AppKit/GTMWindowSheetController.m - external/google-toolbox-for-mac - Git at Google

 //
 //  GTMWindowSheetController.m
 //
 //  Copyright 2009 Google Inc.
 //
 //  Licensed under the Apache License, Version 2.0 (the "License"); you may not
 //  use this file except in compliance with the License.  You may obtain a copy
 //  of the License at
 //
 //  http://www.apache.org/licenses/LICENSE-2.0
 //
 //  Unless required by applicable law or agreed to in writing, software
 //  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 //  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 //  License for the specific language governing permissions and limitations under
 //  the License.
 //

 #import "GTMWindowSheetController.h"

 #import "GTMDefines.h"
 #import "GTMTypeCasting.h"

 @interface GTMWSCSheetInfo : NSObject {
  @public
   NSWindow* overlayWindow_;

   // delegate data
   GTM_WEAK id modalDelegate_;
   SEL didEndSelector_;
   void* contextInfo_;

   // sheet info
   CGFloat sheetAlpha_;
   NSRect sheetFrame_; // relative to overlay window
   BOOL sheetAutoresizesSubviews_;
 }
 @end

 @implementation GTMWSCSheetInfo
 @end

 // The information about how to call up various AppKit-implemented sheets

 struct GTMWSCSystemSheetInfo {
   NSString* className_;
   NSString* methodSignature_;
   NSUInteger modalForWindowIndex_;
   NSUInteger modalDelegateIndex_;
   NSUInteger didEndSelectorIndex_;
   NSUInteger contextInfoIndex_;
   // Callbacks invariably take three parameters. The first is always an id, the
   // third always a void*, but the second can be a BOOL (8 bits), an int (32
   // bits), or an id or NSInteger (64 bits in 64 bit mode). This is the size of
   // the argument in 64-bit mode.
   NSUInteger arg1OfEndSelectorSize_;
 };

 @interface GTMWindowSheetController (PrivateMethods)
 - (void)beginSystemSheet:(id)systemSheet
                 withInfo:(const struct GTMWSCSystemSheetInfo*)info
             modalForView:(NSView*)view
           withParameters:(NSArray*)params;
 - (const struct GTMWSCSystemSheetInfo*)infoForSheet:(id)systemSheet;
 - (void)notificationHappened:(NSNotification*)notification;
 - (void)viewDidChangeSize:(NSView*)view;
 - (NSRect)screenFrameOfView:(NSView*)view;
 - (void)sheetDidEnd:(id)sheet
         returnCode8:(char)returnCode
         contextInfo:(void*)contextInfo;
 - (void)sheetDidEnd:(id)sheet
        returnCode32:(int)returnCode
         contextInfo:(void*)contextInfo;
 - (void)sheetDidEnd:(id)sheet
        returnCode64:(NSInteger)returnCode
         contextInfo:(void*)contextInfo;
 - (void)sheetDidEnd:(id)sheet
          returnCode:(NSInteger)returnCode
         contextInfo:(void*)contextInfo
            arg1Size:(int)size;
 - (void)systemRequestsVisibilityForWindow:(NSWindow*)window;
 - (NSRect)window:(NSWindow*)window
 willPositionSheet:(NSWindow*)sheet
        usingRect:(NSRect)defaultSheetRect;
 @end

 @interface GTMWSCOverlayWindow : NSWindow {
   GTMWindowSheetController* sheetController_;
 }

 - (id)initWithContentRect:(NSRect)contentRect
           sheetController:(GTMWindowSheetController*)sheetController;
 - (void)makeKeyAndOrderFront:(id)sender;

 @end

 @implementation GTMWSCOverlayWindow

 - (id)initWithContentRect:(NSRect)contentRect
           sheetController:(GTMWindowSheetController*)sheetController {
   self = [super initWithContentRect:contentRect
                           styleMask:NSBorderlessWindowMask
                             backing:NSBackingStoreBuffered
                               defer:NO];
   if (self != nil) {
     sheetController_ = sheetController;
     [self setOpaque:NO];
     [self setBackgroundColor:[NSColor clearColor]];
     [self setIgnoresMouseEvents:NO];
   }
   return self;
 }

 - (void)makeKeyAndOrderFront:(id)sender {
   [sheetController_ systemRequestsVisibilityForWindow:self];
 }

 @end

 @implementation GTMWindowSheetController

 - (id)initWithWindow:(NSWindow*)window
             delegate:(id <GTMWindowSheetControllerDelegate>)delegate {
   self = [super init];
   if (self != nil) {
     window_ = window;
     delegate_ = delegate;
     sheets_ = [[NSMutableDictionary alloc] init];
   }
   return self;
 }

 - (void)finalize {
   _GTMDevAssert([sheets_ count] == 0,
                 @"Finalizing a controller with sheets still active!");
   [[NSNotificationCenter defaultCenter] removeObserver:self];

   [super finalize];
 }

 - (void)dealloc {
   _GTMDevAssert([sheets_ count] == 0,
                 @"Deallocing a controller with sheets still active!");
   [[NSNotificationCenter defaultCenter] removeObserver:self];

   [sheets_ release];

