summaryrefslogtreecommitdiffstats
path: root/macosx/tkMacOSXScrlbr.c
blob: 38115ee6fc5300a164e6d97b9cb12ab5858023c5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
/*
 * tkMacOSXScrollbar.c --
 *
 *	This file implements the Macintosh specific portion of the scrollbar
 *	widget.
 *
 * Copyright (c) 1996 by Sun Microsystems, Inc.
 * Copyright 2001-2009, Apple Inc.
 * Copyright (c) 2006-2009 Daniel A. Steffen <das@users.sourceforge.net>
*  Copyright (c) 2014 Marc Culler.
 * Copyright (c) 2014 Kevin Walzer/WordTech Commununications LLC.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tkMacOSXPrivate.h"
#include "tkScrollbar.h"

/*
#ifdef TK_MAC_DEBUG
#define TK_MAC_DEBUG_SCROLLBAR
#endif
*/
 
NSRect                  TkMacOSXGetScrollFrame(TkScrollbar *scrlPtr);

/*
 * A subclass of NSScroller with sanity checking:
 *
 * NSScrollers created by Tk will have their tag set to a pointer to the
 * TkScrollbar which manages the NSScroller.  This allows an NSScroller to be
 * aware of the state of its Tk parent.  This subclass overrides the drawRect
 * method so that it will not draw itself if the widget is completely outside
 * of its container.
 *
 * Custom drawing of the knob seems to work around the flickering visible after  
 * private API's were removed. Based on technique outlined at 
 * http://stackoverflow.com/questions/1604682/nsscroller-
 * graphical-glitches-lag. Only supported on 10.7 and above.
 */
 

@interface TkNSScroller: NSScroller
-(void) drawRect:(NSRect)dirtyRect;
#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
-(BOOL) isHorizontal;
-(void) drawKnob;
- (void)drawArrow:(NSScrollerArrow)arrow highlightPart:(int)flag;
- (void)drawKnobSlotInRect:(NSRect)rect highlight:(BOOL)highlight;
#endif
@end

@implementation TkNSScroller


- (void)drawRect:(NSRect)dirtyRect
{
    NSInteger tag = [self tag];
    if ( tag != -1) {
	TkScrollbar *scrollPtr = (TkScrollbar *)tag;
	MacDrawable* macWin = (MacDrawable *)scrollPtr;
	Tk_Window tkwin = scrollPtr->tkwin;
	NSRect Tkframe = TkMacOSXGetScrollFrame(scrollPtr);
	/* Do not draw if the widget is misplaced or unmapped. */
	if ( NSIsEmptyRect(Tkframe) ||
	     ! macWin->winPtr->flags & TK_MAPPED ||
	     ! NSEqualRects(Tkframe, [self frame])
	     ) {
	    return;
	}

	/*
	 * Do not draw if the widget is completely outside of its parent.
	 */
	if (tkwin) {
	    int parent_height = Tk_Height(Tk_Parent(tkwin));
	    int widget_height = Tk_Height(tkwin);
	    int y = Tk_Y(tkwin);
	    if ( y > parent_height || y + widget_height < 0 ) {
		return;
	    }

	    int parent_width = Tk_Width(Tk_Parent(tkwin));
	    int widget_width = Tk_Width(tkwin);
	    int x = Tk_X(tkwin);
	    if (x > parent_width || x + widget_width < 0) {
		return;
	    }
	}
    }
    [super drawRect:dirtyRect];
}

#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
- (BOOL)isVertical {
    NSRect bounds = [self bounds];
    return NSWidth(bounds) < NSHeight (bounds);
}


- (void)drawKnob
{
    NSRect knobRect = [self rectForPart:NSScrollerKnob];
    
    if ([self isVertical]) {
	NSRect newRect = NSMakeRect(knobRect.origin.x + 3, knobRect.origin.y, knobRect.size.width - 6, knobRect.size.height);
    NSBezierPath  *scrollerPath = [NSBezierPath bezierPathWithRoundedRect:newRect xRadius:4 yRadius:4];
 
