chatcontrol-live-demo/chatapp.svg

<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1"
     xmlns="http://www.w3.org/2000/svg"
     xmlns:xlink="http://www.w3.org/1999/xlink"
     width="300"
     height="500" 
     viewBox="0 0 300 500"
     onload="start_chat('Ven')"
     overflow="auto"
     >
<defs>
  <symbol id="kaereste_foto" width="60" height="200">
    <g style="fill: pink; stroke: pink;">
      <circle cx="20" cy="20" r="20" />
      <line x1="20" y1="40" x2="20" y2="60" />
      <ellipse cx="20" cy="110" rx="10" ry="50" />
      <!-- left arm -->
      <polyline fill="none"
                points="15,70 5,50 0,40" />
      <!-- right arm -->
      <polyline fill="none"
                points="25,70 35,50 40,40" />
      <!-- left leg -->
      <polyline fill="none"
                points="15,155 5,135 0,125" />
      <!-- right leg -->
      <polyline fill="none"
                points="25,155 35,135 40,125" />
      <!-- the thing -->
      <text x="14" y="160" style="font: bold 20px sans-serif" fill="black">?</text>
    </g>
  </symbol>
</defs>
<script type="application/ecmascript">
<![CDATA[
'use strict';

const svgns = "http://www.w3.org/2000/svg";

// must be the same as the SVG dimensions
const width = 300;
const height = 500;

const line_height = 14;
const bubble_padding = 6;
const bubble_spacing = 5;
const visible_chat_area = {'top': 60, 'bottom': 500};
const typing_speed = 7;

var conversation_count = 0;

/// SVG 1.1 doesn't do proper text splitting into several lines.
/// we need to do it ourselves.
function split_text_into_lines(text, upper_line_length) {
  let result = [];

  while(text.length) {
    if(text.length < upper_line_length) {
      result.push(text);
      break; // we are done
    }

    let found_split_point = false;
    for(let i = upper_line_length; i; i--) {
      if(text[i] == ' ') {
        result.push(text.slice(0, i));
        text = text.slice(i+1);
        found_split_point = true;
        break;
      }
    }

    if(!found_split_point) {
      // no <space> found. Split at character boundary instead
      result.push(text.slice(0, upper_line_length));
      text = text.slice(upper_line_length);
    }
  }

  return result;
}

/// A class holding a text chat message.
///
/// *ChatMessages are owned by a Dialog.
function TextChatMessage(message_text, is_myself) {
  let lines = split_text_into_lines(message_text, 28);
  let bubble_color = (is_myself)? 'white': '#DDFF66';
  let container = document.getElementById('messages');

  // attributes
  this.height = 0; // height on screen when fully visible
  this.group = null; // a <g> with a transform=translate(0,y_shift) attribute

  /// Render the chat message on the screen
  this.draw = function(y_offset, y_shift) {
    let group = create_svg_node('g', {'transform': `translate(0, ${y_shift})`});

    let x = (is_myself ? 190 : 110);
    let text = create_svg_node('text', {
      'x': `${x}%`,
      'font-size': `${line_height}px`,
      'text-anchor': is_myself ? 'end' : 'start'
    });

    let height_so_far = y_offset;

    lines.forEach(function(line) {
      let y = height_so_far;
      let tspan = create_svg_node('tspan', {
        'x': `${x}%`,
        'y': `${y + line_height}`, // important: y is lower text baseline
        'fill': 'green',
        'width': '5%'
      });

      tspan.appendChild(document.createTextNode(line));
      text.appendChild(tspan);

      height_so_far += line_height;
    });

    group.appendChild(text); // needs to be part of the DOM *now*
    container.appendChild(group);
    let bubble = create_bubble(text, bubble_color);
    group.appendChild(bubble);
    redraw_on_top(text);

    this.height = bubble.getBBox().height + bubble_spacing;
    this.group = group;
  }

  /// Move a chat message on the screen (to simulate scrolling)
  this.shift_y_pos = function(by) {
    redraw_on_top(document.getElementById('contact_name_box'));
    this.group.setAttribute('transform', `translate(0, ${by})`);
  }
}