   [super dealloc];
 }

 - (void)beginSheet:(NSWindow*)sheet
       modalForView:(NSView*)view
      modalDelegate:(id)modalDelegate
     didEndSelector:(SEL)didEndSelector
        contextInfo:(void*)contextInfo {
   NSArray* params =
       [NSArray arrayWithObjects:sheet,
                                 [NSNull null],
                                 modalDelegate,
                                 [NSValue valueWithPointer:didEndSelector],
                                 [NSValue valueWithPointer:contextInfo],
                                 nil];
   [self beginSystemSheet:[NSApplication sharedApplication]
             modalForView:view
           withParameters:params];
 }

 - (void)beginSystemSheet:(id)systemSheet
             modalForView:(NSView*)view
           withParameters:(NSArray*)params {
   const struct GTMWSCSystemSheetInfo* info = [self infoForSheet:systemSheet];
   if (info) {
     [self beginSystemSheet:systemSheet
                   withInfo:info
               modalForView:view
             withParameters:params];
   } // else already logged
 }


 - (BOOL)isSheetAttachedToView:(NSView*)view {
   NSValue* viewValue = [NSValue valueWithNonretainedObject:view];
   return [sheets_ objectForKey:viewValue] != nil;
 }

 - (NSArray*)viewsWithAttachedSheets {
   NSMutableArray* views = [NSMutableArray array];
   NSValue* key;
   GTM_FOREACH_KEY(key, sheets_) {
     [views addObject:[key nonretainedObjectValue]];
   }

   return views;
 }

 - (void)setActiveView:(NSView*)view {
   // Hide old sheet

   NSValue* oldViewValue = [NSValue valueWithNonretainedObject:activeView_];
   GTMWSCSheetInfo* oldSheetInfo = [sheets_ objectForKey:oldViewValue];
   if (oldSheetInfo) {
     NSWindow* overlayWindow = oldSheetInfo->overlayWindow_;
     _GTMDevAssert(overlayWindow, @"Old sheet info has no overlay window");
     NSWindow* sheetWindow = [overlayWindow attachedSheet];
     _GTMDevAssert(sheetWindow, @"Old sheet info has no active sheet");

     // Why do we hide things this way?
     // - Keeping it local but alpha 0 means we get good Expose behavior
     // - Resizing it to 0 means we get no blurring effect left over

     oldSheetInfo->sheetAlpha_ = [sheetWindow alphaValue];
     [sheetWindow setAlphaValue:(CGFloat)0.0];

     oldSheetInfo->sheetAutoresizesSubviews_ =
         [[sheetWindow contentView] autoresizesSubviews];
     [[sheetWindow contentView] setAutoresizesSubviews:NO];

     NSRect overlayFrame = [overlayWindow frame];
     oldSheetInfo->sheetFrame_ = [sheetWindow frame];
     oldSheetInfo->sheetFrame_.origin.x -= overlayFrame.origin.x;
     oldSheetInfo->sheetFrame_.origin.y -= overlayFrame.origin.y;
     [sheetWindow setFrame:NSZeroRect display:NO];

     [overlayWindow setIgnoresMouseEvents:YES];

     // Make sure the now invisible sheet doesn't keep keyboard focus
     [[overlayWindow parentWindow] makeKeyWindow];
   }

   activeView_ = view;

   // Show new sheet

   NSValue* newViewValue = [NSValue valueWithNonretainedObject:view];
   GTMWSCSheetInfo* newSheetInfo = [sheets_ objectForKey:newViewValue];
   if (newSheetInfo) {
     NSWindow* overlayWindow = newSheetInfo->overlayWindow_;
     _GTMDevAssert(overlayWindow, @"New sheet info has no overlay window");
     NSWindow* sheetWindow = [overlayWindow attachedSheet];
     _GTMDevAssert(sheetWindow, @"New sheet info has no active sheet");

     [overlayWindow setIgnoresMouseEvents:NO];

     NSRect overlayFrame = [overlayWindow frame];
     newSheetInfo->sheetFrame_.origin.x += overlayFrame.origin.x;
     newSheetInfo->sheetFrame_.origin.y += overlayFrame.origin.y;
     [sheetWindow setFrame:newSheetInfo->sheetFrame_ display:NO];

     [[sheetWindow contentView]
         setAutoresizesSubviews:newSheetInfo->sheetAutoresizesSubviews_];

     [sheetWindow setAlphaValue:newSheetInfo->sheetAlpha_];

     [self viewDidChangeSize:view];

     [overlayWindow makeKeyWindow];
   }
 }

 @end

 @implementation GTMWindowSheetController (PrivateMethods)

 - (void)beginSystemSheet:(id)systemSheet
                 withInfo:(const struct GTMWSCSystemSheetInfo*)info
             modalForView:(NSView*)view
           withParameters:(NSArray*)params {
   _GTMDevAssert([view window] == window_,
                 @"Cannot show a sheet for a window for which we are not "
                 @"managing sheets");
   _GTMDevAssert(![self isSheetAttachedToView:view],
                 @"Cannot show another sheet for a view while already managing "
                 @"one");
   _GTMDevAssert(info, @"Missing info for the type of sheet");

   GTMWSCSheetInfo* sheetInfo = [[[GTMWSCSheetInfo alloc] init] autorelease];

   sheetInfo->modalDelegate_ = [params objectAtIndex:info->modalDelegateIndex_];
   sheetInfo->didEndSelector_ =
       [[params objectAtIndex:info->didEndSelectorIndex_] pointerValue];
   sheetInfo->contextInfo_ =
       [[params objectAtIndex:info->contextInfoIndex_] pointerValue];

