Adding mediator for Sign-in promo

ios/chrome/browser/ui/authentication/signin_promo_view.mm

+// 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.
+
+#import "ios/chrome/browser/ui/authentication/signin_promo_view.h"
+
+#include "base/logging.h"
+#import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
+#import "ios/third_party/material_components_ios/src/components/Buttons/src/MaterialButtons.h"
+#import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+// Horizontal padding for label and buttons.
+const CGFloat kHorizontalPadding = 40;
+// Vertical padding for the image and the label.
+const CGFloat kVerticalPadding = 12;
+// Vertical padding for buttons.
+const CGFloat kButtonVerticalPadding = 6;
+// Image size for warm state.
+const CGFloat kProfileImageFixedSize = 48;
+// Image size for cold state.
+const CGFloat kChromeImageFixedSize = 24;
+// Button height.
+const CGFloat kButtonHeight = 36;
+}
+
+@implementation SigninPromoView {
+  NSArray<NSLayoutConstraint*>* _coldStateConstraints;
+  NSArray<NSLayoutConstraint*>* _warmStateConstraints;
+}
+
+@synthesize mode = _mode;
+@synthesize imageView = _imageView;
+@synthesize textLabel = _textLabel;
+@synthesize primaryButton = _primaryButton;
+@synthesize secondaryButton = _secondaryButton;
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  self = [super initWithFrame:frame];
+  if (self) {
+    self.translatesAutoresizingMaskIntoConstraints = NO;
+    self.isAccessibilityElement = YES;
+
+    // Adding subviews.
+    self.clipsToBounds = YES;
+    _imageView = [[UIImageView alloc] init];
+    _imageView.translatesAutoresizingMaskIntoConstraints = NO;
+    [self addSubview:_imageView];
+
+    _textLabel = [[UILabel alloc] init];
+    _textLabel.translatesAutoresizingMaskIntoConstraints = NO;
+    [self addSubview:_textLabel];
+
+    _primaryButton = [[MDCFlatButton alloc] init];
+    _primaryButton.translatesAutoresizingMaskIntoConstraints = NO;
+    _primaryButton.accessibilityIdentifier = @"signin_promo_primary_button";
+    [self addSubview:_primaryButton];
+
+    _secondaryButton = [[MDCFlatButton alloc] init];
+    _secondaryButton.translatesAutoresizingMaskIntoConstraints = NO;
+    _secondaryButton.accessibilityIdentifier = @"signin_promo_secondary_button";
+    [self addSubview:_secondaryButton];
+
+    // Adding style.
+    _imageView.contentMode = UIViewContentModeCenter;
+    _imageView.layer.masksToBounds = YES;
+    _imageView.contentMode = UIViewContentModeScaleAspectFit;
+
+    _textLabel.font = [MDCTypography buttonFont];
+    _textLabel.textColor = [[MDCPalette greyPalette] tint900];
+    _textLabel.numberOfLines = 0;
+    _textLabel.textAlignment = NSTextAlignmentCenter;
+
+    [_primaryButton setBackgroundColor:[[MDCPalette cr_bluePalette] tint500]
+                              forState:UIControlStateNormal];
+    _primaryButton.customTitleColor = [UIColor whiteColor];
+    _primaryButton.inkColor = [UIColor colorWithWhite:1 alpha:0.2];
+
+    _secondaryButton.customTitleColor = [[MDCPalette cr_bluePalette] tint500];
+    _secondaryButton.uppercaseTitle = NO;
+
+    // Adding constraints.
+    NSDictionary* metrics = @{
+      @"kButtonHeight" : @(kButtonHeight),
+      @"kButtonVerticalPadding" : @(kButtonVerticalPadding),
+      @"kButtonVerticalPaddingx2" : @(kButtonVerticalPadding * 2),
+      @"kChromeImageFixedSize" : @(kChromeImageFixedSize),
+      @"kHorizontalPadding" : @(kHorizontalPadding),
+      @"kVerticalPadding" : @(kVerticalPadding),
+      @"kVerticalPaddingx2" : @(kVerticalPadding * 2),
+      @"kVerticalPaddingkButtonVerticalPadding" :
+          @(kVerticalPadding + kButtonVerticalPadding),
+    };
+    NSDictionary* views = @{
+      @"imageView" : _imageView,
+      @"primaryButton" : _primaryButton,
+      @"secondaryButton" : _secondaryButton,
+      @"textLabel" : _textLabel,
+    };
+
+    // Constraints shared between modes.
+    NSString* formatString = @"V:|-kVerticalPaddingx2-[imageView]-"
+                              "kVerticalPadding-[textLabel]-"
+                              "kVerticalPaddingkButtonVerticalPadding-["
+                              "primaryButton(kButtonHeight)]";
+    NSArray* visualConstraints = @[
+      formatString,
+      @"H:|-kHorizontalPadding-[primaryButton]-kHorizontalPadding-|"
+    ];
+    ApplyVisualConstraintsWithMetricsAndOptions(
+        visualConstraints, views, metrics, NSLayoutFormatAlignAllCenterX);
+
+    // Constraints for cold state mode.
+    NSMutableArray* constraints = [NSMutableArray array];

