[ios] Adds GetStyledTextField() to ChromeBrowserProvider.

This will be used to provide custom-styled text fields for use in UI.

BUG=None

Review-Url: https://codereview.chromium.org/2372703002
Cr-Commit-Position: refs/heads/master@{#421186}

ios/public/provider/chrome/browser/BUILD.gn

@@ -25,6 +25,7 @@ source_set("browser") {
     "ui/default_ios_web_view_factory.mm",
     "ui/infobar_view_delegate.h",
     "ui/infobar_view_protocol.h",
+    "ui/text_field_styling.h",
     "updatable_resource_provider.h",
     "updatable_resource_provider.mm",
   ]

ios/public/provider/chrome/browser/chrome_browser_provider.h

@@ -40,8 +40,10 @@ namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
-@class UIView;
 @protocol InfoBarViewProtocol;
+@protocol TextFieldStyling;
+@class UITextField;
+@class UIView;
 typedef UIView<InfoBarViewProtocol>* InfoBarViewPlaceholder;
 
 namespace ios {
@@ -109,6 +111,9 @@ class ChromeBrowserProvider {
       const GURL& page_url,
       const std::vector<int>& desired_sizes_in_pixel,
       const favicon_base::FaviconResultsCallback& callback) const;
+  // Creates and returns a new styled text field with the given |frame|.
+  virtual UITextField<TextFieldStyling>* CreateStyledTextField(
+      CGRect frame) const NS_RETURNS_RETAINED;
 
   // Returns whether safe browsing is enabled. See the comment on
   // metrics_services_manager_client.h for details on |on_update_callback|.

ios/public/provider/chrome/browser/chrome_browser_provider.mm

@@ -97,6 +97,11 @@ void ChromeBrowserProvider::GetFaviconForURL(
     const std::vector<int>& desired_sizes_in_pixel,
     const favicon_base::FaviconResultsCallback& callback) const {}
 
+UITextField<TextFieldStyling>* ChromeBrowserProvider::CreateStyledTextField(
+    CGRect frame) const {
+  return nil;
+}
+
 bool ChromeBrowserProvider::IsSafeBrowsingEnabled(
     const base::Closure& on_update_callback) {
   return false;

ios/public/provider/chrome/browser/test_chrome_browser_provider.h

@@ -9,6 +9,7 @@
 
 #include "base/macros.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
+#include "ios/public/provider/chrome/browser/ui/text_field_styling.h"
 
 namespace ios {
 
@@ -27,6 +28,8 @@ class TestChromeBrowserProvider : public ChromeBrowserProvider {
       std::unique_ptr<ChromeIdentityService> service) override;
   ChromeIdentityService* GetChromeIdentityService() override;
   UpdatableResourceProvider* GetUpdatableResourceProvider() override;
+  UITextField<TextFieldStyling>* CreateStyledTextField(
+      CGRect frame) const override NS_RETURNS_RETAINED;
 
  private:
   std::unique_ptr<ChromeIdentityService> chrome_identity_service_;

ios/public/provider/chrome/browser/test_chrome_browser_provider.mm

@@ -4,11 +4,24 @@
 
 #include "ios/public/provider/chrome/browser/test_chrome_browser_provider.h"
 
+#import <UIKit/UIKit.h>
+
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "ios/public/provider/chrome/browser/signin/fake_chrome_identity_service.h"
 #import "ios/public/provider/chrome/browser/test_updatable_resource_provider.h"
 
+@interface TestStyledTextField : UITextField<TextFieldStyling>
+@end
+
+@implementation TestStyledTextField
+@synthesize placeholderStyle = _placeholderStyle;
+@synthesize textValidator = _textValidator;
+
+- (void)setUseErrorStyling:(BOOL)error {
+}
+@end
+
 namespace ios {
 
 TestChromeBrowserProvider::TestChromeBrowserProvider()
@@ -40,4 +53,9 @@ TestChromeBrowserProvider::GetUpdatableResourceProvider() {
   return test_updatable_resource_provider_.get();
 }
 
+UITextField<TextFieldStyling>* TestChromeBrowserProvider::CreateStyledTextField(
+    CGRect frame) const {
+  return [[TestStyledTextField alloc] initWithFrame:frame];
+}
+
 }  // namespace ios

ios/public/provider/chrome/browser/ui/text_field_styling.h

+// Copyright 2016 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_PUBLIC_PROVIDER_CHROME_BROWSER_UI_TEXT_FIELD_STYLING_H_
+#define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_UI_TEXT_FIELD_STYLING_H_
+
+#import <Foundation/Foundation.h>
+
+@protocol TextFieldValidation;
+
+// Types of styling controlling layout of the placeholder.
+typedef NS_ENUM(NSInteger, TextFieldStylingPlaceholder) {
+  // Effectively the same placeholder as a UITextField.
+  TextFieldStylingPlaceholderDefault = 0,
+  // The placeholder text will float above the field when there is content or
+  // the field is being edited.
+  TextFieldStylingPlaceholderFloatingPlaceholder,
+};
+
+// The TextFieldStyling protocol works with UITextField to add methods related
+// to styling and input validation.
+@protocol TextFieldStyling
+
+// The placement for the placeholder text (if there is any).
+@property(nonatomic, assign) TextFieldStylingPlaceholder placeholderStyle;
+
+// The object used to validate text in this text field.  If nil, no validation
+// is performed.
+@property(nonatomic, assign) id<TextFieldValidation> textValidator;  // weak
+
+// If |error| is YES, display this field using error colors and styling.
+- (void)setUseErrorStyling:(BOOL)error;
+
+@end
+
+// The TextFieldValidation protocol is used to validate the contents of a text
+// field.
+@protocol TextFieldValidation
+
+// Returns an error string to display if the contents of the given |field| are
+// invalid.  If this method returns nil, the contents of the field are presumed
+// to be valid and no error needs to displayed.  This method is called whenever
+// the field's text changes.
+- (NSString*)validationErrorForTextField:(id<TextFieldStyling>)field;
+
+@end
+
+#endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_UI_TEXT_FIELD_STYLING_H_