Drop shadows for packaged apps on the OSX App Launcher.

ui/app_list/cocoa/apps_grid_view_item.mm

 // Copyright 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/app_list/cocoa/apps_grid_view_item.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/memory/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_item_model.h"
 #include "ui/app_list/app_list_item_model_observer.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image_skia_util_mac.h"
 #include "ui/gfx/font.h"
+#include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 
 namespace {
 
 // Padding from the top of the tile to the top of the app icon.
 const CGFloat kTileTopPadding = 10;
 
 }  // namespace
 
 namespace app_list {
 
@@ skipping 56 matching lines @@
  @private
   BOOL selected_;
 }
 
 - (NSButton*)button;
 
 - (void)setSelected:(BOOL)flag;
 
 @end
 
+@interface AppsGridItemButtonCell : NSButtonCell {
+ @private
+  BOOL hasShadow_;
+}
+
+@property(assign, nonatomic) BOOL hasShadow;
+
+@end
+
+@interface AppsGridItemButton : NSButton;
+@end
+
 @implementation AppsGridItemBackgroundView
 
 - (NSButton*)button {
   return base::mac::ObjCCastStrict<NSButton>([[self subviews] objectAtIndex:0]);
 }
 
 - (void)setSelected:(BOOL)flag {
   if (selected_ == flag)
     return;
 
@@ skipping 39 matching lines @@
 @interface AppsGridViewItem ()
 
 - (AppsGridItemBackgroundView*)itemBackgroundView;
 
 @end
 
 @implementation AppsGridViewItem
 
 - (id)initWithSize:(NSSize)tileSize {
   if ((self = [super init])) {
-    scoped_nsobject<NSButton> prototypeButton(
-        [[NSButton alloc] initWithFrame:NSMakeRect(
+    scoped_nsobject<AppsGridItemButton> prototypeButton(
+        [[AppsGridItemButton alloc] initWithFrame:NSMakeRect(
             0, 0, tileSize.width, tileSize.height - kTileTopPadding)]);
 
     // This NSButton style always positions the icon at the very top of the
     // button frame. AppsGridViewItem uses an enclosing view so that it is
     // visually correct.
     [prototypeButton setImagePosition:NSImageAbove];
     [prototypeButton setButtonType:NSMomentaryChangeButton];
     [prototypeButton setBordered:NO];
 
     [[prototypeButton cell]
@@ skipping 11 matching lines @@
 
 - (void)setModel:(app_list::AppListItemModel*)itemModel {
   if (!itemModel) {
     observerBridge_.reset();
     return;
   }
 
   NSButton* button = [self button];
   [button setTitle:base::SysUTF8ToNSString(itemModel->title())];
   [button setImage:gfx::NSImageFromImageSkia(itemModel->icon())];
+  [[button cell] setHasShadow:itemModel->has_shadow()];
   observerBridge_.reset(new app_list::ItemModelObserverBridge(self, itemModel));
 
   if (trackingArea_.get())
     [[self view] removeTrackingArea:trackingArea_.get()];
 
   trackingArea_.reset(
       [[CrTrackingArea alloc] initWithRect:NSZeroRect
                                    options:NSTrackingInVisibleRect |
                                            NSTrackingMouseEnteredAndExited |
                                            NSTrackingActiveInKeyWindow
@@ skipping 23 matching lines @@
 - (void)mouseExited:(NSEvent*)theEvent {
   [self setSelected:NO];
 }
 
 - (void)setSelected:(BOOL)flag {
   [[self itemBackgroundView] setSelected:flag];
   [super setSelected:flag];
 }
 
 @end
+
+@implementation AppsGridItemButton
+
++ (Class)cellClass {
+  return [AppsGridItemButtonCell class];
+}
+
+@end
+
+@implementation AppsGridItemButtonCell
+
+@synthesize hasShadow = hasShadow_;
+
+- (void)drawImage:(NSImage*)image
+        withFrame:(NSRect)frame
+           inView:(NSView*)controlView {
+  if (!hasShadow_) {
+    [super drawImage:image
+           withFrame:frame
+              inView:controlView];
+    return;
+  }
+
+  scoped_nsobject<NSShadow> shadow([[NSShadow alloc] init]);
+  gfx::ScopedNSGraphicsContextSaveGState context;
+  [shadow setShadowOffset:NSMakeSize(0, -2)];
+  [shadow setShadowBlurRadius:2.0];
+  [shadow setShadowColor:[NSColor colorWithCalibratedWhite:0
+                                                     alpha:0.14]];
+  [shadow set];
+
+  [super drawImage:image
+         withFrame:frame
+            inView:controlView];
+}
+
+@end