1 /****************************************************************************
2 ** $Id: fsize.cpp 20691 2016-01-17 14:41:01Z craig $
3 **
4 ** Implementation of FSize class
5 **
6 ** Created : 931028
7 **
8 ** Copyright (C) 1992-2000 Trolltech AS. All rights reserved.
9 **
10 ** This file is part of the kernel module of the Qt GUI Toolkit.
11 **
12 ** This file may be distributed under the terms of the Q Public License
13 ** as defined by Trolltech AS of Norway and appearing in the file
14 ** LICENSE.QPL included in the packaging of this file.
15 **
16 ** This file may be distributed and/or modified under the terms of the
17 ** GNU General Public License version 2 as published by the Free Software
18 ** Foundation and appearing in the file LICENSE.GPL included in the
19 ** packaging of this file.
20 **
21 ** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
22 ** licenses may use this file in accordance with the Qt Commercial License
23 ** Agreement provided with the Software.
24 **
25 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
26 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
27 **
28 ** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
29 ** information about Qt Commercial License Agreements.
30 ** See http://www.trolltech.com/qpl/ for QPL licensing information.
31 ** See http://www.trolltech.com/gpl/ for GPL licensing information.
32 **
33 ** Contact info@trolltech.com if any conditions of this licensing are
34 ** not clear to you.
35 **
36 **********************************************************************/
37
38 #include "fsize.h"
39 //#include "qdatastream.h"
40
41
42 /*!
43 \class FSize
44 \brief The FSize class defines the size of a two-dimensional object.
45
46 \ingroup images
47 \ingroup graphics
48
49 A size is specified by a width and a height.
50
51 The coordinate type is qreal (defined in \c <qwindowdefs.h> as \c qreal).
52 The minimum value of qreal is qreal_MIN (-2147483648) and the maximum
53 value is qreal_MAX (2147483647).
54
55 The size can be set in the constructor and changed with setWidth()
56 and setHeight(), or using operator+=(), operator-=(), operator*=()
57 and operator/=(), etc. You can swap the width and height with
58 transpose(). You can get a size which holds the maximum height and
59 width of two sizes using expandedTo(), and the minimum height and
60 width of two sizes using boundedTo().
61
62
63 \sa QPoint, QRect
64 */
65
66
67 /*****************************************************************************
68 FSize member functions
69 *****************************************************************************/
70
71 /*!
72 \fn FSize::FSize()
73 Constructs a size with invalid (negative) width and height.
74 */
75
76 /*!
77 \fn FSize::FSize( qreal w, qreal h )
78 Constructs a size with width \a w and height \a h.
79 */
80
81 /*!
82 \fn bool FSize::isNull() const
83 Returns TRUE if the width is 0 and the height is 0; otherwise
84 returns FALSE.
85 */
86
87 /*!
88 \fn bool FSize::isEmpty() const
89 Returns TRUE if the width is less than or equal to 0, or the height is
90 less than or equal to 0; otherwise returns FALSE.
91 */
92
93 /*!
94 \fn bool FSize::isValid() const
95 Returns TRUE if the width is equal to or greater than 0 and the height is
96 equal to or greater than 0; otherwise returns FALSE.
97 */
98
99 /*!
100 \fn qreal FSize::width() const
101 Returns the width.
102 \sa height()
103 */
104
105 /*!
106 \fn qreal FSize::height() const
107 Returns the height.
108 \sa width()
109 */
110
111 /*!
112 \fn void FSize::setWidth( qreal w )
113 Sets the width to \a w.
114 \sa width(), setHeight()
115 */
116
117 /*!
118 \fn void FSize::setHeight( qreal h )
119 Sets the height to \a h.
120 \sa height(), setWidth()
121 */
122
123 /*!
124 Swaps the values of width and height.
125 */
126
transpose()127 void FSize::transpose()
128 {
129 qreal tmp = m_wd;
130 m_wd = m_ht;
131 m_ht = tmp;
132 }
133
134 /*! \enum FSize::ScaleMode
135
136 This enum type defines the different ways of scaling a size.
137
138 \img scaling.png
139
140 \value ScaleFree The size is scaled freely. The ratio is not preserved.
141 \value ScaleMin The size is scaled to a rectangle as large as possible
142 inside a given rectangle, preserving the aspect ratio.
