Upstream Chrome on iOS source code [6/11].

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

+// Copyright 2014 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/new_tab_page_header_view.h"
+
+#include "base/logging.h"
+#include "base/mac/scoped_nsobject.h"
+#import "ios/chrome/browser/tabs/tab_model.h"
+#import "ios/chrome/browser/tabs/tab_model_observer.h"
+#import "ios/chrome/browser/ui/image_util.h"
+#import "ios/chrome/browser/ui/ntp/new_tab_page_header_constants.h"
+#import "ios/chrome/browser/ui/ntp/new_tab_page_toolbar_controller.h"
+#import "ios/chrome/common/material_timing.h"
+#include "ios/chrome/grit/ios_theme_resources.h"
+#include "ui/base/resource/resource_bundle.h"
+#import "ui/gfx/ios/uikit_util.h"
+
+namespace {
+
+const CGFloat kOmniboxImageBottomInset = 1;
+const CGFloat kHintLabelSidePadding = 12;
+const CGFloat kMaxConstraintConstantDiff = 5;
+
+}  // namespace
+
+@interface NewTabPageHeaderView ()<TabModelObserver> {
+  base::scoped_nsobject<NewTabPageToolbarController> _toolbarController;
+  base::scoped_nsobject<TabModel> _tabModel;
+  base::scoped_nsobject<UIImageView> _searchBoxBorder;
+  base::scoped_nsobject<UIImageView> _shadow;
+}
+
+@end
+
+@implementation NewTabPageHeaderView
+
+- (instancetype)initWithFrame:(CGRect)frame {
+  self = [super initWithFrame:frame];
+  if (self) {
+    self.clipsToBounds = YES;
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [_tabModel removeObserver:self];
+  [super dealloc];
+}
+
+- (UIView*)toolBarView {
+  return [_toolbarController view];
+}
+
+- (ToolbarController*)relinquishedToolbarController {
+  ToolbarController* relinquishedToolbarController = nil;
+  if ([[_toolbarController view] isDescendantOfView:self]) {
+    // Only relinquish the toolbar controller if it's in the hierarchy.
+    relinquishedToolbarController = _toolbarController.get();
+  }
+  return relinquishedToolbarController;
+}
+
+- (void)reparentToolbarController {
+  [self addSubview:[_toolbarController view]];
+}
+
+- (void)addToolbarWithDelegate:(id<WebToolbarDelegate>)toolbarDelegate
+                       focuser:(id<OmniboxFocuser>)focuser
+                      tabModel:(TabModel*)tabModel
+              readingListModel:(ReadingListModel*)readingListModel {
+  DCHECK(!_toolbarController);
+  DCHECK(focuser);
+
+  _toolbarController.reset([[NewTabPageToolbarController alloc]
+      initWithToolbarDelegate:toolbarDelegate
+                      focuser:focuser]);
+  _toolbarController.get().readingListModel = readingListModel;
+  [_tabModel removeObserver:self];
+  _tabModel.reset([tabModel retain]);
+  [self addTabModelObserver];
+
+  UIView* toolbarView = [_toolbarController view];
+  CGRect toolbarFrame = self.bounds;
+  toolbarFrame.size.height = ntp_header::kToolbarHeight;
+  toolbarView.frame = toolbarFrame;
+  [toolbarView setAutoresizingMask:UIViewAutoresizingFlexibleWidth];
+  [self hideToolbarViewsForNewTabPage];
+
+  [self setAutoresizingMask:UIViewAutoresizingFlexibleWidth];
+  [self addSubview:[_toolbarController view]];
+}
+
+- (void)hideToolbarViewsForNewTabPage {
+  [_toolbarController hideViewsForNewTabPage:YES];
+};
+
+- (void)addTabModelObserver {
+  [_tabModel addObserver:self];
+  [_toolbarController setTabCount:[_tabModel count]];
+}
+
+- (void)addViewsToSearchField:(UIView*)searchField {
+  [searchField setBackgroundColor:[UIColor whiteColor]];
