Assessment Workspace: Module tab reloading on each keystroke in editor

[martin-henz]

Expected Behavior

Editor keystrokes should not affect module loading.

Current Behavior

Currently each editor keystroke reloads the currently loaded modules in mobile workspace.

Steps to Reproduce

1. Load: https://share.sourceacademy.org/oxhil
2. shrink screen to mobile mode
3. press run
4. open the runes tab
5. start typing in editor

you will see that each keystroke restarts the animation and thus the keyboard entry will be slow.

Context

This is a critical issue in modules. Fixing it is necessary for current CS1101S.

[martin-henz]

(Moved here from modules repo: source-academy/modules#168)

[martin-henz]

See also: #2331 (review)

[ianyong]

One of the things that causes a re-render every time the editor value updates is the session button. This is because the session button takes in the current editor value as a prop so that it can initialise new sessions with it:

frontend/src/pages/playground/Playground.tsx

Lines 515 to 525 in 1b16551

	// No point memoing this, it uses props.editorValue
	const sessionButtons = (
	<ControlBarSessionButtons
	editorSessionId={props.editorSessionId}
	// TODO: Hardcoded to make use of the first editor tab. Rewrite after editor tabs are added.
	editorValue={props.editorTabs[0].value}
	handleSetEditorSessionId={id => dispatch(setEditorSessionId(workspaceLocation, id))}
	sharedbConnected={props.sharedbConnected}
	key="session"
	/>
	);

This isn't an issue for the desktop workspace because the control bar is not a parent or child component of the side content, so the re-rendering of the control bar does not affect the side content component at all. However in the mobile workspace, the control bar is a child of the mobile side content component.

I think it should be possible to retrieve the editor value from the Redux store only when it is needed to prevent these unnecessary re-renders.

Not sure how close I am to a fix because I'm more or less playing whack-a-mole using the React profiler.

[martin-henz]

I've renamed this issue from "Mobile Workspace" to "Assessment Workspace", just to keep the context. I've reopened the issue, because the problem currently arises in the desktop version in the deployed Source Academy (sourceacademy.nus.edu.sg).

Screen.Recording.2023-10-16.at.11.55.05.AM.mov

To reproduce this example, here is the program:

const WIDTH = 400;
const HEIGHT = 300;
const FPS = 15; 

// let x = 1; let direction = 1;  // for extra fun
function my_first_filter(ignore, dest) {
    // for extra fun
    // direction = x > 0 && x < 9 ? direction : - direction;
    // x = x + direction;
    const width = image_width();    
    const height = image_height();

    for (let i = 0; i < height; i = i + 1) {
        for (let j = 0; j < width; j = j + 1) {
            dest[i][j][0] = math_min(i, 255);       // for fun: + 10 * x;
            dest[i][j][1] = math_min(j, 255);       // for fun: + 10 * x;
            dest[i][j][2] = math_max(0, 255 - (i + j) / 2);
            dest[i][j][3] = 255;
        }
    }
}

install_filter(my_first_filter);
set_dimensions(WIDTH, HEIGHT);
keep_aspect_ratio(true);
set_fps(FPS);
start();