143 \value ScaleMax The size is scaled to a rectangle as small as possible
144 outside a given rectangle, preserving the aspect ratio.
145
146 \sa FSize::scale(), QImage::scale(), QImage::smoothScale()
147 */
148
149 /*!
150 Scales the size to a rectangle of width \a w and height \a h according
151 to the ScaleMode \a mode.
152
153 \list
154 \i If \a mode is \c ScaleFree, the size is set to (\a w, \a h).
155 \i If \a mode is \c ScaleMin, the current size is scaled to a rectangle
156 as large as possible inside (\a w, \a h), preserving the aspect ratio.
157 \i If \a mode is \c ScaleMax, the current size is scaled to a rectangle
158 as small as possible outside (\a w, \a h), preserving the aspect ratio.
159 \endlist
160
161 Example:
162 \code
163 FSize t1( 10, 12 );
164 t1.scale( 60, 60, FSize::ScaleFree );
165 // t1 is (60, 60)
166
167 FSize t2( 10, 12 );
168 t2.scale( 60, 60, FSize::ScaleMin );
169 // t2 is (50, 60)
170
171 FSize t3( 10, 12 );
172 t3.scale( 60, 60, FSize::ScaleMax );
173 // t3 is (60, 72)
174 \endcode
175 */
scale(qreal w,qreal h,Qt::AspectRatioMode mode)176 void FSize::scale( qreal w, qreal h, Qt::AspectRatioMode mode )
177 {
178 if ( mode == Qt::IgnoreAspectRatio ) {
179 m_wd = (qreal)w;
180 m_ht = (qreal)h;
181 } else {
182 bool useHeight = true;
183 qreal w0 = width();
184 qreal h0 = height();
185 qreal rw = h * w0 / h0;
186
187 if ( mode == Qt::KeepAspectRatio ) {
188 useHeight = ( rw <= w );
189 } else { // mode == ScaleMax
190 useHeight = ( rw >= w );
191 }
192
193 if ( useHeight ) {
194 m_wd = (qreal)rw;
195 m_ht = (qreal)h;
196 } else {
197 m_wd = (qreal)w;
198 m_ht = (qreal)( w * h0 / w0 );
199 }
200 }
201 }
202
203 /*!
204 \overload
205
206 Equivalent to scale(\a{s}.width(), \a{s}.height(), \a mode).
207 */
scale(const FSize & s,Qt::AspectRatioMode mode)208 void FSize::scale( const FSize &s, Qt::AspectRatioMode mode )
209 {
210 scale( s.width(), s.height(), mode );
211 }
212
213 /*!
214 \fn qreal &FSize::rwidth()
215 Returns a reference to the width.
216
217 Using a reference makes it possible to directly manipulate the width.
218
219 Example:
220 \code
221 FSize s( 100, 10 );
222 s.rwidth() += 20; // s becomes (120,10)
223 \endcode
224
225 \sa rheight()
226 */
227
228 /*!
229 \fn qreal &FSize::rheight()
230 Returns a reference to the height.
231
232 Using a reference makes it possible to directly manipulate the height.
233
234 Example:
235 \code
236 FSize s( 100, 10 );
237 s.rheight() += 5; // s becomes (100,15)
238 \endcode
239
240 \sa rwidth()
241 */
242
243 /*!
244 \fn FSize &FSize::operator+=( const FSize &s )
245
246 Adds \a s to the size and returns a reference to this size.
247
248 Example:
249 \code
250 FSize s( 3, 7 );
251 FSize r( -1, 4 );
252 s += r; // s becomes (2,11)
253 \endcode
254 */
255
256 /*!
257 \fn FSize &FSize::operator-=( const FSize &s )
258
259 Subtracts \a s from the size and returns a reference to this size.
260
261 Example:
262 \code
263 FSize s( 3, 7 );
264 FSize r( -1, 4 );
265 s -= r; // s becomes (4,3)
266 \endcode
267 */
268
269 /*!
270 \fn FSize &FSize::operator*=( qreal c )
271 Multiplies both the width and height by \a c and returns a reference to
272 the size.
273 */
274
275 /*!
276 \overload FSize &FSize::operator*=( qreal c )
277
278 Multiplies both the width and height by \a c and returns a reference to
279 the size.
280
281 Note that the result is truncated.
282 */
283
284 /*!