    [[NSColor lightGrayColor] set];
	[scrollerPath fill];
    } else {
	NSRect newRect = NSMakeRect(knobRect.origin.x, knobRect.origin.y + 3, knobRect.size.width, knobRect.size.height - 6);
	NSBezierPath  *scrollerPath = [NSBezierPath bezierPathWithRoundedRect:newRect xRadius:4 yRadius:4];
 
        [[NSColor lightGrayColor] set];
	[scrollerPath fill];
    }
       
}

- (void)drawArrow:(NSScrollerArrow)arrow highlightPart:(int)flag
{
    // We don't want arrows
}

- (void)drawKnobSlotInRect:(NSRect)rect highlight:(BOOL)highlight
{
  
}

#endif

@end



/*
 * Declaration of Mac specific scrollbar structure.
 */

typedef struct MacScrollbar {
    TkScrollbar info;
    TkNSScroller	*scroller;
    int variant;
} MacScrollbar;

typedef struct ScrollbarMetrics {
    SInt32 width, minThumbHeight;
    int minHeight, topArrowHeight, bottomArrowHeight;
    NSControlSize controlSize;
} ScrollbarMetrics;

static ScrollbarMetrics metrics[2] = {
    {15, 54, 26, 14, 14, NSRegularControlSize}, /* kThemeScrollBarMedium */
    {11, 40, 20, 10, 10, NSSmallControlSize},  /* kThemeScrollBarSmall  */
};

/*
 * Declarations for functions defined in this file.
 */

static void		UpdateScrollbarMetrics(void);
static void		ScrollbarEventProc(ClientData clientData,
			    XEvent *eventPtr);


/*
 * The class procedure table for the scrollbar widget.
 */

Tk_ClassProcs tkpScrollbarProcs = {
    sizeof(Tk_ClassProcs),	/* size */
    NULL,					/* worldChangedProc */
    NULL,					/* createProc */
    NULL					/* modalProc */
};

#pragma mark TKApplication(TKScrlbr)

#define NSAppleAquaScrollBarVariantChanged @"AppleAquaScrollBarVariantChanged"

@implementation TKApplication(TKScrlbr)
- (void) tkScroller: (TkNSScroller *) scroller
{
    NSScrollerPart hitPart = [scroller hitPart];
    TkScrollbar *scrollPtr = (TkScrollbar *)[scroller tag];
    Tcl_DString cmdString;
    Tcl_Interp *interp;
    int result;

    if (!scrollPtr || !scrollPtr->command || !scrollPtr->commandSize ||
	    hitPart == NSScrollerNoPart) {
	return;
    }

    Tcl_DStringInit(&cmdString);
    Tcl_DStringAppend(&cmdString, scrollPtr->command,
	    scrollPtr->commandSize);
    switch (hitPart) {
    case NSScrollerKnob:
    case NSScrollerKnobSlot: {
	char valueString[TCL_DOUBLE_SPACE];

