.BI "void \fBqDrawShadeLine\fR ( TQPainter * p, int x1, int y1, int x2, int y2, const TQColorGroup & g, bool sunken, int lineWidth, int midLineWidth )"
.BI "void \fBqDrawShadeRect\fR ( TQPainter * p, int x, int y, int w, int h, const TQColorGroup & g, bool sunken, int lineWidth, int midLineWidth, const TQBrush * fill )"
.BI "void \fBqDrawShadePanel\fR ( TQPainter * p, int x, int y, int w, int h, const TQColorGroup & g, bool sunken, int lineWidth, const TQBrush * fill )"
The painter provides highly optimized functions to do most of the drawing GUI programs require. TQPainter can draw everything from simple lines to complex shapes like pies and chords. It can also draw aligned text and pixmaps. Normally, it draws in a "natural" coordinate system, but it can also do view and world transformation.
Mostly, all this is done inside a paint event. (In fact, 99% of all TQPainter use is in a reimplementation of TQWidget::paintEvent(), and the painter is heavily optimized for such use.) Here's one very simple example:
font() is the currently set font. If you set a font that isn't available, TQt finds a close match. In fact font() returns what you set using setFont() and fontInfo() returns the font actually being used (which may be the same).
brush() is the currently set brush; the color or pattern that's used for filling e.g. circles.
.IP
.TP
pen() is the currently set pen; the color or stipple that's used for drawing lines or boundaries.
.IP
.TP
backgroundMode() is \fCOpaque\fR or \fCTransparent\fR, i.e. whether backgroundColor() is used or not.
.IP
.TP
backgroundColor() only applies when backgroundMode() is Opaque and pen() is a stipple. In that case, it describes the color of the background pixels in the stipple.
.IP
.TP
rasterOp() is how pixels drawn interact with the pixels already there.
.IP
.TP
brushOrigin() is the origin of the tiled brushes, normally the origin of the window.
.IP
.TP
viewport(), window(), worldMatrix() and many more make up the painter's coordinate transformation system. See The Coordinate System for an explanation of this, or see below for a very brief overview of the functions.
.IP
.TP
hasClipping() is whether the painter clips at all. (The paint device clips, too.) If the painter clips, it clips to clipRegion().
.IP
.TP
pos() is the current position, set by moveTo() and used by lineTo().
Note that some of these settings mirror settings in some paint devices, e.g. TQWidget::font(). TQPainter::begin() (or the TQPainter constructor) copies these attributes from the paint device. Calling, for example, TQWidget::setFont() doesn't take effect until the next time a painter begins painting on it.
The core functionality of TQPainter is drawing, and there are functions to draw most primitives: drawPoint(), drawPoints(), drawLine(), drawRect(), drawWinFocusRect(), drawRoundRect(), drawEllipse(), drawArc(), drawPie(), drawChord(), drawLineSegments(), drawPolyline(), drawPolygon(), drawConvexPolygon() and drawCubicBezier(). All of these functions take integer coordinates; there are no floating-point versions since we want drawing to be as fast as possible.
There are functions to draw pixmaps/images, namely drawPixmap(), drawImage() and drawTiledPixmap(). drawPixmap() and drawImage() produce the same result, except that drawPixmap() is faster on-screen and drawImage() faster and sometimes better on TQPrinter and TQPicture.
Text drawing is done using drawText(), and when you need fine-grained positioning, boundingRect() tells you where a given drawText() command would draw.
There is a drawPicture() function that draws the contents of an entire TQPicture using this painter. drawPicture() is the only function that disregards all the painter's settings: the TQPicture has its own settings.
Normally, the TQPainter operates on the device's own coordinate system (usually pixels), but TQPainter has good support for coordinate transformation. See The Coordinate System for a more general overview and a simple example.
The most common functions used are scale(), rotate(), translate() and shear(), all of which operate on the worldMatrix(). setWorldMatrix() can replace or add to the currently set worldMatrix().
setViewport() sets the rectangle on which TQPainter operates. The default is the entire device, which is usually fine, except on printers. setWindow() sets the coordinate system, that is, the rectangle that maps to viewport(). What's drawn inside the window() ends up being inside the viewport(). The window's default is the same as the viewport, and if you don't use the transformations, they are optimized away, gaining another little bit of speed.