285 \fn bool operator==( const FSize &s1, const FSize &s2 )
286 \relates FSize
287 Returns TRUE if \a s1 and \a s2 are equal; otherwise returns FALSE.
288 */
289
290 /*!
291 \fn bool operator!=( const FSize &s1, const FSize &s2 )
292 \relates FSize
293 Returns TRUE if \a s1 and \a s2 are different; otherwise returns FALSE.
294 */
295
296 /*!
297 \fn const FSize operator+( const FSize &s1, const FSize &s2 )
298 \relates FSize
299 Returns the sum of \a s1 and \a s2; each component is added separately.
300 */
301
302 /*!
303 \fn const FSize operator-( const FSize &s1, const FSize &s2 )
304 \relates FSize
305 Returns \a s2 subtracted from \a s1; each component is
306 subtracted separately.
307 */
308
309 /*!
310 \fn const FSize operator*( const FSize &s, qreal c )
311 \relates FSize
312 Multiplies \a s by \a c and returns the result.
313 */
314
315 /*!
316 \overload const FSize operator*( qreal c, const FSize &s )
317 \relates FSize
318 Multiplies \a s by \a c and returns the result.
319 */
320
321 /*!
322 \overload const FSize operator*( const FSize &s, qreal c )
323 \relates FSize
324 Multiplies \a s by \a c and returns the result.
325 */
326
327 /*!
328 \overload const FSize operator*( qreal c, const FSize &s )
329 \relates FSize
330 Multiplies \a s by \a c and returns the result.
331 */
332
333 /*!
334 \fn FSize &FSize::operator/=( qreal c )
335 Divides both the width and height by \a c and returns a reference to the
336 size.
337 */
338
339 /*!
340 \fn FSize &FSize::operator/=( qreal c )
341 \overload
342 Divides both the width and height by \a c and returns a reference to the
343 size.
344
345 Note that the result is truncated.
346 */
347
348 /*!
349 \fn const FSize operator/( const FSize &s, qreal c )
350 \relates FSize
351 Divides \a s by \a c and returns the result.
352 */
353
354 /*!
355 \fn const FSize operator/( const FSize &s, qreal c )
356 \relates FSize
357 \overload
358 Divides \a s by \a c and returns the result.
359
360 Note that the result is truncated.
361 */
362
363 /*!
364 \fn FSize FSize::expandedTo( const FSize & otherSize ) const
365
366 Returns a size with the maximum width and height of this size and
367 \a otherSize.
368 */
369
370 /*!
371 \fn FSize FSize::boundedTo( const FSize & otherSize ) const
372
373 Returns a size with the minimum width and height of this size and
374 \a otherSize.
375 */
376
377
warningDivByZero()378 void FSize::warningDivByZero()
379 {
380 #if defined(QT_CHECK_MATH)
381 qWarning( "FSize: Division by zero error" );
382 #endif
383 }
384
385
386 /*****************************************************************************
387 FSize stream functions
388 *****************************************************************************/
389 // #ifndef QT_NO_DATASTREAM
390 // /*!
391 // \relates FSize
392 // Writes the size \a sz to the stream \a s and returns a reference to
393 // the stream.
394 //
395 // \sa \link datastreamformat.html Format of the QDataStream operators \endlink
396 // */
397 //
398 // QDataStream &operator<<( QDataStream &s, const FSize &sz )
399 // {
400 // if ( s.version() == 1 )
401 // s << (Q_INT16)sz.width() << (Q_INT16)sz.height();
402 // else
403 // s << (Q_INT32)sz.width() << (Q_INT32)sz.height();
404 // return s;
405 // }
406 //
407 // /*!
408 // \relates FSize
409 // Reads the size from the stream \a s into size \a sz and returns a
410 // reference to the stream.
411 //
412 // \sa \link datastreamformat.html Format of the QDataStream operators \endlink
413 // */
414 //
415 // QDataStream &operator>>( QDataStream &s, FSize &sz )
416 // {
417 // if ( s.version() == 1 ) {
418 // Q_INT16 w, h;
419 // s >> w; sz.rwidth() = w;
420 // s >> h; sz.rheight() = h;
421 // }
422 // else {
423 // Q_INT32 w, h;
424 // s >> w; sz.rwidth() = w;
425 // s >> h; sz.rheight() = h;
426 // }
427 // return s;
428 // }
429 // #endif // QT_NO_DATASTREAM
430