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    41 

    42 #include "q3painter.h"

    43 #include "qpaintengine.h"

    44 

    45 #include <private/qpainter_p.h>

    46 

    47 QT_BEGIN_NAMESPACE

    48 

    49 /*!

    50     \class Q3Painter

    51     \brief The Q3Painter class is a Qt 3 compatibility wrapper for QPainter.

    52 

    53     \compat

    54 

    55     Prior to Qt 4, QPainter specialized the pen drawing for rectangle

    56     based functions (in particular: drawRect, drawEllipse,

    57     drawRoundRect, drawArc, drawChord and drawPie). When stroking a

    58     rectangle of width 10, the pen would draw a rectangle of width 10.

    59     Drawing a polygon defined by the corner points of the same

    60     rectangle the stroke would have a width of 11.

    61 

    62     The reason for this is best explained using the picture below:

    63 

    64     \img q3painter_rationale.png

    65 

    66     As we can see, stroking the rectangle so it gets a width of 10,

    67     means the pen is drawn on a rectangle on width 9. The polygon,

    68     however follows a consistent model.

    69 

    70     In Qt 4, all rectangle based functions have changed to follow the

    71     polygon approach, which means that the rectangle defines the size of

    72     the fill, and the pen follows the edges of the shape. For pen widths

    73     of 0 and 1 this means that the stroke will be inside the shape on the

    74     left and the top and outside on the bottom and right.

    75 

    76     The reason for the change in Qt 4 is so that we provide consistency

    77     for all drawing functions even with complex transformations.

    78 */

    79 

    80 /*!

    81     \fn Q3Painter::Q3Painter()

    82 

    83     Constructs a Q3Painter.

    84 */

    85 

    86 /*!

    87     \fn Q3Painter::Q3Painter(QPaintDevice *pdev)

    88 

    89     Constructs a Q3Painter that operates on device \a pdev.

    90 */

    91 

    92 /*!

    93     \internal

    94 */

    95 QRect Q3Painter::adjustedRectangle(const QRect &r)

    96 {

    97     QRect rect = r.normalized();

    98     int subtract = d_func()->rectSubtraction();

    99     if (subtract != 0)

   100         rect.setSize(QSize(rect.width() - subtract, rect.height() - subtract));

   101     return rect;

   102 }

   103 

   104 

   105 /*!

   106     \fn void Q3Painter::drawRect(int x, int y, int w, int h)

   107 

   108     \overload

   109 

   110     Draws the rectangle that fits inside the bounds specified by \a x,

   111     \a y, \a w and \a h using the current pen and brush.

   112 */

   113 

   114 /*!

   115     \fn void Q3Painter::drawRect(const QRect &r)

   116 

   117     Draws a rectangle that fits inside the rectangle \a r using the

   118     current pen and brush.

   119 

   120 */

   121 

   122 

   123 

   124 /*!

   125     \fn Q3Painter::drawEllipse(const QRect &r)

   126 

   127     Draws the ellipse that fits inside the bounds \a r using the

   128     current pen and brush.

   129 

   130 */

   131 

   132 /*!

   133     \fn Q3Painter::drawEllipse(int x, int y, int width, int height)

   134 

   135     \overload

   136 

   137     Draws an ellipse that fits inside the bounds specified by \a x,

   138     \a y, \a width and \a height using the current pen and brush.

   139 

   140 */

   141 

   142 /*!

   143     \fn void Q3Painter::drawPie(int x, int y, int w, int h, int

   144     startAngle, int spanAngle)

   145 

   146     \overload

   147 

   148     Draws a pie segment that fits inside the bounds (\a{x}, \a{y},

   149     \a{w}, \a{h}) with the given \a startAngle and \a spanAngle.

   150 */

   151 

   152 /*!

   153     \fn void Q3Painter::drawPie(const QRect &r, int a, int alen)

   154 

   155     Draws a pie defined by the rectangle \a r, the start angle \a a

   156     and the arc length \a alen.

   157 

   158     The pie is filled with the current brush().

   159 

   160     The angles \a a and \a alen are 1/16th of a degree, i.e. a full

   161     circle equals 5760 (16*360). Positive values of \a a and \a alen

   162     mean counter-clockwise while negative values mean the clockwise

   163     direction. Zero degrees is at the 3 o'clock position.

   164 

   165     \sa drawArc(), drawChord()

   166 */

   167 

   168 /*!

   169     \fn void Q3Painter::drawArc(int x, int y, int w, int h, int

   170     startAngle, int spanAngle)

   171 

   172     \overload

   173 

   174     Draws the arc that fits inside the rectangle (\a{x}, \a{y}, \a{w},

   175     \a{h}), with the given \a startAngle and \a spanAngle.

   176 */

   177 

   178 /*!

   179     \fn void Q3Painter::drawArc(const QRect &r, int a, int alen)

   180 

   181     Draws an arc defined by the rectangle \a r, the start angle \a a

   182     and the arc length \a alen.

   183 

   184     The angles \a a and \a alen are 1/16th of a degree, i.e. a full

   185     circle equals 5760 (16*360). Positive values of \a a and \a alen

   186     mean counter-clockwise while negative values mean the clockwise

   187     direction. Zero degrees is at the 3 o'clock position.

   188 

   189     Example:

   190     \snippet doc/src/snippets/code/src_qt3support_painting_q3painter.cpp 0

   191 

   192     \sa drawPie(), drawChord()

   193 */

   194 

   195 /*!

   196     \fn void Q3Painter::drawChord(int x, int y, int w, int h, int

   197     startAngle, int spanAngle)

   198 

   199     \overload

   200 

   201     Draws a chord that fits inside the rectangle (\a{x}, \a{y}, \a{w},

   202     \a{h}) with the given \a startAngle and \a spanAngle.

   203 */

   204 

   205 

   206 /*!

   207     \fn void Q3Painter::drawChord(const QRect &r, int a, int alen)

   208 

   209     Draws a chord defined by the rectangle \a r, the start angle \a a

   210     and the arc length \a alen.

   211 

   212     The chord is filled with the current brush().

   213 

   214     The angles \a a and \a alen are 1/16th of a degree, i.e. a full

   215     circle equals 5760 (16*360). Positive values of \a a and \a alen

   216     mean counter-clockwise while negative values mean the clockwise

   217     direction. Zero degrees is at the 3 o'clock position.

   218 

   219     \sa drawArc(), drawPie()

   220 */

   221 

   222 /*!

   223     \fn void Q3Painter::drawRoundRect(const QRect &r, int xrnd, int yrnd)

   224 

   225     Draws a rounded rect that fits into the bounds \a r using the current

   226     pen and brush. The parameters \a xrnd and \a yrnd specifies the roundness

   227     in x and y direction.

   228 */

   229 

   230 /*!

   231     \fn void Q3Painter::drawRoundRect(int x, int y, int w, int h, int xrnd, int yrnd)

   232 

   233     \overload

   234 

   235     Draws a rounded rect that fits into the bounds \a x, \a y, \a w

   236     and \a h using the current pen and brush. The parameters \a xrnd

   237     and \a yrnd specifies the roundness in x and y direction.

   238 */

   239 

   240 QT_END_NAMESPACE