Frameworks/AIUtilities Framework/Source/AIImageViewWithImagePicker.m

   1 //
   2 //  AIImageViewWithImagePicker.m
   3 //  Adium
   4 //
   5 //  Created by Evan Schoenberg on Sun Jun 06 2004.
   6 //  Copyright (c) 2004-2005 The Adium Team. All rights reserved.
   7 //
   8
   9 #import "AITigerCompatibility.h"
  10
  11 #import "AIImageViewWithImagePicker.h"
  12 #import <Quartz/Quartz.h>
  13
  14 #import "AIImageAdditions.h"
  15 #import "AIFileManagerAdditions.h"
  16 #import "AIApplicationAdditions.h"
  17 #import "AIStringUtilities.h"
  18 #import "IKPictureTakerForTiger.h"
  19
  20 #define DRAGGING_THRESHOLD 16.0
  21
  22 @interface AIImageViewWithImagePicker (PRIVATE)
  23 - (void)_initImageViewWithImagePicker;
  24 - (void)showPictureTaker;
  25 - (void)copy:(id)sender;
  26 - (void)paste:(id)sender;
  27 - (void)delete;
  28 @end
  29
  30
  31 #define IKPictureTakerClass ([NSApp isOnLeopardOrBetter] ? NSClassFromString(@"IKPictureTaker") : NSClassFromString(@"IKPictureTakerForTiger"))
  32
  33 /*
  34  * @class AIImageViewWithImagePicker
  35  *
  36  * @brief Image view which displays and uses the Image Picker used by Apple Address Book and iChat when activated and also allows other image-setting behaviors.
  37  *
  38  * The following is supported
  39  *              - Address book-style image picker on double-click or enter, with delegate notification
  40  *              - Or, alternately, an Open Panel on double-click or enter, with delegate notification
  41  *              - Copying and pasting, with delegate notification
  42  *              - Drag and drop into and out of the image well, with delegate notification,
  43  *                      with support for animated GIFs and transparency
  44  *              - Notifcation to the delegate of user's attempt to delete the image
  45  *
  46  * Note: AIImageViewWithImagePicker requires Panther or better for the Address Book-style
  47  * image picker to work.
  48  */
  49 @implementation AIImageViewWithImagePicker
  50
  51 // Init ------------------------------------------------------------------------------------------
  52 #pragma mark Init
  53 /*
  54  * @brief Initialize with coder
  55  */
  56 - (id)initWithCoder:(NSCoder *)aDecoder
  57 {
  58     if ((self = [super initWithCoder:aDecoder])) {
  59                 [self _initImageViewWithImagePicker];
  60         }
  61     return self;
  62 }
  63
  64 /*
  65  * @brief Initialize with frame
  66  */
  67 - (id)initWithFrame:(NSRect)frameRect
  68 {
  69         if ((self = [super initWithFrame:frameRect])) {
  70                 [self _initImageViewWithImagePicker];
  71         }
  72         return self;
  73 }
  74
  75 /*
  76  * @brief Private initialization method
  77  */
  78 - (void)_initImageViewWithImagePicker
  79 {
  80         pictureTaker = nil;
  81         title = nil;
  82         delegate = nil;
  83
  84         lastResp = nil;
  85         shouldDrawFocusRing = NO;
  86
  87         mouseDownPos = NSZeroPoint;
  88         maxSize = NSZeroSize;
  89
  90         usePictureTaker = YES;
  91 }
  92
  93 /*
  94  * @brief Deallocate
  95  */
  96 - (void)dealloc
  97 {
  98         if (pictureTaker) {
  99                 [pictureTaker close];
 100                 [pictureTaker release]; pictureTaker = nil;
 101         }
 102
 103         delegate = nil;
 104         [title release];
 105
 106         [super dealloc];
 107 }
 108
 109 // Getters and Setters ----------------------------------------------------------------
 110 #pragma mark Getters and Setters
 111 /*!
 112  * @brief Set the delegate
 113  *
 114  * Set the delegate.  See <tt>AIImageViewWithImagePickerDelegate</tt> protocol discussion for details.
 115  * @param inDelegate The delegate, which may implement any of the methods described in <tt>AIImageViewWithImagePickerDelegate</tt>.
 116  */
 117 - (void)setDelegate:(id)inDelegate
 118 {
 119         delegate = inDelegate;
 120 }
 121
 122 /*!
