tiny-graphics-widgets.js

/**
 * @file
 * This file defines a lot of panels that can be placed on websites to create interactive graphics programs that use tiny-graphics.js.
 */

import {tiny} from './tiny-graphics.js';

// Pull these names into this module's scope for convenience.
const {color, Scene} = tiny;

export const widgets = {};

const Canvas_Widget = widgets.Canvas_Widget =
    class Canvas_Widget {
        // **Canvas_Widget** embeds a WebGL demo onto a website in place of the given placeholder document
        // element.  It creates a WebGL canvas and loads onto it any initial Scene objects in the
        // arguments.  Optionally spawns a Text_Widget and Controls_Widget for showing more information
        // or interactive UI buttons, divided into one panel per each loaded Scene.  You can use up to
        // 16 Canvas_Widgets; browsers support up to 16 WebGL contexts per page.
        constructor(element, initial_scenes, options = {}) {
            this.element = element;

            const defaults = {
                show_canvas: true, make_controls: true, show_explanation: false,
                make_editor: false, make_code_nav: false
            };
            if (initial_scenes && initial_scenes[0])
                Object.assign(options, initial_scenes[0].widget_options);
            Object.assign(this, defaults, options)

            const rules = [".canvas-widget { width: 100%; background: Black; }"];

            if (document.styleSheets.length == 0) document.head.appendChild(document.createElement("style"));
            for (const r of rules) document.styleSheets[document.styleSheets.length - 1].insertRule(r, 0)

            // Fill in the document elements:
            if (this.show_explanation) {
                this.embedded_explanation_area = this.element.appendChild(document.createElement("div"));
                this.embedded_explanation_area.className = "text-widget";
            }

            const canvas = this.element.appendChild(document.createElement("canvas"));

            if (this.make_controls) {
                this.embedded_controls_area = this.element.appendChild(document.createElement("div"));
                this.embedded_controls_area.className = "controls-widget";
            }

            if (this.make_code_nav) {
                this.embedded_code_nav_area = this.element.appendChild(document.createElement("div"));
                this.embedded_code_nav_area.className = "code-widget";
            }

            if (this.make_editor) {
                this.embedded_editor_area = this.element.appendChild(document.createElement("div"));
                this.embedded_editor_area.className = "editor-widget";
            }

            if (!this.show_canvas)
                canvas.style.display = "none";

            this.webgl_manager = new tiny.Webgl_Manager(canvas, color(0, 0, 0, 1));
            // Second parameter sets background color.


            // Add scenes and child widgets
            if (initial_scenes)
                this.webgl_manager.scenes.push(...initial_scenes);

            const primary_scene = initial_scenes ? initial_scenes[0] : undefined;
            const additional_scenes = initial_scenes ? initial_scenes.slice(1) : [];
            const primary_scene_definiton = primary_scene ? primary_scene.constructor : undefined;
            if (this.show_explanation)
                this.embedded_explanation = new Text_Widget(this.embedded_explanation_area, this.webgl_manager.scenes, this.webgl_manager);
            if (this.make_controls)
                this.embedded_controls = new Controls_Widget(this.embedded_controls_area, this.webgl_manager.scenes);
            if (this.make_editor)
                this.embedded_editor = new Editor_Widget(this.embedded_editor_area, primary_scene_definiton, this);
            if (this.make_code_nav)
                this.embedded_code_nav = new Code_Widget(this.embedded_code_nav_area, primary_scene_definiton,
                    additional_scenes, {associated_editor: this.embedded_editor});