After all the coordinate transformation is done, TQPainter can clip the drawing to an arbitrary rectangle or region. hasClipping() is TRUE if TQPainter clips, and clipRegion() returns the clip region. You can set it using either setClipRegion() or setClipRect(). Note that the clipping can be slow. It's all system-dependent, but as a rule of thumb, you can assume that drawing speed is inversely proportional to the number of rectangles in the clip region.
After TQPainter's clipping, the paint device may also clip. For example, most widgets clip away the pixels used by child widgets, and most printers clip away an area near the edges of the paper. This additional clipping is not reflected by the return value of clipRegion() or hasClipping().
isActive() indicates whether the painter is active. begin() (and the most usual constructor) makes it active. end() (and the destructor) deactivates it. If the painter is active, device() returns the paint device on which the painter paints.
Sometimes it is desirable to make someone else paint on an unusual TQPaintDevice. TQPainter supports a static function to do this, redirect(). We recommend not using it, but for some hacks it's perfect.
\fBWarning:\fR Note that TQPainter does not attempt to work around coordinate limitations in the underlying window system. Some platforms may behave incorrectly with coordinates as small as +/-4000.
See also TQPaintDevice, TQWidget, TQPixmap, TQPrinter, TQPicture, Application Walkthrough, Coordinate System Overview, Graphics Classes, and Image Processing Classes.
Constructs a painter that begins painting the paint device \fIpd\fR immediately. Depending on the underlying graphic system the painter will paint over children of the paintdevice if \fIunclipped\fR is TRUE.
This constructor is convenient for short-lived painters, e.g. in a paint event and should be used only once. The constructor calls begin() for you and the TQPainter destructor automatically calls end().
Since the constructor cannot provide feedback when the initialization of the painter failed you should rather use begin() and end() to paint on external devices, e.g. printers.
Constructs a painter that begins painting the paint device \fIpd\fR immediately, with the default arguments taken from \fIcopyAttributes\fR. The painter will paint over children of the paint device if \fIunclipped\fR is TRUE (although this is not supported on all platforms).
Begins painting the paint device \fIpd\fR and returns TRUE if successful; otherwise returns FALSE. If \fIunclipped\fR is TRUE, the painting will not be clipped at the paint device's boundaries, (although this is not supported by all platforms).
.PP
The errors that can occur are serious problems, such as these:
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
This version opens the painter on a paint device \fIpd\fR and sets the initial pen, background color and font from \fIcopyAttributes\fR, painting over the paint device's children when \fIunclipped\fR is TRUE. This is equivalent to:
This begin function is convenient for double buffering. When you draw in a pixmap instead of directly in a widget (to later bitBlt the pixmap into the widget) you will need to set the widget's font etc. This function does exactly that.
Returns the bounding rectangle of the aligned text that would be printed with the corresponding drawText() function using the first \fIlen\fR characters of the string if \fIlen\fR is > -1, or the whole of the string if \fIlen\fR is -1. The drawing, and hence the bounding rectangle, is constrained to the rectangle that begins at point \fI(x, y)\fR with width \fIw\fR and hight \fIh\fR, or to the rectangle required to draw the text, whichever is the larger.
The \fIflags\fR argument is the bitwise OR of the following flags: <center>.nf
.TS
l - l. Flag Meaning AlignAuto aligns according to the language, usually left. AlignLeft aligns to the left border. AlignRight aligns to the right border. AlignHCenter aligns horizontally centered. AlignTop aligns to the top border. AlignBottom aligns to the bottom border. AlignVCenter aligns vertically centered. AlignCenter (== AlignHCenter | AlignVCenter). SingleLine ignores newline characters in the text. ExpandTabs expands tabs. ShowPrefix interprets "&x" as " WordBreak
.TE
.fi
</center>
.PP
Horizontal alignment defaults to AlignLeft and vertical alignment defaults to AlignTop.
.PP
If several of the horizontal or several of the vertical alignment flags are set, the resulting alignment is undefined.
Returns the bounding rectangle of the aligned text that would be printed with the corresponding drawText() function using the first \fIlen\fR characters from \fIstr\fR if \fIlen\fR is > -1, or the whole of \fIstr\fR if \fIlen\fR is -1. The drawing, and hence the bounding rectangle, is constrained to the rectangle \fIr\fR, or to the rectangle required to draw the text, whichever is the larger.
Returns the currently set clip region. Note that the clip region is given in physical device coordinates and \fInot\fR subject to any coordinate transformation if \fIm\fR is equal to CoordDevice (the default). If \fIm\fR equals CoordPainter the returned region is in model coordinates.