[msarda, 2017/03/27 09:34:16]

Optional nit: I think that using a local variable for the constraints is not
really needed (this also leads to arrays being copied below). I would suggest
removing constraints and using _coldStateConstraints or  _warmStateConstraints
here.

[jlebel, 2017/03/27 21:34:42]

My issue about using _coldStateConstraints and _warmStateConstraints is that I
will have to make them mutable. This would imply that contraints can be changed.
But this will be solved with crrev.com/2778073002

[msarda, 2017/03/28 08:12:51]

Acknowledged.

+    formatString =

[msarda, 2017/03/27 09:34:16]

Personal pref: I do not like reusing a previously used variable:
- it is error-prone in the future, if somebody removes the line here and forgets
to remove it below
- the name does not really mean anything

I would rename it to primaryButtonVerticalConstraint

[jlebel, 2017/03/27 21:34:42]

Done.

+        @"V:[primaryButton]-kVerticalPaddingkButtonVerticalPadding-|";
+    [constraints
+        addObjectsFromArray:[NSLayoutConstraint
+                                constraintsWithVisualFormat:formatString
+                                                    options:0
+                                                    metrics:metrics
+                                                      views:views]];
+    // TODO(crbug.com/2749703003): Remove this rule once chrome image is added.

[msarda, 2017/03/27 09:34:16]

Unexpected character: 

[jlebel, 2017/03/27 21:34:43]

Done.

+    formatString = @"V:[imageView(kChromeImageFixedSize)]";

[msarda, 2017/03/27 09:34:16]

Same here: imageViewVerticalSizeConstraint

[jlebel, 2017/03/27 21:34:43]

Done.

+    [constraints
+        addObjectsFromArray:[NSLayoutConstraint
+                                constraintsWithVisualFormat:formatString
+                                                    options:0
+                                                    metrics:metrics
+                                                      views:views]];
+    _coldStateConstraints = [constraints copy];
+
+    // Constraints for warm state mode.
+    constraints = [NSMutableArray array];
+    formatString = @"V:[primaryButton]-kButtonVerticalPaddingx2-["

[msarda, 2017/03/27 09:34:16]

s/buttonsVerticalConstraint

[jlebel, 2017/03/27 21:34:43]

Done.

+                    "secondaryButton(kButtonHeight)]-"
+                    "kVerticalPaddingkButtonVerticalPadding-|";
+    [constraints
+        addObjectsFromArray:[NSLayoutConstraint
+                                constraintsWithVisualFormat:formatString
+                                                    options:0
+                                                    metrics:metrics
+                                                      views:views]];
+    formatString =

[msarda, 2017/03/27 09:34:16]

Same here: secondaryButtonHorizontalConstraint

[jlebel, 2017/03/27 21:34:42]

Done.

+        @"H:|-kHorizontalPadding-[secondaryButton]-kHorizontalPadding-|";
+    [constraints
+        addObjectsFromArray:[NSLayoutConstraint
+                                constraintsWithVisualFormat:formatString
+                                                    options:0
+                                                    metrics:metrics
+                                                      views:views]];
+    _warmStateConstraints = [constraints copy];
+
+    _mode = SigninPromoViewColdStateMode;
+    [self activateColdMode];
+  }
+  return self;
+}
+
+- (void)setMode:(SigninPromoViewMode)mode {
+  if (mode == _mode) {
+    return;
+  }
+  _mode = mode;
+  switch (_mode) {
+    case SigninPromoViewColdStateMode:
+      [self activateColdMode];
+      return;
+    case SigninPromoViewWarmStateMode:
+      [self activateWarmMode];
+      return;
+  }
+  NOTREACHED();
+}
+
+- (void)activateColdMode {
+  // TODO(crbug.com/2749703003) Needs to set the chrome/chromium icon in

[lpromero, 2017/03/27 13:14:46]

Not a crbug. Here and in several places.

