1QBoxLayout(3qt) QBoxLayout(3qt)
2
6 QBoxLayout - Lines up child widgets horizontally or vertically
7
9 #include <qlayout.h>
10 Inherits QLayout.
12 Inherited by QHBoxLayout and QVBoxLayout.
14 Public Members
16 enum Direction { LeftToRight, RightToLeft, TopToBottom, BottomToTop,
17 Down = TopToBottom, Up = BottomToTop }
18 QBoxLayout ( QWidget * parent, Direction d, int margin = 0, int spacing
19 = -1, const char * name = 0 )
20 QBoxLayout ( QLayout * parentLayout, Direction d, int spacing = -1,
21 const char * name = 0 )
22 QBoxLayout ( Direction d, int spacing = -1, const char * name = 0 )
23 ~QBoxLayout ()
24 virtual void addItem ( QLayoutItem * item )
25 Direction direction () const
26 void setDirection ( Direction direction )
27 void addSpacing ( int size )
28 void addStretch ( int stretch = 0 )
29 void addWidget ( QWidget * widget, int stretch = 0, int alignment = 0 )
30 void addLayout ( QLayout * layout, int stretch = 0 )
31 void addStrut ( int size )
32 void insertSpacing ( int index, int size )
33 void insertStretch ( int index, int stretch = 0 )
34 void insertWidget ( int index, QWidget * widget, int stretch = 0, int
35 alignment = 0 )
36 void insertLayout ( int index, QLayout * layout, int stretch = 0 )
37 bool setStretchFactor ( QWidget * w, int stretch )
38 bool setStretchFactor ( QLayout * l, int stretch )
39 virtual QSize sizeHint () const
40 virtual QSize minimumSize () const
41 virtual QSize maximumSize () const
42 virtual bool hasHeightForWidth () const
43 virtual int heightForWidth ( int w ) const
44 virtual QSizePolicy::ExpandData expanding () const
45 virtual void invalidate ()
46 virtual void setGeometry ( const QRect & r )
47 int findWidget ( QWidget * w )
48 Protected Members
50 void insertItem ( int index, QLayoutItem * item )
51
53 The QBoxLayout class lines up child widgets horizontally or vertically.
54 QBoxLayout takes the space it gets (from its parent layout or from the
56 mainWidget()), divides it up into a row of boxes, and makes each
57 managed widget fill one box.
58 <center>
60 [Image Omitted]
61 </center>
63 If the QBoxLayout's orientation is Horizontal the boxes are placed in a
65 row, with suitable sizes. Each widget (or other box) will get at least
66 its minimum size and at most its maximum size. Any excess space is
67 shared according to the stretch factors (more about that below).
68 <center>
70 [Image Omitted]
71 </center>
73 If the QBoxLayout's orientation is Vertical, the boxes are placed in a
75 column, again with suitable sizes.
76 The easiest way to create a QBoxLayout is to use one of the convenience
78 classes, e.g. QHBoxLayout (for Horizontal boxes) or QVBoxLayout (for
79 Vertical boxes). You can also use the QBoxLayout constructor directly,
80 specifying its direction as LeftToRight, Down, RightToLeft or Up.
81 If the QBoxLayout is not the top-level layout (i.e. it is not managing
83 all of the widget's area and children), you must add it to its parent
84 layout before you can do anything with it. The normal way to add a
85 layout is by calling parentLayout->addLayout().
86 Once you have done this, you can add boxes to the QBoxLayout using one
88 of four functions:
89 addWidget() to add a widget to the QBoxLayout and set the widget's
91 stretch factor. (The stretch factor is along the row of boxes.)
92 addSpacing() to create an empty box; this is one of the functions you
94 use to create nice and spacious dialogs. See below for ways to set
95 margins.
96 addStretch() to create an empty, stretchable box.
98 addLayout() to add a box containing another QLayout to the row and set
100 that layout's stretch factor.
101 Use insertWidget(), insertSpacing(), insertStretch() or insertLayout()
103 to insert a box at a specified position in the layout.
104 QBoxLayout also includes two margin widths:
106 setMargin() sets the width of the outer border. This is the width of
108 the reserved space along each of the QBoxLayout's four sides.