 123  * @brief Return the delegate
 124  *
 125  * @return The delegate
 126  */
 127 - (id)delegate
 128 {
 129         return delegate;
 130 }
 131
 132 /*!
 133  * @brief Set the image
 134  *
 135  * We may get here progrmatically, from a user drag-and-drop or paste, etc.
 136  */
 137 - (void)setImage:(NSImage *)inImage
 138 {
 139         [super setImage:inImage];
 140
 141         //Inform the picker controller of a changed selection if it is open, for live updating
 142         if (pictureTaker) {
 143                 [pictureTaker setInputImage:inImage];
 144         }
 145 }
 146
 147 /*!
 148  * @brief Set the title of the Image Picker
 149  *
 150  * Set the title of the Image Picker window which will be displayed if the user activates it (see class discussion).
 151  * @param inTitle An <tt>NSString</tt> of the title
 152  */
 153 - (void)setTitle:(NSString *)inTitle
 154 {
 155         if (title != inTitle) {
 156                 [title release]; title = [inTitle retain];
 157                 if (pictureTaker) {
 158                         [pictureTaker setTitle:title];
 159                 }
 160         }
 161 }
 162
 163 /*
 164  * @brief The title of the image picker
 165  */
 166 - (NSString *)title
 167 {
 168         return (title ? title : AILocalizedStringFromTableInBundle(@"Image Picker", nil, [NSBundle bundleWithIdentifier:AIUTILITIES_BUNDLE_ID], nil));
 169 }
 170
 171 /*!
 172  * @brief Should the image view use the address book Image Picker?
 173  *
 174  * If NO, a standard Open panel is used instead.
 175  */
 176 - (void)setUsePictureTaker:(BOOL)inUsePictureTaker
 177 {
 178         usePictureTaker = inUsePictureTaker;
 179 }
 180
 181 - (void)setPresentPictureTakerAsSheet:(BOOL)inPresentPictureTakerAsSheet
 182 {
 183         presentPictureTakerAsSheet  = inPresentPictureTakerAsSheet;
 184 }
 185
 186 - (BOOL)presentPictureTakerAsSheet
 187 {
 188         return presentPictureTakerAsSheet;
 189 }
 190
 191 - (void)setMaxSize:(NSSize)inMaxSize
 192 {
 193         maxSize = inMaxSize;
 194 }
 195
 196 - (NSSize)maxSize
 197 {
 198         return maxSize;
 199 }
 200
 201 // Monitoring user interaction --------------------------------------------------------
 202 #pragma mark Monitoring user interaction
 203
 204 /*
 205  * @brief Mouse down
 206  *
 207  * Intercept mouse down events so we can begin a drag out of the image view if appropriate
 208  */
 209 - (void)mouseDown:(NSEvent *)theEvent
 210 {
 211         if ([self isEnabled]) {
 212                 NSEvent *nextEvent;
 213
 214                 //Wait for the next event
 215                 nextEvent = [[self window] nextEventMatchingMask:(NSLeftMouseUpMask | NSLeftMouseDraggedMask | NSPeriodicMask)
 216                                                                                            untilDate:[NSDate distantFuture]
 217                                                                                                   inMode:NSEventTrackingRunLoopMode
 218                                                                                                  dequeue:NO];
 219
 220                 mouseDownPos = [self convertPoint:[theEvent locationInWindow] fromView:nil];
 221
 222                 /* If the user starts dragging, don't call mouse down as we won't receive mouse dragged events, as it seems that
 223                         * NSImageView does some sort of event loop modification in response to a click. We didn't dequeue the event, so
 224                         * we don't have to handle it ourselves -- instead, the event loop will handle it after this invocation is complete.
