xref: /xsrc/external/mit/libXaw/dist/specs/StripChart.xml

<sect1 id="StripChart_Widget">
<title>StripChart Widget</title>
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<!-- 	StripChart Widget -->
<!-- .XE -->
<indexterm significance="preferred"><primary>StripChart widget</primary></indexterm>
<literallayout class="monospaced">
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Application Header file	&lt;Xaw/StripChart.h&gt;
<indexterm><primary>StripChart.h</primary></indexterm>
Class Header file	&lt;Xaw/StripCharP.h&gt;
<indexterm><primary>StripCharP.h</primary></indexterm>
Class		stripChartWidgetClass
<indexterm><primary>stripChartWidgetClass</primary></indexterm>
Class Name	StripChart
<indexterm><primary>StripChart widget</primary><secondary>class name</secondary></indexterm>
Superclass	Simple
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</literallayout>
<para>
<!-- .LP -->
The StripChart widget is used to provide a roughly real
time graphical chart of a single value.  For example,
it is used by the common client program <function>xload</function>
to provide a graph of processor load.  The StripChart
reads data from an application, and updates the chart
at the <function>update</function> interval specified.
</para>
<sect2 id='StripChart::Resources'>
<title>Resources</title>
<para>
<!-- .LP -->
When creating a StripChart widget instance, the following resources are
retrieved from the argument list or from the resource database:
</para>
<para>
<!-- .LP -->
<indexterm><primary>StripChart widget</primary><secondary>resources</secondary></indexterm>
<informaltable>
  <tgroup cols='5' align='center'>
  <colspec colname='c1'/>
  <colspec colname='c2'/>
  <colspec colname='c3'/>
  <colspec colname='c4'/>
  <colspec colname='c5'/>
  <thead>
    <row>
      <entry>Name</entry>
      <entry>Class</entry>
      <entry>Type</entry>
      <entry>Notes</entry>
      <entry>Default Value</entry>
    </row>
  </thead>
  <tbody>
    <row>
      <entry>accelerators</entry>
      <entry>Accelerators</entry>
      <entry>AcceleratorTable</entry>
      <entry></entry>
      <entry>NULL</entry>
    </row>
    <row>
      <entry>ancestorSensitive</entry>
      <entry>AncestorSensitive</entry>
      <entry>Boolean</entry>
      <entry>D</entry>
      <entry>True</entry>
    </row>
    <row>
      <entry>background</entry>
      <entry>Background</entry>
      <entry>Pixel</entry>
      <entry></entry>
      <entry>XtDefaultBackground</entry>
    </row>
    <row>
      <entry>backgroundPixmap</entry>
      <entry>Pixmap</entry>
      <entry>Pixmap</entry>
      <entry></entry>
      <entry>XtUnspecifiedPixmap</entry>
    </row>
    <row>
      <entry>borderColor</entry>
      <entry>BorderColor</entry>
      <entry>Pixel</entry>
      <entry></entry>
      <entry>XtDefaultForeground</entry>
    </row>
    <row>
      <entry>borderPixmap</entry>
      <entry>Pixmap</entry>
      <entry>Pixmap</entry>
      <entry></entry>
      <entry>XtUnspecifiedPixmap</entry>
    </row>
    <row>
      <entry>borderWidth</entry>
      <entry>BorderWidth</entry>
      <entry>Dimension</entry>
      <entry></entry>
      <entry>1</entry>
    </row>
    <row>
      <entry>colormap</entry>
      <entry>Colormap</entry>
      <entry>Colormap</entry>
      <entry></entry>
      <entry>Parent's Colormap</entry>
    </row>
    <row>
      <entry>cursor</entry>
      <entry>Cursor</entry>
      <entry>Cursor</entry>
      <entry></entry>
      <entry>None</entry>
    </row>
    <row>
      <entry>cursorName</entry>
      <entry>Cursor</entry>
      <entry>String</entry>
      <entry></entry>
      <entry>NULL</entry>
    </row>
    <row>
      <entry>depth</entry>
      <entry>Depth</entry>
      <entry>int</entry>
      <entry>C</entry>
      <entry>Parent's Depth</entry>
    </row>
    <row>
      <entry>destroyCallback</entry>
      <entry>Callback</entry>
      <entry>XtCallbackList</entry>
      <entry></entry>
      <entry>NULL</entry>
    </row>
    <row>
      <entry>foreground</entry>
      <entry>Foreground</entry>
      <entry>Pixel</entry>
      <entry></entry>
      <entry>XtDefaultForeground</entry>
    </row>
    <row>
      <entry>getValue</entry>
      <entry>Callback</entry>
      <entry>XtCallbackList</entry>
      <entry></entry>
      <entry>NULL</entry>
    </row>
    <row>
      <entry>height</entry>
      <entry>Height</entry>
      <entry>Dimension</entry>
      <entry></entry>
      <entry>120</entry>
    </row>
    <row>
      <entry>highlight</entry>
      <entry>Foreground</entry>
      <entry>Pixel</entry>
      <entry></entry>
      <entry>XtDefaultForeground</entry>
    </row>
    <row>
      <entry>insensitiveBorder</entry>
      <entry>Insensitive</entry>
      <entry>Pixmap</entry>
      <entry></entry>
      <entry>GreyPixmap</entry>
    </row>
    <row>
      <entry>international</entry>
      <entry>International</entry>
      <entry>Boolean</entry>
      <entry>C</entry>
      <entry>False</entry>
    </row>
    <row>
      <entry>jumpScroll</entry>
      <entry>JumpScroll</entry>
      <entry>int</entry>
      <entry>A</entry>
      <entry>half the width of the widget</entry>
    </row>
    <row>
      <entry>mappedWhenManaged</entry>
      <entry>MappedWhenManaged</entry>
      <entry>Boolean</entry>
      <entry></entry>
      <entry>True</entry>
    </row>
    <row>
      <entry>minScale</entry>
      <entry>Scale</entry>
      <entry>int</entry>
      <entry></entry>
      <entry>1</entry>
    </row>
    <row>
      <entry>pointerColor</entry>
