1QPaintDevice(3qt) QPaintDevice(3qt)
2
6 QPaintDevice - The base class of objects that can be painted
7
9 #include <qpaintdevice.h>
10 Inherited by QWidget, QPixmap, QPicture, and QPrinter.
12 Public Members
14 virtual ~QPaintDevice ()
15 bool isExtDev () const
16 bool paintingActive () const
17 virtual HDC handle () const
18 virtual Qt::HANDLE handle () const
19 Display * x11Display () const
20 int x11Screen () const
21 int x11Depth () const
22 int x11Cells () const
23 Qt::HANDLE x11Colormap () const
24 bool x11DefaultColormap () const
25 void * x11Visual () const
26 bool x11DefaultVisual () const
27 Static Public Members
29 Display * x11AppDisplay ()
30 int x11AppScreen ()
31 int x11AppDpiX ()
32 int x11AppDpiY ()
33 void x11SetAppDpiX ( int dpi )
34 void x11SetAppDpiY ( int dpi )
35 int x11AppDepth ()
36 int x11AppCells ()
37 Qt::HANDLE x11AppRootWindow ()
38 Qt::HANDLE x11AppColormap ()
39 bool x11AppDefaultColormap ()
40 void * x11AppVisual ()
41 bool x11AppDefaultVisual ()
42 int x11AppDepth ( int screen )
43 int x11AppCells ( int screen )
44 Qt::HANDLE x11AppRootWindow ( int screen )
45 Qt::HANDLE x11AppColormap ( int screen )
46 void * x11AppVisual ( int screen )
47 bool x11AppDefaultColormap ( int screen )
48 bool x11AppDefaultVisual ( int screen )
49 int x11AppDpiX ( int screen )
50 int x11AppDpiY ( int screen )
51 void x11SetAppDpiX ( int dpi, int screen )
52 void x11SetAppDpiY ( int dpi, int screen )
53 Protected Members
55 QPaintDevice ( uint devflags )
56 virtual bool cmd ( int, QPainter *, QPDevCmdParam * )
57
59 void bitBlt ( QPaintDevice * dst, int dx, int dy, const QPaintDevice *
60 src, int sx, int sy, int sw, int sh, Qt::RasterOp rop, bool
61 ignoreMask )
62 void bitBlt ( QPaintDevice * dst, const QPoint & dp, const QPaintDevice
63 * src, const QRect & sr, RasterOp rop )
64
66 The QPaintDevice class is the base class of objects that can be
67 painted.
68 A paint device is an abstraction of a two-dimensional space that can be
70 drawn using a QPainter. The drawing capabilities are implemented by the
71 subclasses QWidget, QPixmap, QPicture and QPrinter.
72 The default coordinate system of a paint device has its origin located
74 at the top-left position. X increases to the right and Y increases
75 downward. The unit is one pixel. There are several ways to set up a
76 user-defined coordinate system using the painter, for example, using
77 QPainter::setWorldMatrix().
78 Example (draw on a paint device):
80 void MyWidget::paintEvent( QPaintEvent * )
82 {
83 QPainter p; // our painter
84 p.begin( this ); // start painting the widget
85 p.setPen( red ); // red outline
86 p.setBrush( yellow ); // yellow fill
87 p.drawEllipse( 10, 20, 100,100 ); // 100x100 ellipse at position (10, 20)
88 p.end(); // painting done
89 }
90 The bit block transfer is an extremely useful operation for copying
92 pixels from one paint device to another (or to itself). It is
93 implemented as the global function bitBlt().
94 Example (scroll widget contents 10 pixels to the right):
96 bitBlt( myWidget, 10, 0, myWidget );
98 Warning: Qt requires that a QApplication object exists before any paint
100 devices can be created. Paint devices access window system resources,
101 and these resources are not initialized before an application object is
102 created.
103 See also Graphics Classes and Image Processing Classes.
105
108 Constructs a paint device with internal flags devflags. This
109 constructor can be invoked only from QPaintDevice subclasses.
110
112 Destroys the paint device and frees window system resources.
113
115 protected]
116 Internal virtual function that interprets drawing commands from the
117 painter.
118 Implemented by subclasses that have no direct support for drawing
120 graphics (external paint devices, for example, QPicture).
121
123 Returns the window system handle of the paint device, for low-level
124 access. Using this function is not portable.
125 The HANDLE type varies with platform; see qpaintdevice.h and
127 qwindowdefs.h for details.
