[Android Q&A, Help & Troubleshooting] ponchofiesta:
Hi,

I've read some infos about that and tried different ways but it didn't work.

I try to add volume buttons to my tablets (exotic model: Rockchip M742E) navigation bar.

What I tried:

- pulled original SystemUI.apk

- decompiled it using apktool

- opened res/layout/system_bar.xml and found:

<LinearLayout android:orientation="horizontal" android:id="@id/navigationArea" android:clipChildren="false" android:clipToPadding="false" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_alignParentLeft="true">
<com.android.systemui.statusbar.policy.KeyButtonView android:id="@id/back" android:layout_width="@dimen/navigation_key_width" android:layout_height="fill_parent" android:src="@drawable/ic_sysbar_back" android:contentDescription="@string/accessibility_back" systemui:keyCode="4" systemui:glowBackground="@drawable/ic_sysbar_highlight" />
<com.android.systemui.statusbar.policy.KeyButtonView android:id="@id/home" android:layout_width="@dimen/navigation_key_width" android:layout_height="fill_parent" android:src="@drawable/ic_sysbar_home" android:contentDescription="@string/accessibility_home" systemui:keyCode="3" systemui:glowBackground="@drawable/ic_sysbar_highlight" />
<com.android.systemui.statusbar.policy.KeyButtonView android:id="@id/recent_apps" android:layout_width="@dimen/navigation_key_width" android:layout_height="fill_parent" android:src="@drawable/ic_sysbar_recent" android:contentDescription="@string/accessibility_recent" systemui:glowBackground="@drawable/ic_sysbar_highlight" />
<com.android.systemui.statusbar.policy.KeyButtonView android:layout_gravity="center_vertical" android:id="@id/screenshot" android:layout_width="@dimen/navigation_key_width" android:layout_height="wrap_content" android:src="@drawable/capture" android:contentDescription="@string/accessibility_recent" systemui:glowBackground="@drawable/ic_sysbar_highlight" />
<com.android.systemui.statusbar.policy.KeyButtonView android:id="@id/menu" android:visibility="invisible" android:layout_width="@dimen/navigation_menu_key_width" android:layout_height="fill_parent" android:src="@drawable/ic_sysbar_menu" android:contentDescription="@string/accessibility_menu" systemui:keyCode="82" systemui:glowBackground="@drawable/ic_sysbar_highlight" />
<com.android.systemui.statusbar.policy.KeyButtonView android:id="@id/sub" android:background="@drawable/sub_normal" android:visibility="gone" android:layout_width="@dimen/navigation_menu_key_width" android:layout_height="fill_parent" systemui:keyCode="25" systemui:glowBackground="@drawable/ic_sysbar_highlight" />
<com.android.systemui.statusbar.policy.KeyButtonView android:id="@id/add" android:background="@drawable/add_normal" android:visibility="gone" android:layout_width="@dimen/navigation_menu_key_width" android:layout_height="fill_parent" systemui:keyCode="24" systemui:glowBackground="@drawable/ic_sysbar_highlight" />
</LinearLayout>

OK, there already are hidden volume buttons... great (i thought).

- I removed android:visibility="gone"

- recompiled SystemUI.apk with apktool

- pushed SystemUI.apk to the device

- rebooted... no navbar and other UI elements :(

I also tried this tutorial but had no luck

Does someone know what I am doing wrong?

I added the original apk to this post.