 225                         */
 226                 if ([nextEvent type] != NSLeftMouseDragged) {
 227                         [super mouseDown:theEvent];
 228                 }
 229
 230                 if ([theEvent clickCount] == 2) {
 231                         [self showPictureTaker];
 232                 }
 233
 234         } else {
 235                 [super mouseDown:theEvent];
 236         }
 237 }
 238
 239 /*
 240  * @brief Key down
 241  *
 242  * Intercept key down events to delete the image on delete/backspace or to show the image picker on enter/return
 243  */
 244 - (void)keyDown:(NSEvent *)theEvent
 245 {
 246         NSString *characters = [theEvent charactersIgnoringModifiers];
 247         unichar key = ([characters length] ? [characters characterAtIndex:0] : 0);
 248
 249         if ((key == NSBackspaceCharacter) || (key == NSDeleteCharacter) || (key == NSDeleteFunctionKey) || (key == NSDeleteCharFunctionKey)) {
 250                 [self delete];
 251         } else if (key == NSEnterCharacter || key == NSCarriageReturnCharacter) {
 252                 [self showPictureTaker];
 253         } else {
 254                 [super keyDown:theEvent];
 255         }
 256 }
 257
 258 /*
 259  * @brief Mouse dragged
 260  *
 261  * Begin an image drag as appropriate
 262  */
 263 - (void)mouseDragged:(NSEvent *)theEvent
 264 {
 265         if (![self image]) return;
 266
 267         // Work out if the mouse has been dragged far enough - it stops accidental drags
 268         NSPoint mousePos = [self convertPoint:[theEvent locationInWindow] fromView:nil];
 269         float dx = mousePos.x-mouseDownPos.x;
 270         float dy = mousePos.y-mouseDownPos.y;
 271         if ((dx*dx) + (dy*dy) < DRAGGING_THRESHOLD) {
 272                 return;
 273         }
 274
 275         //Start the drag
 276         [self dragPromisedFilesOfTypes:[NSArray arrayWithObject:@"png"]
 277                                                   fromRect:NSZeroRect
 278                                                         source:self
 279                                                  slideBack:YES
 280                                                          event:theEvent];
 281 }
 282
 283 - (void)dragImage:(NSImage *)anImage at:(NSPoint)imageLoc offset:(NSSize)mouseOffset event:(NSEvent *)theEvent pasteboard:(NSPasteboard *)pboard source:(id)sourceObject slideBack:(BOOL)slideBack
 284 {
 285         [pboard addTypes:[NSArray arrayWithObjects:NSTIFFPboardType,NSPDFPboardType,nil] owner:self];
 286
 287         NSImage *dragImage = [[NSImage alloc] initWithSize:[[self image] size]];
 288
 289         //Draw our original image as 50% transparent
 290         [dragImage lockFocus];
 291         [[self image] dissolveToPoint:NSZeroPoint fraction:0.5];
 292         [dragImage unlockFocus];
 293
 294         //We want the image to resize
 295         [dragImage setScalesWhenResized:YES];
 296         //Change to the size we are displaying
 297         [dragImage setSize:[self bounds].size];
 298
 299         [super dragImage:dragImage
 300                                   at:imageLoc
 301                           offset:mouseOffset
 302                            event:theEvent
 303                   pasteboard:pboard
 304                           source:sourceObject
 305                    slideBack:slideBack];
 306         [dragImage release];
 307 }
 308
 309 /*
 310  * @brief Declare what operations we can participate in as a drag and drop source
 311  */
 312 - (unsigned int)draggingSourceOperationMaskForLocal:(BOOL)flag
 313 {
 314         return NSDragOperationCopy;
 315 }
 316
 317 /*
 318  * @brief Method called to support drag types we said we could offer
 319  */
 320 - (void)pasteboard:(NSPasteboard *)sender provideDataForType:(NSString *)type
 321 {
 322     //sender has accepted the drag and now we need to send the data for the type we promised
 323     if ([type isEqualToString:NSTIFFPboardType]) {
 324                 //set data for TIFF type on the pasteboard as requested
 325                 [sender setData:[[self image] TIFFRepresentation]
 326                                 forType:NSTIFFPboardType];
 327
 328     } else if ([type isEqualToString:NSPDFPboardType]) {
 329                 [sender setData:[self dataWithPDFInsideRect:[self bounds]]
 330                                 forType:NSPDFPboardType];
 331     }
 332 }
 333
 334 /*
 335  * @brief Dragging entered
 336  */
 337 - (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender
 338 {
 339         if ([sender draggingSource] == self) {
 340                 return NSDragOperationNone;
 341         } else {
 342                 return [super draggingEntered:sender];
 343         }
 344 }
 345
 346 /*
 347  * @brief Dragging updated
 348  */
 349 - (NSDragOperation)draggingUpdated:(id <NSDraggingInfo>)sender
 350 {
 351         if ([sender draggingSource] == self) {
 352                 return NSDragOperationNone;
 353         } else {
 354                 return [super draggingUpdated:sender];
 355         }
 356 }
 357
 358 - (NSArray *)namesOfPromisedFilesDroppedAtDestination:(NSURL *)inDropDestination
 359 {
