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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
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<h1 align=center>QFontMetrics Class Reference</h1><br clear="all">
<p>
The QFontMetrics class provides font metrics information about fonts.
<a href="#details">More...</a>
<p>
<code>#include <<a href="qfontmetrics-h.html">qfontmetrics.h</a>></code>
<p><a href="qfontmetrics-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class="fn"><a href="#d22d87"><b>QFontMetrics</b></a>(constQFont&)</div>
<li><div class="fn"><a href="#8ed93e"><b>QFontMetrics</b></a>(constQFontMetrics&)</div>
<li><div class="fn"><a href="#f41284"><b>~QFontMetrics</b></a>()</div>
<li><div class="fn">QFontMetrics&<a href="#e1c2e9"><b>operator=</b></a>(constQFontMetrics&)</div>
<li><div class="fn">int<a href="#72c9fb"><b>ascent</b></a>()const</div>
<li><div class="fn">int<a href="#200b74"><b>descent</b></a>()const</div>
<li><div class="fn">int<a href="#341253"><b>height</b></a>()const</div>
<li><div class="fn">int<a href="#c04e17"><b>leading</b></a>()const</div>
<li><div class="fn">int<a href="#e6e380"><b>lineSpacing</b></a>()const</div>
<li><div class="fn">int<a href="#de5799"><b>minLeftBearing</b></a>()const</div>
<li><div class="fn">int<a href="#108c37"><b>minRightBearing</b></a>()const</div>
<li><div class="fn">int<a href="#20f575"><b>maxWidth</b></a>()const</div>
<li><div class="fn">bool<a href="#245094"><b>inFont</b></a>(QChar)const</div>
<li><div class="fn">int<a href="#54cc7d"><b>leftBearing</b></a>(QChar)const</div>
<li><div class="fn">int<a href="#1057f3"><b>rightBearing</b></a>(QChar)const</div>
<li><div class="fn">int<a href="#3b6f39"><b>width</b></a>(constQString&, intlen=-1)const</div>
<li><div class="fn">int<a href="#a6372a"><b>width</b></a>(QChar)const</div>
<li><div class="fn">intwidth(charc)const<em>(obsolete)</em></div>
<li><div class="fn">QRect<a href="#f7aeff"><b>boundingRect</b></a>(constQString&, intlen=-1)const</div>
<li><div class="fn">QRect<a href="#bc3e56"><b>boundingRect</b></a>(QChar)const</div>
<li><div class="fn">QRect<a href="#b1cd55"><b>boundingRect</b></a>(intx, inty, intw, inth, intflags, constQString&str, intlen=-1, inttabstops=0, int*tabarray=0, char**intern=0)const</div>
<li><div class="fn">QSize<a href="#43e1b4"><b>size</b></a>(intflags, constQString&str, intlen=-1, inttabstops=0, int*tabarray=0, char**intern=0)const</div>
<li><div class="fn">int<a href="#cb7ddb"><b>underlinePos</b></a>()const</div>
<li><div class="fn">int<a href="#2963f9"><b>strikeOutPos</b></a>()const</div>
<li><div class="fn">int<a href="#81cc3d"><b>lineWidth</b></a>()const</div>
</ul>
<hr><h2><a name="details"></a>Detailed Description</h2>
The QFontMetrics class provides font metrics information about fonts.
<p>
QFontMetrics functions calculate size of characters and strings for
a given font. There are three ways you can create a QFontMetrics object:
<p>The QFontMetrics constructor with a <a href="qfont.html">QFont</a> creates a font metrics
object for a screen-compatible font, i.e. the font can not be a
printer font.
<p><a href="qwidget.html#386569">QWidget::fontMetrics</a>() returns the font metrics for a widget's font.
This is equivalent to QFontMetrics(widget->font()). Setting a new
font for the widget later does not affect the font metrics object.
<p><a href="qpainter.html#73b2e5">QPainter::fontMetrics</a>() returns the font metrics for a painter's
current font. The font metrics object is automatically updated if
somebody sets a new painter font (unlike the two above cases, which
take a "snapshot" of a font).
<p>Once created, the object provides functions to access the individual
metrics of the font, its characters, and for strings rendered in
this font.