Draws an arc defined by the rectangle \fI(x, y, w, h)\fR, the start angle \fIa\fR and the arc length \fIalen\fR.
.PP
The angles \fIa\fR and \fIalen\fR are 1/16th of a degree, i.e. a full circle equals 5760 (16*360). Positive values of \fIa\fR and \fIalen\fR mean counter-clockwise while negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.
Draws a chord defined by the rectangle \fI(x, y, w, h)\fR, the start angle \fIa\fR and the arc length \fIalen\fR.
.PP
The chord is filled with the current brush().
.PP
The angles \fIa\fR and \fIalen\fR are 1/16th of a degree, i.e. a full circle equals 5760 (16*360). Positive values of \fIa\fR and \fIalen\fR mean counter-clockwise while negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.
Draws at (\fIx\fR, \fIy\fR) the \fIsw\fR by \fIsh\fR area of pixels from (\fIsx\fR, \fIsy\fR) in \fIimage\fR, using \fIconversionFlags\fR if the image needs to be converted to a pixmap. The default value for \fIconversionFlags\fR is 0; see convertFromImage() for information about what other values do.
This function may convert \fIimage\fR to a pixmap and then draw it, if device() is a TQPixmap or a TQWidget, or else draw it directly, if device() is a TQPrinter or TQPicture.
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Draws the image \fIi\fR at point \fIp\fR.
.PP
If the image needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the \fIconversion_flags\fR to specify how you'd prefer this to happen.
Draws \fInlines\fR separate lines from points defined in \fIa\fR, starting at \fIa[index]\fR (\fIindex\fR defaults to 0). If \fInlines\fR is -1 (the default) all points until the end of the array are used (i.e. (a.size()-index)/2 lines are drawn).
.PP
Draws the 1st line from \fIa[index]\fR to \fIa[index+1]\fR. Draws the 2nd line from \fIa[index+2]\fR to \fIa[index+3]\fR etc.
Draws a pie defined by the rectangle \fI(x, y, w, h)\fR, the start angle \fIa\fR and the arc length \fIalen\fR.
.PP
The pie is filled with the current brush().
.PP
The angles \fIa\fR and \fIalen\fR are 1/16th of a degree, i.e. a full circle equals 5760 (16*360). Positive values of \fIa\fR and \fIalen\fR mean counter-clockwise while negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.
.PP
See also drawArc() and drawChord().
.PP
Examples:
.)l drawdemo/drawdemo.cpp, grapher/grapher.cpp, t10/cannon.cpp, and t9/cannon.cpp.
Draws a pixmap at \fI(x, y)\fR by copying a part of \fIpixmap\fR into the paint device.
.PP
\fI(x, y)\fR specifies the top-left point in the paint device that is to be drawn onto. \fI(sx, sy)\fR specifies the top-left point in \fIpixmap\fR that is to be drawn. The default is (0, 0).
.PP
\fI(sw, sh)\fR specifies the size of the pixmap that is to be drawn. The default, (-1, -1), means all the way to the bottom right of the pixmap.
Draws/plots an array of points, \fIa\fR, using the current pen.
.PP
If \fIindex\fR is non-zero (the default is zero) only points from \fIindex\fR are drawn. If \fInpoints\fR is negative (the default) the rest of the points from \fIindex\fR are drawn. If \fInpoints\fR is zero or greater, \fInpoints\fR points are drawn.
Draws the polygon defined by the \fInpoints\fR points in \fIa\fR starting at \fIa[index]\fR. (\fIindex\fR defaults to 0.)
.PP
If \fInpoints\fR is -1 (the default) all points until the end of the array are used (i.e. a.size()-index line segments define the polygon).
.PP
The first point is always connected to the last point.
.PP
The polygon is filled with the current brush(). If \fIwinding\fR is TRUE, the polygon is filled using the winding fill algorithm. If \fIwinding\fR is FALSE, the polygon is filled using the even-odd (alternative) fill algorithm.
Draws the text from position \fIpos\fR, at point \fIp\fR. If \fIlen\fR is -1 the entire string is drawn, otherwise just the first \fIlen\fR characters. The text's direction is specified by \fIdir\fR.
.PP
Note that the meaning of \fIy\fR is not the same for the two drawText() varieties. For overloads that take a simple \fIx\fR, \fIy\fR pair (or a point), the \fIy\fR value is the text's baseline; for overloads that take a rectangle, \fIrect.y()\fR is the top of the rectangle and the text is aligned within that rectangle in accordance with the alignment flags.