 360         NSString *name = nil;
 361         if ([[self delegate] respondsToSelector:@selector(fileNameForImageInImagePicker:)]) {
 362                 name = [[self delegate] fileNameForImageInImagePicker:self];
 363                 if (![name length]) name = nil;
 364         }
 365
 366         if (!name)
 367                 name = NSLocalizedString(@"Picture", nil);
 368
 369         name = [name stringByAppendingPathExtension:@"png"];
 370
 371         NSString *fullPath = [[inDropDestination path] stringByAppendingPathComponent:name];
 372         fullPath = [[NSFileManager defaultManager] uniquePathForPath:fullPath];
 373
 374         [[[self image] PNGRepresentation] writeToFile:fullPath
 375                                                                            atomically:YES];
 376
 377         return [NSArray arrayWithObject:[fullPath lastPathComponent]];
 378 }
 379
 380 /*
 381  * @brief Conclude a drag operation
 382  *
 383  * A new image was dragged into our view.  -[super concludeDragOperation:] will change [self image] to match it.
 384  * We then want to update our pictureTaker's selection if it is open.
 385  * Also, if we're dropped a promised file, use its data directly as it may be better than what NSImageView's natural
 386  * loading retrieves... this way we can get transparency or animation data, for example.
 387  */
 388 - (void)concludeDragOperation:(id <NSDraggingInfo>)sender
 389 {
 390         BOOL    notified = NO, resized = NO;
 391         NSImage *droppedImage;
 392         NSSize  droppedImageSize;
 393
 394         [super concludeDragOperation:sender];
 395
 396         droppedImage = [self image];
 397         droppedImageSize = [droppedImage size];
 398
 399         if ((maxSize.width > 0 && droppedImageSize.width > maxSize.width) ||
 400                 (maxSize.height > 0 && droppedImageSize.height > maxSize.height)) {
 401                 droppedImage = [droppedImage imageByScalingToSize:maxSize];
 402                 //This will notify the picker controller that the selection changed, as well
 403                 [self setImage:droppedImage];
 404                 resized = YES;
 405
 406         } else if (pictureTaker) {
 407                 [pictureTaker setInputImage:droppedImage];
 408         }
 409
 410         //Use the file's data if possible and the image wasn't too big
 411         if (!resized && [delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)]) {
 412                 NSPasteboard    *pboard = [sender draggingPasteboard];
 413
 414                 if ([[pboard types] containsObject:NSFilenamesPboardType]) {
 415                         NSArray *files = [pboard propertyListForType:NSFilenamesPboardType];
 416
 417                         if ([files count]) {
 418                                 NSString        *imageFile = [files objectAtIndex:0];
 419                                 NSData          *imageData = [NSData dataWithContentsOfFile:imageFile];
 420
 421                                 if (imageData) {
 422                                         [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)
 423                                                                    withObject:self
 424                                                                    withObject:[NSData dataWithContentsOfFile:imageFile]];
 425
 426                                         notified = YES;
 427                                 }
 428                         }
 429                 }
 430         }
 431
 432         //Inform the delegate if we haven't informed it yet
 433         if (!notified) {
 434                 if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)]) {
 435                         [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)
 436                                                    withObject:self
 437                                                    withObject:[droppedImage PNGRepresentation]];
 438
 439                 } else if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImage:)]) {
 440                         [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImage:)
 441                                                    withObject:self
 442                                                    withObject:droppedImage];
 443                 }
 444         }
 445 }
 446
 447 // Copy / Paste ----------------------------------------------------------------
 448 #pragma mark Copy / Paste
 449 /*
 450  * @brief Copy
 451  */
 452 - (void)copy:(id)sender
 453 {
 454         NSImage *image = [self image];
 455         if (image) {
 456                 [[NSPasteboard generalPasteboard] declareTypes:[NSArray arrayWithObject:NSTIFFPboardType] owner:nil];
 457                 [[NSPasteboard generalPasteboard] setData:[image TIFFRepresentation] forType:NSTIFFPboardType];
 458         }
 459 }
 460
 461 /*
 462  * @brief Paste
 463  */
 464 - (void)paste:(id)sender
 465 {
 466         NSPasteboard    *pb = [NSPasteboard generalPasteboard];
 467         NSString                *type = [pb availableTypeFromArray:
 468                 [NSArray arrayWithObjects:NSTIFFPboardType, NSPDFPboardType, NSPICTPboardType,nil]];
