Support Latin letters in the smart card pin dialog

Add UI support for alphanumeric pins used on user login via
smart cards.

Previously, Latin letters were consciously ignored.
Also added a unit test for non-digit pin inputs.

Bug: 1144194

Change-Id: I556f1fd8a07fa1a8a1d76130ee116c3a0e86e2b7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518976Reviewed-by: Fabian Sommer <fabiansommer@chromium.org>
Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Commit-Queue: Aya Nader Elgendy‎ <ayag@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826492}

ash/login/ui/access_code_input.cc

@@ -161,10 +161,6 @@ bool FlexCodeInput::HandleKeyEvent(views::Textfield* sender,
     return true;
   }
 
-  // We only expect digits in the PIN, so we swallow all letters.
-  if (key_code >= ui::VKEY_A && key_code <= ui::VKEY_Z)
-    return true;
-
   return false;
 }
 

ash/login/ui/access_code_input.h

@@ -55,11 +55,11 @@ class FlexCodeInput : public AccessCodeInput {
   using OnEscape = base::RepeatingClosure;
 
   // Builds the view for an access code that consists out of an unknown number
-  // of digits. |on_input_change| will be called upon digit insertion, deletion
-  // or change. |on_enter| will be called when code is complete and user presses
-  // enter to submit it for validation. |on_escape| will be called when pressing
-  // the escape key. |obscure_pin| determines whether the entered pin is
-  // displayed as clear text or as bullet points.
+  // of characters. |on_input_change| will be called upon character insertion,
+  // deletion or change. |on_enter| will be called when code is complete and
+  // user presses enter to submit it for validation. |on_escape| will be called
+  // when pressing the escape key. |obscure_pin| determines whether the entered
+  // pin is displayed as clear text or as bullet points.
   FlexCodeInput(OnInputChange on_input_change,
                 OnEnter on_enter,
                 OnEscape on_escape,
@@ -104,8 +104,8 @@ class FlexCodeInput : public AccessCodeInput {
  private:
   views::Textfield* code_field_;
 
-  // To be called when access input code changes (digit is inserted, deleted or
-  // updated). Passes true when code non-empty.
+  // To be called when access input code changes (character is inserted, deleted
+  // or updated). Passes true when code non-empty.
   OnInputChange on_input_change_;
 
   // To be called when user pressed enter to submit.

ash/login/ui/pin_request_view_unittest.cc

@@ -356,7 +356,7 @@ TEST_F(PinRequestViewTest, Backspace) {
   EXPECT_EQ("012323", last_code_submitted_);
 }
 
-// Tests input with unknown pin length.
+// Tests digit-only input with unknown pin length.
 TEST_F(PinRequestViewTest, FlexCodeInput) {
   StartView(base::nullopt);
   PinRequestView::TestApi test_api(view_);
@@ -381,6 +381,36 @@ TEST_F(PinRequestViewTest, FlexCodeInput) {
   EXPECT_EQ("0123456", last_code_submitted_);
 }
 
+// Tests non-digit input with unknown pin length.
+TEST_F(PinRequestViewTest, FlexCodeInputCharacters) {
+  StartView(base::nullopt);
+  PinRequestView::TestApi test_api(view_);
+  ui::test::EventGenerator* generator = GetEventGenerator();
+  will_authenticate_ = false;
+
+  EXPECT_FALSE(test_api.submit_button()->GetEnabled());
+
+  for (int i = 0; i < 3; ++i) {
+    generator->PressKey(ui::KeyboardCode(ui::KeyboardCode::VKEY_A + i),
+                        ui::EF_NONE);
+    base::RunLoop().RunUntilIdle();
+  }
+  for (int i = 0; i < 3; ++i) {
+    generator->PressKey(ui::KeyboardCode(ui::KeyboardCode::VKEY_A + i),
+                        ui::EF_SHIFT_DOWN);
+    base::RunLoop().RunUntilIdle();
+  }
+  generator->PressKey(ui::KeyboardCode(ui::KeyboardCode::VKEY_ADD),
+                      ui::EF_NONE);
+  generator->PressKey(ui::KeyboardCode(ui::KeyboardCode::VKEY_SUBTRACT),
+                      ui::EF_NONE);
+
+  EXPECT_TRUE(test_api.submit_button()->GetEnabled());
+  SimulateMouseClickAt(GetEventGenerator(), test_api.submit_button());
+  EXPECT_EQ(1, pin_submitted_);
+  EXPECT_EQ("abcABC+-", last_code_submitted_);
+}
+
 // Tests input with virtual pin keyboard.
 TEST_F(PinRequestViewTest, PinKeyboard) {
   ShowWidget();