128 See also x11Display().
130
132 Returns TRUE if the device is an external paint device; otherwise
133 returns FALSE.
134 External paint devices cannot be bitBlt()'ed from. QPicture and
136 QPrinter are external paint devices.
137
139 Returns TRUE if the device is being painted, i.e. someone has called
140 QPainter::begin() but not yet called QPainter::end() for this device;
141 otherwise returns FALSE.
142 See also QPainter::isActive().
144
146 Returns the number of entries in the colormap for the default screen of
147 the X display global to the application (X11 only). Using this function
148 is not portable.
149 See also x11Colormap().
151
153 This is an overloaded member function, provided for convenience. It
154 behaves essentially like the above function.
155 Returns the number of entries in the colormap for screen screen of the
157 X display global to the application (X11 only). Using this function is
158 not portable.
159 See also x11Colormap().
161
163 Returns the colormap for the default screen of the X display global to
164 the application (X11 only). Using this function is not portable.
165 See also x11Cells().
167
169 This is an overloaded member function, provided for convenience. It
170 behaves essentially like the above function.
171 Returns the colormap for screen screen of the X display global to the
173 application (X11 only). Using this function is not portable.
174 See also x11Cells().
176
178 Returns the default colormap for the default screen of the X display
179 global to the application (X11 only). Using this function is not
180 portable.
181 See also x11Cells().
183
185 This is an overloaded member function, provided for convenience. It
186 behaves essentially like the above function.
187 Returns the default colormap for screen screen of the X display global
189 to the application (X11 only). Using this function is not portable.
190 See also x11Cells().
192
194 Returns TRUE if the Visual used is the default for the default screen
195 of the X display global to the application (X11 only); otherwise
196 returns FALSE. Using this function is not portable.
197
199 This is an overloaded member function, provided for convenience. It
200 behaves essentially like the above function.
201 Returns TRUE if the Visual used is the default for screen screen of the
203 X display global to the application (X11 only); otherwise returns
204 FALSE. Using this function is not portable.
205
207 Returns the depth for screen screen of the X display global to the
208 application (X11 only). Using this function is not portable.
209 See also QPixmap::defaultDepth().
211
213 This is an overloaded member function, provided for convenience. It
214 behaves essentially like the above function.
215 Returns the depth for the default screen of the X display global to the
217 application (X11 only). Using this function is not portable.
218 See also QPixmap::defaultDepth().
220
222 Returns a pointer to the X display global to the application (X11
223 only). Using this function is not portable.
224 See also handle().
226
228 Returns the horizontal DPI of the X display (X11 only) for screen
229 screen. Using this function is not portable. See QPaintDeviceMetrics
230 for portable access to related information. Using this function is not
231 portable.
232 See also x11AppDpiY(), x11SetAppDpiX(), and
234 QPaintDeviceMetrics::logicalDpiX().
235
237 This is an overloaded member function, provided for convenience. It
238 behaves essentially like the above function.
239 Returns the horizontal DPI of the X display (X11 only) for the default
241 screen. Using this function is not portable. See QPaintDeviceMetrics
242 for portable access to related information. Using this function is not
243 portable.
244
246 Returns the vertical DPI of the X11 display (X11 only) for screen
247 screen. Using this function is not portable. See QPaintDeviceMetrics
248 for portable access to related information. Using this function is not
249 portable.
250 See also x11AppDpiX(), x11SetAppDpiY(), and
252 QPaintDeviceMetrics::logicalDpiY().
253
255 This is an overloaded member function, provided for convenience. It
256 behaves essentially like the above function.
257 Returns the vertical DPI of the X11 display (X11 only) for the default
259 screen. Using this function is not portable. See QPaintDeviceMetrics
260 for portable access to related information. Using this function is not
261 portable.
262 See also x11AppDpiX(), x11SetAppDpiY(), and
264 QPaintDeviceMetrics::logicalDpiY().
265
267 Returns the root window for the default screen of the X display global
268 to the applicatoin (X11 only). Using this function is not portable.
269
271 This is an overloaded member function, provided for convenience. It
272 behaves essentially like the above function.
273 Returns the root window for screen screen of the X display global to
275 the applicatoin (X11 only). Using this function is not portable.
276
278 Returns the screen number on the X display global to the application
279 (X11 only). Using this function is not portable.
280
282 Returns the Visual for the default screen of the X display global to
283 the application (X11 only). Using this function is not portable.
284
286 This is an overloaded member function, provided for convenience. It
287 behaves essentially like the above function.
