Mobile performance issues

[rask]

I'm implementing code-input on my personal website, inside an admin panel to write Markdown posts with.

On desktop it performs well, and is great to use. But on a mobile browser, it is literally unusable.

I have a regular text field above the code-input field, which can receive near instant character input if I keep fiddling randomly on the virtual mobile keyboard, typing in tons of characters per second. The code-input field on the other hand freezes for a second or two after each character typed in, and any characters typed during this period get discarded.

I'm running Firefox mobile with an up to date Android system on a new-ish XR21 Nokia phone. I'm not a mobile development expert so I can't even begin to think what might be causing this. I do understand that JavaScript powered text areas on steroids cannot compete with a plain input field in any way, but this does not seem like normal operation to me either.

Any ideas on how to start debugging this?

[WebCoder49]

Thank you for pointing this out, and sorry for the inconvenience - as this library builds on top of a textarea, it should work as well as a textarea on a mobile phone. I can reproduce your bug in Chrome on Android for code-input version 2.3, but not for 2.2.

I believe the bug is due to these lines of code, because these lines' functionality was first introduced in version 2.3, the first version of code-input in which this specific bug occurs:

code-input/code-input.js

Lines 526 to 532 in a404473

	// If editing here, scroll to the caret by focusing, though this shouldn't count as a focus event
	if(this.textareaElement === document.activeElement) {
	this.handleEventsFromTextarea = false;
	this.textareaElement.blur();
	this.textareaElement.focus();
	this.handleEventsFromTextarea = true;
	}

Short-term Workaround

You can downgrade to version 2.2.1 of code-input. There shouldn't be too noticeable a difference unless you use a screenreader / solely keyboard navigation, and no plugins should be lost.

Long term Solution

We need another way to scroll to the textarea's caret that doesn't temporarily blur the textarea, and/or remove this scrolling (Issue #93).

[rask]

Hey, downgrading to 2.2.1 fixed the performance issue. Many thanks! :)

I'll close this as you already seem to know what's up and have a separate issue for it. Let me know if you need more info so I can maybe try to find time to test things out.

[WebCoder49]

Note to self: I missed this because it was "worked around" (by downgrading) and I was inobservant - although not immediately noticeable (the autocomplete suggestions flash and typing speed is very slightly limited) when testing on my mobile device, it should be one of the top priorities to fix. @WebCoder49 - remember!