Implemented chording. Pressing down the shift key while typing other characters will now transition to capslock until the shift key is released.

BUG=252707

Review URL: https://chromiumcodereview.appspot.com/23496075

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225065 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 25 insertions, 12 deletions

diff --git a/ui/keyboard/resources/elements/kb-keyboard.html b/ui/keyboard/resources/elements/kb-keyboard.html
index ea09e37..e515b65 100644
--- a/ui/keyboard/resources/elements/kb-keyboard.html
+++ b/ui/keyboard/resources/elements/kb-keyboard.html
@@ -427,20 +427,22 @@
         if (swipeInProgress)
           return;
         this.lastPressedKey.classList.remove('active');
-        if (this.lastPressedKey.char != event.target.char)
-          return;
-        if (repeatKey.key == event.target) {
-          repeatKey.cancel();
-          return;
-        }
+        // Changes keyset if necessary.
         var toKeysetId = detail.toKeyset;
         // Keyset transition key. This is needed to transition from upper
-        // to lower case when we are not in caps mode.
+        // to lower case when we are not in caps mode, as well as when
+        // we're ending chording.
         if (toKeysetId) {
           this.keyset = toKeysetId;
           this.querySelector('#' + this.layout + '-' + this.keyset).nextKeyset =
               detail.nextKeyset;
         }
+        if (this.lastPressedKey.charValue != event.target.charValue)
+          return;
+        if (repeatKey.key == event.target) {
+          repeatKey.cancel();
+          return;
+        }
         var toLayoutId = detail.toLayout;
         // Layout transition key.
         if (toLayoutId)
diff --git a/ui/keyboard/resources/elements/kb-shift-key.html b/ui/keyboard/resources/elements/kb-shift-key.html
index 686a59c..bb874f0 100644
--- a/ui/keyboard/resources/elements/kb-shift-key.html
+++ b/ui/keyboard/resources/elements/kb-shift-key.html
@@ -21,7 +21,8 @@
         PRESSED: "pressed", // Key-down on shift key.
         LOCKED: "locked", // Key is capslocked.
         UNLOCKED: "unlocked", // Default state.
-        TAPPED: "tapped" // Key-down followed by key-up.
+        TAPPED: "tapped", // Key-down followed by key-up.
+        CHORDING: "chording" // Key-down followed by other keys.
       };
 
       /**
@@ -49,7 +50,11 @@
         up: function(event) {
           if (state == KEY_STATES.PRESSED) {
             state = KEY_STATES.TAPPED;
-            // TODO(rsadam@): Add chording logic here.
+          } else if (state == KEY_STATES.CHORDING) {
+            // Resets shift state.
+            state = KEY_STATES.UNLOCKED;
+            // TODO(rsadam@): Only end chording if the key-up is on the same
+            // shift key that started the chording.
           }
           this.super();
         },
@@ -66,9 +71,10 @@
               state = KEY_STATES.UNLOCKED;
               break;
             case KEY_STATES.PRESSED:
+            case KEY_STATES.CHORDING:
               // We pressed another shift key at the same time,
               // so ignore second press.
-              break;
+              return;
             default:
               console.error("Undefined shift key state: " + state);
               break;
@@ -113,13 +119,13 @@
          * A control key is defined as one of shift, control or alt.
          */
         onNonControlKeyDown: function() {
-           // TODO(rsadam@): add logic for chording here.
            switch (state) {
              case (KEY_STATES.TAPPED):
                state = KEY_STATES.UNLOCKED;
                break;
              case (KEY_STATES.PRESSED):
-               // Enter chording mode. First disable longpress timer.
+               state = KEY_STATES.CHORDING;
+               // Disable longpress timer.
                clearTimeout(this.shiftLongPressTimer);
                break;
              default:
@@ -155,6 +161,11 @@
               detail.toKeyset = this.upperCaseKeysetId;
               detail.nextKeyset = this.lowerCaseKeysetId;
               break;
+            case(KEY_STATES.CHORDING):
+              detail.toKeyset = this.lowerCaseKeysetId;
+              break;
+            default:
+              break;
           }
           return detail;
         },