	Tcl_PrintDouble(NULL, [scroller doubleValue] *
		(1.0 - [scroller knobProportion]), valueString);
	Tcl_DStringAppendElement(&cmdString, "moveto");
	Tcl_DStringAppendElement(&cmdString, valueString);
	break;
    }
    case NSScrollerDecrementLine:
    case NSScrollerIncrementLine:
	Tcl_DStringAppendElement(&cmdString, "scroll");
	Tcl_DStringAppendElement(&cmdString,
		(hitPart == NSScrollerDecrementLine) ? "-1" : "1");
	Tcl_DStringAppendElement(&cmdString, "unit");
	break;
    case NSScrollerDecrementPage:
    case NSScrollerIncrementPage:
	Tcl_DStringAppendElement(&cmdString, "scroll");
	Tcl_DStringAppendElement(&cmdString,
		(hitPart == NSScrollerDecrementPage) ? "-1" : "1");
	Tcl_DStringAppendElement(&cmdString, "page");
	break;
    }
    interp = scrollPtr->interp;
    Tcl_Preserve(interp);
    Tcl_Preserve(scrollPtr);
    result = Tcl_EvalEx(interp, Tcl_DStringValue(&cmdString),
	    Tcl_DStringLength(&cmdString), TCL_EVAL_GLOBAL);
    if (result != TCL_OK && result != TCL_CONTINUE && result != TCL_BREAK) {
	Tcl_AddErrorInfo(interp, "\n    (scrollbar command)");
	Tcl_BackgroundError(interp);
    }
    Tcl_Release(scrollPtr);
    Tcl_Release(interp);
    Tcl_DStringFree(&cmdString);
#ifdef TK_MAC_DEBUG_SCROLLBAR
    TKLog(@"scroller %s value %f knobProportion %f",
	    ((TkWindow *)scrollPtr->tkwin)->pathName, [scroller doubleValue],
	    [scroller knobProportion]);
#endif
}

- (void) scrollBarVariantChanged: (NSNotification *) notification
{
#ifdef TK_MAC_DEBUG_NOTIFICATIONS
    TKLog(@"-[%@(%p) %s] %@", [self class], self, _cmd, notification);
#endif
    UpdateScrollbarMetrics();
}

- (void) _setupScrollBarNotifications
{
    NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];

#define observe(n, s) [nc addObserver:self selector:@selector(s) name:(n) object:nil]
    observe(NSAppleAquaScrollBarVariantChanged, scrollBarVariantChanged:);
#undef observe

    UpdateScrollbarMetrics();
}
@end

#pragma mark -

/*
 *----------------------------------------------------------------------
 *
 * UpdateScrollbarMetrics --
 *
 *	This function retrieves the current system metrics for a scrollbar.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Updates the geometry cache info for all scrollbars.
 *
 *----------------------------------------------------------------------
 */

static void
UpdateScrollbarMetrics(void)
{
    const short height = 100, width = 50;
    HIThemeTrackDrawInfo info = {
	.version = 0,
	.bounds = {{0, 0}, {width, height}},
	.min = 0,
	.max = 1,
	.value = 0,
	.attributes = kThemeTrackShowThumb,
	.enableState = kThemeTrackActive,
	.trackInfo.scrollbar = {.viewsize = 1, .pressState = 0},
    };
    CGRect bounds;

    ChkErr(GetThemeMetric, kThemeMetricScrollBarWidth, &metrics[0].width);
    ChkErr(GetThemeMetric, kThemeMetricScrollBarMinThumbHeight,
	    &metrics[0].minThumbHeight);
    info.kind = kThemeScrollBarMedium;
    ChkErr(HIThemeGetTrackDragRect, &info, &bounds);
    metrics[0].topArrowHeight = bounds.origin.y;
    metrics[0].bottomArrowHeight = height - (bounds.origin.y +
	    bounds.size.height);
    metrics[0].minHeight = metrics[0].minThumbHeight +
	    metrics[0].topArrowHeight + metrics[0].bottomArrowHeight;
    ChkErr(GetThemeMetric, kThemeMetricSmallScrollBarWidth, &metrics[1].width);
    ChkErr(GetThemeMetric, kThemeMetricSmallScrollBarMinThumbHeight,
	    &metrics[1].minThumbHeight);
    info.kind = kThemeScrollBarSmall;
    ChkErr(HIThemeGetTrackDragRect, &info, &bounds);
    metrics[1].topArrowHeight = bounds.origin.y;
    metrics[1].bottomArrowHeight = height - (bounds.origin.y +
	    bounds.size.height);
    metrics[1].minHeight = metrics[1].minThumbHeight +
	    metrics[1].topArrowHeight + metrics[1].bottomArrowHeight;

    sprintf(tkDefScrollbarWidth, "%d", (int)(metrics[0].width));
}

/*
 *----------------------------------------------------------------------
 *
 * TkpCreateScrollbar --
 *
 *	Allocate a new TkScrollbar structure.
 *
 * Results:
 *	Returns a newly allocated TkScrollbar structure.
 *
 * Side effects:
 *	Registers an event handler for the widget.
 *
 *----------------------------------------------------------------------
 */

