skip"
    android:layout_centerHorizontal="true"
    android:text="ENTER YOUR DETAILS"
    android:textColor="@android:color/white" />

I deleted

android:layout_alignParentTop="true"

in the two buttons, and applied:

android:layout_centerVertical="true"

to both buttons, and it now can vertically centered within the ActionBar

Solution 2

According to this post Android ActionBar: How to vertical align views in top

I can apply the android:layout_marginBottom or android:paddingBottom to the buttons to make it centered.

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However I still prefer the android:layout_centerVertical method which is not hard-coded to numbers.