            // Start WebGL initialization.  Note that render() will re-queue itself for continuous calls.
            this.webgl_manager.render();
        }
    }


const Controls_Widget = widgets.Controls_Widget =
    class Controls_Widget {
        // **Controls_Widget** adds an array of panels to the document, one per loaded
        // Scene object, each providing interactive elements such as buttons with key
        // bindings, live readouts of Scene data members, etc.
        constructor(element, scenes) {
            const rules = [".controls-widget * {height: 0px; width: 0px; display: none;}",
            ".dropdown { height: 0px; width: 0px; display: none; }"];

            const style = document.head.appendChild(document.createElement("style"));
            for (const r of rules) document.styleSheets[document.styleSheets.length - 1].insertRule(r, 0)

            const table = element.appendChild(document.createElement("table"));
            table.className = "control-box";
            this.row = table.insertRow(0);

            this.panels = [];
            this.scenes = scenes;

            this.render();
        }

        make_panels(time) {
            this.timestamp = time;
            this.row.innerHTML = "";
            // Traverse all scenes and their children, recursively:
            const open_list = [...this.scenes];
            while (open_list.length) {
                open_list.push(...open_list[0].children);
                const scene = open_list.shift();

                const control_box = this.row.insertCell();
                this.panels.push(control_box);
                // Draw top label bar:
                control_box.appendChild(Object.assign(document.createElement("div"), {
                    textContent: scene.constructor.name, className: "control-title"
                }))

                const control_panel = control_box.appendChild(document.createElement("div"));
                control_panel.className = "control-div";
                scene.control_panel = control_panel;
                scene.timestamp = time;
                // Draw each registered animation:
                scene.make_control_panel();
            }
        }

        render(time = 0) {
            // Check to see if we need to re-create the panels due to any scene being new.
            // Traverse all scenes and their children, recursively:
            const open_list = [...this.scenes];
            while (open_list.length) {
                open_list.push(...open_list[0].children);
                const scene = open_list.shift();
                if (!scene.timestamp || scene.timestamp > this.timestamp) {
                    this.make_panels(time);
                    break;
                }

                // TODO: Check for updates to each scene's desired_controls_position, including if the
                // scene just appeared in the tree, in which case call make_control_panel().
            }

            for (let panel of this.panels)
                for (let live_string of panel.querySelectorAll(".live_string")) live_string.onload(live_string);
            // TODO: Cap this so that it can't be called faster than a human can read?
            this.event = window.requestAnimFrame(this.render.bind(this));
        }
    }


const Code_Manager = widgets.Code_Manager =
    class Code_Manager {
        // **Code_Manager** breaks up a string containing code (any ES6 JavaScript).  The RegEx being used
        // to parse is from https://github.com/lydell/js-tokens which states the following limitation:
        // "If the end of a statement looks like a regex literal (even if it isn’t), it will be treated
        // as one."  (This can miscolor lines of code containing divisions and comments).
        constructor(code) {
            const es6_tokens_parser = RegExp([
                /((['"])(?:(?!\2|\\).|\\(?:\r\n|[\s\S]))*(\2)?|`(?:[^`\\$]|\\[\s\S]|\$(?!{)|\${(?:[^{}]|{[^}]*}?)*}?)*(`)?)/,    // Any string.
                /(\/\/.*)|(\/\*(?:[^*]|\*(?!\/))*(\*\/)?)/,                                                                           // Any comment (2 forms).  And next, any regex:
                /(\/(?!\*)(?:\[(?:(?![\]\\]).|\\.)*]|(?![\/\]\\]).|\\.)+\/(?:(?!\s*(?:\b|[\u0080-\uFFFF$\\'"~({]|[+\-!](?!=)|\.?\d))|[gmiyu]{1,5}\b(?![\u0080-\uFFFF$\\]|\s*(?:[+\-*%&|^<>!=?({]|\/(?![\/*])))))/,
                /(0[xX][\da-fA-F]+|0[oO][0-7]+|0[bB][01]+|(?:\d*\.\d+|\d+\.?)(?:[eE][+-]?\d+)?)/,                                     // Any number.
                /((?!\d)(?:(?!\s)[$\w\u0080-\uFFFF]|\\u[\da-fA-F]{4}|\\u{[\da-fA-F]+})+)/,                                          // Any name.
                /(--|\+\+|&&|\|\||=>|\.{3}|(?:[+\-\/%&|^]|\*{1,2}|<{1,2}|>{1,3}|!=?|={1,2})=?|[?~.,:;[\](){}])/,                      // Any punctuator.
                /(\s+)|(^$|[\s\S])/                                                                                                   // Any whitespace. Lastly, blank/invalid.
            ].map(r => r.source).join('|'), 'g');

