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

ios/chrome/browser/ui/no_tabs/no_tabs_toolbar_controller.mm

+// Copyright 2012 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/no_tabs/no_tabs_toolbar_controller.h"
+
+#include "base/mac/scoped_nsobject.h"
+#import "ios/chrome/browser/ui/commands/UIKit+ChromeExecuteCommand.h"
+#include "ios/chrome/browser/ui/commands/ios_command_ids.h"
+#import "ios/chrome/browser/ui/rtl_geometry.h"
+#include "ios/chrome/browser/ui/toolbar/new_tab_button.h"
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
+#import "ui/gfx/ios/uikit_util.h"
+
+namespace {
+
+const CGFloat kNewTabButtonLeading = 8;
+const CGFloat kModeToggleWidth = 34;
+const CGFloat kModeToggleHeight = 38;
+
+}  // end namespace
+
+@interface NoTabsToolbarController () {
+  // Top-level view for notabs-specific content.
+  base::scoped_nsobject<UIView> _noTabsToolbar;
+  base::scoped_nsobject<UIButton> _buttonNewTab;
+  base::scoped_nsobject<UIButton> _modeToggleButton;
+}
+
+@end
+
+@implementation NoTabsToolbarController
+
+- (instancetype)initWithNoTabs {
+  self = [super initWithStyle:ToolbarControllerStyleDarkMode];
+  if (self) {
+    _noTabsToolbar.reset([[UIView alloc] initWithFrame:self.view.bounds]);
+    [_noTabsToolbar setBackgroundColor:[UIColor clearColor]];
+    [_noTabsToolbar setAutoresizingMask:UIViewAutoresizingFlexibleWidth |
+                                        UIViewAutoresizingFlexibleBottomMargin];
+
+    // Resize the container to match the available area.
+    // Do this before the layouts of subviews are computed.
+    [_noTabsToolbar setFrame:[self specificControlsArea]];
+
+    CGFloat boundingHeight = [_noTabsToolbar bounds].size.height;
+    CGFloat boundingWidth = [_noTabsToolbar bounds].size.width;
+    LayoutRect newTabButtonLayout = LayoutRectMake(
+        kNewTabButtonLeading, boundingWidth, 0, boundingHeight, boundingHeight);
+    _buttonNewTab.reset([[NewTabButton alloc]
+        initWithFrame:LayoutRectGetRect(newTabButtonLayout)]);
+    [_buttonNewTab
+        setAutoresizingMask:UIViewAutoresizingFlexibleTrailingMargin()];
+
+    LayoutRect modeToggleButtonLayout = LayoutRectMake(
+        boundingWidth - kModeToggleWidth - boundingHeight, boundingWidth,
+        ui::AlignValueToUpperPixel((boundingHeight - kModeToggleHeight) / 2),
+        kModeToggleWidth, kModeToggleHeight);
+
+    _modeToggleButton.reset([[UIButton alloc]
+        initWithFrame:LayoutRectGetRect(modeToggleButtonLayout)]);
+    [_modeToggleButton setHidden:YES];
+    [_modeToggleButton
+        setAutoresizingMask:UIViewAutoresizingFlexibleLeadingMargin()];
+    [_modeToggleButton setImageEdgeInsets:UIEdgeInsetsMakeDirected(7, 5, 7, 5)];
+    [_modeToggleButton setImage:[UIImage imageNamed:@"tabstrip_switch"]
+                       forState:UIControlStateNormal];
+    [_modeToggleButton setTag:IDC_SWITCH_BROWSER_MODES];
+    [_modeToggleButton addTarget:self
+                          action:@selector(recordUserMetrics:)
+                forControlEvents:UIControlEventTouchUpInside];
+    [_modeToggleButton addTarget:_modeToggleButton
+                          action:@selector(chromeExecuteCommand:)
+                forControlEvents:UIControlEventTouchUpInside];
+
+    // The toolbar background is not supposed to show in the no-tabs UI.
+    [self.backgroundView setHidden:YES];
+
+    [self.view addSubview:_noTabsToolbar];
+    [_noTabsToolbar addSubview:_buttonNewTab];
+    [_noTabsToolbar addSubview:_modeToggleButton];
+
+    self.shadowView.hidden = YES;
+  }
+  return self;
+}
+
+// Applies the given transform to this toolbar's controls.
+- (void)setControlsTransform:(CGAffineTransform)transform {
+  [self setStandardControlsTransform:transform];
+  [_buttonNewTab setTransform:transform];
+  [_modeToggleButton setTransform:transform];
+}
+
+// Shows or hides the mode toggle switch.
+- (void)setHasModeToggleSwitch:(BOOL)hasModeToggle {
+  [_modeToggleButton setHidden:!hasModeToggle];
+}
+
+// Called when a button is pressed.
+- (void)recordUserMetrics:(id)sender {
+  if (sender == _buttonNewTab.get()) {
+    // TODO(rohitrao): Record metrics. http://crbug.com/437418
+  } else if (sender == _modeToggleButton.get()) {
+    // TODO(rohitrao): Record metrics. http://crbug.com/437418
+  } else {
+    [super recordUserMetrics:sender];
+  }
+}
+
+- (UIButton*)modeToggleButton {
+  return _modeToggleButton;
+}
+
+@end