CyberChef/src/web/WindowWaiter.mjs

/**
 * @author n1474335 [n1474335@gmail.com]
 * @copyright Crown Copyright 2016
 * @license Apache-2.0
 */

/**
 * Waiter to handle events related to the window object.
 */
class WindowWaiter {

    /**
     * WindowWaiter constructor.
     *
     * @param {App} app - The main view object for CyberChef.
     */
    constructor(app) {
        this.app = app;
    }


    /**
     * Handler for window resize events.
     * Resets the layout of CyberChef's panes after 200ms (so that continuous resizing doesn't cause
     * continuous resetting).
     */
    windowResize() {
        clearTimeout(this.resetLayoutTimeout);
        this.resetLayoutTimeout = setTimeout(this.app.resetLayout.bind(this.app), 200);
    }


    /**
     * Handler for window blur events.
     * Saves the current time so that we can calculate how long the window was unfocussed for when
     * focus is returned.
     */
    windowBlur() {
        this.windowBlurTime = new Date().getTime();
    }


    /**
     * Handler for window focus events.
     *
     * When a browser tab is unfocused and the browser has to run lots of dynamic content in other
     * tabs, it swaps out the memory for that tab.
     * If the CyberChef tab has been unfocused for more than a minute, we run a silent bake which will
     * force the browser to load and cache all the relevant JavaScript code needed to do a real bake.
     * This will stop baking taking a long time when the CyberChef browser tab has been unfocused for
     * a long time and the browser has swapped out all its memory.
     */
    windowFocus() {
        const unfocusedTime = new Date().getTime() - this.windowBlurTime;
        if (unfocusedTime > 60000) {
            this.app.silentBake();
        }
    }

}

export default WindowWaiter;