109 setSpacing() sets the width between neighboring boxes. (You can use
111 addSpacing() to get more space at a particular spot.)
112 The margin defaults to 0. The spacing defaults to the same as the
114 margin width for a top-level layout, or to the same as the parent
115 layout. Both are parameters to the constructor.
116 To remove a widget from a layout, call remove(). Calling
118 QWidget::hide() on a widget also effectively removes the widget from
119 the layout until QWidget::show() is called.
120 You will almost always want to use QVBoxLayout and QHBoxLayout rather
122 than QBoxLayout because of their convenient constructors.
123 See also QGrid, Layout Overview, Widget Appearance and Style, and
125 Layout Management.
126 Member Type Documentation
129 This type is used to determine the direction of a box layout.
130 QBoxLayout::LeftToRight - Horizontal, from left to right
132 QBoxLayout::RightToLeft - Horizontal, from right to left
134 QBoxLayout::TopToBottom - Vertical, from top to bottom
136 QBoxLayout::Down - The same as TopToBottom
138 QBoxLayout::BottomToTop - Vertical, from bottom to top
140 QBoxLayout::Up - The same as BottomToTop
142
145 spacing = -1, const char * name = 0 )
146 Constructs a new QBoxLayout with direction d and main widget parent.
147 parent may not be 0.
148 The margin is the number of pixels between the edge of the widget and
150 its managed children. The spacing is the default number of pixels
151 between neighboring children. If spacing is -1 the value of margin is
152 used for spacing.
153 name is the internal object name.
155 See also direction().
157
159 -1, const char * name = 0 )
160 Constructs a new QBoxLayout called name, with direction d, and inserts
161 it into parentLayout.
162 The spacing is the default number of pixels between neighboring
164 children. If spacing is -1, the layout will inherit its parent's
165 spacing().
166
168 )
169 Constructs a new QBoxLayout called name, with direction d.
170 If spacing is -1, the layout will inherit its parent's spacing();
172 otherwise spacing is used.
173 You must insert this box into another layout.
175
177 Destroys this box layout.
178 The layout's widgets aren't destroyed.
180
182 Adds item to the end of this box layout.
183 Examples:
185 Reimplemented from QLayout.
187
189 Adds layout to the end of the box, with serial stretch factor stretch.
190 When a layout is constructed with another layout as its parent, you
192 don't need to call addLayout(); the child layout is automatically added
193 to the parent layout as it is constructed.
194 See also insertLayout(), setAutoAdd(), addWidget(), and addSpacing().
196 Examples:
198
200 Adds a non-stretchable space with size size to the end of this box
201 layout. QBoxLayout provides default margin and spacing. This function
202 adds additional space.
203 See also insertSpacing() and addStretch().
205 Example: listbox/listbox.cpp.
207
209 Adds a stretchable space with zero minimum size and stretch factor
210 stretch to the end of this box layout.
211 See also addSpacing().
213 Examples:
215
217 Limits the perpendicular dimension of the box (e.g. height if the box
218 is LeftToRight) to a minimum of size. Other constraints may increase
219 the limit.
220
222 = 0 )
223 Adds widget to the end of this box layout, with a stretch factor of
224 stretch and alignment alignment.
225 The stretch factor applies only in the direction of the QBoxLayout, and
227 is relative to the other boxes and widgets in this QBoxLayout. Widgets
228 and boxes with higher stretch factors grow more.
229 If the stretch factor is 0 and nothing else in the QBoxLayout has a
231 stretch factor greater than zero, the space is distributed according to
232 the QWidget:sizePolicy() of each widget that's involved.
233 Alignment is specified by alignment which is a bitwise OR of
235 Qt::AlignmentFlags values. The default alignment is 0, which means that
236 the widget fills the entire cell.
237 From Qt 3.0, the alignment parameter is interpreted more aggressively
239 than in previous versions of Qt. A non-default alignment now indicates
240 that the widget should not grow to fill the available space, but should
241 be sized according to sizeHint().
242 See also insertWidget(), setAutoAdd(), addLayout(), and addSpacing().
244 Examples:
246
248 Returns the direction of the box. addWidget() and addSpacing() work in
249 this direction; the stretch stretches in this direction.