TkScrollbar *
TkpCreateScrollbar(
    Tk_Window tkwin)
{
    MacScrollbar *scrollPtr = (MacScrollbar *) ckalloc(sizeof(MacScrollbar));

    scrollPtr->scroller = nil;
    Tk_CreateEventHandler(tkwin, StructureNotifyMask|FocusChangeMask|
	    ActivateMask|ExposureMask, ScrollbarEventProc, (ClientData) scrollPtr);
    return (TkScrollbar *) scrollPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * TkpDestroyScrollbar --
 *
 *	Free data structures associated with the scrollbar control.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void
TkpDestroyScrollbar(
    TkScrollbar *scrollPtr)
{
    MacScrollbar *macScrollPtr = (MacScrollbar *) scrollPtr;
    TkNSScroller *scroller = macScrollPtr->scroller;
    [scroller setTag:(NSInteger)-1];

    TkMacOSXMakeCollectableAndRelease(macScrollPtr->scroller);
}

/*
 *--------------------------------------------------------------
 *
 * TkpDisplayScrollbar --
 *
 *	This procedure redraws the contents of a scrollbar window. It is
 *	invoked as a do-when-idle handler, so it only runs when there's nothing
 *	else for the application to do.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information appears on the screen.
 *
 *--------------------------------------------------------------
 */

void
TkpDisplayScrollbar(
    ClientData clientData)	/* Information about window. */
{
    TkScrollbar *scrollPtr = (TkScrollbar *) clientData;
    MacScrollbar *macScrollPtr = (MacScrollbar *) clientData;
    TkNSScroller *scroller = macScrollPtr->scroller;
    Tk_Window tkwin = scrollPtr->tkwin;
    TkWindow *winPtr = (TkWindow *) tkwin;
    MacDrawable *macWin =  (MacDrawable *) winPtr->window;
    TkMacOSXDrawingContext dc;
    NSView *view = TkMacOSXDrawableView(macWin);
    CGFloat viewHeight = [view bounds].size.height;
    CGAffineTransform t = { .a = 1, .b = 0, .c = 0, .d = -1, .tx = 0,
	    .ty = viewHeight};
    NSRect frame;
    double knobProportion = scrollPtr->lastFraction - scrollPtr->firstFraction;

    scrollPtr->flags &= ~REDRAW_PENDING;
    if (!scrollPtr->tkwin || !Tk_IsMapped(tkwin) || !view ||
	    !TkMacOSXSetupDrawingContext((Drawable) macWin, NULL, 1, &dc)) {
	return;
    }
    CGContextConcatCTM(dc.context, t);
    if (scrollPtr->highlightWidth != 0) {
	GC fgGC, bgGC;

