Bind 'h' and '/' keys to toggle help screen

Fixed anvaka#8

src/galaxy/help.jsx

@@ -8,6 +8,7 @@
  */
 import React from 'react';
 import appEvents from './service/appEvents.js';
+import Key from './utils/key.js';
 
 export default require('maco')(help);
 
@@ -101,6 +102,7 @@ function help(x) {
     if (window.orientation !== undefined) return;
     appEvents.graphDownloaded.on(showHelpIfNeeded);
     appEvents.downloadGraphRequested.on(resetHelp);
+    appEvents.toggleHelp.on(toggleHelp);
 
     listenToKeys();
     listenToWheel();
@@ -110,6 +112,7 @@ function help(x) {
     if (window.orientation !== undefined) return;
     appEvents.graphDownloaded.off(showHelpIfNeeded);
     appEvents.downloadGraphRequested.off(resetHelp);
+    appEvents.toggleHelp.off(toggleHelp);
 
     releaseKeyListener();
     releaseWheel();
@@ -122,12 +125,21 @@ function help(x) {
     x.forceUpdate();
   }
 
+  function toggleHelp() {
+    helpWasShown = !helpWasShown;
+    x.forceUpdate();
+  }
+
   function resetHelp() {
     graphDownloaded = false;
     x.forceUpdate();
   }
 
   function handlekey(e) {
+    if (Key.isModifier(e)) {
+      // ignore modifiers
+      return;
+    }
     var needsUpdate = !helpWasShown;
     helpWasShown = true;
 

src/galaxy/native/sceneKeyboardBinding.js

@@ -6,6 +6,7 @@
 export default sceneKeyboardBinding;
 
 import events from '../service/appEvents.js';
+import Key from '../utils/key.js';
 
 function sceneKeyboardBinding(container) {
   var api = {
@@ -23,12 +24,18 @@ function sceneKeyboardBinding(container) {
   }
 
   function keydown(e) {
-    if (e.which === 32) { // spacebar
+    if (e.which === Key.Space) {
       events.toggleSteering.fire();
-    } else if (e.which === 76) { // L - toggle links
+    } else if (e.which === Key.L) { // L - toggle links
       if (!e.ctrlKey && !e.metaKey) {
         events.toggleLinks.fire();
       }
+    } else if (e.which === Key.H || (e.which === Key['/'] && e.shiftKey)) { // 'h' or '?' key
+      // Need to stop propagation, since help screen attempts to close itself
+      // once user presses any key. We don't want that now, since this is
+      // explicit request to render help
+      e.stopPropagation();
+      events.toggleHelp.fire();
     }
     if (e.shiftKey && !lastShiftKey) {
       lastShiftKey = true;

src/galaxy/service/appEvents.js

@@ -53,6 +53,9 @@ export default eventMirror([
    */
   'toggleSteering',
 
+  /**
+   * Fired when user wants to show or hide links
+   */
   'toggleLinks',
 
   /**
@@ -65,6 +68,12 @@ export default eventMirror([
    */
   'commandBarChanged',
 
+  /**
+   * fired when user requesed to show or hide help screen
+   */
+  'toggleHelp',
+
+  // These events are not documented since I'm not sure whether to keep them
    'showNodeListWindow',
    'hideNodeListWindow',
    'showDegree',

src/galaxy/utils/key.js

@@ -0,0 +1,12 @@
+export default {
+  isModifier,
+
+  H: 72,
+  L: 76,
+  Space: 32,
+  '/': 191
+};
+
+function isModifier(e) {
+  return e.altKey || e.ctrlKey || e.metaKey || e.shiftKey;
+}