<p>There are several functions that operate on the font: <a href="#72c9fb">ascent</a>(),
<a href="#200b74">descent</a>(), <a href="#341253">height</a>(), <a href="#c04e17">leading</a>() and <a href="#e6e380">lineSpacing</a>() return the basic
size properties of the font, and <a href="#cb7ddb">underlinePos</a>(), <a href="#2963f9">strikeOutPos</a>() and
<a href="#81cc3d">lineWidth</a>() return properties of the line that underlines or strikes
out the characters. These functions are all fast.
<p>There are also some functions that operate on the set of glyphs in
the font: <a href="#de5799">minLeftBearing</a>(), <a href="#108c37">minRightBearing</a>() and <a href="#20f575">maxWidth</a>(). These
are by necessity slow, and we recommend avoiding them if possible.
<p>For each character, you can get its <a href="#3b6f39">width</a>(), <a href="#54cc7d">leftBearing</a>() and
<a href="#1057f3">rightBearing</a>() and find out whether it is in the font using
<a href="#245094">inFont</a>(). You can also treat the character as a string, and use the
string functions on it.
<p>The string functions include width(), to return the width of a
string in pixels (or points, for a printer), <a href="#b1cd55">boundingRect</a>(), to
return the rectangle necessary to render a string, and <a href="#43e1b4">size</a>(), to
return the size of that rectangle.
<p>Example:
<pre> <a href="qfont.html">QFont</a> font("times",24);
<a href="qfontmetrics.html">QFontMetrics</a> fm(font);
int w = fm.<a href="#3b6f39">width</a>("What's the width of this text");
int h = fm.<a href="#341253">height</a>();
</pre>
<p>See also <a href="qfont.html">QFont</a> and <a href="qfontinfo.html">QFontInfo</a>.
<p>Examples:
<a href="grapher-grapher-cpp.html#QFontMetrics">grapher/grapher.cpp</a>
<a href="xform-xform-cpp.html#QFontMetrics">xform/xform.cpp</a>
<a href="drawdemo-drawdemo-cpp.html#QFontMetrics">drawdemo/drawdemo.cpp</a>
<a href="scrollview-scrollview-cpp.html#QFontMetrics">scrollview/scrollview.cpp</a>
<a href="movies-main-cpp.html#QFontMetrics">movies/main.cpp</a>
<hr><h2>Member Function Documentation</h2>
<h3 class="fn"><a name="d22d87"></a>QFontMetrics::QFontMetrics(const<a href="qfont.html">QFont</a>&font)</h3>
<p>Constructs a font metrics object for <em>font.</em>
<p>The font must be screen-compatible, i.e. a font you use when drawing
text in <a href="qwidget.html">QWidget</a> or <a href="qpixmap.html">QPixmap</a> objects, not <a href="qpicture.html">QPicture</a> or <a href="qprinter.html">QPrinter</a>.
If <em>font</em> is a printer font, you'll probably get wrong results.
<p>Use <a href="qpainter.html#73b2e5">QPainter::fontMetrics</a>() to get the font metrics when painting.
This is a little slower than using this constructor, but it always
gives correct results.
<h3 class="fn"><a name="8ed93e"></a>QFontMetrics::QFontMetrics(constQFontMetrics&fm)</h3>
<p>Constructs a copy of <em>fm.</em>
<h3 class="fn"><a name="f41284"></a>QFontMetrics::~QFontMetrics()</h3>
<p>Destructs the font metrics object.
<h3 class="fn">int<a name="72c9fb"></a>QFontMetrics::ascent()const</h3>
<p>Returns the maximum ascent of the font.
<p>The ascent is the distance from the base line to the uppermost line
where pixels may be drawn.
<p>See also <a href="#200b74">descent</a>().
<p>Examples:
<a href="drawdemo-drawdemo-cpp.html#ascent">drawdemo/drawdemo.cpp</a>
<a href="scrollview-scrollview-cpp.html#ascent">scrollview/scrollview.cpp</a>
<h3 class="fn"><a href="qrect.html">QRect</a><a name="bc3e56"></a>QFontMetrics::boundingRect(<a href="qchar.html">QChar</a>ch)const</h3>
<p>Returns the bounding rectangle of <em>ch</em> relative to the leftmost
point on the base line.
<p>Note that the bounding rectangle may extend to the left of (0,0),
e.g. for italicized fonts, and that the text output may cover <em>all</em>
pixels in the bounding rectangle.
<p>Note that the rectangle usually extends both above and below the
base line.