            this.tokens = [];
            this.no_comments = [];
            let single_token = null;
            while ((single_token = es6_tokens_parser.exec(code)) !== null) {
                let token = {type: "invalid", value: single_token[0]}
                if (single_token[1]) {
                    token.type = "string";
                    token.closed = !!(single_token[3] || single_token[4]);
                } else if (single_token[5]) token.type = "comment"
                else if (single_token[6]) {
                    token.type = "comment";
                    token.closed = !!single_token[7];
                } else if (single_token[8]) token.type = "regex"
                else if (single_token[9]) token.type = "number"
                else if (single_token[10]) token.type = "name"
                else if (single_token[11]) token.type = "punctuator"
                else if (single_token[12]) token.type = "whitespace"
                this.tokens.push(token)
                if (token.type != "whitespace" && token.type != "comment") this.no_comments.push(token.value);
            }
        }
    }


const Code_Widget = widgets.Code_Widget =
    class Code_Widget {
        // **Code_Widget** draws a code navigator panel with inline links to the entire program source code.
        constructor(element, main_scene, additional_scenes, options = {}) {
            // TODO: Update color and board here
            const rules = [".code-widget .code-panel { margin:auto; background:white; overflow:auto; font-family:monospace; \
                width:1058px; padding:10px; padding-bottom:40px; max-height: 500px; \
                border-radius:10px; border: 1px solid black; }",
                ".code-widget .code-display { min-width:1200px; padding:10px; white-space:pre-wrap; background:transparent }",
                ".code-widget table { display:block; margin:auto; overflow-x:auto; width:1080px; border-radius:10px; " +
                "border-collapse:collapse; border: 1px solid black }",
                ".code-widget table.class-list td { border-width:thin; background: White; padding:10px; " +
                "font-family:monospace; border: 1px solid black }"
            ];

            if (document.styleSheets.length == 0)
                document.head.appendChild(document.createElement("style"));
            for (const r of rules)
                document.styleSheets[document.styleSheets.length - 1].insertRule(r, 0)

            this.associated_editor_widget = options.associated_editor;

            if (!main_scene)
                return;

            import( './main-scene.js' )
                .then(module => {
                    this.build_reader(element, main_scene, additional_scenes, module.defs);
                    if (!options.hide_navigator)
                        this.build_navigator(element, main_scene, additional_scenes, module.defs);
                })
        }

        build_reader(element, main_scene, additional_scenes, definitions) {
            // (Internal helper function)
            this.definitions = definitions;
            const code_panel = element.appendChild(document.createElement("div"));
            code_panel.className = "code-panel";
            // const text        = code_panel.appendChild( document.createElement( "p" ) );
            // text.textContent  = "Code for the above scene:";
            this.code_display = code_panel.appendChild(document.createElement("div"));
            this.code_display.className = "code-display";
            // Default textbox contents:
            this.display_code(main_scene);
        }

        build_navigator(element, main_scene, additional_scenes, definitions) {
            // (Internal helper function)
            const class_list = element.appendChild(document.createElement("table"));
            class_list.className = "class-list";
            const top_cell = class_list.insertRow(-1).insertCell(-1);
            top_cell.colSpan = 2;
            top_cell.appendChild(document.createTextNode("Click below to navigate through all classes that are defined."));
            const content = top_cell.appendChild(document.createElement("p"));
            content.style = "text-align:center; margin:0; font-weight:bold";
            content.innerHTML = "main-scene.js<br>Main Scene: ";
            const main_scene_link = content.appendChild(document.createElement("a"));
            main_scene_link.href = "javascript:void(0);"
            main_scene_link.addEventListener('click', () => this.display_code(main_scene));
            main_scene_link.textContent = main_scene.name;

