[Payment Request] Generic edit form

ios/chrome/browser/payments/payment_request_edit_view_controller+internal.h

+// Copyright 2017 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.
+
+#ifndef IOS_CHROME_BROWSER_PAYMENTS_PAYMENT_REQUEST_EDIT_VIEW_CONTROLLER_INTERNAL_H_
+#define IOS_CHROME_BROWSER_PAYMENTS_PAYMENT_REQUEST_EDIT_VIEW_CONTROLLER_INTERNAL_H_
+
+#import "ios/chrome/browser/payments/payment_request_edit_view_controller.h"
+
+// Internal API for subclasses of PaymentRequestEditViewController.
+@interface PaymentRequestEditViewController (Internal)
+
+// Validates each field. If there is a validation error, displays an error
+// message item in the same section as the field and returns NO. Otherwise
+// removes the error message item in that section if one exists and sets the
+// value on the field. Returns YES if all the fields are validated successfully.
+- (BOOL)validateForm;
+
+// Called after the editor field items have been added to the the collection
+// view model. Subclasses override this method to add items after the editor
+// fields.
+- (void)loadFooterItems;
+
+// Returns the index path for the cell associated with the currently focused
+// text field.
+- (NSIndexPath*)indexPathForCurrentTextField;
+
+// Adds an error message item in the section |sectionIdentifier| if
+// |errorMessage| is non-empty. Otherwise removes such an item if one exists.
+- (void)addOrRemoveErrorMessage:(NSString*)errorMessage
+        inSectionWithIdentifier:(NSInteger)sectionIdentifier;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_PAYMENTS_PAYMENT_REQUEST_EDIT_VIEW_CONTROLLER_INTERNAL_H_