	bgGC = Tk_GCForColor(scrollPtr->highlightBgColorPtr, (Pixmap) macWin);
	if (scrollPtr->flags & GOT_FOCUS) {
	    fgGC = Tk_GCForColor(scrollPtr->highlightColorPtr, (Pixmap) macWin);
	} else {
	    fgGC = bgGC;
	}
	TkpDrawHighlightBorder(tkwin, fgGC, bgGC, scrollPtr->highlightWidth,
		(Pixmap) macWin);
    }
    Tk_Draw3DRectangle(tkwin, (Pixmap) macWin, scrollPtr->bgBorder,
	    scrollPtr->highlightWidth, scrollPtr->highlightWidth,
	    Tk_Width(tkwin) - 2*scrollPtr->highlightWidth,
	    Tk_Height(tkwin) - 2*scrollPtr->highlightWidth,
	    scrollPtr->borderWidth, scrollPtr->relief);
    Tk_Fill3DRectangle(tkwin, (Pixmap) macWin, scrollPtr->bgBorder,
	    scrollPtr->inset, scrollPtr->inset,
	    Tk_Width(tkwin) - 2*scrollPtr->inset,
	    Tk_Height(tkwin) - 2*scrollPtr->inset, 0, TK_RELIEF_FLAT);
    if ([scroller superview] != view) {
	[view addSubview:scroller];
    }
    frame = NSMakeRect(macWin->xOff, macWin->yOff, Tk_Width(tkwin),
	    Tk_Height(tkwin));
    frame = NSInsetRect(frame, scrollPtr->inset, scrollPtr->inset);
    frame.origin.y = viewHeight - (frame.origin.y + frame.size.height);

    if (!NSEqualRects(frame, [scroller frame])) {
	[scroller setFrame:frame];
    }
    [scroller setEnabled:(knobProportion < 1.0 &&
	    (scrollPtr->vertical ? frame.size.height : frame.size.width) >
	    metrics[macScrollPtr->variant].minHeight)];
    // [scroller setEnabled: YES];
    [scroller setDoubleValue:scrollPtr->firstFraction / (1.0 - knobProportion)];
    [scroller setKnobProportion:knobProportion];
    [scroller displayRectIgnoringOpacity:[scroller bounds]];
    TkMacOSXRestoreDrawingContext(&dc);
    #ifdef TK_MAC_DEBUG_SCROLLBAR
    TKLog(@"scroller %s frame %@ width %d height %d",
	    ((TkWindow *)scrollPtr->tkwin)->pathName, NSStringFromRect(frame),
	    Tk_Width(tkwin), Tk_Height(tkwin));
    #endif
}

/*
 *----------------------------------------------------------------------
 *
 * TkpComputeScrollbarGeometry --
 *
 *	After changes in a scrollbar's size or configuration, this procedure
 *	recomputes various geometry information used in displaying the
 *	scrollbar.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The scrollbar will be displayed differently.
 *
 *----------------------------------------------------------------------
 */

void
TkpComputeScrollbarGeometry(
    register TkScrollbar *scrollPtr)
				/* Scrollbar whose geometry may have
				 * changed. */
{
    MacScrollbar *macScrollPtr = (MacScrollbar *) scrollPtr;
    TkNSScroller *scroller = macScrollPtr->scroller;
    int width, height, variant, fieldLength;

    if (scrollPtr->highlightWidth < 0) {
	scrollPtr->highlightWidth = 0;
    }
    scrollPtr->inset = scrollPtr->highlightWidth + scrollPtr->borderWidth;
    width = Tk_Width(scrollPtr->tkwin) - 2 * scrollPtr->inset;
    height = Tk_Height(scrollPtr->tkwin) - 2 * scrollPtr->inset;
    variant = ((scrollPtr->vertical ?  width : height) < metrics[0].width) ?
	    1 : 0;
    macScrollPtr->variant = variant;
    if (scroller) {
	NSSize size = [scroller frame].size;

	if ((size.width > size.height) ^ !scrollPtr->vertical) {
	    /*
	     * Orientation changed, need new scroller.
	     */

	    if ([scroller superview]) {
		[scroller removeFromSuperviewWithoutNeedingDisplay];
	    }
	    TkMacOSXMakeCollectableAndRelease(scroller);
	}
    }
    if (!scroller) {
	if ((width > height) ^ !scrollPtr->vertical) {
	    /* -[NSScroller initWithFrame:] determines horizontalness for the
	     * lifetime of the scroller via isHoriz = (width > height) */
	    if (scrollPtr->vertical) {
		width = height;
	    } else if (width > 1) {
		height = width - 1;
	    } else {
		height = 1;
		width = 2;
	    }
	}
	scroller = [[TkNSScroller alloc] initWithFrame:
		NSMakeRect(0, 0, width, height)];
	macScrollPtr->scroller = TkMacOSXMakeUncollectable(scroller);
	[scroller setAction:@selector(tkScroller:)];
	[scroller setTarget:NSApp];
	[scroller setTag:(NSInteger)scrollPtr];
    }
    [[scroller cell] setControlSize:metrics[variant].controlSize];

