Upstream Chrome on iOS source code [5/11].

ios/chrome/browser/ui/ntp/most_visited_cell.mm

+// 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.
+
+#import "ios/chrome/browser/ui/ntp/most_visited_cell.h"
+
+#include <memory>
+
+#import "base/ios/weak_nsobject.h"
+#include "base/mac/bind_objc_block.h"
+#import "base/mac/scoped_nsobject.h"
+#include "base/memory/ref_counted_memory.h"
+#include "base/strings/sys_string_conversions.h"
+#include "base/task/cancelable_task_tracker.h"
+#include "components/favicon/core/fallback_url_util.h"
+#include "components/favicon/core/large_icon_service.h"
+#include "components/favicon_base/fallback_icon_style.h"
+#include "components/favicon_base/favicon_types.h"
+#include "components/history/core/browser/top_sites.h"
+#include "components/suggestions/suggestions_service.h"
+#import "ios/chrome/browser/favicon/favicon_loader.h"
+#include "ios/chrome/browser/favicon/favicon_service_factory.h"
+#include "ios/chrome/browser/favicon/ios_chrome_favicon_loader_factory.h"
+#include "ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h"
+#include "ios/chrome/browser/favicon/ios_chrome_large_icon_service_factory.h"
+#include "ios/chrome/browser/favicon/large_icon_cache.h"
+#include "ios/chrome/browser/history/top_sites_factory.h"
+#include "ios/chrome/browser/suggestions/suggestions_service_factory.h"
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
+#import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
+#import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
+#include "skia/ext/skia_utils_ios.h"
+
+const CGFloat kFaviconSize = 48;
+const CGFloat kFaviconMinSize = 32;
+const CGFloat kImageViewBackgroundColor = 0.941;
+const CGFloat kImageViewCornerRadius = 3;
+const NSInteger kLabelNumLines = 2;
+const CGFloat kLabelTextColor = 0.314;
+const CGFloat kMaximumWidth = 73;
+const CGFloat kMaximumHeight = 100;
+
+@interface MostVisitedCell () {
+  // Backs property with the same name.
+  GURL _URL;
+  // Weak reference to the relevant BrowserState.
+  ios::ChromeBrowserState* _browserState;
+  // Backs property with the same name.
+  ntp_tiles::metrics::MostVisitedTileType _tileType;
+
+  base::scoped_nsobject<UILabel> _label;
+  base::scoped_nsobject<UILabel> _noIconLabel;
+  base::scoped_nsobject<UIImageView> _imageView;
+  // Used to cancel tasks for the LargeIconService.
+  base::CancelableTaskTracker _cancelable_task_tracker;
+}
+// Set the background color and center the first letter of the site title (or
+// domain if the title is a url).
+- (void)updateIconLabelWithColor:(UIColor*)textColor
+                 backgroundColor:(UIColor*)backgroundColor
+        isDefaultBackgroundColor:(BOOL)isDefaultBackgroundColor;
+// Set icon of top site.
+- (void)setImage:(UIImage*)image;
+@end
+
+@implementation MostVisitedCell
+
+@synthesize URL = _URL;
+@synthesize browserState = _browserState;
+@synthesize tileType = _tileType;
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  self = [super initWithFrame:frame];
+  if (!self) {
+    return nil;
+  }
+  _label.reset([[UILabel alloc] initWithFrame:CGRectZero]);
+  [_label setTextColor:[UIColor colorWithWhite:kLabelTextColor alpha:1.0]];
+  [_label setBackgroundColor:[UIColor clearColor]];
+  [_label setFont:[MDCTypography captionFont]];
+  [_label setTextAlignment:NSTextAlignmentCenter];
+  CGSize maxSize = [self.class maximumSize];
+  [_label setPreferredMaxLayoutWidth:maxSize.width];
+  [_label setNumberOfLines:kLabelNumLines];
+
+  _noIconLabel.reset([[UILabel alloc] initWithFrame:CGRectZero]);
+  [_noIconLabel setBackgroundColor:[UIColor clearColor]];
+  [_noIconLabel setFont:[MDCTypography headlineFont]];
+  [_noIconLabel setTextAlignment:NSTextAlignmentCenter];
+
+  _imageView.reset([[UIImageView alloc] initWithFrame:CGRectZero]);
+  [_imageView layer].cornerRadius = kImageViewCornerRadius;
+  [_imageView setClipsToBounds:YES];
+  [self addSubview:_imageView];
+  [self addSubview:_label];
+  [self addSubview:_noIconLabel];
+
+  [_noIconLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
+  [_imageView setTranslatesAutoresizingMaskIntoConstraints:NO];
+  [_label setTranslatesAutoresizingMaskIntoConstraints:NO];
+
+  NSDictionary* views =
+      @{ @"label" : _label,
+         @"image" : _imageView,
+         @"noIcon" : _noIconLabel };
+  NSArray* constraints = @[
+    @"V:|[image(==iconSize)]-10-[label]", @"V:[noIcon(==iconSize)]",
+    @"H:[image(==iconSize)]", @"H:|[label]|", @"H:|[noIcon]|"
+  ];
+  ApplyVisualConstraintsWithMetrics(constraints, views,
+                                    @{ @"iconSize" : @(kFaviconSize) });
+  AddSameCenterXConstraint(self, _imageView);
+  AddSameCenterXConstraint(self, _noIconLabel);
+
+  [self prepareForReuse];
+  return self;
+}
+
+- (void)prepareForReuse {
+  [super prepareForReuse];
+  [self setImage:nil];
+  [self setText:nil];
+  // TODO(crbug.com/495600): -stepToVerifyAccessibilityOnCurrentScreen does not
+  // honor -setIsAccessibilityElement and setAccessibilityElementsHidden for
+  // UICollectionViewCell's, so setting the label to a single space string to
+  // pass tests. This string will not be read by screen readers.