   _GTMDevAssert([sheetInfo->modalDelegate_
                   respondsToSelector:sheetInfo->didEndSelector_],
                 @"Delegate does not respond to the specified selector");

   [view setPostsFrameChangedNotifications:YES];
   [[NSNotificationCenter defaultCenter]
       addObserver:self
          selector:@selector(notificationHappened:)
              name:NSViewFrameDidChangeNotification
            object:view];

   sheetInfo->overlayWindow_ =
       [[GTMWSCOverlayWindow alloc]
        initWithContentRect:[self screenFrameOfView:view]
            sheetController:self];

   [sheets_ setObject:sheetInfo
               forKey:[NSValue valueWithNonretainedObject:view]];

   [window_ addChildWindow:sheetInfo->overlayWindow_
                   ordered:NSWindowAbove];

   SEL methodSelector = NSSelectorFromString((NSString*)info->methodSignature_);
   NSInvocation* invocation =
       [NSInvocation invocationWithMethodSignature:
        [systemSheet methodSignatureForSelector:methodSelector]];
   [invocation setSelector:methodSelector];
   for (NSUInteger i = 0; i < [params count]; ++i) {
     // Remember that args 0 and 1 are the target and selector, thus the |i+2|s
     if (i == info->modalForWindowIndex_) {
       [invocation setArgument:&sheetInfo->overlayWindow_ atIndex:i+2];
     } else if (i == info->modalDelegateIndex_) {
       [invocation setArgument:&self atIndex:i+2];
     } else if (i == info->didEndSelectorIndex_) {
       if (info->arg1OfEndSelectorSize_ == 64)
         [invocation setArgument:&@selector(sheetDidEnd:returnCode64:contextInfo:)
                         atIndex:i+2];
       else if (info->arg1OfEndSelectorSize_ == 32)
         [invocation setArgument:&@selector(sheetDidEnd:returnCode32:contextInfo:)
                         atIndex:i+2];
       else if (info->arg1OfEndSelectorSize_ == 8)
         [invocation setArgument:&@selector(sheetDidEnd:returnCode8:contextInfo:)
                         atIndex:i+2];
     } else if (i == info->contextInfoIndex_) {
       [invocation setArgument:&view atIndex:i+2];
     } else {
       id param = [params objectAtIndex:i];
       if ([param isKindOfClass:[NSValue class]]) {
         char buffer[16];
         [param getValue:buffer];
         [invocation setArgument:buffer atIndex:i+2];
       } else {
         [invocation setArgument:&param atIndex:i+2];
       }
     }
   }
   [invocation invokeWithTarget:systemSheet];

   _GTMDevAssert(!activeView_ || activeView_ == view,
                 @"You have to call setActiveView:view before "
                  "calling beginSheet:modalForView:view");
   activeView_ = view;
 }

 - (const struct GTMWSCSystemSheetInfo*)infoForSheet:(id)systemSheet {
   static const struct GTMWSCSystemSheetInfo kGTMWSCSystemSheetInfoData[] =
   {
     {
       @"ABIdentityPicker",
       @"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 64,
     },
     {
       @"CBIdentityPicker",
       @"runModalForWindow:modalDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 64,
     },
     {
       @"DRSetupPanel",
       @"beginSetupSheetForWindow:modalDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 32,
     },
     {
       @"NSAlert",
       @"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 32,
     },
     {
       @"NSApplication",
       @"beginSheet:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
       1, 2, 3, 4, 64,
     },
     {
       @"IKFilterBrowserPanel",
       @"beginSheetWithOptions:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
       1, 2, 3, 4, 32,
     },
     {
       @"IKPictureTaker",
       @"beginPictureTakerSheetForWindow:withDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 64,
     },
     {
       @"IOBluetoothDeviceSelectorController",
       @"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 32,
     },
     {
       @"IOBluetoothObjectPushUIController",
       @"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 32,
     },
     {
       @"IOBluetoothServiceBrowserController",
       @"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
       0, 1, 2, 3, 32,
     },
     {
       @"NSOpenPanel",
       @"beginSheetForDirectory:file:types:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
       3, 4, 5, 6, 32,
     },
     {
       @"NSPageLayout",
       @"beginSheetWithPrintInfo:modalForWindow:delegate:didEndSelector:contextInfo:",
       1, 2, 3, 4, 32,
     },
     {
       @"NSPrintOperation",
       @"runOperationModalForWindow:delegate:didRunSelector:contextInfo:",
       0, 1, 2, 3, 8,
     },
     {
       @"NSPrintPanel",
       @"beginSheetWithPrintInfo:modalForWindow:delegate:didEndSelector:contextInfo:",
       1, 2, 3, 4, 32,
     },
     {
       @"NSSavePanel",
       @"beginSheetForDirectory:file:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
       2, 3, 4, 5, 32,
     },
     {
       @"SFCertificatePanel",
       @"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:certificates:showGroup:",
       0, 1, 2, 3, 32,
     },
     {
       @"SFCertificateTrustPanel",
       @"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:trust:message:",
       0, 1, 2, 3, 32,
     },
     {
       @"SFChooseIdentityPanel",
       @"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:identities:message:",
       0, 1, 2, 3, 32,
     },
     {
       @"SFKeychainSettingsPanel",
       @"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:settings:keychain:",
       0, 1, 2, 3, 32,
     },
     {
       @"SFKeychainSavePanel",
       @"beginSheetForDirectory:file:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
       2, 3, 4, 5, 32,
     },
   };

   static const size_t kGTMWSCSystemSheetInfoDataSize =
       sizeof(kGTMWSCSystemSheetInfoData)/sizeof(kGTMWSCSystemSheetInfoData[0]);

   for (size_t i = 0; i < kGTMWSCSystemSheetInfoDataSize; ++i) {
     Class testClass =
       NSClassFromString(kGTMWSCSystemSheetInfoData[i].className_);
     if (testClass && [systemSheet isKindOfClass:testClass]) {
       return &kGTMWSCSystemSheetInfoData[i];
     }
   }

