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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #import "ui/base/cocoa/underlay_opengl_hosting_window.h"
      6 
      7 #import <objc/runtime.h>
      8 
      9 #include "base/logging.h"
     10 #include "base/mac/mac_util.h"
     11 #include "base/mac/scoped_nsautorelease_pool.h"
     12 #include "base/mac/scoped_nsobject.h"
     13 
     14 @interface NSWindow (UndocumentedAPI)
     15 // Normally, punching a hole in a window by painting a subview with a
     16 // transparent color causes the shadow for that area to also not be present.
     17 // That feature is "content has shadow", which means that shadows are effective
     18 // even in the content area of the window. If, however, "content has shadow" is
     19 // turned off, then the transparent area of the content casts a shadow. The one
     20 // tricky part is that even if "content has shadow" is turned off, "the content"
     21 // is defined as being the scanline from the leftmost opaque part to the
     22 // rightmost opaque part.  Therefore, to force the entire window to have a
     23 // shadow, make sure that for the entire content region, there is an opaque area
     24 // on the right and left edge of the window.
     25 - (void)_setContentHasShadow:(BOOL)shadow;
     26 @end
     27 
     28 @interface OpaqueView : NSView
     29 @end
     30 
     31 namespace {
     32 
     33 NSComparisonResult OpaqueViewsOnTop(id view1, id view2, void* context) {
     34   BOOL view_1_is_opaque_view = [view1 isKindOfClass:[OpaqueView class]];
     35   BOOL view_2_is_opaque_view = [view2 isKindOfClass:[OpaqueView class]];
     36   if (view_1_is_opaque_view && view_2_is_opaque_view)
     37     return NSOrderedSame;
     38   if (view_1_is_opaque_view)
     39     return NSOrderedDescending;
     40   if (view_2_is_opaque_view)
     41     return NSOrderedAscending;
     42   return NSOrderedSame;
     43 }
     44 
     45 }  // namespace
     46 
     47 @implementation OpaqueView
     48 
     49 - (void)drawRect:(NSRect)r {
     50   [[NSColor blackColor] set];
     51   NSRectFill(r);
     52 }
     53 
     54 - (void)resetCursorRects {
     55   // When a view is moved relative to its peers, its cursor rects are reset.
     56   // (This is an undocumented side-effect.) At that time, verify that any
     57   // OpaqueViews are z-ordered in the front, and enforce it if need be.
     58 
     59   NSView* rootView = [self superview];
     60   DCHECK_EQ((NSView*)nil, [rootView superview]);
     61   NSArray* subviews = [rootView subviews];
     62 
     63   // If a window has any opaques, it will have exactly two.
     64   DCHECK_EQ(2U, [[subviews indexesOfObjectsPassingTest:
     65       ^(id el, NSUInteger i, BOOL *stop) {
     66         return [el isKindOfClass:[OpaqueView class]];
     67       }] count]);
     68 
     69   NSUInteger count = [subviews count];
     70   if (count < 2)
     71     return;
     72 
     73   if (![[subviews objectAtIndex:count - 1] isKindOfClass:[OpaqueView class]] ||
     74       ![[subviews objectAtIndex:count - 2] isKindOfClass:[OpaqueView class]]) {
     75     // Do not sort the subviews array here and call -[NSView setSubviews:] as
     76     // that causes a crash on 10.6.
     77     [rootView sortSubviewsUsingFunction:OpaqueViewsOnTop context:NULL];
     78   }
     79 }
     80 
     81 @end
     82 
     83 @implementation UnderlayOpenGLHostingWindow
     84 
     85 - (id)initWithContentRect:(NSRect)contentRect
     86                 styleMask:(NSUInteger)windowStyle
     87                   backing:(NSBackingStoreType)bufferingType
     88                     defer:(BOOL)deferCreation {
     89   // It is invalid to create windows with zero width or height. It screws things
     90   // up royally:
     91   // - It causes console spew: <http://crbug.com/78973>
     92   // - It breaks Expose: <http://sourceforge.net/projects/heat-meteo/forums/forum/268087/topic/4582610>
     93   //
     94   // This is a banned practice
     95   // <http://www.chromium.org/developers/coding-style/cocoa-dos-and-donts>. Do
     96   // not do this. Use kWindowSizeDeterminedLater in
     97   // ui/base/cocoa/window_size_constants.h instead.
     98   //
     99   // (This is checked here because UnderlayOpenGLHostingWindow is the base of
    100   // most Chromium windows, not because this is related to its functionality.)
    101   DCHECK(!NSIsEmptyRect(contentRect));
    102   if ((self = [super initWithContentRect:contentRect
    103                                styleMask:windowStyle
    104                                  backing:bufferingType
    105                                    defer:deferCreation])) {
    106     // OpenGL-accelerated content works by punching holes in windows. Therefore
    107     // all windows hosting OpenGL content must not be opaque.
    108     [self setOpaque:NO];
    109 
    110     if (windowStyle & NSTitledWindowMask) {
    111       // Only fiddle with shadows if the window is a proper window with a
    112       // title bar and all.
    113       [self _setContentHasShadow:NO];
    114 
    115       NSView* rootView = [[self contentView] superview];
    116       const NSRect rootBounds = [rootView bounds];
    117 
    118       // On 10.7/8, the bottom corners of the window are rounded by magic at a
    119       // deeper level than the NSThemeFrame, so it is OK to have the opaques
    120       // go all the way to the bottom.
    121       const CGFloat kTopEdgeInset = 16;
    122       const CGFloat kAlphaValueJustOpaqueEnough = 0.005;
    123 
    124       base::scoped_nsobject<NSView> leftOpaque([[OpaqueView alloc]
    125           initWithFrame:NSMakeRect(NSMinX(rootBounds),
    126                                    NSMinY(rootBounds),
    127                                    1,
    128                                    NSHeight(rootBounds) - kTopEdgeInset)]);
    129       [leftOpaque setAutoresizingMask:NSViewMaxXMargin |
    130                                       NSViewHeightSizable];
    131       [leftOpaque setAlphaValue:kAlphaValueJustOpaqueEnough];
    132       [rootView addSubview:leftOpaque];
    133 
    134       base::scoped_nsobject<NSView> rightOpaque([[OpaqueView alloc]
    135           initWithFrame:NSMakeRect(NSMaxX(rootBounds) - 1,
    136                                    NSMinY(rootBounds),
    137                                    1,
    138                                    NSHeight(rootBounds) - kTopEdgeInset)]);
    139       [rightOpaque setAutoresizingMask:NSViewMinXMargin |
    140                                        NSViewHeightSizable];
    141       [rightOpaque setAlphaValue:kAlphaValueJustOpaqueEnough];
    142       [rootView addSubview:rightOpaque];
    143     }
    144   }
    145 
    146   return self;
    147 }
    148 
    149 @end
    150