summaryrefslogtreecommitdiffstats
path: root/tqtinterface/qt4/src/kernel/tqlayoutengine.cpp
blob: 8c364d9a3b6f4ce0fd66a11bfccda40a6935316f (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
/****************************************************************************
**
** Implementation of TQLayout functionality
**
** Created : 981231
**
** Copyright (C) 1998-2008 Trolltech ASA.  All rights reserved.
**
** This file is part of the kernel module of the TQt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free TQt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.TQPL
** included in the packaging of this file.  Licensees holding valid TQt
** Commercial licenses may use this file in accordance with the TQt
** Commercial License Agreement provided with the Software.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/

#include "tqlayout.h"
#include "private/tqlayoutengine_p.h"

#ifndef TQT_NO_LAYOUT

static inline int toFixed( int i ) { return i * 256; }
static inline int fRound( int i ) {
    return ( i % 256 < 128 ) ? i / 256 : 1 + i / 256;
}

/*
  This is the main workhorse of the TQGridLayout. It portions out
  available space to the chain's tqchildren.

  The calculation is done in fixed point: "fixed" variables are
  scaled by a factor of 256.

  If the tqlayout runs "backwards" (i.e. RightToLeft or Up) the tqlayout
  is computed mirror-reversed, and it's the caller's responsibility
  do reverse the values before use.

  chain tqcontains input and output parameters describing the tqgeometry.
  count is the count of items in the chain; pos and space give the
  interval (relative to parentWidget topLeft).
*/
TQ_EXPORT void qGeomCalc( TQMemArray<TQLayoutStruct> &chain, int start, int count,
			 int pos, int space, int spacer )
{
    typedef int fixed;
    int cHint = 0;
    int cMin = 0;
    int cMax = 0;
    int sumStretch = 0;
    int spacerCount = 0;

    bool wannaGrow = FALSE; // anyone who really wants to grow?
    //    bool canShrink = FALSE; // anyone who could be persuaded to shrink?

    int i;
    for ( i = start; i < start + count; i++ ) {
	chain[i].done = FALSE;
	cHint += chain[i].smartSizeHint();
	cMin += chain[i].tqminimumSize;
	cMax += chain[i].tqmaximumSize;
	sumStretch += chain[i].stretch;
	if ( !chain[i].empty )
	    spacerCount++;
	wannaGrow = wannaGrow || chain[i].expansive || chain[i].stretch > 0;
    }

    int extraspace = 0;
    if ( spacerCount )
	spacerCount--; // only spacers between things
    if ( space < cMin + spacerCount * spacer ) {
	for ( i = start; i < start+count; i++ ) {
	    chain[i].size = chain[i].tqminimumSize;
	    chain[i].done = TRUE;
	}
    } else if ( space < cHint + spacerCount*spacer ) {
	/*
	  Less space than smartSizeHint(), but more than tqminimumSize.
	  Currently take space equally from each, as in TQt 2.x.
	  Commented-out lines will give more space to stretchier
	  items.
	*/
	int n = count;
	int space_left = space - spacerCount*spacer;
	int overdraft = cHint - space_left;

	// first give to the fixed ones:
	for ( i = start; i < start + count; i++ ) {
	    if ( !chain[i].done
		 && chain[i].tqminimumSize >= chain[i].smartSizeHint() ) {
		chain[i].size = chain[i].smartSizeHint();
		chain[i].done = TRUE;
		space_left -= chain[i].smartSizeHint();
		// sumStretch -= chain[i].stretch;
		n--;
	    }
	}
	bool finished = n == 0;
	while ( !finished ) {
	    finished = TRUE;
	    fixed fp_over = toFixed( overdraft );
	    fixed fp_w = 0;

	    for ( i = start; i < start+count; i++ ) {
		if ( chain[i].done )
		    continue;
		// if ( sumStretch <= 0 )
		fp_w += fp_over / n;
		// else
		//    fp_w += (fp_over * chain[i].stretch) / sumStretch;
		int w = fRound( fp_w );
		chain[i].size = chain[i].smartSizeHint() - w;
		fp_w -= toFixed( w ); // give the difference to the next
		if ( chain[i].size < chain[i].tqminimumSize ) {
		    chain[i].done = TRUE;
		    chain[i].size = chain[i].tqminimumSize;
		    finished = FALSE;
		    overdraft -= ( chain[i].smartSizeHint()
				   - chain[i].tqminimumSize );
		    // sumStretch -= chain[i].stretch;
		    n--;
		    break;
		}
	    }
	}
    } else { // extra space
	int n = count;
	int space_left = space - spacerCount*spacer;
	// first give to the fixed ones, and handle non-expansiveness
	for ( i = start; i < start + count; i++ ) {
	    if ( !chain[i].done
		 && (chain[i].tqmaximumSize <= chain[i].smartSizeHint()
		     || (wannaGrow && !chain[i].expansive && chain[i].stretch == 0)) ) {
		chain[i].size = chain[i].smartSizeHint();
		chain[i].done = TRUE;
		space_left -= chain[i].smartSizeHint();
		sumStretch -= chain[i].stretch;
		n--;
	    }
	}
	extraspace = space_left;

	/*
	  Do a trial distribution and calculate how much it is off.
	  If there are more deficit pixels than surplus pixels, give
	  the minimum size items what they need, and repeat.
	  Otherwise give to the maximum size items, and repeat.