   _GTMDevLog(@"Failed to find info for sheet of type %@", [systemSheet class]);
   return nil;
 }

 - (void)notificationHappened:(NSNotification*)notification {
   NSView *view = GTM_STATIC_CAST(NSView, [notification object]);
   [self viewDidChangeSize:view];
 }

 - (void)viewDidChangeSize:(NSView*)view {
   GTMWSCSheetInfo* sheetInfo =
       [sheets_ objectForKey:[NSValue valueWithNonretainedObject:view]];
   if (!sheetInfo)
     return;

   if (view != activeView_)
     return;

   NSWindow* overlayWindow = sheetInfo->overlayWindow_;
   if (!overlayWindow)
     return;

   [overlayWindow setFrame:[self screenFrameOfView:view] display:YES];
   [[overlayWindow attachedSheet] makeKeyWindow];
 }

 - (NSRect)screenFrameOfView:(NSView*)view {
   NSRect viewFrame = [view convertRect:[view bounds] toView:nil];
   viewFrame.origin = [[view window] convertBaseToScreen:viewFrame.origin];
   return viewFrame;
 }

 - (void)sheetDidEnd:(id)sheet
         returnCode8:(char)returnCode
         contextInfo:(void*)contextInfo {
   [self sheetDidEnd:sheet
          returnCode:returnCode
         contextInfo:contextInfo
            arg1Size:8];
 }

 - (void)sheetDidEnd:(id)sheet
        returnCode32:(int)returnCode
         contextInfo:(void*)contextInfo {
   [self sheetDidEnd:sheet
          returnCode:returnCode
         contextInfo:contextInfo
            arg1Size:32];
 }

 - (void)sheetDidEnd:(id)sheet
        returnCode64:(NSInteger)returnCode
         contextInfo:(void*)contextInfo {
   [self sheetDidEnd:sheet
          returnCode:returnCode
         contextInfo:contextInfo
            arg1Size:64];
 }

 - (void)sheetDidEnd:(id)sheet
          returnCode:(NSInteger)returnCode
         contextInfo:(void*)contextInfo
            arg1Size:(int)size {
   NSValue* viewKey = [NSValue valueWithNonretainedObject:(NSView*)contextInfo];
   // Retain a reference to sheetInfo so we can use it after it is
   // removed from sheets_.
   GTMWSCSheetInfo* sheetInfo =
       [[[sheets_ objectForKey:viewKey] retain] autorelease];
   _GTMDevAssert(sheetInfo, @"Could not find information about the sheet that "
                            @"just ended");
   _GTMDevAssert(size == 8 || size == 32 || size == 64,
                 @"Incorrect size information in the sheet entry; don't know "
                 @"how big the second parameter is");

   // Can't turn off view's frame notifications as we don't know if someone else
   // wants them.
   [[NSNotificationCenter defaultCenter]
       removeObserver:self
                 name:NSViewFrameDidChangeNotification
               object:contextInfo];

   // We clean up the sheet before calling the callback so that the
   // callback is free to fire another sheet if it so desires.
   [window_ removeChildWindow:sheetInfo->overlayWindow_];
   [sheetInfo->overlayWindow_ release];
   [sheets_ removeObjectForKey:viewKey];

   NSInvocation* invocation =
       [NSInvocation invocationWithMethodSignature:
        [sheetInfo->modalDelegate_
         methodSignatureForSelector:sheetInfo->didEndSelector_]];
   [invocation setSelector:sheetInfo->didEndSelector_];
   // Remember that args 0 and 1 are the target and selector
   [invocation setArgument:&sheet atIndex:2];
   if (size == 64) {
     [invocation setArgument:&returnCode atIndex:3];
   } else if (size == 32) {
     int shortReturnCode = (int)returnCode;
     [invocation setArgument:&shortReturnCode atIndex:3];
   } else if (size == 8) {
     char charReturnCode = returnCode;
     [invocation setArgument:&charReturnCode atIndex:3];
   }
   [invocation setArgument:&sheetInfo->contextInfo_ atIndex:4];
   [invocation invokeWithTarget:sheetInfo->modalDelegate_];
 }

 - (void)systemRequestsVisibilityForWindow:(NSWindow*)window {
   NSValue* key;
   GTM_FOREACH_KEY(key, sheets_) {
     GTMWSCSheetInfo* sheetInfo = [sheets_ objectForKey:key];
     if (sheetInfo->overlayWindow_ == window) {
       NSView* view = [key nonretainedObjectValue];
       [delegate_ gtm_systemRequestsVisibilityForView:view];
     }
   }
 }

 - (NSRect)window:(NSWindow*)window
 willPositionSheet:(NSWindow*)sheet
        usingRect:(NSRect)defaultSheetRect {
   // Ensure that the sheets come out of the very top of the overlay windows.
   NSRect windowFrame = [window frame];
   defaultSheetRect.origin.y = windowFrame.size.height;
   return defaultSheetRect;
 }

