Add color enhancer as a chromium accessibility extensions.

ui/accessibility/extensions/colorenhancer/src/popup.js

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var site;
+
+
+/**
+ * Update the popup controls based on settings for this site or the default.
+ */
+function update() {
+  if (site) {
+    console.log('updated site ' + site + ' to ' +
+                getSiteDelta(site) + ',' + getSiteSeverity(site));

[kevers, 2015/03/10 14:07:51]

Please wrap console.log output so that it only appears when debugging. e.g.

// Set to true when debugging.
enableDebugPrint = false;

function DebugPrint(message) {
  if (enableDebugPrint) {
    console.log(message);
  }
}

[Peter Wen, 2015/03/10 19:00:55]

I changed it so we automatically enable logging for debugging (unpacked
extension) and turn it off for production (crx from webstore).

+    $('delta').value = getSiteDelta(site);
+    $('severity').value = getSiteSeverity(site);
+  } else {
+    console.log('updated site ' + site + ' to ' +
+                getDefaultDelta() + ',' + getDefaultSeverity());
+    $('delta').value = getDefaultDelta();
+    $('severity').value = getDefaultSeverity();
+  }
+
+  console.log('updated site ' + site + ' type ' + getDefaultType());
+  $('type').value = getDefaultType();
+
+  // TODO(mustaq): Finish simulate feature.
+  //console.log('updated site ' + site + ' simulate ' + getDefaultSimulate());
+  //$('simulate').checked = getDefaultSimulate();
+
+  chrome.extension.getBackgroundPage().updateTabs();
+}
+
+
+/**
+ * Callback for color rotation slider.

[kevers, 2015/03/10 14:07:51]

@param here and below.

[Peter Wen, 2015/03/10 19:00:56]

Done.

+ */
+function onDeltaChange(value) {
+  console.log('delta changing to ' + value + ' for site ' + site);
+  if (site) {
+    setSiteDelta(site, value);
+  }
+  setDefaultDelta(value);
+  update();
+}
+
+
+/**
+ * Callback for severity slider.
+ */
+function onSeverityChange(value) {
+  console.log('severity changing to ' + value + ' for site ' + site);
+  if (site) {
+    setSiteSeverity(site, value);
+  }
+  setDefaultSeverity(value);
+  update();
+}
+
+
+/**
+ * Callback for changing color deficiency type.
+ */
+function onTypeChange(value) {
+  console.log('type changing to ' + value + ' for site ' + site);
+  setDefaultType(value);
+  update();
+}
+
+
+/**
+ * TODO(mustaq): JsDoc.
+ */
+function onSimulateChange(value) {
+  console.log('simulate changing to ' + value + ' for site ' + site);
+  setDefaultSimulate(value);
+  update();
+}
+
+
+/**
+ * Reset all stored per-site and default values.
+ */
+function onReset() {
+  console.log('resetting sites');
+  resetSiteDeltas();
+  resetSiteSeverities();
+  update();
+}
+
+
+/**
+ * Attach event handlers to controls and update the filter config values for the
+ * currently visible tab.
+ */
+function initialize() {
+  $('delta').addEventListener('input', function() {
+    onDeltaChange(parseFloat(this.value));
+  });
+  $('severity').addEventListener('input', function() {
+    onSeverityChange(parseFloat(this.value));
+  });
+  $('type').addEventListener('input', function() {
+    onTypeChange(this.value);
+  });
+  // TODO(mustaq): Finish simulate feature.

[kevers, 2015/03/10 14:07:51]

Do we want the simulate feature in the color enhancer extension or only in dev
tools?

[Peter Wen, 2015/03/10 19:00:55]

Originally yes, but we thought it would be beneficial to have it visible and
tested in the extension before integrating into dev tools.

+  //$('simulate').addEventListener('change', function() {
+  //  onSimulateChange(!this.checked);
+  //});
+  $('resetall').addEventListener('click', function() {
+    onReset();
+  });
+
+  chrome.windows.getLastFocused({'populate': true}, function(window) {
+    for (var i = 0; i < window.tabs.length; i++) {
+      var tab = window.tabs[i];
+      if (tab.active) {
+        site = siteFromUrl(tab.url);
+        console.log('active tab update ' + site);
+        update();
+        return;
+      }
+    }
+    site = 'unknown site';
+    update();
+  });
+}
+
+// TODO(wnwen): Use Promise instead, more reliable.
+window.addEventListener('load', initialize, false);