[lpromero, 2017/03/27 13:14:46]

Chrome/Chromium

[jlebel, 2017/03/27 21:34:43]

Done.

[jlebel, 2017/03/27 21:34:43]

Done.

+  // |imageView|.
+  DCHECK(_mode == SigninPromoViewColdStateMode);

[msarda, 2017/03/27 09:34:16]

Prefer DCHECK_EQSigninPromoViewColdStateMode, _mode) as it has better logging.

[jlebel, 2017/03/27 21:34:43]

Done.

+  [NSLayoutConstraint deactivateConstraints:_warmStateConstraints];
+  [NSLayoutConstraint activateConstraints:_coldStateConstraints];
+  _secondaryButton.hidden = YES;
+}
+
+- (void)activateWarmMode {
+  DCHECK(_mode == SigninPromoViewWarmStateMode);

[msarda, 2017/03/27 09:34:16]

DCHECK_EQ

[jlebel, 2017/03/27 21:34:42]

Done.

+  [NSLayoutConstraint deactivateConstraints:_coldStateConstraints];
+  [NSLayoutConstraint activateConstraints:_warmStateConstraints];
+  _secondaryButton.hidden = NO;
+}
+
+- (void)setProfileImage:(UIImage*)image {

[msarda, 2017/03/27 09:34:16]

I think this method should never be called in the cold mode. Change the if to a
DCHECK:
DCHECK_EQ(WarmMode, _mode).

[lpromero, 2017/03/27 13:14:46]

If you DCHECK, you need to remove the early return then.

[jlebel, 2017/03/27 21:34:43]

The if() makes more sense to me. But I can change it to a DCHECK().

[msarda, 2017/03/28 08:12:51]

DCHECK_EQ is better than the if IMHO, for the following reason:

If the caller does the following calls:
[signinPromoView setProfileImage:profileImage];
[signinPromoView setMode:Warm];
- With the if, tthere is no error, but the image is not set correctly.
- With the DCHECK, in dev, we get a crash in debug and we know we need to fix
it.

[lpromero, 2017/03/28 09:43:15]

What I mean is that if you DCHECK, the Chromium style guide says you shouldn't
handle the case where it fails:
https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++.md...

+  if (SigninPromoViewColdStateMode == _mode) {
+    return;
+  }
+  _imageView.image = CircularImageFromImage(image, kProfileImageFixedSize);
+}
+
+- (void)accessibilityPrimaryAction:(id)unused {
+  [_primaryButton sendActionsForControlEvents:UIControlEventTouchUpInside];
+}
+
+- (void)accessibilitySecondaryAction:(id)unused {
+  [_secondaryButton sendActionsForControlEvents:UIControlEventTouchUpInside];
+}
+
+- (CGFloat)horizontalPadding {
+  return kHorizontalPadding;
+}
+
+#pragma mark - NSObject(Accessibility)
+
+- (NSArray<UIAccessibilityCustomAction*>*)accessibilityCustomActions {
+  NSString* primaryActionName =
+      [_primaryButton titleForState:UIControlStateNormal];
+  UIAccessibilityCustomAction* primaryCustomAction =
+      [[UIAccessibilityCustomAction alloc]
+          initWithName:primaryActionName
+                target:self
+              selector:@selector(accessibilityPrimaryAction:)];
+  if (_mode == SigninPromoViewColdStateMode) {
+    return @[ primaryCustomAction ];
+  }
+  NSString* secondaryActionName =
+      [_secondaryButton titleForState:UIControlStateNormal];
+  UIAccessibilityCustomAction* secondaryCustomAction =
+      [[UIAccessibilityCustomAction alloc]
+          initWithName:secondaryActionName
+                target:self
+              selector:@selector(accessibilitySecondaryAction:)];
+  return @[ primaryCustomAction, secondaryCustomAction ];
+}
+
+- (NSString*)accessibilityLabel {
+  return _textLabel.text;
+}
+
+@end