+  UIImage* searchBorderImage =
+      StretchableImageNamed(@"ntp_google_search_box", 12, 12);
+  _searchBoxBorder.reset([[UIImageView alloc] initWithImage:searchBorderImage]);
+  [_searchBoxBorder setFrame:[searchField bounds]];
+  [_searchBoxBorder setAutoresizingMask:UIViewAutoresizingFlexibleWidth |
+                                        UIViewAutoresizingFlexibleHeight];
+  [searchField insertSubview:_searchBoxBorder atIndex:0];
+
+  ResourceBundle& rb = ResourceBundle::GetSharedInstance();
+  UIImage* fullBleedShadow =
+      rb.GetNativeImageNamed(IDR_IOS_TOOLBAR_SHADOW_FULL_BLEED).ToUIImage();
+  _shadow.reset([[UIImageView alloc] initWithImage:fullBleedShadow]);
+  CGRect shadowFrame = [searchField bounds];
+  shadowFrame.origin.y =
+      searchField.bounds.size.height - kOmniboxImageBottomInset;
+  shadowFrame.size.height = fullBleedShadow.size.height;
+  [_shadow setFrame:shadowFrame];
+  [_shadow setUserInteractionEnabled:NO];
+  [_shadow setAutoresizingMask:UIViewAutoresizingFlexibleWidth |
+                               UIViewAutoresizingFlexibleTopMargin];
+  [searchField addSubview:_shadow];
+  [_shadow setAlpha:0];
+}
+
+- (void)tabModelDidChangeTabCount:(TabModel*)model {
+  DCHECK(model == _tabModel);
+  [_toolbarController setTabCount:[_tabModel count]];
+}
+
+- (void)updateSearchField:(UIView*)searchField
+         withInitialFrame:(CGRect)initialFrame
+       subviewConstraints:(NSArray*)constraints
+                forOffset:(CGFloat)offset {
+  // The scroll offset at which point |searchField|'s frame should stop growing.
+  CGFloat maxScaleOffset =
+      self.frame.size.height - ntp_header::kMinHeaderHeight;
+  // The scroll offset at which point |searchField|'s frame should start
+  // growing.
+  CGFloat startScaleOffset = maxScaleOffset - ntp_header::kAnimationDistance;
+  CGFloat percent = 0;
+  if (offset > startScaleOffset) {
+    CGFloat animatingOffset = offset - startScaleOffset;
+    percent = MIN(1, MAX(0, animatingOffset / ntp_header::kAnimationDistance));
+  }
+
+  // Calculate the amount to grow the width and height of |searchField| so that
+  // its frame covers the entire toolbar area.
+  CGFloat maxXInset = ui::AlignValueToUpperPixel(
+      (initialFrame.size.width - self.bounds.size.width) / 2 - 1);
+  CGFloat maxYOffset = ui::AlignValueToUpperPixel(
+      (ntp_header::kToolbarHeight - initialFrame.size.height) / 2 +
+      kOmniboxImageBottomInset - 0.5);
+  CGRect searchFieldFrame = CGRectInset(initialFrame, maxXInset * percent, 0);
+  searchFieldFrame.origin.y += maxYOffset * percent;
+  searchFieldFrame.size.height += 2 * maxYOffset * percent;
+  [searchField setFrame:CGRectIntegral(searchFieldFrame)];
+  [_searchBoxBorder setAlpha:(1 - percent)];
+  [_shadow setAlpha:percent];
+
+  // Adjust the position of the search field's subviews by adjusting their
+  // constraint constant value.
+  CGFloat constantDiff = percent * kMaxConstraintConstantDiff;
+  for (NSLayoutConstraint* constraint in constraints) {
+    if (constraint.constant > 0)
+      constraint.constant = constantDiff + kHintLabelSidePadding;
+    else
+      constraint.constant = -constantDiff;
+  }
+}
+
+- (void)fadeOutShadow {
+  [UIView animateWithDuration:ios::material::kDuration1
+                   animations:^{
+                     [_shadow setAlpha:0];
+                   }];
+}
+
+@end