/usr/share/doc/python-gtk2-tutorial/html/sec-ScaleWidgets.html is in python-gtk2-tutorial 2.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>8.2. Scale Widgets</title><meta name="generator" content="DocBook XSL Stylesheets V1.65.1"><link rel="home" href="index.html" title="PyGTK 2.0 Tutorial"><link rel="up" href="ch-RangeWidgets.html" title="Chapter 8. Range Widgets"><link rel="previous" href="ch-RangeWidgets.html" title="Chapter 8. Range Widgets"><link rel="next" href="sec-CommonRangeMethods.html" title="8.3. Common Range Methods"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">8.2. Scale Widgets</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch-RangeWidgets.html">Prev</a> </td><th width="60%" align="center">Chapter 8. Range Widgets</th><td width="20%" align="right"> <a accesskey="n" href="sec-CommonRangeMethods.html">Next</a></td></tr></table><hr></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec-ScaleWidgets"></a>8.2. Scale Widgets</h2></div></div><div></div></div><p><tt class="classname">Scale</tt> widgets are used to allow the user
to visually select and manipulate a value within a specific range. You might
want to use a scale widget, for example, to adjust the magnification level
on a zoomed preview of a picture, or to control the brightness of a color,
or to specify the number of minutes of inactivity before a screensaver takes
over the screen.</p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id3049331"></a>8.2.1. Creating a Scale Widget</h3></div></div><div></div></div><p>As with scrollbars, there are separate widget types for
horizontal and vertical scale widgets. (Most programmers seem to favour
horizontal scale widgets.) Since they work essentially the same way, there's
no need to treat them separately here. The following methods create vertical
and horizontal scale widgets, respectively:</p><table border="0" bgcolor="#E0E0E0" width="100%"><tr><td><pre class="programlisting">
vscale = gtk.VScale(<b class="parameter"><tt>adjustment</tt></b>=None)
hscale = gtk.HScale(<b class="parameter"><tt>adjustment</tt></b>=None)
</pre></td></tr></table><p>The <i class="parameter"><tt>adjustment</tt></i> argument can either be
an adjustment which has already been created with
<tt class="function">gtk.Adjustment</tt>() , or nothing, in which case, an
anonymous <tt class="classname">Adjustment</tt> is created with all of its
values set to 0.0 (which isn't very useful in this case). In order to avoid
confusing yourself, you probably want to create your adjustment with a
<i class="parameter"><tt>page_size</tt></i> of 0.0 so that its
<i class="parameter"><tt>upper</tt></i> value actually corresponds to the highest value
the user can select. (If you're already thoroughly confused, read <a href="ch-Adjustments.html" title="Chapter 7. Adjustments">Chapter 7, <i>Adjustments</i></a> again for an explanation of what exactly
adjustments do and how to create and manipulate them.)</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id3049384"></a>8.2.2. Methods and Signals (well, methods, at least)</h3></div></div><div></div></div><p>Scale widgets can display their current value as a number
beside the trough. The default behaviour is to show the value, but you can
change this with this method:</p><table border="0" bgcolor="#E0E0E0" width="100%"><tr><td><pre class="programlisting">
scale.set_draw_value(<b class="parameter"><tt>draw_value</tt></b>)
</pre></td></tr></table><p>As you might have guessed, <i class="parameter"><tt>draw_value</tt></i>
is either <tt class="literal">TRUE</tt> or <tt class="literal">FALSE</tt>, with
predictable consequences for either one.</p><p>The value displayed by a scale widget is rounded to one
decimal point by default, as is the value field in its
<tt class="classname">Adjustment</tt>. You can change this with:</p><table border="0" bgcolor="#E0E0E0" width="100%"><tr><td><pre class="programlisting">
scale.set_digits(<b class="parameter"><tt>digits</tt></b>)
</pre></td></tr></table><p>where <i class="parameter"><tt>digits</tt></i> is the number of decimal
places you want. You can set digits to anything you like, but no more than
13 decimal places will actually be drawn on screen.</p><p>Finally, the value can be drawn in different positions
relative to the trough:</p><table border="0" bgcolor="#E0E0E0" width="100%"><tr><td><pre class="programlisting">
scale.set_value_pos(<b class="parameter"><tt>pos</tt></b>)
</pre></td></tr></table><p>The argument <i class="parameter"><tt>pos</tt></i> can take one of the
following values:</p><table border="0" bgcolor="#E0E0E0" width="100%"><tr><td><pre class="programlisting">
POS_LEFT
POS_RIGHT
POS_TOP
POS_BOTTOM
</pre></td></tr></table><p>If you position the value on the "side" of the trough (e.g.,
on the top or bottom of a horizontal scale widget), then it will follow the
slider up and down the trough.</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch-RangeWidgets.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch-RangeWidgets.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sec-CommonRangeMethods.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 8. Range Widgets </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 8.3. Common Range Methods</td></tr></table></div></body></html>
|