Centering turn on Bluetooth message on the chooser

chrome/browser/ui/cocoa/device_chooser_content_view_cocoa.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 "chrome/browser/ui/cocoa/device_chooser_content_view_cocoa.h"
 
 #include <algorithm>
+#include <cmath>
 
 #include "base/macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/chooser_controller/chooser_controller.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_button.h"
 #include "chrome/browser/ui/cocoa/spinner_view.h"
 #include "chrome/grit/generated_resources.h"
 #include "skia/ext/skia_utils_mac.h"
 #import "third_party/google_toolbox_for_mac/src/AppKit/GTMUILocalizerAndLayoutTweaker.h"
 #import "ui/base/cocoa/controls/hyperlink_button_cell.h"
@@ skipping 35 matching lines @@
 // Separator alpha value.
 const CGFloat kSeparatorAlphaValue = 0.6f;
 
 // Separator height.
 const CGFloat kSeparatorHeight = 1.0f;
 
 // Distance between two views inside the table row view.
 const CGFloat kTableRowViewHorizontalPadding = 5.0f;
 const CGFloat kTableRowViewVerticalPadding = 1.0f;
 
-// Distance between the adapter off help link and the scroll view boundaries.
-const CGFloat kAdapterOffHelpLinkPadding = 5.0f;
-
 // The lookup table for signal strength level image.
 const int kSignalStrengthLevelImageIds[5] = {IDR_SIGNAL_0_BAR, IDR_SIGNAL_1_BAR,
                                              IDR_SIGNAL_2_BAR, IDR_SIGNAL_3_BAR,
                                              IDR_SIGNAL_4_BAR};
 const int kSignalStrengthLevelImageSelectedIds[5] = {
     IDR_SIGNAL_0_BAR_SELECTED, IDR_SIGNAL_1_BAR_SELECTED,
     IDR_SIGNAL_2_BAR_SELECTED, IDR_SIGNAL_3_BAR_SELECTED,
     IDR_SIGNAL_4_BAR_SELECTED};
 
 // Creates a label with |text|.
@@ skipping 351 matching lines @@
         createHyperlinkButtonWithText:
             l10n_util::GetNSString(
                 IDS_BLUETOOTH_DEVICE_CHOOSER_TURN_ON_BLUETOOTH_LINK_TEXT)];
     CGFloat adapterOffHelpButtonWidth = NSWidth([adapterOffHelpButton_ frame]);
     CGFloat adapterOffHelpButtonHeight =
         NSHeight([adapterOffHelpButton_ frame]);
 
     // Adapter turned off message.
     adapterOffMessage_ = CreateLabel(l10n_util::GetNSStringF(
         IDS_BLUETOOTH_DEVICE_CHOOSER_TURN_ADAPTER_OFF, base::string16()));
+    CGFloat adapterOffMessageWidth = NSWidth([adapterOffMessage_ frame]);
 
     // Connect button.
     connectButton_ = [self createConnectButton];
     CGFloat connectButtonWidth = NSWidth([connectButton_ frame]);
     CGFloat connectButtonHeight = NSHeight([connectButton_ frame]);
 
     // Cancel button.
     cancelButton_ = [self createCancelButton];
     CGFloat cancelButtonWidth = NSWidth([cancelButton_ frame]);
 
@@ skipping 74 matching lines @@
                                  kSpinnerSize)]);
 
     // Lay out the views.
     // Title.
     CGFloat titleOriginX = kMarginX;
     CGFloat titleOriginY = kChooserHeight - kMarginY - titleHeight;
     [titleView_ setFrameOrigin:NSMakePoint(titleOriginX, titleOriginY)];
     [self addSubview:titleView_];
 
     // Adapter turned off help button.
-    CGFloat adapterOffHelpButtonOriginX = kMarginX + kAdapterOffHelpLinkPadding;
-    CGFloat adapterOffHelpButtonOriginY = titleOriginY - kVerticalPadding -
-                                          adapterOffHelpButtonHeight -
-                                          kAdapterOffHelpLinkPadding;
+    CGFloat adapterOffHelpButtonOriginX = std::floor(
+        scrollViewOriginX +
+        (scrollViewWidth - adapterOffHelpButtonWidth - adapterOffMessageWidth) /
+            2);
+    CGFloat adapterOffHelpButtonOriginY =
+        std::floor(scrollViewOriginY +
+                   (scrollViewHeight - adapterOffHelpButtonHeight) / 2);
     [adapterOffHelpButton_
         setFrameOrigin:NSMakePoint(adapterOffHelpButtonOriginX,
                                    adapterOffHelpButtonOriginY)];
     [adapterOffHelpButton_ setTarget:self];
     [adapterOffHelpButton_ setAction:@selector(onAdapterOffHelp:)];
     [adapterOffHelpButton_ setHidden:YES];
     [self addSubview:adapterOffHelpButton_];
 
     // Adapter turned off message.
     CGFloat adapterOffMessageOriginX = adapterOffHelpButtonOriginX +
@@ skipping 355 matching lines @@
 
 - (void)drawRect:(NSRect)rect {
   [[NSColor colorWithCalibratedWhite:245.0f / 255.0f alpha:1.0f] setFill];
   NSRect footnoteFrame =
       NSMakeRect(0.0f, 0.0f, kChooserWidth, separatorOriginY_);
   NSRectFill(footnoteFrame);
   [super drawRect:footnoteFrame];
 }
 
 @end