<p>See also <a href="#3b6f39">width</a>().
<h3 class="fn"><a href="qrect.html">QRect</a><a name="f7aeff"></a>QFontMetrics::boundingRect(const<a href="qstring.html">QString</a>&str, intlen=-1)const</h3>
<p>Returns the bounding rectangle of the first <em>len</em> characters of <em>str,</em>
which is the set of pixels the text would cover if drawn at (0,0).
<p>If <em>len</em> is negative (default value), the whole string is used.
<p>Note that the bounding rectangle may extend to the left of (0,0),
e.g. for italicized fonts, and that the text output may cover <em>all</em>
pixels in the bounding rectangle.
<p>Newline characters are processed as regular characters, <em>not</em> as
linebreaks.
<p>Due to the different actual character heights, the height of the
bounding rectangle of e.g. "Yes" and "yes" may be different.
<p>See also <a href="#3b6f39">width</a>() and <a href="qpainter.html#c89857">QPainter::boundingRect</a>().
<h3 class="fn"><a href="qrect.html">QRect</a><a name="b1cd55"></a>QFontMetrics::boundingRect(intx, inty, intw, inth, intflgs, const<a href="qstring.html">QString</a>&str, intlen=-1, inttabstops=0, int*tabarray=0, char**intern=0)const</h3>
<p>Returns the bounding rectangle of the first <em>len</em> characters of <em>str,</em>
which is the set of pixels the text would cover if drawn at (0,0). The
drawing, and hence the bounding rectangle, is constrained to the rectangle
<em>(x,y,w,h).</em>
<p>If <em>len</em> is negative (default value), the whole string is used.
<p>The <em>flgs</em> argument is
the bitwise OR of the following flags: <ul>
<li> <code>AlignLeft</code> aligns to the left border.
<li> <code>AlignRight</code> aligns to the right border.
<li> <code>AlignHCenter</code> aligns horizontally centered.
<li> <code>AlignTop</code> aligns to the top border.
<li> <code>AlignBottom</code> aligns to the bottom border.
<li> <code>AlignVCenter</code> aligns vertically centered
<li> <code>AlignCenter</code> (= <code>AlignHCenter</code> | AlignVCenter)
<li> <code>SingleLine</code> ignores newline characters in the text.
<li> <code>ExpandTabs</code> expands tabulators.
<li> <code>ShowPrefix</code> interprets "&x" as "x" underlined.
<li> <code>WordBreak</code> breaks the text to fit the rectangle.
</ul>
<p>Horizontal alignment defaults to AlignLeft and vertical alignment
defaults to AlignTop.
<p>If several of the horizontal or several of the vertical alignment flags
are set, the resulting alignment is undefined.
<p>These flags are defined in <a href="qnamespace-h.html">qnamespace.h</a>.
<p>If <code>ExpandTabs</code> is set in <em>flgs,</em> then:
if <em>tabarray</em> is non.zero, it specifies a 0-terminated sequence
of pixel-positions for tabs; otherwise
if <em>tabstops</em> is non-zero, it is used as the tab spacing (in pixels).
<p>Note that the bounding rectangle may extend to the left of (0,0),
e.g. for italicized fonts, and that the text output may cover <em>all</em>
pixels in the bounding rectangle.
<p>Newline characters are processed as linebreaks.
<p>Despite the different actual character heights, the heights of the
bounding rectangles of "Yes" and "yes" are the same.
<p>The bounding rectangle given by this function is somewhat larger
than that calculated by the simpler boundingRect() function. This
function uses the <a href="#de5799">maximum left</a> and
<a href="#108c37">right</a> font bearings as is necessary
for multi-line text to align correctly. Also, fontHeight() and
<a href="#e6e380">lineSpacing</a>() are used to calculate the height, rather than
individual character heights.
<p>The <em>internal</em> argument is for internal purposes.
<p>See also <a href="#3b6f39">width</a>(), <a href="qpainter.html#c89857">QPainter::boundingRect</a>() and <a href="qt.html#AlignmentFlags">Qt::AlignmentFlags</a>.
<p>Examples:
<a href="xform-xform-cpp.html#boundingRect">xform/xform.cpp</a>
<h3 class="fn">int<a name="200b74"></a>QFontMetrics::descent()const</h3>
<p>Returns the maximum descent of the font.
