specs/StripChart.xml

   1 <sect1 id="StripChart_Widget">
   2 <title>StripChart Widget</title>
   3 <!-- .XS -->
   4 <!--    StripChart Widget -->
   5 <!-- .XE -->
   6 <!-- .IN "StripChart widget" "" "@DEF@" -->
   7 <literallayout class="monospaced">
   8 <!-- .TA 2.0i -->
   9 <!-- .ta 2.0i -->
  10 <!-- .sp -->
  11 Application Header file &lt;Xaw/StripChart.h&gt;
  12 <!-- .IN "StripChart.h" "" -->
  13 Class Header file       &lt;Xaw/StripCharP.h&gt;
  14 <!-- .IN "StripCharP.h" "" -->
  15 Class           stripChartWidgetClass
  16 <!-- .IN "stripChartWidgetClass" "" -->
  17 Class Name      StripChart
  18 <!-- .IN "StripChart widget" "class name" -->
  19 Superclass      Simple
  20 <!-- .sp -->
  21 </literallayout>
  22 <para>
  23 <!-- .LP -->
  24 The StripChart widget is used to provide a roughly real
  25 time graphical chart of a single value.  For example,
  26 it is used by the common client program <function>xload</function>
  27 to provide a graph of processor load.  The StripChart
  28 reads data from an application, and updates the chart
  29 at the <function>update</function> interval specified.
  30 </para>
  31 <sect2 id='StripChart::Resources'>
  32 <title>Resources</title>
  33 <para>
  34 <!-- .LP -->
  35 When creating a StripChart widget instance, the following resources are
  36 retrieved from the argument list or from the resource database:
  37 </para>
  38 <para>
  39 <!-- .LP -->
  40 <!-- .IN "StripChart widget" "resources" -->
  41 <informaltable>
  42   <tgroup cols='5' align='center'>
  43   <colspec colname='c1'/>
  44   <colspec colname='c2'/>
  45   <colspec colname='c3'/>
  46   <colspec colname='c4'/>
  47   <colspec colname='c5'/>
  48   <thead>
  49     <row>
  50       <entry>Name</entry>
  51       <entry>Class</entry>
  52       <entry>Type</entry>
  53       <entry>Notes</entry>
  54       <entry>Default Value</entry>
  55     </row>
  56   </thead>
  57   <tbody>
  58     <row>
  59       <entry>accelerators</entry>
  60       <entry>Accelerators</entry>
  61       <entry>AcceleratorTable</entry>
  62       <entry></entry>
  63       <entry>NULL</entry>
  64     </row>
  65     <row>
  66       <entry>ancestorSensitive</entry>
  67       <entry>AncestorSensitive</entry>
  68       <entry>Boolean</entry>
  69       <entry>D</entry>
  70       <entry>True</entry>
  71     </row>
  72     <row>
  73       <entry>background</entry>
  74       <entry>Background</entry>
  75       <entry>Pixel</entry>
  76       <entry></entry>
  77       <entry>XtDefaultBackground</entry>
  78     </row>
  79     <row>
  80       <entry>backgroundPixmap</entry>
  81       <entry>Pixmap</entry>
  82       <entry>Pixmap</entry>
  83       <entry></entry>
  84       <entry>XtUnspecifiedPixmap</entry>
  85     </row>
  86     <row>
  87       <entry>borderColor</entry>
  88       <entry>BorderColor</entry>
  89       <entry>Pixel</entry>
  90       <entry></entry>
  91       <entry>XtDefaultForeground</entry>
  92     </row>
  93     <row>
  94       <entry>borderPixmap</entry>
  95       <entry>Pixmap</entry>
  96       <entry>Pixmap</entry>
  97       <entry></entry>
  98       <entry>XtUnspecifiedPixmap</entry>
  99     </row>
 100     <row>
 101       <entry>borderWidth</entry>
 102       <entry>BorderWidth</entry>
 103       <entry>Dimension</entry>
 104       <entry></entry>
 105       <entry>1</entry>
 106     </row>
 107     <row>
 108       <entry>colormap</entry>
 109       <entry>Colormap</entry>
 110       <entry>Colormap</entry>
 111       <entry></entry>
 112       <entry>Parent's Colormap</entry>
 113     </row>
 114     <row>
 115       <entry>cursor</entry>
 116       <entry>Cursor</entry>
 117       <entry>Cursor</entry>
 118       <entry></entry>
 119       <entry>None</entry>
 120     </row>
 121     <row>
 122       <entry>cursorName</entry>
 123       <entry>Cursor</entry>
 124       <entry>String</entry>
 125       <entry></entry>
 126       <entry>NULL</entry>
 127     </row>
 128     <row>
 129       <entry>depth</entry>
 130       <entry>Depth</entry>
 131       <entry>int</entry>
 132       <entry>C</entry>
 133       <entry>Parent's Depth</entry>
 134     </row>
 135     <row>
 136       <entry>destroyCallback</entry>
 137       <entry>Callback</entry>