288 Returns the Visual for screen screen of the X display global to the
290 application (X11 only). Using this function is not portable.
291
293 Returns the number of entries in the colormap of the X display for the
294 paint device (X11 only). Using this function is not portable.
295 See also x11Colormap().
297
299 Returns the colormap of the X display for the paint device (X11 only).
300 Using this function is not portable.
301 See also x11Cells().
303
305 Returns the default colormap of the X display for the paint device (X11
306 only). Using this function is not portable.
307 See also x11Cells().
309
311 Returns the default Visual of the X display for the paint device (X11
312 only). Using this function is not portable.
313
315 Returns the depth of the X display for the paint device (X11 only).
316 Using this function is not portable.
317 See also QPixmap::defaultDepth().
319
321 Returns a pointer to the X display for the paint device (X11 only).
322 Using this function is not portable.
323 See also handle().
325
327 Returns the screen number on the X display for the paint device (X11
328 only). Using this function is not portable.
329
331 Sets the value returned by x11AppDpiX() to dpi for screen screen. The
332 default is determined by the display configuration. Changing this value
333 will alter the scaling of fonts and many other metrics and is not
334 recommended. Using this function is not portable.
335 See also x11SetAppDpiY().
337
339 This is an overloaded member function, provided for convenience. It
340 behaves essentially like the above function.
341 Sets the value returned by x11AppDpiX() to dpi for the default screen.
343 The default is determined by the display configuration. Changing this
344 value will alter the scaling of fonts and many other metrics and is not
345 recommended. Using this function is not portable.
346
348 Sets the value returned by x11AppDpiY() to dpi for screen screen. The
349 default is determined by the display configuration. Changing this value
350 will alter the scaling of fonts and many other metrics and is not
351 recommended. Using this function is not portable.
352 See also x11SetAppDpiX().
354
356 This is an overloaded member function, provided for convenience. It
357 behaves essentially like the above function.
358 Sets the value returned by x11AppDpiY() to dpi for the default screen.
360 The default is determined by the display configuration. Changing this
361 value will alter the scaling of fonts and many other metrics and is not
362 recommended. Using this function is not portable.
363
365 Returns the Visual of the X display for the paint device (X11 only).
366 Using this function is not portable.
367
370 int sx, int sy, int sw, int sh, Qt::RasterOp rop, bool ignoreMask )
371 Copies a block of pixels from src to dst, perhaps merging each pixel
372 according to the raster operation rop. sx, sy is the top-left pixel in
373 src (0, 0) by default, dx, dy is the top-left position in dst and sw,
374 sh is the size of the copied block (all of src by default).
375 The most common values for rop are CopyROP and XorROP; the Qt::RasterOp
377 documentation defines all the possible values.
378 If ignoreMask is FALSE (the default) and src is a masked QPixmap, the
380 entire blit is masked by src->mask().
381 If src, dst, sw or sh is 0, bitBlt() does nothing. If sw or sh is
383 negative bitBlt() copies starting at sx (and respectively, sy) and
384 ending at the right end (respectively, bottom) of src.
385 src must be a QWidget or QPixmap. You cannot blit from a QPrinter, for
387 example. bitBlt() does nothing if you attempt to blit from an
388 unsupported device.
389 bitBlt() does nothing if src has a greater depth than dst. If you need
391 to for example, draw a 24-bit pixmap on an 8-bit widget, you must use
392 drawPixmap().
393
395 const QRect & sr, RasterOp rop )
396 This is an overloaded member function, provided for convenience. It
397 behaves essentially like the above function.
398 Overloaded bitBlt() with the destination point dp and source rectangle
400 sr.
401
404 http://doc.trolltech.com/qpaintdevice.html
405 http://www.trolltech.com/faq/tech.html
406
408 Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
409 license file included in the distribution for a complete license
410 statement.
411
413 Generated automatically from the source code.
414
416 If you find a bug in Qt, please report it as described in
417 http://doc.trolltech.com/bughowto.html. Good bug reports help us to
418 help you. Thank you.
419 The definitive Qt documentation is provided in HTML format; it is
421 located at $QTDIR/doc/html and can be read using Qt Assistant or with a
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423 who prefer man pages, although this format is not officially supported
424 by Trolltech.
425 If you find errors in this manual page, please report them to qt-
427 bugs@trolltech.com. Please include the name of the manual page
428 (qpaintdevice.3qt) and the Qt version (3.3.8).
429Trolltech AS 2 February 2007 QPaintDevice(3qt)