Adding mediator for Sign-in promo

ios/chrome/browser/ui/authentication/signin_promo_view.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_UI_AUTHENTICATION_SIGN_PROMO_VIEW_H_
+#define IOS_CHROME_BROWSER_UI_AUTHENTICATION_SIGN_PROMO_VIEW_H_
+
+#import <UIKit/UIKit.h>
+
+@class MDCFlatButton;
+@class SigninPromoView;
+
+// Configures a SigninPromoView view.
+@protocol SigninPromoViewConfigurator<NSObject>
+
+@property(nonatomic, readonly) BOOL coldStart;

[msarda, 2017/03/16 22:15:31]

Avoid using bool and prefer using the enum SigninPromoViewMode below. Also, why
is this a public property of the protocol?

[jlebel, 2017/03/21 17:22:28]

Done.

+
+- (void)configureSigninPromoView:(SigninPromoView*)signinPromoView;
+
+@end
+
+typedef NS_ENUM(NSInteger, SigninPromoViewMode) {
+  // No profile is known.
+  SigninPromoViewColdStartMode,

[msarda, 2017/03/16 22:15:31]

I think we should drop this enum entirely and pass a ChromeIdentity (this one
https://cs.chromium.org/chromium/src/ios/public/provider/chrome/browser/signi...)
to the SigninPromoViewConfigurator.
Basically, if |ChromeIdentity| is no-nil, then it is similar to cold start.
Basically, if |ChromeIdentity| is no-nil, then it is similar to warm start.

I think this change will actually leads to a big change in the code (sorry for
that).

To get image for a profile, consider using
https://cs.chromium.org/chromium/src/ios/public/provider/chrome/browser/signi...
(I think for now using the cached image should be fine).

Note that an identity may have a NULL user full name and image. It is very rare
that an identity has a null email (this in general means there was an error
fetching this info).

[jlebel, 2017/03/21 17:22:29]

The view should not know anything related to the profile. The point of the
mediator is to
have an abstraction layer.

[msarda, 2017/03/22 12:18:38]

For completeness sake: ChromeIdentity and ChromeIdentityService do not depend on
the profile.
I now understand that the intent for the view is to very simple and not depend
at all on the model. Thank you for clarifying this.

+  // At least one profile is known and the user can sign without entering their
+  // password.
+  SigninPromoViewWarmStartMode,

[msarda, 2017/03/16 22:15:31]

I would not name this |coldStart| or |warmStart| as this makes me thing about
the application being started after it was killed or just foregrounded.

[jlebel, 2017/03/21 17:22:29]

I'm not sure what could be a better name. Do you prefer:
SigninPromoViewNoProfileMode,
SigninPromoViewProfileFoundMode,

?

+};
+
+// This class creates an image view, a label and 2 buttons. This view can be
+// configured with 2 modes : "Cold Start" and "Warm Start".
+// + "Cold Start" mode displays the chrome/chomium icon in the image view, and
+//    only displays the primary button.
+// + "Warm Start" mode displays the image view (big than the cold start mode),
+//   displays both buttons.
+//
+// The owner is in charge to set:
+//   - the image for |imageView|, using -[SigninPromoView setProfileImage:]
+//     (only for "Warm Start")
+//   - the label for |textLabel|
+//   - the title for |primaryButton|
+//   - the title for |secondaryButton|
+@interface SigninPromoView : UIView
+
+@property(nonatomic) SigninPromoViewMode mode;
+@property(nonatomic, readonly) UIImageView* imageView;
+@property(nonatomic, readonly) UILabel* textLabel;
+@property(nonatomic, readonly) MDCFlatButton* primaryButton;
+@property(nonatomic, readonly) MDCFlatButton* secondaryButton;

[msarda, 2017/03/16 22:15:31]

Nit: Blank line to ease code review in the code review tool (unfortunately there
is not highlight in code review, compared to regular IDE).

[jlebel, 2017/03/21 17:22:28]

Done.

+// Horizontal padding used for |textLabel|, |primaryButton| and
+// |secondaryButton|. Available to be able to compute

[msarda, 2017/03/16 22:15:31]

Nit: s/Available to be able to compute.../Used to compute the preferred max
layout of the text label?

[jlebel, 2017/03/21 17:22:28]

Done.

+// |_signinPromoView.textLabel.preferredMaxLayoutWidth|
+@property(nonatomic, readonly) CGFloat horizontalPadding;
+
+- (instancetype)initWithCoder:(NSCoder*)aDecoder NS_UNAVAILABLE;
+
+// Changes the image in |imageView| with a circular image. Should be called
+// only with the "Warm Start" mode. The image is not changed when "Cold Start"
+// mode.
+- (void)setProfileImage:(UIImage*)image;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_AUTHENTICATION_SIGN_PROMO_VIEW_H_