	  Paul Olav Tvete has a wonderful mathematical proof of the
	  correctness of this principle, but unfortunately this
	  comment is too small to contain it.
	*/
	int surplus, deficit;
	do {
	    surplus = deficit = 0;
	    fixed fp_space = toFixed( space_left );
	    fixed fp_w = 0;
	    for ( i = start; i < start+count; i++ ) {
		if ( chain[i].done )
		    continue;
		extraspace = 0;
		if ( sumStretch <= 0 )
		    fp_w += fp_space / n;
		else
		    fp_w += (fp_space * chain[i].stretch) / sumStretch;
		int w = fRound( fp_w );
		chain[i].size = w;
		fp_w -= toFixed( w ); // give the difference to the next
		if ( w < chain[i].smartSizeHint() ) {
		    deficit +=  chain[i].smartSizeHint() - w;
		} else if ( w > chain[i].tqmaximumSize ) {
		    surplus += w - chain[i].tqmaximumSize;
		}
	    }
	    if ( deficit > 0 && surplus <= deficit ) {
		// give to the ones that have too little
		for ( i = start; i < start+count; i++ ) {
		    if ( !chain[i].done &&
			 chain[i].size < chain[i].smartSizeHint() ) {
			chain[i].size = chain[i].smartSizeHint();
			chain[i].done = TRUE;
			space_left -= chain[i].smartSizeHint();
			sumStretch -= chain[i].stretch;
			n--;
		    }
		}
	    }
	    if ( surplus > 0 && surplus >= deficit ) {
		// take from the ones that have too much
		for ( i = start; i < start+count; i++ ) {
		    if ( !chain[i].done &&
			 chain[i].size > chain[i].tqmaximumSize ) {
			chain[i].size = chain[i].tqmaximumSize;
			chain[i].done = TRUE;
			space_left -= chain[i].tqmaximumSize;
			sumStretch -= chain[i].stretch;
			n--;
		    }
		}
	    }
	} while ( n > 0 && surplus != deficit );
	if ( n == 0 )
	    extraspace = space_left;
    }

    /*
      As a last resort, we distribute the unwanted space equally
      among the spacers (counting the start and end of the chain). We
      could, but don't, attempt a sub-pixel allocation of the extra
      space.
    */
    int extra = extraspace / ( spacerCount + 2 );
    int p = pos + extra;
    for ( i = start; i < start+count; i++ ) {
	chain[i].pos = p;
	p = p + chain[i].size;
	if ( !chain[i].empty )
	    p += spacer+extra;
    }
}

TQ_EXPORT TQSize tqSmartMinSize( const TQWidgetItem *i )
{
    TQWidget *w = ((TQWidgetItem *)i)->widget();

    TQSize s( 0, 0 );
    if ( w->tqlayout() ) {
	s = w->tqlayout()->totalMinimumSize();
    } else {
	TQSize sh;

	if ( TQT_TQSIZEPOLICY_OBJECT(w->sizePolicy()).horData() != TQSizePolicy::Ignored ) {
	    if ( TQT_TQSIZEPOLICY_OBJECT(w->sizePolicy()).mayShrinkHorizontally() ) {
		s.setWidth( w->tqminimumSizeHint().width() );
	    } else {
		sh = w->sizeHint();
		s.setWidth( sh.width() );
	    }
	}

	if ( TQT_TQSIZEPOLICY_OBJECT(w->sizePolicy()).verData() != TQSizePolicy::Ignored ) {
	    if ( TQT_TQSIZEPOLICY_OBJECT(w->sizePolicy()).mayShrinkVertically() ) {
		s.setHeight( w->tqminimumSizeHint().height() );
	    } else {
		s.setHeight( sh.isValid() ? sh.height()
			     : w->sizeHint().height() );
	    }
	}
    }
    s = s.boundedTo( w->tqmaximumSize() );
    TQSize min = w->tqminimumSize();
    if ( min.width() > 0 )
	s.setWidth( min.width() );
    if ( min.height() > 0 )
	s.setHeight( min.height() );

    if ( i->hasHeightForWidth() && min.height() == 0 && min.width() > 0 )
	s.setHeight( i->heightForWidth(s.width()) );

    s = s.expandedTo( TQSize(1, 1) );
    return s;
}

TQ_EXPORT TQSize tqSmartMinSize( TQWidget *w )
{
    TQWidgetItem item( w );
    return tqSmartMinSize( &item );
}

TQ_EXPORT TQSize tqSmartMaxSize( const TQWidgetItem *i, int align )
{
    TQWidget *w = ( (TQWidgetItem*)i )->widget();
    if ( align & TQt::AlignHorizontal_Mask && align & TQt::AlignVertical_Mask )
	return TQSize( TQLAYOUTSIZE_MAX, TQLAYOUTSIZE_MAX );
    TQSize s = w->tqmaximumSize();
    if ( s.width() == TQWIDGETSIZE_MAX && !(align & TQt::AlignHorizontal_Mask) )
	if ( !TQT_TQSIZEPOLICY_OBJECT(w->sizePolicy()).mayGrowHorizontally() )
	    s.setWidth( w->sizeHint().width() );

    if ( s.height() == TQWIDGETSIZE_MAX && !(align & TQt::AlignVertical_Mask) )
	if ( !TQT_TQSIZEPOLICY_OBJECT(w->sizePolicy()).mayGrowVertically() )
	    s.setHeight( w->sizeHint().height() );

    s = s.expandedTo( w->tqminimumSize() );

    if ( align & TQt::AlignHorizontal_Mask )
	s.setWidth( TQLAYOUTSIZE_MAX );
    if ( align & TQt::AlignVertical_Mask )
	s.setHeight( TQLAYOUTSIZE_MAX );
    return s;
}

TQ_EXPORT TQSize tqSmartMaxSize( TQWidget *w, int align )
{
    TQWidgetItem item( w );
    return tqSmartMaxSize( &item, align );
}

#endif // TQT_NO_LAYOUT