mac: Minor tweaks to notifications code.

ui/message_center/cocoa/notification_controller.mm

 // Copyright (c) 2013 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 "ui/message_center/cocoa/notification_controller.h"
 
 #include "base/strings/sys_string_conversions.h"
 #include "grit/ui_resources.h"
 #include "skia/ext/skia_utils_mac.h"
 #import "third_party/GTM/AppKit/GTMUILocalizerAndLayoutTweaker.h"
 #import "ui/base/cocoa/hover_image_button.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/message_center_constants.h"
 #include "ui/message_center/notification.h"
 
-namespace {
-
-// Compensates for padding already provided by UI elements involved.
-const int kTextTopPaddingAdjustment = -6;
-
-}  // namespace
-
 @interface MCNotificationController (Private)
 // Configures a NSBox to be borderless, titleless, and otherwise appearance-
 // free.
 - (void)configureCustomBox:(NSBox*)box;
 
 // Initializes the icon_ ivar and returns the view to insert into the hierarchy.
 - (NSView*)createImageView;
 
 // Initializes the closeButton_ ivar with the configured button.
 - (void)configureCloseButtonInFrame:(NSRect)rootFrame;
@@ skipping 59 matching lines @@
   DCHECK_EQ(notification->id(), notificationID_);
   notification_ = notification;
 
   NSRect rootFrame = NSMakeRect(0, 0,
       message_center::kNotificationPreferredImageSize,
       message_center::kNotificationIconSize);
 
   // Update the icon.
   [icon_ setImage:notification_->icon().AsNSImage()];
 
+  // The message_center:: constants are relative to capHeight at the top and
+  // relative to the baseline at the bottom, but NSTextField uses the full line
+  // height for its height.
+  CGFloat titleTopGap = [[title_ font] ascender] - [[title_ font] capHeight];
+  CGFloat titleBottomGap = fabs([[title_ font] descender]);
+  CGFloat titlePadding = message_center::kTextTopPadding - titleTopGap;
+
+  CGFloat messageTopGap =
+      [[message_ font] ascender] - [[message_ font] capHeight];
+  CGFloat messagePadding =
+      message_center::kTextTopPadding - titleBottomGap - messageTopGap;
+
   // Set the title and recalculate the frame.
   [title_ setStringValue:base::SysUTF16ToNSString(notification_->title())];
   [GTMUILocalizerAndLayoutTweaker sizeToFitFixedWidthTextField:title_];
   NSRect titleFrame = [title_ frame];
-  titleFrame.origin.y = NSMaxY(rootFrame) - message_center::kTextTopPadding -
-                        NSHeight(titleFrame);
+  titleFrame.origin.y = NSMaxY(rootFrame) - titlePadding - NSHeight(titleFrame);
 
   // Set the message and recalculate the frame.
   [message_ setStringValue:base::SysUTF16ToNSString(notification_->message())];
   [GTMUILocalizerAndLayoutTweaker sizeToFitFixedWidthTextField:message_];
   NSRect messageFrame = [message_ frame];
-  messageFrame.origin.y = NSMinY(titleFrame) - message_center::kTextTopPadding -
-                          NSHeight(messageFrame);
+  messageFrame.origin.y =
+      NSMinY(titleFrame) - messagePadding - NSHeight(messageFrame);
   messageFrame.size.height = NSHeight([message_ frame]);
 
   // In this basic notification UI, the message body is the bottom-most
   // vertical element. If it is out of the rootView's bounds, resize the view.
-  if (NSMinY(messageFrame) <
-          message_center::kTextTopPadding + kTextTopPaddingAdjustment) {
-    CGFloat delta = message_center::kTextTopPadding +
-                    kTextTopPaddingAdjustment - NSMinY(messageFrame);
+  if (NSMinY(messageFrame) < messagePadding) {
+    CGFloat delta = messagePadding - NSMinY(messageFrame);
     rootFrame.size.height += delta;
     titleFrame.origin.y += delta;
     messageFrame.origin.y += delta;
   }
 
   [[self view] setFrame:rootFrame];
   [title_ setFrame:titleFrame];
   [message_ setFrame:messageFrame];
 
   return rootFrame;
@@ skipping 97 matching lines @@
 
   NSRect iconFrame, contentFrame;
   NSDivideRect([[self view] bounds], &iconFrame, &contentFrame,
       NSWidth([icon_ frame]) + message_center::kIconToTextPadding,
       NSMinXEdge);
   contentFrame.size.width -= NSWidth([closeButton_ frame]);
   return contentFrame;
 }
 
 @end