 @end
	//
	// GTMWindowSheetController.m
	//
	// Copyright 2009 Google Inc.
	//
	// Licensed under the Apache License, Version 2.0 (the "License"); you may not
	// use this file except in compliance with the License. You may obtain a copy
	// of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	// License for the specific language governing permissions and limitations under
	// the License.
	//

	#import "GTMWindowSheetController.h"

	#import "GTMDefines.h"
	#import "GTMTypeCasting.h"

	@interface GTMWSCSheetInfo : NSObject {
	@public
	NSWindow* overlayWindow_;

	// delegate data
	GTM_WEAK id modalDelegate_;
	SEL didEndSelector_;
	void* contextInfo_;

	// sheet info
	CGFloat sheetAlpha_;
	NSRect sheetFrame_; // relative to overlay window
	BOOL sheetAutoresizesSubviews_;
	}
	@end

	@implementation GTMWSCSheetInfo
	@end

	// The information about how to call up various AppKit-implemented sheets

	struct GTMWSCSystemSheetInfo {
	NSString* className_;
	NSString* methodSignature_;
	NSUInteger modalForWindowIndex_;
	NSUInteger modalDelegateIndex_;
	NSUInteger didEndSelectorIndex_;
	NSUInteger contextInfoIndex_;
	// Callbacks invariably take three parameters. The first is always an id, the
	// third always a void*, but the second can be a BOOL (8 bits), an int (32
	// bits), or an id or NSInteger (64 bits in 64 bit mode). This is the size of
	// the argument in 64-bit mode.
	NSUInteger arg1OfEndSelectorSize_;
	};

	@interface GTMWindowSheetController (PrivateMethods)
	- (void)beginSystemSheet:(id)systemSheet
	withInfo:(const struct GTMWSCSystemSheetInfo*)info
	modalForView:(NSView*)view
	withParameters:(NSArray*)params;
	- (const struct GTMWSCSystemSheetInfo*)infoForSheet:(id)systemSheet;
	- (void)notificationHappened:(NSNotification*)notification;
	- (void)viewDidChangeSize:(NSView*)view;
	- (NSRect)screenFrameOfView:(NSView*)view;
	- (void)sheetDidEnd:(id)sheet
	returnCode8:(char)returnCode
	contextInfo:(void*)contextInfo;
	- (void)sheetDidEnd:(id)sheet
	returnCode32:(int)returnCode
	contextInfo:(void*)contextInfo;
	- (void)sheetDidEnd:(id)sheet
	returnCode64:(NSInteger)returnCode
	contextInfo:(void*)contextInfo;
	- (void)sheetDidEnd:(id)sheet
	returnCode:(NSInteger)returnCode
	contextInfo:(void*)contextInfo
	arg1Size:(int)size;
	- (void)systemRequestsVisibilityForWindow:(NSWindow*)window;
	- (NSRect)window:(NSWindow*)window
	willPositionSheet:(NSWindow*)sheet
	usingRect:(NSRect)defaultSheetRect;
	@end

	@interface GTMWSCOverlayWindow : NSWindow {
	GTMWindowSheetController* sheetController_;
	}

	- (id)initWithContentRect:(NSRect)contentRect
	sheetController:(GTMWindowSheetController*)sheetController;
	- (void)makeKeyAndOrderFront:(id)sender;

	@end

	@implementation GTMWSCOverlayWindow

	- (id)initWithContentRect:(NSRect)contentRect
	sheetController:(GTMWindowSheetController*)sheetController {
	self = [super initWithContentRect:contentRect
	styleMask:NSBorderlessWindowMask
	backing:NSBackingStoreBuffered
	defer:NO];
	if (self != nil) {
	sheetController_ = sheetController;
	[self setOpaque:NO];
	[self setBackgroundColor:[NSColor clearColor]];
	[self setIgnoresMouseEvents:NO];
	}
	return self;
	}

	- (void)makeKeyAndOrderFront:(id)sender {
	[sheetController_ systemRequestsVisibilityForWindow:self];
	}

	@end

	@implementation GTMWindowSheetController

	- (id)initWithWindow:(NSWindow*)window
	delegate:(id <GTMWindowSheetControllerDelegate>)delegate {
	self = [super init];
	if (self != nil) {
	window_ = window;
	delegate_ = delegate;
	sheets_ = [[NSMutableDictionary alloc] init];
	}
	return self;
	}

	- (void)finalize {
	_GTMDevAssert([sheets_ count] == 0,
	@"Finalizing a controller with sheets still active!");
	[[NSNotificationCenter defaultCenter] removeObserver:self];

	[super finalize];
	}

	- (void)dealloc {
	_GTMDevAssert([sheets_ count] == 0,
	@"Deallocing a controller with sheets still active!");
	[[NSNotificationCenter defaultCenter] removeObserver:self];

	[sheets_ release];

	[super dealloc];
	}

	- (void)beginSheet:(NSWindow*)sheet
	modalForView:(NSView*)view
	modalDelegate:(id)modalDelegate
	didEndSelector:(SEL)didEndSelector
	contextInfo:(void*)contextInfo {
	NSArray* params =
	[NSArray arrayWithObjects:sheet,
	[NSNull null],
	modalDelegate,
	[NSValue valueWithPointer:didEndSelector],
	[NSValue valueWithPointer:contextInfo],
	nil];
	[self beginSystemSheet:[NSApplication sharedApplication]
	modalForView:view
	withParameters:params];
	}

