Why would you want to enable the on-screen navigation button when you already have the hard keys? Well, some people want the Nexus look, and some find it more convenient -no need to hold the home button to show Recents and no more accidentally pressing the back/menu button while typing or watching.
This tutorial requires your device to be rooted and running Android 4.0 Ice Cream Sandwich or above.
DO THIS AT YOUR OWN RISK!
- Using Root Explorer, or any file manager that has root access, go to System and Mount R/W.
- Tap and hold build.prop then choose Open in Text Editor.
- Scroll to the end and on a new line input:
- Save and Exit. Then Reboot.
If you think the navbar is too big, try setting your DPI to 200 or 180 with Rom ToolBox or simply navigate to /system/build.prop find and change the value of ro.sf.lcd_density=200 — Or the DPI value that you want– save and exit, then reboot. Note that you need to wipe Google Play (Settings/Apps/Google Play – Wipe/Clear Data/Cache) to avoid errors/FC.
If you want to Disable On-Screen Navigation Button, follow the steps above, but input this line instead:
Disabling Hardware Keys
If you’re using On-Screen Navigation Menu then you might want to disable the hardware keys to avoid accidentally pressing the menu or back button. But disabling hardware keys may be different for every device.
For Samsung Galaxy S2 GTI-9100:
Open your file manager that has root access and navigate to system/usr/keylayout and edit sec_touchkey.kl and input “#” before the key that you want to disable:
#key 158 BACK VIRTUAL
#key 139 MENU VIRTUAL
#key 172 HOME VIRTUAL
For Sony Xperia, you can edit system/usr/keylayout/cyttsp_key.kl
For Samsung Galaxy S3 using JellyBean or Sammy ROM, edit /system/usr/layout/Generic.kl
If you know the filename to edit for other devices, please share in the comments section below to help other users. Thanks!
Source: XDA – Credits goes to those who shared their knowledge on XDA. I’ve simply read the threads and compiled the infos together with my knowledge in this post.