250 See also QBoxLayout::Direction, addWidget(), and addSpacing().
252
254 Returns whether this layout can make use of more space than sizeHint().
255 A value of Vertical or Horizontal means that it wants to grow in only
256 one dimension, whereas BothDirections means that it wants to grow in
257 both dimensions.
258 Reimplemented from QLayout.
260
262 Searches for widget w in this layout (not including child layouts).
263 Returns the index of w, or -1 if w is not found.
265
267 Returns TRUE if this layout's preferred height depends on its width;
268 otherwise returns FALSE.
269 Reimplemented from QLayoutItem.
271
273 Returns the layout's preferred height when it is w pixels wide.
274 Reimplemented from QLayoutItem.
276
278 Inserts item into this box layout at position index. If index is
279 negative, the item is added at the end.
280 Warning: Does not call QLayout::insertChildLayout() if item is a
282 QLayout.
283 See also addItem() and findWidget().
285
287 Inserts layout at position index, with stretch factor stretch. If index
289 is negative, the layout is added at the end.
290 layout becomes a child of the box layout.
292 See also setAutoAdd(), insertWidget(), and insertSpacing().
294
296 Inserts a non-stretchable space at position index, with size size. If
297 index is negative the space is added at the end.
298 The box layout has default margin and spacing. This function adds
300 additional space.
301 See also insertStretch().
303
305 Inserts a stretchable space at position index, with zero minimum size
306 and stretch factor stretch. If index is negative the space is added at
307 the end.
308 See also insertSpacing().
310
312 int alignment = 0 )
313 Inserts widget at position index, with stretch factor stretch and
314 alignment alignment. If index is negative, the widget is added at the
315 end.
316 The stretch factor applies only in the direction of the QBoxLayout, and
318 is relative to the other boxes and widgets in this QBoxLayout. Widgets
319 and boxes with higher stretch factors grow more.
320 If the stretch factor is 0 and nothing else in the QBoxLayout has a
322 stretch factor greater than zero, the space is distributed according to
323 the QWidget:sizePolicy() of each widget that's involved.
324 Alignment is specified by alignment, which is a bitwise OR of
326 Qt::AlignmentFlags values. The default alignment is 0, which means that
327 the widget fills the entire cell.
328 From Qt 3.0, the alignment parameter is interpreted more aggressively
330 than in previous versions of Qt. A non-default alignment now indicates
331 that the widget should not grow to fill the available space, but should
332 be sized according to sizeHint().
333 See also setAutoAdd(), insertLayout(), and insertSpacing().
335
337 Resets cached information.
338 Reimplemented from QLayout.
340
342 Returns the maximum size needed by this box layout.
343 Reimplemented from QLayout.
345
347 Returns the minimum size needed by this box layout.
348 Reimplemented from QLayout.
350
352 Sets the direction of this layout to direction.
353
355 Resizes managed widgets within the rectangle r.
356 Reimplemented from QLayout.
358
360 Sets the stretch factor for widget w to stretch and returns TRUE if w
361 is found in this layout (not including child layouts); otherwise
362 returns FALSE.
363
365 This is an overloaded member function, provided for convenience. It
366 behaves essentially like the above function.
367 Sets the stretch factor for the layout l to stretch and returns TRUE if
369 l is found in this layout (not including child layouts); otherwise
370 returns FALSE.
371
373 Returns the preferred size of this box layout.
374 Reimplemented from QLayoutItem.
376
379 http://doc.trolltech.com/qboxlayout.html
380 http://www.trolltech.com/faq/tech.html
381
383 Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
384 license file included in the distribution for a complete license
385 statement.
386
388 Generated automatically from the source code.
389
391 If you find a bug in Qt, please report it as described in
392 http://doc.trolltech.com/bughowto.html. Good bug reports help us to
393 help you. Thank you.
394 The definitive Qt documentation is provided in HTML format; it is
396 located at $QTDIR/doc/html and can be read using Qt Assistant or with a
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399 by Trolltech.
400 If you find errors in this manual page, please report them to qt-
402 bugs@trolltech.com. Please include the name of the manual page
403 (qboxlayout.3qt) and the Qt version (3.3.8).
404Trolltech AS 2 February 2007 QBoxLayout(3qt)