 469         BOOL                    success = NO;
 470
 471     NSData                      *imageData = (type ? [pb dataForType:type] : nil);
 472         if (imageData) {
 473                 NSImage *image = [[[NSImage alloc] initWithData:imageData] autorelease];
 474                 if (image) {
 475                         NSSize  imageSize = [image size];
 476
 477                         if ((maxSize.width > 0 && imageSize.width > maxSize.width) ||
 478                                 (maxSize.height > 0 && imageSize.height > maxSize.height)) {
 479                                 image = [image imageByScalingToSize:maxSize];
 480                                 imageData = [image PNGRepresentation];
 481                         }
 482
 483                         [self setImage:image];
 484
 485                         if (pictureTaker) {
 486                                 [pictureTaker setInputImage:image];
 487                         }
 488
 489                         //Inform the delegate
 490                         if (delegate) {
 491                                 if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)]) {
 492                                         [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)
 493                                                                    withObject:self
 494                                                                    withObject:imageData];
 495                                 } else if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImage:)]) {
 496                                         [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImage:)
 497                                                                    withObject:self
 498                                                                    withObject:image];
 499                                 }
 500                         }
 501
 502                         success = YES;
 503                 }
 504         }
 505
 506         if (!success) NSBeep();
 507 }
 508
 509 /*
 510  * @brief Cut
 511  *
 512  * Cut = copy + delete
 513  */
 514 - (void)cut:(id)sender
 515 {
 516         [self copy:sender];
 517         [self delete];
 518 }
 519
 520 /*
 521  * @brief Delete
 522  */
 523 - (void)delete
 524 {
 525         if (delegate && [delegate respondsToSelector:@selector(deleteInImageViewWithImagePicker:)]) {
 526                 [delegate performSelector:@selector(deleteInImageViewWithImagePicker:)
 527                                            withObject:self];
 528         }
 529 }
 530
 531 // NSImagePicker Access and Delegate ----------------------------------------------------------------
 532 #pragma mark NSImagePicker Access and Delegate
 533 /*!
 534  * @brief Action to call -[self showPictureTaker]
 535  */
 536 - (IBAction)showImagePicker:(id)sender
 537 {
 538         [self showPictureTaker];
 539 }
 540
 541 - (void)pictureTakerDidEnd:(id)inPictureTaker returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo
 542 {
 543         if (returnCode == NSOKButton) {
 544                 NSImage *image = [inPictureTaker outputImage];
 545
 546                 //Update the NSImageView
 547                 [self setImage:image];
 548
 549                 //Inform the delegate, but only if NOT using NSOpenPanel
 550                 if (delegate && usePictureTaker) {
 551                         if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)]) {
 552                                 [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)
 553                                                            withObject:self
 554                                                            withObject:[image PNGRepresentation]];
 555
 556                         } else if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImage:)]) {
 557                                 [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImage:)
 558                                                            withObject:self
 559                                                            withObject:image];
 560                         }
 561                 }
 562         }
 563 }
 564
 565 /*
 566  * @brief Show the image picker controller
 567  */
 568 - (void)showPictureTaker
 569 {
 570         if (usePictureTaker) {
 571                 if (!pictureTaker) {
 572                         pictureTaker = [[IKPictureTakerClass pictureTaker] retain];
 573                         [pictureTaker setDelegate:self];
 574                         [pictureTaker setTitle:title];
 575                 }
 576
 577                 NSImage *theImage = nil;
 578
 579                 //Give the delegate an opportunity to supply an image which differs from the NSImageView's image
 580                 if (delegate && [delegate respondsToSelector:@selector(imageForImageViewWithImagePicker:)]) {
 581                         theImage = [delegate imageForImageViewWithImagePicker:self];
 582                 }
 583
 584                 [pictureTaker setInputImage:(theImage ? theImage : [self image])];
 585                 [pictureTaker setValue:[NSValue valueWithSize:[self maxSize]]