 138       <entry>XtCallbackList</entry>
 139       <entry></entry>
 140       <entry>NULL</entry>
 141     </row>
 142     <row>
 143       <entry>foreground</entry>
 144       <entry>Foreground</entry>
 145       <entry>Pixel</entry>
 146       <entry></entry>
 147       <entry>XtDefaultForeground</entry>
 148     </row>
 149     <row>
 150       <entry>getValue</entry>
 151       <entry>Callback</entry>
 152       <entry>XtCallbackList</entry>
 153       <entry></entry>
 154       <entry>NULL</entry>
 155     </row>
 156     <row>
 157       <entry>height</entry>
 158       <entry>Height</entry>
 159       <entry>Dimension</entry>
 160       <entry></entry>
 161       <entry>120</entry>
 162     </row>
 163     <row>
 164       <entry>highlight</entry>
 165       <entry>Foreground</entry>
 166       <entry>Pixel</entry>
 167       <entry></entry>
 168       <entry>XtDefaultForeground</entry>
 169     </row>
 170     <row>
 171       <entry>insensitiveBorder</entry>
 172       <entry>Insensitive</entry>
 173       <entry>Pixmap</entry>
 174       <entry></entry>
 175       <entry>GreyPixmap</entry>
 176     </row>
 177     <row>
 178       <entry>international</entry>
 179       <entry>International</entry>
 180       <entry>Boolean</entry>
 181       <entry>C</entry>
 182       <entry>False</entry>
 183     </row>
 184     <row>
 185       <entry>jumpScroll</entry>
 186       <entry>JumpScroll</entry>
 187       <entry>int</entry>
 188       <entry>A</entry>
 189       <entry>half the width of the widget</entry>
 190     </row>
 191     <row>
 192       <entry>mappedWhenManaged</entry>
 193       <entry>MappedWhenManaged</entry>
 194       <entry>Boolean</entry>
 195       <entry></entry>
 196       <entry>True</entry>
 197     </row>
 198     <row>
 199       <entry>minScale</entry>
 200       <entry>Scale</entry>
 201       <entry>int</entry>
 202       <entry></entry>
 203       <entry>1</entry>
 204     </row>
 205     <row>
 206       <entry>pointerColor</entry>
 207       <entry>Foreground</entry>
 208       <entry>Pixel</entry>
 209       <entry></entry>
 210       <entry>XtDefaultForeground</entry>
 211     </row>
 212     <row>
 213       <entry>pointerColorBackground</entry>
 214       <entry>Background</entry>
 215       <entry>Pixel</entry>
 216       <entry></entry>
 217       <entry>XtDefaultBackground</entry>
 218     </row>
 219     <row>
 220       <entry>screen</entry>
 221       <entry>Screen</entry>
 222       <entry>Pointer</entry>
 223       <entry>R</entry>
 224       <entry>Parent's Screen</entry>
 225     </row>
 226     <row>
 227       <entry>sensitive</entry>
 228       <entry>Sensitive</entry>
 229       <entry>Boolean</entry>
 230       <entry></entry>
 231       <entry>True</entry>
 232     </row>
 233     <row>
 234       <entry>translations</entry>
 235       <entry>Translations</entry>
 236       <entry>TranslationTable</entry>
 237       <entry></entry>
 238       <entry>NULL</entry>
 239     </row>
 240     <row>
 241       <entry>update</entry>
 242       <entry>Interval</entry>
 243       <entry>int</entry>
 244       <entry></entry>
 245       <entry>10</entry>
 246     </row>
 247     <row>
 248       <entry>width</entry>
 249       <entry>Width</entry>
 250       <entry>Dimension</entry>
 251       <entry></entry>
 252       <entry>120</entry>
 253     </row>
 254     <row>
 255       <entry>x</entry>
 256       <entry>Position</entry>
 257       <entry>Position</entry>
 258       <entry></entry>
 259       <entry>0</entry>
 260     </row>
 261     <row>
 262       <entry>y</entry>
 263       <entry>Position</entry>
 264       <entry>Position</entry>
 265       <entry></entry>
 266       <entry>0</entry>
 267     </row>
 268   </tbody>
 269   </tgroup>
 270 </informaltable>
 271 <!-- .Ac -->
 272 <!-- .As -->
 273 <!-- .Bg -->
 274 <!-- .Gp -->
 275 <!-- .Bc -->
 276 <!-- .Bp -->
 277 <!-- .Bw -->
 278 <!-- .Cm -->
 279 <!-- .Cu -->
 280 <!-- .Cn -->
 281 <!-- .Dp -->
 282 <!-- .Dc -->
 283 <variablelist>
 284   <varlistentry>
 285     <term>
 286       <function>foreground</function>
 287     </term>
 288     <listitem>
 289       <para>
 290 A pixel value which indexes the widget's colormap to derive the color
 291 that will be used to draw the graph.