/// A class holding a image-based chat message.
///
/// *ChatMessages are owned by a Dialog.
function ImageChatMessage(symbol_id, is_myself) {
  let container = document.getElementById('messages');
  let bubble_color = (is_myself)? 'white': '#DDFF66';

  // attributes
  this.height = 0; // height on screen when fully visible
  this.group = null; // a <g> with a transform=translate(0,y_shift) attribute

  this.draw = function(y_offset, y_shift) {
    let group = create_svg_node('g', {'transform': `translate(0, ${y_shift})`});

    let x = (is_myself ? 190 : 110);
    let img = create_svg_node('use', {
        'href': symbol_id,
        x: `${x}%`,
        y: y_offset,
    });

    group.appendChild(img); // needs to be part of the DOM *now*
    container.appendChild(group);
    let bubble = create_bubble(img, bubble_color);
    group.appendChild(bubble);
    redraw_on_top(img);

    this.height = bubble.getBBox().height + bubble_spacing;
    this.group = group;
  }

  this.shift_y_pos = function(by) {
    redraw_on_top(document.getElementById('contact_name_box'));
    this.group.setAttribute('transform', `translate(0, ${by})`);
  }
}

function create_chat_message(content, is_myself) {
  let constr = (content.startsWith('#'))? ImageChatMessage: TextChatMessage;
  return new constr(content, is_myself);
}

/// Promise-based version of setTimeout
const wait = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

/// toggle viewport between message list and contact list
/// That means: show either the left or right side of the SVG
function swipe_viewport() {
  let svg = document.getElementsByTagName('svg')[0];
  let coords = svg.getAttribute('viewBox').split(' ');
  let x = parseInt(coords.shift());
  if(x == 0) {
      // moving from messages to contacts
      var step = 5;
      var end = width;
  } else {
      // moving from contacts to messages
      var step = -5;
      var end = 0;
  }

  let viewBox_suffix = coords.join(' '); // only 3 elements

  async function animate(resolve, reject) {
    while(x!=end) {
      await wait(1);
      x += step;
      svg.setAttribute('viewBox', `${x} ${viewBox_suffix}`);
    }
    resolve();
  };
  new Promise(animate);
}


// Create a chat bubble around an element.
//
// The element must already be inside the DOM for this to work.
function create_bubble(inner_element, color) {
  const bbox = inner_element.getBBox();
  const y_percent = Math.round(((bbox.y - bubble_padding) / height) * 100);
  let bubble = create_svg_node('rect', {
    'x': bbox.x - bubble_padding,
    'y': `${y_percent}%`,
    'width': bbox.width + 2 * bubble_padding,
    'height': bbox.height + 2 * bubble_padding,
    'rx': 8,
    'fill': color,
  });
  return bubble;
}

function create_svg_node(tag_name, attrs) {
  let node = document.createElementNS(svgns, tag_name);
  for(let attr in attrs) {
    node.setAttribute(attr, attrs[attr]);
  }
  return node;
}

/// Ensure that an element is redrawn above all other elements
///
/// The element's children will also be redrawn on top
function redraw_on_top(element) {
  let parent = element.parentNode;
  parent.appendChild(parent.removeChild(element));
}

function removeAllChildren(parentNode) {
  while(parentNode.firstChild) {
    parentNode.removeChild(parentNode.lastChild);
  }
}

function start_chat(who) {
  let indicator = document.getElementById('contact_indicator');
  indicator.childNodes[0].data = `Kontakt: ${who}`;
  removeAllChildren(document.getElementById('messages'));
  swipe_viewport();

  switch(who) {
    case 'Ven':
      dialog_ven();
      break;
    case 'Mor':
      dialog_mor();
      break;
    case 'Kæreste':
      dialog_kaereste();
      break;
    default:
      alert(`Unknown contact: ${who}`);
  }
}

function Dialog(chat_partner) {
  let conversation_id = ++conversation_count;
  this.messages = [];
  this.y_shift = visible_chat_area.top; // for scrolling
  this.all_elements_height = 0; // also for scrolling

  async function post_message(dialog, message, is_myself) {
    if(dialog.messages.length) await wait(message.length * typing_speed); // first message should be instant

