var scrollTarget = window

var lastAction = null

const generatorIterateInputs = iterateInputs()

const actions = {

'j': _=> scrollTarget.scrollBy(0, 50),

'k': _=> scrollTarget.scrollBy(0, -50),

'h': _=> history.back(),

'l': _=> history.forward(),

't': _=> chrome.runtime.sendMessage('t'),

'w': _=> chrome.runtime.sendMessage('w'),

// setTimeout seems to fix pressing escape in google search

'Escape': _=> setTimeout(_=>document.activeElement.blur(), 5),

'G': _=> scrollTarget.scrollTo(0, scrollTarget.scrollHeight),

'g': _=> lastAction === 'g' && scrollTarget.scrollTo(0, 0),

'r': _=> location.reload(),

'i': _=> generatorIterateInputs.next(),

'n': _=> chrome.runtime.sendMessage('n'),

'p': _=> chrome.runtime.sendMessage('p'),

'o': _=> chrome.runtime.sendMessage('o'),

// make CTRL-c analog to Escape

'c': e => e.ctrlKey && setTimeout(_=>document.activeElement.blur(), 5)

}

function* iterateInputs(){

// Iterate through all textinputs on a website by pressing i

while(true){

const allInputs = document.querySelectorAll(`

input:not([type]):not([disabled]):not([readonly]):not([hidden]):not([style="display:none"]):not([style="visibility:hidden"]),

input[type="text"]:not([disabled]):not([readonly]):not([hidden]):not([style="display:none"]):not([style="visibility:hidden"]),

input[type="password"]:not([disabled]):not([readonly]):not([hidden]):not([style="display:none"]):not([style="visibility:hidden"]),

textarea:not([disabled]):not([readonly]):not([hidden]):not([style="display:none"]):not([style="visibility:hidden"]),

div[contenteditable="true"]:not([disabled]):not([hidden]):not([style="display:none"]):not([style="visibility:hidden"])`

)

let foundInput = false

for (let i = 0; i < allInputs.length; i++) {

// skip if element or any ancestor has the display property set to none

// https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/offsetParent

if(!allInputs[i].offsetParent)

continue

foundInput = true

yield allInputs[i].focus()

}

if(!allInputs.length || !foundInput)

yield

}

}

addEventListener('keydown', event => {

// check if jkscroll was manually disabled

if(localStorage.getItem('jkdisable')) return

// don't hook into native browser shortcuts

if(

event.altKey ||

event.metaKey ||

(event.ctrlKey && event.key !== 'c')

)

return

// only continue if a key from defined actions is pressed

if(!actions[event.key]) return

const isEditing = event.composedPath().some(el =>

el instanceof HTMLElement &&

(

el.tagName === "SELECT" ||

el.tagName === "TEXTAREA" ||

(el.tagName === "INPUT" && !["checkbox", "radio", "button", "submit"].includes(el.type)) ||

el.isContentEditable

)

)

// don't hook if user is typing text into some kind of input field

// except if Escape key was pressed or CTRL-C

if(

isEditing && (event.key !== 'Escape' && !(event.ctrlKey && event.key === 'c'))

) return

// store key pressed in lastAction and run the according action function

actions[event.key](event)

lastAction = event.key

// don't allow websites to do their own shortcut actions for defined jkscroll

// actions. But allow CTRL+c (copy).

if(event.key !== 'c' && !event.ctrlKey)

event.preventDefault()

}, true)

// it's hard to figure out which element exactly should be addressed with

// scrollBy(), window.scrollBy() does often not work, document does never.

// that's why every scroll event will safe whatever was the target of of the

// event into a variable, which will later be used by jkscroll

// if jk scrolling does not work by default on visiting a page it would help to

// either press space or scroll with a mouse for scrollTarget to get populated

addEventListener('scroll', event => {

scrollTarget = event.target.scrollingElement || event.target

}, true)