<p>The descent is the distance from the base line to the lowermost line
where pixels may be drawn. (Note that this is different from X, which
adds 1 pixel.)
<p>See also <a href="#72c9fb">ascent</a>().
<p>Examples:
<a href="drawdemo-drawdemo-cpp.html#descent">drawdemo/drawdemo.cpp</a>
<h3 class="fn">int<a name="341253"></a>QFontMetrics::height()const</h3>
<p>Returns the height of the font.
<p>This is always equal to <a href="#72c9fb">ascent</a>()+<a href="#200b74">descent</a>()+1 (the 1 is for the base line).
<p>See also <a href="#c04e17">leading</a>() and <a href="#e6e380">lineSpacing</a>().
<p>Examples:
<a href="grapher-grapher-cpp.html#height">grapher/grapher.cpp</a>
<h3 class="fn">bool<a name="245094"></a>QFontMetrics::inFont(<a href="qchar.html">QChar</a>ch)const</h3>
<p>Returns TRUE if <em>ch</em> is a valid character in the font.
<h3 class="fn">int<a name="c04e17"></a>QFontMetrics::leading()const</h3>
<p>Returns the leading of the font.
<p>This is the natural inter-line spacing.
<p>See also <a href="#341253">height</a>() and <a href="#e6e380">lineSpacing</a>().
<h3 class="fn">int<a name="54cc7d"></a>QFontMetrics::leftBearing(<a href="qchar.html">QChar</a>ch)const</h3>
<p>Returns the left bearing of character <em>ch</em> in the font.
<p>The left bearing is the rightward distance of the left-most pixel
of the character from the logical origin of the character.
This value is negative if the pixels of the character extend
to the left of the logical origin.
<p>See <a href="#3b6f39">width</a>(<a href="qchar.html">QChar</a>) for a graphical description of this metric.
<p>See also <a href="#1057f3">rightBearing</a>(<a href="qchar.html">QChar</a>), <a href="#de5799">minLeftBearing</a>() and <a href="#3b6f39">width</a>().
<h3 class="fn">int<a name="e6e380"></a>QFontMetrics::lineSpacing()const</h3>
<p>Returns the distance from one base line to the next.
<p>This value is always equal to <a href="#c04e17">leading</a>()+<a href="#341253">height</a>().
<p>See also <a href="#341253">height</a>() and <a href="#c04e17">leading</a>().
<p>Examples:
<a href="scrollview-scrollview-cpp.html#lineSpacing">scrollview/scrollview.cpp</a>
<h3 class="fn">int<a name="81cc3d"></a>QFontMetrics::lineWidth()const</h3>
<p>Returns the width of the underline and strike-out lines, adjusted for
the point size of the font.
<p>See also <a href="#cb7ddb">underlinePos</a>() and <a href="#2963f9">strikeOutPos</a>().
<h3 class="fn">int<a name="20f575"></a>QFontMetrics::maxWidth()const</h3>
<p>Returns the width of the widest character in the font.
<h3 class="fn">int<a name="de5799"></a>QFontMetrics::minLeftBearing()const</h3>
<p>Returns the minimum left bearing of the font.
<p>This is the smallest <a href="#54cc7d">leftBearing</a>(char) of all characters in the font.
<p>Note that this function can be very slow if the font is big.
<p>See also <a href="#108c37">minRightBearing</a>() and <a href="#54cc7d">leftBearing</a>(char).
<h3 class="fn">int<a name="108c37"></a>QFontMetrics::minRightBearing()const</h3>
<p>Returns the minimum right bearing of the font.
<p>This is the smallest <a href="#1057f3">rightBearing</a>(char) of all characters in the
font.
<p>Note that this function can be very slow if the font is big.
<p>See also <a href="#de5799">minLeftBearing</a>() and <a href="#1057f3">rightBearing</a>(char).
<h3 class="fn">QFontMetrics&<a name="e1c2e9"></a>QFontMetrics::operator=(constQFontMetrics&fm)</h3>
<p>Font metrics assignment.
<h3 class="fn">int<a name="1057f3"></a>QFontMetrics::rightBearing(<a href="qchar.html">QChar</a>ch)const</h3>
<p>Returns the right bearing of character <em>ch</em> in the font.
<p>The right bearing is the leftward distance of the right-most pixel
of the character from the logical origin of a subsequent character.
