Instant Extended: Reduce clipping in omnibox

chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.mm

 // Copyright (c) 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.
 
 #include "chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.h"
 
 #include <Carbon/Carbon.h>  // kVK_Return
 
 #include "base/mac/foundation_util.h"
 #include "base/string_util.h"
@@ skipping 137 matching lines @@
   [field_ setObserver:this];
 
   // Needed so that editing doesn't lose the styling.
   [field_ setAllowsEditingTextAttributes:YES];
 
   // Get the appropriate line height for the font that we use.
   scoped_nsobject<NSLayoutManager>
       layoutManager([[NSLayoutManager alloc] init]);
   [layoutManager setUsesScreenFonts:YES];
   line_height_ = [layoutManager defaultLineHeightForFont:GetFieldFont()];
+
+  // Extended instant uses a larger font so increase line height to reduce
+  // clipping.

[Scott Hess - ex-Googler, 2013/05/22 19:56:37]

No, it's getting the line height from the font.  Is the font wrong?  Is the
wrong metric being used?  Are we shifting something incorrectly elsewhere?

[sail, 2013/05/22 20:23:55]

The line height doesn't account for accents and stuff. By setting a fixed
min/max line height the text will get clipped regardless of how big the drawing
rect is.

[Scott Hess - ex-Googler, 2013/05/22 21:02:36]

Yeah, but fields are doing this stuff somehow.

[sail, 2013/05/22 21:10:35]

I'm not sure what this comment means.

+  if (chrome::IsInstantExtendedAPIEnabled())
+    line_height_ += 1;
+
   DCHECK_GT(line_height_, 0);
 }
 
 OmniboxViewMac::~OmniboxViewMac() {
   // Destroy popup view before this object in case it tries to call us
   // back in the destructor.
   popup_view_.reset();
 
   // Disconnect from |field_|, it outlives this object.
   [field_ setObserver:NULL];
@@ skipping 263 matching lines @@
 
   [as addAttribute:NSFontAttributeName value:GetFieldFont()
              range:as_entire_string];
 
   // A kinda hacky way to add breaking at periods. This is what Safari does.
   // This works for IDNs too, despite the "en_US".
   [as addAttribute:@"NSLanguage" value:@"en_US_POSIX"
              range:as_entire_string];
 
   // Make a paragraph style locking in the standard line height as the maximum,
   // otherwise the baseline may shift "downwards".

[Scott Hess - ex-Googler, 2013/05/22 21:02:36]

This seems like the relevant issue.  Sure hope I didn't write it, because this
makes little to no sense.

   scoped_nsobject<NSMutableParagraphStyle>
       paragraph_style([[NSMutableParagraphStyle alloc] init]);
   [paragraph_style setMaximumLineHeight:line_height_];
   [paragraph_style setMinimumLineHeight:line_height_];
   [as addAttribute:NSParagraphStyleAttributeName value:paragraph_style
              range:as_entire_string];
 
   url_parse::Component scheme, host;
   AutocompleteInput::ParseForEmphasizeComponents(
       display_text, &scheme, &host);
@@ skipping 525 matching lines @@
 
 NSUInteger OmniboxViewMac::GetTextLength() const {
   return [field_ currentEditor] ?  [[[field_ currentEditor] string] length] :
                                    [[field_ stringValue] length];
 }
 
 bool OmniboxViewMac::IsCaretAtEnd() const {
   const NSRange selection = GetSelectedRange();
   return NSMaxRange(selection) == GetTextLength();
 }