Update Android Card Unmask prompt to rely on the controller a bit more.

ui/android/java/src/org/chromium/ui/autofill/CardUnmaskPrompt.java

 // Copyright 2014 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.
 
 package org.chromium.ui.autofill;
 
 import android.app.AlertDialog;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.os.Handler;
+import android.text.Editable;
+import android.text.TextWatcher;
 import android.view.LayoutInflater;
 import android.view.View;
+import android.view.inputmethod.InputMethodManager;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
 
 import org.chromium.ui.R;
 
 /**
  * A prompt that bugs users to enter their CVC when unmasking a Wallet instrument (credit card).
  */
-public class CardUnmaskPrompt implements DialogInterface.OnDismissListener {
+public class CardUnmaskPrompt implements DialogInterface.OnDismissListener, TextWatcher {
     private CardUnmaskPromptDelegate mDelegate;
     private AlertDialog mDialog;
 
     /**
      * An interface to handle the interaction with an CardUnmaskPrompt object.
      */
     public interface CardUnmaskPromptDelegate {
         /**
          * Called when the dialog has been dismissed.
          */
         void dismissed();
 
         /**
+         * Returns whether |userResponse| represents a valid value.
+         */
+        boolean checkUserInputValidity(String userResponse);
+
+        /**
          * Called when the user has entered a value and pressed "verify".
          * @param userResponse The value the user entered (a CVC), or an empty string if the
          *        user canceled.
          */
         void onUserInput(String userResponse);
     }
 
-    public CardUnmaskPrompt(Context context, CardUnmaskPromptDelegate delegate) {
+    public CardUnmaskPrompt(
+            Context context, CardUnmaskPromptDelegate delegate, String title, String instructions) {
         mDelegate = delegate;
 
         LayoutInflater inflater = LayoutInflater.from(context);
         View v = inflater.inflate(R.layout.autofill_card_unmask_prompt, null);
+        ((TextView) v.findViewById(R.id.card_unmask_instructions)).setText(instructions);
 
         mDialog = new AlertDialog.Builder(context)
-                          .setTitle("Unlocking Visa - 1111")
+                          .setTitle(title)
                           .setView(v)
                           .setNegativeButton("Back", null)
                           .setPositiveButton("Rock on", null)
                           .setOnDismissListener(this)
                           .create();
     }
 
     public void show() {
         mDialog.show();
 
         // Override the View.OnClickListener so that pressing the positive button doesn't dismiss
         // the dialog.
         Button verifyButton = mDialog.getButton(AlertDialog.BUTTON_POSITIVE);
+        verifyButton.setEnabled(false);
         verifyButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
                 mDelegate.onUserInput(cardUnmaskInput().getText().toString());
             }
         });
+
+        final EditText input = cardUnmaskInput();
+        input.addTextChangedListener(this);
+        input.post(new Runnable() {
+            @Override
+            public void run() {
+                showKeyboardForUnmaskInput();
+            }
+        });
     }
 
     public void dismiss() {
         mDialog.dismiss();
     }
 
     public void disableAndWaitForVerification() {
         cardUnmaskInput().setEnabled(false);
+        mDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
         TextView message = verificationView();
         message.setText("Verifying...");
         message.setVisibility(View.VISIBLE);
     }
 
-    public void verificationFailed() {
-        verificationView().setText("Verification failed. Please try again.");
-        cardUnmaskInput().setEnabled(true);
+    public void verificationFinished(boolean success) {
+        if (!success) {
+            verificationView().setText("Verification failed. Please try again.");
+            EditText input = cardUnmaskInput();
+            input.setEnabled(true);
+            showKeyboardForUnmaskInput();
+            // TODO(estade): UI decision - should we clear the input?
+        } else {
+            verificationView().setText("Success!");
+            Handler h = new Handler();
+            h.postDelayed(new Runnable() {
+                public void run() {
+                    dismiss();
+                }
+            }, 1000);
+        }
     }
 
     @Override
     public void onDismiss(DialogInterface dialog) {
         mDelegate.dismissed();
     }
 
+    @Override
+    public void afterTextChanged(Editable s) {
+        boolean valid = mDelegate.checkUserInputValidity(cardUnmaskInput().getText().toString());
+        mDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(valid);
+    }
+
+    @Override
+    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
+
+    @Override
+    public void onTextChanged(CharSequence s, int start, int before, int count) {}
+
+    private void showKeyboardForUnmaskInput() {
+        InputMethodManager imm = (InputMethodManager) mDialog.getContext().getSystemService(
+                Context.INPUT_METHOD_SERVICE);
+        imm.showSoftInput(cardUnmaskInput(), InputMethodManager.SHOW_IMPLICIT);
+    }
+
     private EditText cardUnmaskInput() {
         return (EditText) mDialog.findViewById(R.id.card_unmask_input);
     }
 
     private TextView verificationView() {
         return (TextView) mDialog.findViewById(R.id.card_unmask_verification_message);
     }
 }