      <entry>Foreground</entry>
      <entry>Pixel</entry>
      <entry></entry>
      <entry>XtDefaultForeground</entry>
    </row>
    <row>
      <entry>pointerColorBackground</entry>
      <entry>Background</entry>
      <entry>Pixel</entry>
      <entry></entry>
      <entry>XtDefaultBackground</entry>
    </row>
    <row>
      <entry>screen</entry>
      <entry>Screen</entry>
      <entry>Pointer</entry>
      <entry>R</entry>
      <entry>Parent's Screen</entry>
    </row>
    <row>
      <entry>sensitive</entry>
      <entry>Sensitive</entry>
      <entry>Boolean</entry>
      <entry></entry>
      <entry>True</entry>
    </row>
    <row>
      <entry>translations</entry>
      <entry>Translations</entry>
      <entry>TranslationTable</entry>
      <entry></entry>
      <entry>NULL</entry>
    </row>
    <row>
      <entry>update</entry>
      <entry>Interval</entry>
      <entry>int</entry>
      <entry></entry>
      <entry>10</entry>
    </row>
    <row>
      <entry>width</entry>
      <entry>Width</entry>
      <entry>Dimension</entry>
      <entry></entry>
      <entry>120</entry>
    </row>
    <row>
      <entry>x</entry>
      <entry>Position</entry>
      <entry>Position</entry>
      <entry></entry>
      <entry>0</entry>
    </row>
    <row>
      <entry>y</entry>
      <entry>Position</entry>
      <entry>Position</entry>
      <entry></entry>
      <entry>0</entry>
    </row>
  </tbody>
  </tgroup>
</informaltable>
<!-- .Ac -->
<!-- .As -->
<!-- .Bg -->
<!-- .Gp -->
<!-- .Bc -->
<!-- .Bp -->
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<variablelist>
  <varlistentry>
    <term>
      <function>foreground</function>
    </term>
    <listitem>
      <para>
A pixel value which indexes the widget's colormap to derive the color
that will be used to draw the graph.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>getValue</function>
    </term>
    <listitem>
      <para>
A list of callback functions to call every <function>update</function> seconds.
This list should contain one function, which returns the
value to be graphed by the StripChart widget.  The following
section describes the procedural interface.  Behavior when this list has
more than one function is undefined.
<!-- .Hw -->
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>highlight</function>
    </term>
    <listitem>
      <para>
A pixel value which indexes the widget's colormap to derive the color
that will be used to draw the scale lines on the graph.
<!-- .Ib -->
<!-- .Ix -->
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>jumpScroll</function>
    </term>
    <listitem>
      <para>
When the graph reaches the right edge of the window it must be
scrolled to the left.  This resource specifies the number of pixels
it will jump.  Smooth scrolling can be achieved by setting this resource
to 1.
<!-- .Mm -->
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>minScale</function>
    </term>
    <listitem>
      <para>
The minimum scale for the graph.  The number of divisions on the graph
will always be greater than or equal to this value.
<!-- .Pf -->
<!-- .Pb -->
<!-- .Sc -->
<!-- .Se -->
<!-- .Tr -->
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>update</function>
    </term>
    <listitem>
      <para>
The number of seconds between graph updates.  Each update is
represented on the graph as a 1 pixel wide line.  Every <function>update</function> seconds
the <function>getValue</function> procedure will be used to get a new graph point,
and this point will be added to the right end of the StripChart.
<!-- .Xy -->
    </para>
  </listitem>
  </varlistentry>
</variablelist>
</para>
</sect2>
<sect2 id="Getting_the_StripChart_Value">
<title>Getting the StripChart Value</title>
<indexterm><primary>StripChart widget</primary><secondary>getting the value</secondary></indexterm>
<para>
<!-- .LP -->
The StripChart widget will call the application routine passed to it
as the <function>getValue</function> callback function every <function>update</function> seconds to
obtain another point for the StripChart graph.
</para>
<para>
<!-- .LP -->
The calling interface for the <function>getValue</function> callback is:
<indexterm significance="preferred"><primary>StripChart widget</primary><secondary>getValue callback</secondary></indexterm>
<funcsynopsis>
<funcprototype>
  <funcdef><function> void</function>(*getValueProc)</funcdef>
  <paramdef>Widget<parameter> w</parameter></paramdef>
  <paramdef>XtPointer<parameter> client_data</parameter></paramdef>
  <paramdef>XtPointer<parameter> value</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<!-- .FN -->
<variablelist>
  <varlistentry>
    <term>
      <emphasis remap='I'>w</emphasis>
    </term>
    <listitem>
      <para>
Specifies the StripChart widget.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <emphasis remap='I'>client_data</emphasis>
    </term>
    <listitem>
      <para>
Specifies the client data.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <emphasis remap='I'>value</emphasis>
    </term>
    <listitem>
      <para>
Returns a pointer to a double.  The application should set the address
pointed to by this argument to a double containing the value to be
graphed on the StripChart.
    </para>
  </listitem>
  </varlistentry>
</variablelist>
</para>
<para>
<!-- .LP -->
This function is used by the StripChart to call an application routine.
The routine will pass the value to be graphed back to the the StripChart
in the <function>value</function> field of this routine.

</para>
</sect2>
</sect1>