This is taken from Gerda OS. You just need to replace 3 files from the js folder of system app with those from Gerda OS.
This is what you get at the end.
Slider full open + power button = minimize app (If you exit an app by pressing Back-button, now the app closes completely)
Slider partial open + power button = screenshot
Slider full closed + power button = normal power button function
Slider full open + hold power button = task manager
Download js.zip from below link and extract.
https://drive.google.com/file/d/1GOatLqWvmze1Drc_ILWOVAc6lfY1YAda/view?usp=sharing
You will get 3 files :-
task_manager.js
hardware_buttons.js
app_window_manager.js
Steps:
1. Get copy of system folder
adb pull /system/b2g/webapps/system.gaiamobile.org
(if you edited system folder before, you need this command :adb pull /data/local/webapps/system.gaiamobile.org)2.Now open system.gaiamobile.org/application.zip/js/
Now drag the downloaded js files to the opened js folder one by one.
Now close the zip3.Push the app and its folder on the data partition, exactly in/data/local/webappsusing a temporary root access
adb push system.gaiamobile.org /data/local/webapps4.Get the webapps.json file:adb pull /data/local/webapps/webapps.json
And change the value of the system.gaiamobile.org app
5.After this change push the webapps.json file in its place and reboot the phone:
adb push webapps.json /data/local/webapps/
adb rebootNote :-
Do not press Back-button in task manager. To go back, press Power-button. If you accidentally pressed Back-button don't
worry. Just hold Power-button, it will again open task manager, then press power-button.