zbar-main.js

// Copyright (c) 2013 Yury Delendik
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

var takePicture = document.getElementById("take-picture");
var canvas = document.createElement("canvas");
var codeType = document.getElementById("code-type");
var codeContent = document.getElementById("code-content");
var openUrlButton = document.getElementById("open-url");
var searchCodeButton = document.getElementById("search-code");


function scan() {
  if (typeof MozActivity !== 'undefined') {
    // in Firefox OS v1.0.1, input[file] does not work, using Web Activities
    takePictureUsingWebActivity();
    return;
  }

  takePicture.click();
}
function openUrl() {
  window.open(codeContent.value);
}
function searchCode() {
  window.open('https://www.google.com/search?q=' + codeContent.value);        
}

// https://hacks.mozilla.org/2013/01/introducing-web-activities/
function takePictureUsingWebActivity() {
  var pick = new MozActivity({
    name: "pick",
    data: { type: ["image/png", "image/jpg", "image/jpeg"] }
  });
  pick.onsuccess = function () {
    loadImage(URL.createObjectURL(this.result.blob));
  };
}

takePicture.onchange = function (event) {
  var files = event.target.files;
  if (!files || files.length === 0) {
    return;
  }

  var file = files[0];
  var imgURL = (window.URL || window.webkitURL).createObjectURL(file);
  loadImage(imgURL);
}

function loadImage(imgURL) {
  // clean
  codeType.textContent = '';
  codeContent.value = '';
  openUrlButton.setAttribute('hidden', 'hidden');
  searchCodeButton.setAttribute('hidden', 'hidden');

  var img = new Image();
  img.onload = function () {
    var canvas = document.createElement('canvas');
    // resizing image to 320x240 for slow devices
    var k = (320 + 240) / (img.width + img.height);
    canvas.width = Math.ceil(img.width * k);
    canvas.height = Math.ceil(img.height * k);
    var ctx = canvas.getContext('2d');
    ctx.drawImage(img, 0, 0, img.width, img.height,
                  0, 0, canvas.width, canvas.height);

    var data = ctx.getImageData(0, 0, canvas.width, canvas.height);

    var t0 = Date.now();
    var codes = zbarProcessImageData(data);
    var t = Date.now() - t0;
    document.body.classList.remove('processing');

    if (codes.length === 0) {
      codeType.textContent = 'N/A';
      document.body.classList.add('not-detected');
      return;
    }
      
    var type = codes[0][0];
    var data = codes[0][2];
    // publishing data
    codeType.textContent = type;
    codeContent.value = data;

    var isUrl = /^(http|https|ftp|mailto):/.test(data);
    if (isUrl) {
      openUrlButton.removeAttribute('hidden');
    } else {
      searchCodeButton.removeAttribute('hidden');
    }
  };
  img.src = imgURL;
  document.body.classList.add('processing');
  document.body.classList.remove('not-detected');
  document.getElementById('info').removeAttribute('hidden');
};

codeContent.value = '';

setTimeout(scan, 500); // trying to start "scanning"

var canInstall = !!(navigator.mozApps && navigator.mozApps.install);
if (canInstall) {
  var installButton = document.getElementById('install');
  var manifestURL = installButton.href;
  var request = window.navigator.mozApps.checkInstalled(manifestURL);
  request.onsuccess = function(e) {
    if (request.result) {
      return;
    }

    // App is not installed
    installButton.removeAttribute('hidden');
    installButton.addEventListener('click', function (e) {
      var request = navigator.mozApps.install(manifestURL);
      request.onsuccess = function (e) {
        alert('Application installed');
      };
      e.preventDefault();
    }, false);
  };
}