 292       </para>
 293     </listitem>
 294   </varlistentry>
 295   <varlistentry>
 296     <term>
 297       <function>getValue</function>
 298     </term>
 299     <listitem>
 300       <para>
 301 A list of callback functions to call every <function>update</function> seconds.
 302 This list should contain one function, which returns the
 303 value to be graphed by the StripChart widget.  The following
 304 section describes the procedural interface.  Behavior when this list has
 305 more than one function is undefined.
 306 <!-- .Hw -->
 307       </para>
 308     </listitem>
 309   </varlistentry>
 310   <varlistentry>
 311     <term>
 312       <function>highlight</function>
 313     </term>
 314     <listitem>
 315       <para>
 316 A pixel value which indexes the widget's colormap to derive the color
 317 that will be used to draw the scale lines on the graph.
 318 <!-- .Ib -->
 319 <!-- .Ix -->
 320       </para>
 321     </listitem>
 322   </varlistentry>
 323   <varlistentry>
 324     <term>
 325       <function>jumpScroll</function>
 326     </term>
 327     <listitem>
 328       <para>
 329 When the graph reaches the right edge of the window it must be
 330 scrolled to the left.  This resource specifies the number of pixels
 331 it will jump.  Smooth scrolling can be achieved by setting this resource
 332 to 1.
 333 <!-- .Mm -->
 334       </para>
 335     </listitem>
 336   </varlistentry>
 337   <varlistentry>
 338     <term>
 339       <function>minScale</function>
 340     </term>
 341     <listitem>
 342       <para>
 343 The minimum scale for the graph.  The number of divisions on the graph
 344 will always be greater than or equal to this value.
 345 <!-- .Pf -->
 346 <!-- .Pb -->
 347 <!-- .Sc -->
 348 <!-- .Se -->
 349 <!-- .Tr -->
 350       </para>
 351     </listitem>
 352   </varlistentry>
 353   <varlistentry>
 354     <term>
 355       <function>update</function>
 356     </term>
 357     <listitem>
 358       <para>
 359 The number of seconds between graph updates.  Each update is
 360 represented on the graph as a 1 pixel wide line.  Every <function>update</function> seconds
 361 the <function>getValue</function> procedure will be used to get a new graph point,
 362 and this point will be added to the right end of the StripChart.
 363 <!-- .Xy -->
 364     </para>
 365   </listitem>
 366   </varlistentry>
 367 </variablelist>
 368 </para>
 369 </sect2>
 370 <sect2 id="Getting_the_StripChart_Value">
 371 <title>Getting the StripChart Value</title>
 372 <!-- .IN "StripChart widget" "getting the value" -->
 373 <para>
 374 <!-- .LP -->
 375 The StripChart widget will call the application routine passed to it
 376 as the <function>getValue</function> callback function every <function>update</function> seconds to
 377 obtain another point for the StripChart graph.
 378 </para>
 379 <para>
 380 <!-- .LP -->
 381 The calling interface for the <function>getValue</function> callback is:
 382 <!-- .IN "StripChart widget" "getValue callback" "@DEF@" -->
 383 <funcsynopsis>
 384 <funcprototype>
 385   <funcdef><function> void</function>(*getValueProc)</funcdef>
 386   <paramdef>Widget<parameter> w</parameter></paramdef>
 387   <paramdef>XtPointer<parameter> client_data</parameter></paramdef>
 388   <paramdef>XtPointer<parameter> value</parameter></paramdef>
 389 </funcprototype>
 390 </funcsynopsis>
 391 <!-- .FN -->
 392 <variablelist>
 393   <varlistentry>
 394     <term>
 395       <emphasis remap='I'>w</emphasis>
 396     </term>
 397     <listitem>
 398       <para>
 399 Specifies the StripChart widget.
 400       </para>
 401     </listitem>
 402   </varlistentry>
 403   <varlistentry>
 404     <term>
 405       <emphasis remap='I'>client_data</emphasis>
 406     </term>
 407     <listitem>
 408       <para>
 409 Specifies the client data.
 410       </para>
 411     </listitem>
 412   </varlistentry>
 413   <varlistentry>
 414     <term>
 415       <emphasis remap='I'>value</emphasis>
 416     </term>
 417     <listitem>
 418       <para>
 419 Returns a pointer to a double.  The application should set the address
 420 pointed to by this argument to a double containing the value to be
 421 graphed on the StripChart.
 422     </para>
 423   </listitem>
 424   </varlistentry>
 425 </variablelist>
 426 </para>
 427 <para>
 428 <!-- .LP -->
 429 This function is used by the StripChart to call an application routine.
 430 The routine will pass the value to be graphed back to the the StripChart
 431 in the <function>value</function> field of this routine.
 432
 433 </para>
 434 </sect2>
 435 </sect1>