Improve tab-closability of right-most tab.

chrome/browser/cocoa/tab_strip_controller.mm

 // Copyright (c) 2009 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/cocoa/tab_strip_controller.h"
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/mac_util.h"
 #include "base/sys_string_conversions.h"
@@ skipping 270 matching lines @@
   DCHECK([sender isKindOfClass:[NSView class]]);
   if ([hoveredTab_ isEqual:sender]) {
     hoveredTab_ = nil;
   }
   int index = [self indexForTabView:sender];
   if (tabModel_->ContainsIndex(index)) {
     TabContents* contents = tabModel_->GetTabContentsAt(index);
     if (contents)
       UserMetrics::RecordAction(L"CloseTab_Mouse", contents->profile());
     if ([self numberOfTabViews] > 1) {
-      // Limit the width available for laying out tabs so that tabs are not
-      // resized until a later time (when the mouse leaves the tab strip).
-      // TODO(pinkerton): re-visit when handling tab overflow.
-      NSView* penultimateTab = [self viewAtIndex:[tabArray_ count] - 2];
-      availableResizeWidth_ = NSMaxX([penultimateTab frame]);
+      if (static_cast<size_t>(index) != [tabArray_ count] - 1) {

[pink (ping after 24hrs), 2009/09/16 14:37:16]

i'd reverse the if/else cases here. check for the rightmost tab in the if, and
the else can be the normal case.

+        // Limit the width available for laying out tabs so that tabs are not
+        // resized until a later time (when the mouse leaves the tab strip).
+        // TODO(pinkerton): re-visit when handling tab overflow.
+        NSView* penultimateTab = [self viewAtIndex:[tabArray_ count] - 2];
+        availableResizeWidth_ = NSMaxX([penultimateTab frame]);
+      } else {
+        // If the rightmost tab is closed, change the available width so that
+        // another tab's close button lands below the cursor (assuming the tabs
+        // are currently below their maximum width and can grow).
+        NSView* lastTab = [self viewAtIndex:[tabArray_ count] - 1];
+        availableResizeWidth_ = NSMaxX([lastTab frame]);
+      }
       tabModel_->CloseTabContentsAt(index);
     } else {
       // Use the standard window close if this is the last tab
       // this prevents the tab from being removed from the model until after
       // the window dissapears
       [[tabView_ window] performClose:nil];
     }
   }
 }
 
@@ skipping 663 matching lines @@
   BrowserWindowController* controller =
       (BrowserWindowController*)[[switchView_ window] windowController];
   DCHECK(index >= 0);
   if (index >= 0) {
     [controller setTab:[self viewAtIndex:index] isDraggable:YES];
   }
 }
 
 
 @end