zulip/web/src/keydown_util.ts

/*
    See hotkey.js for handlers that are more app-wide.
*/

export const vim_left = "h";
export const vim_down = "j";
export const vim_up = "k";
export const vim_right = "l";

export function handle(opts: {
    $elem: JQuery;
    handlers: {
        [handler: string]: (() => boolean) | undefined;
    };
}): void {
    opts.$elem.on("keydown", (e) => {
        if (e.altKey || e.ctrlKey || e.shiftKey) {
            return;
        }

        const {key} = e;
        const handler = opts.handlers[key];
        if (!handler) {
            return;
        }

        const handled = handler();
        if (handled) {
            e.preventDefault();
            e.stopPropagation();
        }
    });
}

export function is_enter_event(event: JQuery.KeyDownEvent): boolean {
    // In addition to checking whether the key pressed was an Enter
    // key, we need to check whether the keypress was part of an IME
    // composing session, such as selecting a character using a
    // phonetic input method like ZhuYin in a character-based
    // language. See #22062 for details. Further reading:
    // https://developer.mozilla.org/en-US/docs/Glossary/Input_method_editor
    const isComposing: boolean = event.originalEvent?.isComposing || false;
    return !isComposing && event.key === "Enter";
}