	- (void)beginSystemSheet:(id)systemSheet
	modalForView:(NSView*)view
	withParameters:(NSArray*)params {
	const struct GTMWSCSystemSheetInfo* info = [self infoForSheet:systemSheet];
	if (info) {
	[self beginSystemSheet:systemSheet
	withInfo:info
	modalForView:view
	withParameters:params];
	} // else already logged
	}


	- (BOOL)isSheetAttachedToView:(NSView*)view {
	NSValue* viewValue = [NSValue valueWithNonretainedObject:view];
	return [sheets_ objectForKey:viewValue] != nil;
	}

	- (NSArray*)viewsWithAttachedSheets {
	NSMutableArray* views = [NSMutableArray array];
	NSValue* key;
	GTM_FOREACH_KEY(key, sheets_) {
	[views addObject:[key nonretainedObjectValue]];
	}

	return views;
	}

	- (void)setActiveView:(NSView*)view {
	// Hide old sheet

	NSValue* oldViewValue = [NSValue valueWithNonretainedObject:activeView_];
	GTMWSCSheetInfo* oldSheetInfo = [sheets_ objectForKey:oldViewValue];
	if (oldSheetInfo) {
	NSWindow* overlayWindow = oldSheetInfo->overlayWindow_;
	_GTMDevAssert(overlayWindow, @"Old sheet info has no overlay window");
	NSWindow* sheetWindow = [overlayWindow attachedSheet];
	_GTMDevAssert(sheetWindow, @"Old sheet info has no active sheet");

	// Why do we hide things this way?
	// - Keeping it local but alpha 0 means we get good Expose behavior
	// - Resizing it to 0 means we get no blurring effect left over

	oldSheetInfo->sheetAlpha_ = [sheetWindow alphaValue];
	[sheetWindow setAlphaValue:(CGFloat)0.0];

	oldSheetInfo->sheetAutoresizesSubviews_ =
	[[sheetWindow contentView] autoresizesSubviews];
	[[sheetWindow contentView] setAutoresizesSubviews:NO];

	NSRect overlayFrame = [overlayWindow frame];
	oldSheetInfo->sheetFrame_ = [sheetWindow frame];
	oldSheetInfo->sheetFrame_.origin.x -= overlayFrame.origin.x;
	oldSheetInfo->sheetFrame_.origin.y -= overlayFrame.origin.y;
	[sheetWindow setFrame:NSZeroRect display:NO];

	[overlayWindow setIgnoresMouseEvents:YES];

	// Make sure the now invisible sheet doesn't keep keyboard focus
	[[overlayWindow parentWindow] makeKeyWindow];
	}

	activeView_ = view;

	// Show new sheet

	NSValue* newViewValue = [NSValue valueWithNonretainedObject:view];
	GTMWSCSheetInfo* newSheetInfo = [sheets_ objectForKey:newViewValue];
	if (newSheetInfo) {
	NSWindow* overlayWindow = newSheetInfo->overlayWindow_;
	_GTMDevAssert(overlayWindow, @"New sheet info has no overlay window");
	NSWindow* sheetWindow = [overlayWindow attachedSheet];
	_GTMDevAssert(sheetWindow, @"New sheet info has no active sheet");

	[overlayWindow setIgnoresMouseEvents:NO];

	NSRect overlayFrame = [overlayWindow frame];
	newSheetInfo->sheetFrame_.origin.x += overlayFrame.origin.x;
	newSheetInfo->sheetFrame_.origin.y += overlayFrame.origin.y;
	[sheetWindow setFrame:newSheetInfo->sheetFrame_ display:NO];

	[[sheetWindow contentView]
	setAutoresizesSubviews:newSheetInfo->sheetAutoresizesSubviews_];

	[sheetWindow setAlphaValue:newSheetInfo->sheetAlpha_];

	[self viewDidChangeSize:view];

	[overlayWindow makeKeyWindow];
	}
	}

	@end

	@implementation GTMWindowSheetController (PrivateMethods)

	- (void)beginSystemSheet:(id)systemSheet
	withInfo:(const struct GTMWSCSystemSheetInfo*)info
	modalForView:(NSView*)view
	withParameters:(NSArray*)params {
	_GTMDevAssert([view window] == window_,
	@"Cannot show a sheet for a window for which we are not "
	@"managing sheets");
	_GTMDevAssert(![self isSheetAttachedToView:view],
	@"Cannot show another sheet for a view while already managing "
	@"one");
	_GTMDevAssert(info, @"Missing info for the type of sheet");

	GTMWSCSheetInfo* sheetInfo = [[[GTMWSCSheetInfo alloc] init] autorelease];

	sheetInfo->modalDelegate_ = [params objectAtIndex:info->modalDelegateIndex_];
	sheetInfo->didEndSelector_ =
	[[params objectAtIndex:info->didEndSelectorIndex_] pointerValue];
	sheetInfo->contextInfo_ =
	[[params objectAtIndex:info->contextInfoIndex_] pointerValue];

	_GTMDevAssert([sheetInfo->modalDelegate_
	respondsToSelector:sheetInfo->didEndSelector_],
	@"Delegate does not respond to the specified selector");

