Update input focus on registration page

The issue 385 is already resolved. This commit sets up the same behavior
for the other sections of the registration page (i.e. the mnemonic and
the link device sections)
Fixes #385

js/views/standalone_registration_view.js

@@ -145,7 +145,10 @@
       this.$('#display-name').focus();
     },
     onKeyup(event) {
-      if (currentPageIndex !== PROFILE_INDEX) {
+      if (
+        currentPageIndex !== PROFILE_INDEX &&
+        currentPageIndex !== REGISTER_INDEX
+      ) {
         // Only want enter/escape keys to work on profile page
         return;
       }
@@ -153,7 +156,11 @@
       const validName = this.sanitiseNameInput();
       switch (event.key) {
         case 'Enter':
-          if (validName) {
+          if (event.target.id === 'mnemonic') {
+            this.registerWithMnemonic();
+          } else if (event.target.id === 'primary-pubkey') {
+            this.registerSecondaryDevice();
+          } else if (validName) {
             this.onSaveProfile();
           }
           break;
@@ -388,13 +395,22 @@
         this.$('#number-container').addClass('invalid');
       }
     },
+
     toggleSection(e) {
+      function focusInput() {
+        const inputs = $(this).find('input');
+        if ($(this).is(':visible')) {
+          if (inputs[0]) {
+            inputs[0].focus();
+          }
+        }
+      }
       // Expand or collapse this panel
       const $target = this.$(e.currentTarget);
       const $next = $target.next();
 
       // Toggle section visibility
-      $next.slideToggle('fast');
+      $next.slideToggle('fast', focusInput);
       $target.toggleClass('section-toggle-visible');
 
       // Hide the other sections