This value is negative if the pixels of the character extend
to the right of the <a href="#3b6f39">width</a>() of the character.
<p>See width() for a graphical description of this metric.
<p>See also <a href="#54cc7d">leftBearing</a>(char), <a href="#108c37">minRightBearing</a>() and <a href="#3b6f39">width</a>().
<h3 class="fn"><a href="qsize.html">QSize</a><a name="43e1b4"></a>QFontMetrics::size(intflgs, const<a href="qstring.html">QString</a>&str, intlen=-1, inttabstops=0, int*tabarray=0, char**intern=0)const</h3>
<p>Returns the size in pixels of the first <em>len</em> characters of <em>str.</em>
<p>If <em>len</em> is negative (default value), the whole string is used.
<p>The <em>flgs</em> argument is
the bitwise OR of the following flags: <ul>
<li> <code>SingleLine</code> ignores newline characters in the text.
<li> <code>ExpandTabs</code> expands tabulators.
<li> <code>ShowPrefix</code> interprets "&x" as "x" underlined.
<li> <code>WordBreak</code> breaks the text to fit the rectangle.
</ul>
<p>These flags are defined in <a href="qnamespace-h.html">qnamespace.h</a>.
<p>If <code>ExpandTabs</code> is set in <em>flgs,</em> then:
if <em>tabarray</em> is non.zero, it specifies a 0-terminated sequence
of pixel-positions for tabs; otherwise
if <em>tabstops</em> is non-zero, it is used as the tab spacing (in pixels).
<p>Newline characters are processed as linebreaks.
<p>Despite the different actual character heights, the heights of the
bounding rectangles of "Yes" and "yes" are the same.
<p>The <em>internal</em> argument is for internal purposes.
<p>See also <a href="#b1cd55">boundingRect</a>().
<h3 class="fn">int<a name="2963f9"></a>QFontMetrics::strikeOutPos()const</h3>
<p>Returns the distance from the base line to where the strike-out line
should be drawn.
<p>See also <a href="#cb7ddb">underlinePos</a>() and <a href="#81cc3d">lineWidth</a>().
<h3 class="fn">int<a name="cb7ddb"></a>QFontMetrics::underlinePos()const</h3>
<p>Returns the distance from the base line to where an underscore should be
drawn.
<p>See also <a href="#2963f9">strikeOutPos</a>() and <a href="#81cc3d">lineWidth</a>().
<h3 class="fn">int<a name="a6372a"></a>QFontMetrics::width(<a href="qchar.html">QChar</a>ch)const</h3>
<p><img src="bearings.png" align=right> Returns the logical width of a
<em>ch</em> in pixels. This is a distance appropriate for drawing a
subsequent character after <em>ch.</em>
<p>Some of the metrics are described in the image to the right. The
tall dark rectangle covers the logical <a href="#3b6f39">width</a>() of a character. The
shorter pale rectangles cover <a href="#54cc7d">leftBearing</a>() and <a href="#1057f3">rightBearing</a>() of
the characters. Notice that the bearings of "f" in this particular
font are both negative, while the bearings of "o" are both positive.
<p>See also <a href="#b1cd55">boundingRect</a>().
<h3 class="fn">int<a name="3b6f39"></a>QFontMetrics::width(const<a href="qstring.html">QString</a>&str, intlen=-1)const</h3>
<p>Returns the width in pixels of the first <em>len</em> characters of <em>str.</em>
<p>If <em>len</em> is negative (the default value is), the whole string is used.
<p>Note that this value is <em>not</em> equal to <a href="#b1cd55">boundingRect</a>().width();
boundingRect() returns a rectangle describing the pixels this string
will cover whereas width() returns the distance to where the next string
should be drawn.
<p>See also <a href="#b1cd55">boundingRect</a>().
<p>Examples:
<a href="drawdemo-drawdemo-cpp.html#width">drawdemo/drawdemo.cpp</a>
<a href="scrollview-scrollview-cpp.html#width">scrollview/scrollview.cpp</a>
<a href="movies-main-cpp.html#width">movies/main.cpp</a>
<h3 class="fn">int<a name="2f88fb"></a>QFontMetrics::width(charc)const</h3>
<p><b>This function is obsolete.</b> It is provided to keep old source working, and will probably be removed in a future version of Qt. We strongly advise against using it in new code.<p>This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
<p>Provided to aid porting from Qt 1.x.
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