	[view setPostsFrameChangedNotifications:YES];
	[[NSNotificationCenter defaultCenter]
	addObserver:self
	selector:@selector(notificationHappened:)
	name:NSViewFrameDidChangeNotification
	object:view];

	sheetInfo->overlayWindow_ =
	[[GTMWSCOverlayWindow alloc]
	initWithContentRect:[self screenFrameOfView:view]
	sheetController:self];

	[sheets_ setObject:sheetInfo
	forKey:[NSValue valueWithNonretainedObject:view]];

	[window_ addChildWindow:sheetInfo->overlayWindow_
	ordered:NSWindowAbove];

	SEL methodSelector = NSSelectorFromString((NSString*)info->methodSignature_);
	NSInvocation* invocation =
	[NSInvocation invocationWithMethodSignature:
	[systemSheet methodSignatureForSelector:methodSelector]];
	[invocation setSelector:methodSelector];
	for (NSUInteger i = 0; i < [params count]; ++i) {
	// Remember that args 0 and 1 are the target and selector, thus the \|i+2\|s
	if (i == info->modalForWindowIndex_) {
	[invocation setArgument:&sheetInfo->overlayWindow_ atIndex:i+2];
	} else if (i == info->modalDelegateIndex_) {
	[invocation setArgument:&self atIndex:i+2];
	} else if (i == info->didEndSelectorIndex_) {
	if (info->arg1OfEndSelectorSize_ == 64)
	[invocation setArgument:&@selector(sheetDidEnd:returnCode64:contextInfo:)
	atIndex:i+2];
	else if (info->arg1OfEndSelectorSize_ == 32)
	[invocation setArgument:&@selector(sheetDidEnd:returnCode32:contextInfo:)
	atIndex:i+2];
	else if (info->arg1OfEndSelectorSize_ == 8)
	[invocation setArgument:&@selector(sheetDidEnd:returnCode8:contextInfo:)
	atIndex:i+2];
	} else if (i == info->contextInfoIndex_) {
	[invocation setArgument:&view atIndex:i+2];
	} else {
	id param = [params objectAtIndex:i];
	if ([param isKindOfClass:[NSValue class]]) {
	char buffer[16];
	[param getValue:buffer];
	[invocation setArgument:buffer atIndex:i+2];
	} else {
	[invocation setArgument:&param atIndex:i+2];
	}
	}
	}
	[invocation invokeWithTarget:systemSheet];

	_GTMDevAssert(!activeView_ \|\| activeView_ == view,
	@"You have to call setActiveView:view before "
	"calling beginSheet:modalForView:view");
	activeView_ = view;
	}

	- (const struct GTMWSCSystemSheetInfo*)infoForSheet:(id)systemSheet {
	static const struct GTMWSCSystemSheetInfo kGTMWSCSystemSheetInfoData[] =
	{
	{
	@"ABIdentityPicker",
	@"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 64,
	},
	{
	@"CBIdentityPicker",
	@"runModalForWindow:modalDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 64,
	},
	{
	@"DRSetupPanel",
	@"beginSetupSheetForWindow:modalDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 32,
	},
	{
	@"NSAlert",
	@"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 32,
	},
	{
	@"NSApplication",
	@"beginSheet:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
	1, 2, 3, 4, 64,
	},
	{
	@"IKFilterBrowserPanel",
	@"beginSheetWithOptions:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
	1, 2, 3, 4, 32,
	},
	{
	@"IKPictureTaker",
	@"beginPictureTakerSheetForWindow:withDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 64,
	},
	{
	@"IOBluetoothDeviceSelectorController",
	@"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 32,
	},
	{
	@"IOBluetoothObjectPushUIController",
	@"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 32,
	},
	{
	@"IOBluetoothServiceBrowserController",
	@"beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:",
	0, 1, 2, 3, 32,
	},
	{
	@"NSOpenPanel",
	@"beginSheetForDirectory:file:types:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
	3, 4, 5, 6, 32,
	},
	{
	@"NSPageLayout",
	@"beginSheetWithPrintInfo:modalForWindow:delegate:didEndSelector:contextInfo:",
	1, 2, 3, 4, 32,
	},
	{
	@"NSPrintOperation",
	@"runOperationModalForWindow:delegate:didRunSelector:contextInfo:",
	0, 1, 2, 3, 8,
	},
	{
	@"NSPrintPanel",
	@"beginSheetWithPrintInfo:modalForWindow:delegate:didEndSelector:contextInfo:",
	1, 2, 3, 4, 32,
	},
	{
	@"NSSavePanel",
	@"beginSheetForDirectory:file:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
	2, 3, 4, 5, 32,
	},
	{
	@"SFCertificatePanel",
	@"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:certificates:showGroup:",
	0, 1, 2, 3, 32,
	},
	{
	@"SFCertificateTrustPanel",
	@"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:trust:message:",
	0, 1, 2, 3, 32,
	},
	{
	@"SFChooseIdentityPanel",
	@"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:identities:message:",
	0, 1, 2, 3, 32,
	},
	{
	@"SFKeychainSettingsPanel",
	@"beginSheetForWindow:modalDelegate:didEndSelector:contextInfo:settings:keychain:",
	0, 1, 2, 3, 32,
	},
	{
	@"SFKeychainSavePanel",
	@"beginSheetForDirectory:file:modalForWindow:modalDelegate:didEndSelector:contextInfo:",
	2, 3, 4, 5, 32,
	},
	};

	static const size_t kGTMWSCSystemSheetInfoDataSize =
	sizeof(kGTMWSCSystemSheetInfoData)/sizeof(kGTMWSCSystemSheetInfoData[0]);

	for (size_t i = 0; i < kGTMWSCSystemSheetInfoDataSize; ++i) {
	Class testClass =
	NSClassFromString(kGTMWSCSystemSheetInfoData[i].className_);
	if (testClass && [systemSheet isKindOfClass:testClass]) {
	return &kGTMWSCSystemSheetInfoData[i];
	}
	}