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Draws the given text at position \fIx\fR, \fIy\fR. If \fIlen\fR is -1 (the default) all the text is drawn, otherwise the first \fIlen\fR characters are drawn. The text's direction is given by \fIdir\fR.
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Draws the text from position \fIpos\fR, at point \fI(x, y)\fR. If \fIlen\fR is -1 the entire string is drawn, otherwise just the first \fIlen\fR characters. The text's direction is specified by \fIdir\fR.
Draws the given text within the rectangle starting at \fIx\fR, \fIy\fR, with width \fIw\fR and height \fIh\fR. If \fIlen\fR is -1 (the default) all the text is drawn, otherwise the first \fIlen\fR characters are drawn. The text's flags that are given in the \fIflags\fR parameter are TQt::AlignmentFlags and TQt::TextFlags OR'd together. \fIbr\fR (if not null) is set to the actual bounding rectangle of the output. The \fIinternal\fR parameter is for internal use only.
Draws a tiled \fIpixmap\fR in the specified rectangle.
.PP
\fI(x, y)\fR specifies the top-left point in the paint device that is to be drawn onto; with the width and height given by \fIw\fR and \fIh\fR. \fI(sx, sy)\fR specifies the top-left point in \fIpixmap\fR that is to be drawn. The default is (0, 0).
.PP
Calling drawTiledPixmap() is similar to calling drawPixmap() several times to fill (tile) an area with a pixmap, but is potentially much more efficient depending on the underlying window system.
Draws a Windows focus rectangle with upper left corner at (\fIx\fR, \fIy\fR) and with width \fIw\fR and height \fIh\fR using a pen color that contrasts with \fIbgColor\fR.
.PP
This function draws a stippled rectangle (XOR is not used) that is used to indicate keyboard focus (when the QApplication::style() is \fCWindowStyle\fR).
Ends painting. Any resources used while painting are released.
.PP
Note that while you mostly don't need to call end(), the destructor will do it, there is at least one common case when it is needed, namely double buffering.
Returns the font info for the painter, if the painter is active. It is not possible to obtain font information for an inactive painter, so the return value is undefined if the painter is not active.
Returns the font metrics for the painter, if the painter is active. It is not possible to obtain metrics for an inactive painter, so the return value is undefined if the painter is not active.
.PP
See also fontInfo() and isActive().
.PP
Examples:
.)l action/application.cpp, application/application.cpp, desktop/desktop.cpp, drawdemo/drawdemo.cpp, helpviewer/helpwindow.cpp, mdi/application.cpp, and qwerty/qwerty.cpp.
Redirects all paint commands for a paint device, \fIpdev\fR, to another paint device, \fIreplacement\fR, unless \fIreplacement\fR is 0. If \fIreplacement\fR is 0, the redirection for \fIpdev\fR is removed.
Sets the background color of the painter to \fIc\fR.
.PP
The background color is the color that is filled in when drawing opaque text, stippled lines and bitmaps. The background color has no effect in transparent background mode (which is the default).
.PP
See also backgroundColor(), setBackgroundMode(), and BackgroundMode.
Sets the clip region to the rectangle \fIx\fR, \fIy\fR, \fIw\fR, \fIh\fR and enables clipping. The clip mode is set to \fIm\fR.
.PP
If \fIm\fR is CoordDevice (the default), the coordinates given for the clip region are taken to be physical device coordinates and are \fInot\fR subject to any coordinate transformations. If \fIm\fR is CoordPainter, the coordinates given for the clip region are taken to be model coordinates.
Set the tab stop width to \fIts\fR, i.e. locates tab stops at \fIts\fR, 2*\fIts\fR, 3*\fIts\fR and so on.
.PP
Tab stops are used when drawing formatted text with ExpandTabs set. This fixed tab stop value is used only if no tab array is set (which is the default case).
.PP
A value of 0 (the default) implies a tabstop setting of 8 times the width of the character 'x' in the font currently set on the painter.
.PP
See also tabStops(), setTabArray(), drawText(), and fontMetrics().
Sets the viewport rectangle view transformation for the painter and enables view transformation.
.PP
The viewport rectangle is part of the view transformation. The viewport specifies the device coordinate system and is specified by the \fIx\fR, \fIy\fR, \fIw\fR width and \fIh\fR height parameters. Its sister, the window(), specifies the logical coordinate system.