+  [_label setText:@" "];
+  [self setURL:GURL()];
+  [_imageView
+      setBackgroundColor:[UIColor colorWithWhite:kImageViewBackgroundColor
+                                           alpha:1.0]];
+  [_noIconLabel setText:nil];
+}
+
+#pragma mark - Public Setters
+
+- (void)setText:(NSString*)text {
+  [_label setText:text];
+  [self setAccessibilityLabel:text];
+  [self setIsAccessibilityElement:text != nil];
+  [self setAccessibilityElementsHidden:text == nil];
+  [self setUserInteractionEnabled:YES];
+}
+
+- (void)showPlaceholder {
+  [_imageView setBackgroundColor:[[MDCPalette greyPalette] tint50]];
+}
+
+- (void)setupWithURL:(GURL)URL
+               title:(NSString*)title
+        browserState:(ios::ChromeBrowserState*)browserState {
+  _browserState = browserState;
+  _tileType = ntp_tiles::metrics::NONE;
+  [self setText:title];
+  [self setURL:URL];
+  base::WeakNSObject<MostVisitedCell> weakSelf(self);
+
+  void (^faviconBlock)(const favicon_base::LargeIconResult&) =
+      ^(const favicon_base::LargeIconResult& result) {
+        base::scoped_nsobject<MostVisitedCell> strongSelf([weakSelf retain]);
+        if (!strongSelf)
+          return;
+
+        if (URL == [strongSelf URL]) {  // Tile has not been reused.
+          if (result.bitmap.is_valid()) {
+            scoped_refptr<base::RefCountedMemory> data =
+                result.bitmap.bitmap_data.get();
+            UIImage* favicon =
+                [UIImage imageWithData:[NSData dataWithBytes:data->front()
+                                                      length:data->size()]
+                                 scale:[UIScreen mainScreen].scale];
+            [strongSelf setImage:favicon];
+          } else if (result.fallback_icon_style) {
+            UIColor* backgroundColor = skia::UIColorFromSkColor(
+                result.fallback_icon_style->background_color);
+            UIColor* textColor = skia::UIColorFromSkColor(
+                result.fallback_icon_style->text_color);
+            [strongSelf updateIconLabelWithColor:textColor
+                                 backgroundColor:backgroundColor
+                        isDefaultBackgroundColor:result.fallback_icon_style->
+                                                 is_default_background_color];
+          }
+        }
+
+        if (result.bitmap.is_valid() || result.fallback_icon_style) {
+          IOSChromeLargeIconCacheFactory::GetForBrowserState(
+              [strongSelf browserState])
+              ->SetCachedResult(URL, result);
+        }
+      };
+
+  LargeIconCache* cache =
+      IOSChromeLargeIconCacheFactory::GetForBrowserState(self.browserState);
+  std::unique_ptr<favicon_base::LargeIconResult> cached_result =
+      cache->GetCachedResult(URL);
+  if (cached_result) {
+    faviconBlock(*cached_result);
+  }
+
+  // Always call LargeIconService in case the favicon was updated.
+  favicon::LargeIconService* large_icon_service =
+      IOSChromeLargeIconServiceFactory::GetForBrowserState(self.browserState);
+  CGFloat faviconSize = [UIScreen mainScreen].scale * kFaviconSize;
+  CGFloat faviconMinSize = [UIScreen mainScreen].scale * kFaviconMinSize;
+  large_icon_service->GetLargeIconOrFallbackStyle(
+      URL, faviconMinSize, faviconSize, base::BindBlock(faviconBlock),
+      &_cancelable_task_tracker);
+}
+
+- (void)removePlaceholderImage {
+  [_imageView setBackgroundColor:nil];
+  [self setUserInteractionEnabled:NO];
+}
+
+#pragma mark - Class methods
+
++ (CGSize)maximumSize {
+  return CGSizeMake(kMaximumWidth, kMaximumHeight);
+}
+
+#pragma mark - Private methods
+
+- (void)updateIconLabelWithColor:(UIColor*)textColor
+                 backgroundColor:(UIColor*)backgroundColor
+        isDefaultBackgroundColor:(BOOL)isDefaultBackgroundColor {
+  [self setImage:nil];
+  [_noIconLabel
+      setText:base::SysUTF16ToNSString(favicon::GetFallbackIconText(_URL))];
+  [_noIconLabel setTextColor:textColor];
+  [_imageView setBackgroundColor:backgroundColor];
+  _tileType = isDefaultBackgroundColor ? ntp_tiles::metrics::ICON_DEFAULT
+                                       : ntp_tiles::metrics::ICON_COLOR;
+}
+
+- (void)setImage:(UIImage*)image {
+  [_imageView setBackgroundColor:nil];
+  [_noIconLabel setText:nil];
+  [_imageView setImage:image];
+  _tileType = ntp_tiles::metrics::ICON_REAL;
+}
+
+@end