	_GTMDevLog(@"Failed to find info for sheet of type %@", [systemSheet class]);
	return nil;
	}

	- (void)notificationHappened:(NSNotification*)notification {
	NSView *view = GTM_STATIC_CAST(NSView, [notification object]);
	[self viewDidChangeSize:view];
	}

	- (void)viewDidChangeSize:(NSView*)view {
	GTMWSCSheetInfo* sheetInfo =
	[sheets_ objectForKey:[NSValue valueWithNonretainedObject:view]];
	if (!sheetInfo)
	return;

	if (view != activeView_)
	return;

	NSWindow* overlayWindow = sheetInfo->overlayWindow_;
	if (!overlayWindow)
	return;

	[overlayWindow setFrame:[self screenFrameOfView:view] display:YES];
	[[overlayWindow attachedSheet] makeKeyWindow];
	}

	- (NSRect)screenFrameOfView:(NSView*)view {
	NSRect viewFrame = [view convertRect:[view bounds] toView:nil];
	viewFrame.origin = [[view window] convertBaseToScreen:viewFrame.origin];
	return viewFrame;
	}

	- (void)sheetDidEnd:(id)sheet
	returnCode8:(char)returnCode
	contextInfo:(void*)contextInfo {
	[self sheetDidEnd:sheet
	returnCode:returnCode
	contextInfo:contextInfo
	arg1Size:8];
	}

	- (void)sheetDidEnd:(id)sheet
	returnCode32:(int)returnCode
	contextInfo:(void*)contextInfo {
	[self sheetDidEnd:sheet
	returnCode:returnCode
	contextInfo:contextInfo
	arg1Size:32];
	}

	- (void)sheetDidEnd:(id)sheet
	returnCode64:(NSInteger)returnCode
	contextInfo:(void*)contextInfo {
	[self sheetDidEnd:sheet
	returnCode:returnCode
	contextInfo:contextInfo
	arg1Size:64];
	}

	- (void)sheetDidEnd:(id)sheet
	returnCode:(NSInteger)returnCode
	contextInfo:(void*)contextInfo
	arg1Size:(int)size {
	NSValue* viewKey = [NSValue valueWithNonretainedObject:(NSView*)contextInfo];
	// Retain a reference to sheetInfo so we can use it after it is
	// removed from sheets_.
	GTMWSCSheetInfo* sheetInfo =
	[[[sheets_ objectForKey:viewKey] retain] autorelease];
	_GTMDevAssert(sheetInfo, @"Could not find information about the sheet that "
	@"just ended");
	_GTMDevAssert(size == 8 \|\| size == 32 \|\| size == 64,
	@"Incorrect size information in the sheet entry; don't know "
	@"how big the second parameter is");

	// Can't turn off view's frame notifications as we don't know if someone else
	// wants them.
	[[NSNotificationCenter defaultCenter]
	removeObserver:self
	name:NSViewFrameDidChangeNotification
	object:contextInfo];

	// We clean up the sheet before calling the callback so that the
	// callback is free to fire another sheet if it so desires.
	[window_ removeChildWindow:sheetInfo->overlayWindow_];
	[sheetInfo->overlayWindow_ release];
	[sheets_ removeObjectForKey:viewKey];

	NSInvocation* invocation =
	[NSInvocation invocationWithMethodSignature:
	[sheetInfo->modalDelegate_
	methodSignatureForSelector:sheetInfo->didEndSelector_]];
	[invocation setSelector:sheetInfo->didEndSelector_];
	// Remember that args 0 and 1 are the target and selector
	[invocation setArgument:&sheet atIndex:2];
	if (size == 64) {
	[invocation setArgument:&returnCode atIndex:3];
	} else if (size == 32) {
	int shortReturnCode = (int)returnCode;
	[invocation setArgument:&shortReturnCode atIndex:3];
	} else if (size == 8) {
	char charReturnCode = returnCode;
	[invocation setArgument:&charReturnCode atIndex:3];
	}
	[invocation setArgument:&sheetInfo->contextInfo_ atIndex:4];
	[invocation invokeWithTarget:sheetInfo->modalDelegate_];
	}

	- (void)systemRequestsVisibilityForWindow:(NSWindow*)window {
	NSValue* key;
	GTM_FOREACH_KEY(key, sheets_) {
	GTMWSCSheetInfo* sheetInfo = [sheets_ objectForKey:key];
	if (sheetInfo->overlayWindow_ == window) {
	NSView* view = [key nonretainedObjectValue];
	[delegate_ gtm_systemRequestsVisibilityForView:view];
	}
	}
	}

	- (NSRect)window:(NSWindow*)window
	willPositionSheet:(NSWindow*)sheet
	usingRect:(NSRect)defaultSheetRect {
	// Ensure that the sheets come out of the very top of the overlay windows.
	NSRect windowFrame = [window frame];
	defaultSheetRect.origin.y = windowFrame.size.height;
	return defaultSheetRect;
	}

	@end