 586                                                 forKey:IKPictureTakerOutputImageMaxSizeKey];
 587
 588                 if ([self presentPictureTakerAsSheet]) {
 589                         [pictureTaker beginPictureTakerSheetForWindow:[self window]
 590                                                                                          withDelegate:self
 591                                                                                    didEndSelector:@selector(pictureTakerDidEnd:returnCode:contextInfo:)
 592                                                                                           contextInfo:nil];
 593                 } else {
 594                         [pictureTaker beginPictureTakerWithDelegate:self
 595                                                                                  didEndSelector:@selector(pictureTakerDidEnd:returnCode:contextInfo:)
 596                                                                                         contextInfo:nil];
 597                 }
 598
 599         } else {
 600                 /* If we aren't using or can't use the image picker, use an open panel  */
 601                 NSOpenPanel *openPanel;
 602
 603                 openPanel = [NSOpenPanel openPanel];
 604                 [openPanel setTitle:[NSString stringWithFormat:AILocalizedStringFromTableInBundle(@"Select Image", nil, [NSBundle bundleWithIdentifier:AIUTILITIES_BUNDLE_ID], nil)]];
 605
 606                 if ([openPanel runModalForDirectory:nil file:nil types:[NSImage imageFileTypes]] == NSOKButton) {
 607                         NSData  *imageData;
 608                         NSImage *image;
 609                         NSSize  imageSize;
 610
 611                         imageData = [NSData dataWithContentsOfFile:[openPanel filename]];
 612                         image = (imageData ? [[[NSImage alloc] initWithData:imageData] autorelease] : nil);
 613                         imageSize = (image ? [image size] : NSZeroSize);
 614
 615                         if ((maxSize.width > 0 && imageSize.width > maxSize.width) ||
 616                                 (maxSize.height > 0 && imageSize.height > maxSize.height)) {
 617                                 image = [image imageByScalingToSize:maxSize];
 618                                 imageData = [image PNGRepresentation];
 619                         }
 620
 621                         //Update the image view
 622                         [self setImage:image];
 623
 624                         //Inform the delegate
 625                         if (delegate) {
 626                                 if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)]) {
 627                                         [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImageData:)
 628                                                                    withObject:self
 629                                                                    withObject:imageData];
 630
 631                                 } else if ([delegate respondsToSelector:@selector(imageViewWithImagePicker:didChangeToImage:)]) {
 632                                         [delegate performSelector:@selector(imageViewWithImagePicker:didChangeToImage:)
 633                                                                    withObject:self
 634                                                                    withObject:image];
 635                                 }
 636                         }
 637                 }
 638         }
 639 }
 640
 641 // Drawing ------------------------------------------------------------------------
 642 #pragma mark Drawing
 643 /*
 644  * @brief Note when the focus ring needs to be displayed
 645  *
 646  * Focus ring drawing code by Nicholas Riley, posted unlicensed as public domain on cocoadev and available at:
 647  * http://cocoa.mamasam.com/COCOADEV/2002/03/2/29535.php
 648  */
 649 - (BOOL)needsDisplay
 650 {
 651         NSResponder *resp = nil;
 652         NSWindow        *window = [self window];
 653
 654         if ([window isKeyWindow]) {
 655                 resp = [window firstResponder];
 656                 if (resp == lastResp) {
 657                         return [super needsDisplay];
 658                 }
 659
 660         } else if (lastResp == nil) {
 661                 return [super needsDisplay];
 662
 663         }
 664
 665         shouldDrawFocusRing = (resp != nil &&
 666                                                    [resp isKindOfClass:[NSView class]] &&
 667                                                    [(NSView *)resp isDescendantOf:self]); // [sic]
 668         lastResp = resp;
 669
 670         [self setKeyboardFocusRingNeedsDisplayInRect:[self bounds]];
 671         return YES;
 672 }
 673
 674 /*
 675  * @brief Draw the focus ring around our view if necessary
 676  */
 677 - (void)drawRect:(NSRect)rect
 678 {
 679         [super drawRect:rect];
 680
 681         if (shouldDrawFocusRing) {
 682                 NSSetFocusRingStyle(NSFocusRingOnly);
 683                 NSRectFill(rect);
 684         }
 685 }
 686
 687 @end