    scrollPtr->arrowLength = (metrics[variant].topArrowHeight +
	    metrics[variant].bottomArrowHeight) / 2;
    fieldLength = (scrollPtr->vertical ? Tk_Height(scrollPtr->tkwin)
	    : Tk_Width(scrollPtr->tkwin))
	    - 2 * (scrollPtr->arrowLength + scrollPtr->inset);
    if (fieldLength < 0) {
	fieldLength = 0;
    }
    scrollPtr->sliderFirst = fieldLength * scrollPtr->firstFraction;
    scrollPtr->sliderLast = fieldLength * scrollPtr->lastFraction;

    /*
     * Adjust the slider so that some piece of it is always displayed in the
     * scrollbar and so that it has at least a minimal width (so it can be
     * grabbed with the mouse).
     */

    if (scrollPtr->sliderFirst > (fieldLength - 2*scrollPtr->borderWidth)) {
	scrollPtr->sliderFirst = fieldLength - 2*scrollPtr->borderWidth;
    }
    if (scrollPtr->sliderFirst < 0) {
	scrollPtr->sliderFirst = 0;
    }
    if (scrollPtr->sliderLast < (scrollPtr->sliderFirst +
	    metrics[variant].minThumbHeight)) {
	scrollPtr->sliderLast = scrollPtr->sliderFirst +
		metrics[variant].minThumbHeight;
    }
    if (scrollPtr->sliderLast > fieldLength) {
	scrollPtr->sliderLast = fieldLength;
    }
    scrollPtr->sliderFirst += scrollPtr->inset +
	    metrics[variant].topArrowHeight;
    scrollPtr->sliderLast += scrollPtr->inset +
	    metrics[variant].bottomArrowHeight;

    /*
     * Register the desired geometry for the window (leave enough space for
     * the two arrows plus a minimum-size slider, plus border around the whole
     * window, if any). Then arrange for the window to be redisplayed.
     */

    if (scrollPtr->vertical) {
	Tk_GeometryRequest(scrollPtr->tkwin, scrollPtr->width +
		2 * scrollPtr->inset, 2 * (scrollPtr->arrowLength +
		scrollPtr->borderWidth + scrollPtr->inset) +
		metrics[variant].minThumbHeight);
    } else {
	Tk_GeometryRequest(scrollPtr->tkwin, 2 * (scrollPtr->arrowLength +
		scrollPtr->borderWidth + scrollPtr->inset) +
		metrics[variant].minThumbHeight, scrollPtr->width +
		2 * scrollPtr->inset);
    }
    Tk_SetInternalBorder(scrollPtr->tkwin, scrollPtr->inset);
#ifdef TK_MAC_DEBUG_SCROLLBAR
    TKLog(@"scroller %s bounds %@ width %d height %d inset %d borderWidth %d",
	    ((TkWindow *)scrollPtr->tkwin)->pathName,
	    NSStringFromRect([scroller bounds]),
	    width, height, scrollPtr->inset, scrollPtr->borderWidth);
#endif
}

/*
 *----------------------------------------------------------------------
 *
 * TkpConfigureScrollbar --
 *
 *	This procedure is called after the generic code has finished
 *	processing configuration options, in order to configure platform
 *	specific options.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void
TkpConfigureScrollbar(
    register TkScrollbar *scrollPtr)
				/* Information about widget; may or may not
				 * already have values for some fields. */
{
}