.PP
The default viewport rectangle is the same as the device's rectangle. See the Coordinate System Overview for an overview of coordinate transformation.
.PP
See also viewport(), setWindow(), setViewXForm(), setWorldMatrix(), setWorldXForm(), and xForm().
Sets the window rectangle view transformation for the painter and enables view transformation.
.PP
The window rectangle is part of the view transformation. The window specifies the logical coordinate system and is specified by the \fIx\fR, \fIy\fR, \fIw\fR width and \fIh\fR height parameters. Its sister, the viewport(), specifies the device coordinate system.
.PP
The default window rectangle is the same as the device's rectangle. See the Coordinate System Overview for an overview of coordinate transformation.
.PP
See also window(), setViewport(), setViewXForm(), setWorldMatrix(), and setWorldXForm().
Sets the world transformation matrix to \fIm\fR and enables world transformation.
.PP
If \fIcombine\fR is TRUE, then \fIm\fR is combined with the current transformation matrix, otherwise \fIm\fR replaces the current transformation matrix.
If \fIm\fR is the identity matrix and \fIcombine\fR is FALSE, this function calls setWorldXForm(FALSE). (The identity matrix is the matrix where TQWMatrix::m11() and TQWMatrix::m22() are 1.0 and the rest are 0.0.)
Note that you should always use \fIcombine\fR when you are drawing into a TQPicture. Otherwise it may not be possible to replay the picture with additional transformations. Using translate(), scale(), etc., is safe.
Enables world transformations if \fIenable\fR is TRUE, or disables world transformations if \fIenable\fR is FALSE. The world transformation matrix is not changed.
.PP
See also setWorldMatrix(), setWindow(), setViewport(), setViewXForm(), and xForm().
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Returns the point array \fIav\fR transformed from model coordinates to device coordinates. The \fIindex\fR is the first point in the array and \fInpoints\fR denotes the number of points to be transformed. If \fInpoints\fR is negative, all points from \fIav[index]\fR until the last point in the array are transformed.
.PP
The returned point array consists of the number of points that were transformed.
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Returns the point array \fIad\fR transformed from device coordinates to model coordinates. The \fIindex\fR is the first point in the array and \fInpoints\fR denotes the number of points to be transformed. If \fInpoints\fR is negative, all points from \fIad[index]\fR until the last point in the array are transformed.
.PP
The returned point array consists of the number of points that were transformed.
If you want to use a TQFrame widget instead, you can make it display a plain rectangle, for example \fCTQFrame::setFrameStyle( TQFrame::Box | TQFrame::Plain )\fR.
\fBWarning:\fR This function does not look at TQWidget::style() or QApplication::style(). Use the drawing functions in TQStyle to make widgets that follow the current GUI style.
If you want to use a TQFrame widget instead, you can make it display a shaded line, for example \fCTQFrame::setFrameStyle( TQFrame::HLine | TQFrame::Sunken )\fR.
\fBWarning:\fR This function does not look at TQWidget::style() or QApplication::style(). Use the drawing functions in TQStyle to make widgets that follow the current GUI style.
If you want to use a TQFrame widget instead, you can make it display a shaded panel, for example \fCTQFrame::setFrameStyle( TQFrame::Panel | TQFrame::Sunken )\fR.
\fBWarning:\fR This function does not look at TQWidget::style() or QApplication::style(). Use the drawing functions in TQStyle to make widgets that follow the current GUI style.
.SH "void qDrawShadeRect ( TQPainter * p, int x, int y, int w, int h, const TQColorGroup & g, bool sunken, int lineWidth, int midLineWidth, const TQBrush * fill )"
If you want to use a TQFrame widget instead, you can make it display a shaded rectangle, for example \fCTQFrame::setFrameStyle( TQFrame::Box | TQFrame::Raised )\fR.
\fBWarning:\fR This function does not look at TQWidget::style() or QApplication::style(). Use the drawing functions in TQStyle to make widgets that follow the current GUI style.
\fBWarning:\fR This function does not look at TQWidget::style() or QApplication::style(). Use the drawing functions in TQStyle to make widgets that follow the current GUI style.
If you want to use a TQFrame widget instead, you can make it display a shaded panel, for example \fCTQFrame::setFrameStyle( TQFrame::WinPanel | TQFrame::Raised )\fR.
\fBWarning:\fR This function does not look at TQWidget::style() or QApplication::style(). Use the drawing functions in TQStyle to make widgets that follow the current GUI style.
