Screen Display Log

ipadやiphone用に、画面にログを出力する。console.log() の代わりに screenLog() で利用する。

As of 2026-05-10. See the latest version.

This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/577436/1820903/Screen%20Display%20Log.js

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Screen Display Log
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  ipadやiphone用に、画面にログを出力する。console.log() の代わりに screenLog() で利用する。
// @author       YourName
// @grant        none
// ==/UserScript==

/**
 * 画面端にデバッグ用UIを表示するクラス
 */
class ScreenLogger {
    constructor() {
        this.id = 'tm-debug-console';
        this.container = null;
        this.logArea = null;
        this._setup();
    }

    async _setup() {
        // bodyが読み込まれるまで待機
        while (!document.body) {
            await new Promise(r => setTimeout(r, 100));
        }
        if (document.getElementById(this.id)) return;
        this._injectStyles();
        this._createUI();
    }

    _injectStyles() {
        const style = document.createElement('style');
        style.textContent = `
            #${this.id} { position: fixed; bottom: 10px; right: 10px; width: 280px; max-height: 250px; background-color: rgba(0, 0, 0, 0.85); color: #00ff00; font-size: 11px; font-family: monospace; padding: 5px; border-radius: 5px; overflow-y: auto; z-index: 999999; pointer-events: auto; border: 1px solid #444; box-shadow: 0 0 10px rgba(0,0,0,0.5); }
            #${this.id} .tm-header { border-bottom: 1px solid #444; margin-bottom: 5px; padding-bottom: 3px; display: flex; justify-content: space-between; align-items: center; }
            #${this.id} .tm-header b { color: #fff; }
            #${this.id} button { font-size: 9px; cursor: pointer; margin-left: 4px; }
            #${this.id} .tm-log-area { display: block; }
            #${this.id} .tm-line { border-bottom: 1px solid #222; padding: 2px 0; white-space: pre-wrap; word-break: break-all; }
            #${this.id}.minimized { height: 25px; overflow: hidden; }
            #${this.id}.minimized .tm-log-area { display: none; }
        `;
        document.head.appendChild(style);
    }

    _createUI() {
        this.container = document.createElement('div');
        this.container.id = this.id;
        this.container.innerHTML = `
            <div class="tm-header">
                <span><b>[DEBUG]</b></span>
                <div>
                    <button id="tm-clear-log">Clear</button>
                    <button id="tm-toggle-log">Min</button>
                </div>
            </div>
            <div class="tm-log-area"></div>
        `;
        this.logArea = this.container.querySelector('.tm-log-area');
        document.body.appendChild(this.container);

        this.container.querySelector('#tm-clear-log').onclick = () => this.clear();
        this.container.querySelector('#tm-toggle-log').onclick = (e) => this._toggle(e.target);
    }

    _toggle(btn) {
        const isMinimized = this.container.classList.toggle('minimized');
        btn.innerText = isMinimized ? 'Max' : 'Min';
    }

    clear() {
        if (this.logArea) this.logArea.innerHTML = '';
    }

    _format(arg) {
        if (arg === null) return 'null';
        if (arg === undefined) return 'undefined';
        if (arg instanceof HTMLElement) {
            const id = arg.id ? `#${arg.id}` : '';
            const classes = arg.className ? `.${Array.from(arg.classList).join('.')}` : '';
            return `<${arg.tagName.toLowerCase()}${id}${classes}>`;
        }
        if (typeof arg === 'object') {
            try { return JSON.stringify(arg); } catch (e) { return String(arg); }
        }
        return String(arg);
    }

    log(...args) {
        if (!this.logArea) return; // UIがまだ作られていない場合は無視
        const msg = args.map(arg => this._format(arg)).join(' ');
        const line = document.createElement('div');
        line.className = 'tm-line';
        line.innerText = `> ${msg}`;
        this.logArea.appendChild(line);
        this.container.scrollTop = this.container.scrollHeight;
    }
}

// グローバルスコープ(window)に公開する
window.screenLog = (function() {
    const logger = new ScreenLogger();
    return logger.log.bind(logger);
})();