/*
 *--------------------------------------------------------------
 *
 * TkpScrollbarPosition --
 *
 *	Determine the scrollbar element corresponding to a given position.
 *
 * Results:
 *	One of TOP_ARROW, TOP_GAP, etc., indicating which element of the
 *	scrollbar covers the position given by (x, y). If (x,y) is outside the
 *	scrollbar entirely, then OUTSIDE is returned.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

int
TkpScrollbarPosition(
    register TkScrollbar *scrollPtr,
				/* Scrollbar widget record. */
    int x, int y)		/* Coordinates within scrollPtr's window. */
{
    TkNSScroller *scroller = ((MacScrollbar *) scrollPtr)->scroller;
    MacDrawable *macWin =  (MacDrawable *)
	    ((TkWindow *) scrollPtr->tkwin)->window;
    NSView *view = TkMacOSXDrawableView(macWin);

    switch ([scroller testPart:NSMakePoint(macWin->xOff + x,
	    [view bounds].size.height - (macWin->yOff + y))]) {
    case NSScrollerDecrementLine:
	return TOP_ARROW;
    case NSScrollerDecrementPage:
	return TOP_GAP;
    case NSScrollerKnob:
	return SLIDER;
    case NSScrollerIncrementPage:
	return BOTTOM_GAP;
    case NSScrollerIncrementLine:
	return BOTTOM_ARROW;
    case NSScrollerKnobSlot:
    case NSScrollerNoPart:
    default:
	return OUTSIDE;
    }
}

/*
 *--------------------------------------------------------------
 *
 * ScrollbarEventProc --
 *
 *	This procedure is invoked by the Tk dispatcher for various events on
 *	scrollbars.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	When the window gets deleted, internal structures get cleaned up. When
 *	it gets exposed, it is redisplayed.
 *
 *--------------------------------------------------------------
 */

static void
ScrollbarEventProc(
    ClientData clientData,	/* Information about window. */
    XEvent *eventPtr)		/* Information about event. */
{
    TkScrollbar *scrollPtr = (TkScrollbar *) clientData;

    switch (eventPtr->type) {
    case UnmapNotify:
	TkMacOSXSetScrollbarGrow((TkWindow *) scrollPtr->tkwin, false);
	break;
    case ActivateNotify:
    case DeactivateNotify:
	TkScrollbarEventuallyRedraw((ClientData) scrollPtr);
	break;
    default:
	TkScrollbarEventProc(clientData, eventPtr);
    }
}


/*
 *----------------------------------------------------------------------
 *
 * TkMacOSXGetScrollFrame --
 *
 *	Computes a frame for an NSScroller that will correspond to where
 *	Tk thinks the scroller is located.
 *
 * Results:
 *	Returns an NSRect describing a frame for an NSScrollbar.
 *
 * Side effects:
 *	None
 *
 *----------------------------------------------------------------------
 */
NSRect TkMacOSXGetScrollFrame(
     TkScrollbar *scrlPtr)
{
    MacScrollbar *macscrlPtr = (MacScrollbar *) scrlPtr;
    Tk_Window tkwin = scrlPtr->tkwin;
    TkWindow *winPtr = (TkWindow *) tkwin;
    if (tkwin) {
	MacDrawable *macWin =  (MacDrawable *) winPtr->window;
	NSView *view = TkMacOSXDrawableView(macWin);
	CGFloat viewHeight = [view bounds].size.height;
	NSRect frame = NSMakeRect(macWin->xOff, macWin->yOff,
				  Tk_Width(tkwin), Tk_Height(tkwin));

	frame.origin.y = viewHeight - (frame.origin.y + frame.size.height);
	return frame;
    } else {
	return NSZeroRect;
    }
}



/*
 * Local Variables:
 * mode: objc
 * c-basic-offset: 4
 * fill-column: 79
 * coding: utf-8
 * End:
 */