    if(conversation_id != conversation_count) {
      return; // Do not add messages to old conversation
    }

    let chat_message = create_chat_message(message, is_myself);
    chat_message.draw(dialog.all_elements_height, // offset
                      dialog.y_shift);
    dialog.all_elements_height += chat_message.height;
    dialog.messages.push(chat_message);

    let bottom = dialog.all_elements_height + dialog.y_shift;
    let scroll = Math.max(0, bottom - visible_chat_area.bottom);
    while(scroll > line_height) {
      dialog.y_shift -= line_height;
      scroll -= line_height;
      dialog.messages.forEach(msg => msg.shift_y_pos(dialog.y_shift));
      await wait(50);
    }
  }

  this.me = async function(message) {
    await post_message(this, message, true);
  }
  this.you = async function(message) {
    await post_message(this, message, false);
  }
}

async function dialog_ven() {
  let d = new Dialog('Ven');
  await d.me("hej");
  await d.you("tak for sidst!");
  await d.you('Har du hørt om den nye EU lov "ChatControl"?');
  await d.me("nej, det har jeg ikke");
  await d.me("hvad handler det om?");
  await d.you('EU kommissionen planlægger at læse alle chatbeskeder i EU');
  await d.me('Ja, men vi krypterer jo vores beskeder? Tough luck!');
  await d.you('Det tager de højde for. Aflytningen vil ske før krypteringen på din telefon!');
  await d.me('Det lyder overhovedet ikke rart. Hvorfor vil de gøre det?');
  await d.you('De siger at det er for at beskytte børn på nettet.');
  await d.you('Men det giver ikke meget mening');
  await d.me('Alle vores beskeder skal scannes på grund af børn på nettet? Det lyder dumt!');
  await d.you('Her kan du læse mere om det:');
  await d.you('https://chatcontrol.eu');
  }

async function dialog_mor() {
  let d = new Dialog('Mor');
  await d.you("Jeg har fundet nogle gamle familiebilleder fra vores ferie 10 år siden");
  await d.you("Her leger du på stranden");
  await d.you("(naked stick figure image here)");
}

async function dialog_kaereste() {
  let d = new Dialog('Kæreste');
  await d.me('hej smukkeste');
  await d.you('hej, jeg har lige tænkt på dig!');
  await d.you('og derfor har jeg taget et sexet billede');
  await d.you('#kaereste_foto');
  await d.me('tak. Det har jeg savnet!');
  await d.me('du ser stadig så ung ud.');
  await d.me('Jeg tror at vi skal være forsigtige, fordi der er en overvågning af vores beskeder');
  await d.you('What the fuck??? Hvem overvågner os?????');
  await d.me('Ingen lige nu. Men EU\'en vil forpligte tilbyderne af messagingtjenester til at scanne alle beskeder');
  await d.me('Og hvis der er beskeder som "ligner" børneborno får politiet en kopi af dem');
  await d.you('Jeg vil hellere ikke at politiet får mine nøgenbilleder. Det er min krop og jeg vil selv bestemme over det!');
}

]]>
</script>

<!-- [right] contact name view -->
<g id="contact_name_box">
  <rect x="300" y="0" width="300" height="50" fill="yellow" />
  <polyline points="300,20 320,0 320,40" fill="blue" onclick="swipe_viewport()" /> <!-- XXX: these polyline points depend on the svg width -->
  <text x="375" y="30" id="contact_indicator">loading...</text>
</g>

<!-- [right] messages view -->
<rect x="300" y="50" width="300" height="450" fill="aqua" />
<g id="messages"></g>

<!-- [left] contact list -->
<rect x="0" y="0" width="300" height="50" fill="yellow" />
<text x="60" y="30">Dine kontakter</text>
<rect x="0" y="50" width="300" height="450" style="stroke: green; stroke-width: 10px" fill="aqua" />

<text x="15" y="75" onclick="start_chat('Ven')">Ven</text>
<text x="15" y="100" onclick="start_chat('Mor')">Mor</text>
<text x="15" y="125" onclick="start_chat('Kæreste')">Kæreste&#10084;</text>

</svg>