            const second_cell = class_list.insertRow(-1).insertCell(-1);
            second_cell.colSpan = 2;
            second_cell.style = "text-align:center; font-weight:bold";
            const index_src_link = second_cell.appendChild(document.createElement("a"));
            index_src_link.href = "javascript:void(0);"
            index_src_link.addEventListener('click', () => this.display_code());
            index_src_link.textContent = "This page's complete HTML source";

            const third_row = class_list.insertRow(-1);
            third_row.style = "text-align:center";
            third_row.innerHTML = "<td><b>tiny-graphics.js</b><br>(Always the same)</td> \
                             <td><b>All other class definitions from dependencies:</td>";

            const fourth_row = class_list.insertRow(-1);
            // Generate the navigator table of links:
            for (let list of [tiny, definitions]) {
                const cell = fourth_row.appendChild(document.createElement("td"));
                // List all class names except the main one, which we'll display separately:
                const class_names = Object.keys(list).filter(x => x != main_scene.name);
                cell.style = "white-space:normal"
                for (let name of class_names) {
                    const class_link = cell.appendChild(document.createElement("a"));
                    class_link.style["margin-right"] = "80px"
                    class_link.href = "javascript:void(0);"
                    class_link.addEventListener('click', () => this.display_code(tiny[name] || definitions[name]));
                    class_link.textContent = name;
                    cell.appendChild(document.createTextNode(" "));
                }
            }
        }

        display_code(class_to_display) {
            // display_code():  Populate the code textbox.
            // Pass undefined to choose index.html source.
            if (this.associated_editor_widget)
                this.associated_editor_widget.select_class(class_to_display);
            if (class_to_display) this.format_code(class_to_display.toString());
            else fetch(document.location.href)
                .then(response => response.text())
                .then(pageSource => this.format_code(pageSource));
        }

        format_code(code_string) {
            // (Internal helper function)
            this.code_display.innerHTML = "";
            const color_map = {
                string: "chocolate", comment: "green", regex: "blue", number: "magenta",
                name: "black", punctuator: "red", whitespace: "black"
            };

            for (let t of new Code_Manager(code_string).tokens)
                if (t.type == "name" && [...Object.keys(tiny), ...Object.keys(this.definitions)].includes(t.value)) {
                    const link = this.code_display.appendChild(document.createElement('a'));
                    link.href = "javascript:void(0);"
                    link.addEventListener('click', () => this.display_code(tiny[t.value] || this.definitions[t.value]));
                    link.textContent = t.value;
                } else {
                    const span = this.code_display.appendChild(document.createElement('span'));
                    span.style.color = color_map[t.type];
                    span.textContent = t.value;
                }
        }
    }


const Editor_Widget = widgets.Editor_Widget =
    class Editor_Widget {
        constructor(element, initially_selected_class, canvas_widget, options = {}) {
            let rules = [".editor-widget { margin:auto; background:white; overflow:auto; font-family:monospace; width:1060px; padding:10px; \
                                      border-radius:10px; box-shadow: 20px 20px 90px 0px powderblue inset, 5px 5px 30px 0px blue inset }",
                ".editor-widget button { background: #4C9F50; color: white; padding: 6px; border-radius:10px; margin-right:5px; \
                                         box-shadow: 4px 6px 16px 0px rgba(0,0,0,0.3); transition: background .3s, transform .3s }",
                ".editor-widget input { margin-right:5px }",
                ".editor-widget textarea { white-space:pre; width:1040px; margin-bottom:30px }",
                ".editor-widget button:hover, button:focus { transform: scale(1.3); color:#252424 }"
            ];

            for (const r of rules) document.styleSheets[0].insertRule(r, 1);

            this.associated_canvas = canvas_widget;
            this.options = options;

            const form = this.form = element.appendChild(document.createElement("form"));
            // Don't refresh the page on submit:
            form.addEventListener('submit', event => {
                event.preventDefault();
                this.submit_demo()
            }, false);

            const explanation = form.appendChild(document.createElement("p"));
            explanation.innerHTML = `<i><b>What can I put here?</b></i>  
                A JavaScript class, with any valid JavaScript inside.  Your code can use classes from this demo,
                <br>or from ANY demo on Demopedia --  the dependencies will automatically be pulled in to run your demo!<br>`;

            const run_button = this.run_button = form.appendChild(document.createElement("button"));
            run_button.type = "button";
            run_button.style = "background:maroon";
            run_button.textContent = "Run with Changes";

            const submit = this.submit = form.appendChild(document.createElement("button"));
            submit.type = "submit";
            submit.textContent = "Save as New Webpage";

            const author_box = this.author_box = form.appendChild(document.createElement("input"));
            author_box.name = "author";
            author_box.type = "text";
            author_box.placeholder = "Author name";

            const password_box = this.password_box = form.appendChild(document.createElement("input"));
            password_box.name = "password";
            password_box.type = "text";
            password_box.placeholder = "Password";
            password_box.style = "display:none";

            const overwrite_panel = this.overwrite_panel = form.appendChild(document.createElement("span"));
            overwrite_panel.style = "display:none";
            overwrite_panel.innerHTML = "<label>Overwrite?<input type='checkbox' name='overwrite' autocomplete='off'></label>";

            const submit_result = this.submit_result = form.appendChild(document.createElement("div"));
            submit_result.style = "margin: 10px 0";

            const new_demo_code = this.new_demo_code = form.appendChild(document.createElement("textarea"));
            new_demo_code.name = "new_demo_code";
            new_demo_code.rows = this.options.rows || 25;
            new_demo_code.cols = 140;
            if (initially_selected_class)
                this.select_class(initially_selected_class);
        }

        select_class(class_definition) {
            this.new_demo_code.value = class_definition.toString();
        }

        fetch_handler(url, body) {
            // A general utility function for sending / receiving JSON, with error handling.
            return fetch(url,
                {
                    body: body, method: body === undefined ? 'GET' : 'POST',
                    headers: {'content-type': 'application/json'}
                }).then(response => {
                if (response.ok) return Promise.resolve(response.json())
                else return Promise.reject(response.status)
            })
        }

        submit_demo() {
            const form_fields = Array.from(this.form.elements).reduce((accum, elem) => {
                if (elem.value && !(['checkbox', 'radio'].includes(elem.type) && !elem.checked))
                    accum[elem.name] = elem.value;
                return accum;
            }, {});

            this.submit_result.innerHTML = "";
            return this.fetch_handler("/submit-demo?Unapproved", JSON.stringify(form_fields))
                .then(response => {
                    if (response.show_password) this.password_box.style.display = "inline";
                    if (response.show_overwrite) this.overwrite_panel.style.display = "inline";
                    this.submit_result.innerHTML += response.message + "<br>";
                })
                .catch(error => {
                    this.submit_result.innerHTML += "Error " + error + " when trying to upload.<br>"
                })
        }
    }


const Text_Widget = widgets.Text_Widget =
    class Text_Widget {
        // **Text_Widget** generates HTML documentation and fills a panel with it.  This
        // documentation is extracted from whichever Scene object gets loaded first.
        constructor(element, scenes, webgl_manager) {
            const rules = [".text-widget { background: white; width:1060px;\
                             padding:0 10px; overflow:auto; transition:1s; \
                             overflow-y:scroll; box-shadow: 10px 10px 90px 0 inset LightGray}",
                ".text-widget div { transition:none } "
            ];
            if (document.styleSheets.length == 0) document.head.appendChild(document.createElement("style"));
            for (const r of rules) document.styleSheets[document.styleSheets.length - 1].insertRule(r, 0)

            Object.assign(this, {element, scenes, webgl_manager});
            this.render();
        }

        render(time = 0) {
            if (this.scenes[0])
                this.scenes[0].show_explanation(this.element, this.webgl_manager)
            else
                this.event = window.requestAnimFrame(this.render.bind(this))
        }
    }