path: root/specs/Command.xml

<sect1 id="Command_Widget">
<title>Command Widget</title>
<!-- .XS -->
<!-- 	Command Widget -->
<!-- .XE -->
<indexterm significance="preferred"><primary>Command widget</primary></indexterm>
<literallayout class="monospaced">
<!-- .TA 2.0i -->
<!-- .ta 2.0i -->
<!-- .sp -->
Application header file	&lt;X11/Xaw/Command.h&gt;
<indexterm><primary>Command.h</primary></indexterm>
Class header file	&lt;X11/Xaw/CommandP.h&gt;
<indexterm><primary>CommandP.h</primary></indexterm>
Class	commandWidgetClass
<indexterm><primary>commandWidgetClass</primary></indexterm>
Class Name	Command
<indexterm><primary>Command widget</primary><secondary>class name</secondary></indexterm>
Superclass	Label
<!-- .sp -->
</literallayout>
<para>
<!-- .LP -->
The Command widget is an area, often rectangular, that contains text
or a graphical image. Command widgets are often referred to as
<quote>push buttons.</quote>  When the pointer is over a Command widget, the
widget becomes highlighted by drawing a rectangle around its perimeter.
This highlighting indicates that the widget is ready for selection.
When mouse button 1 is pressed, the Command widget indicates that
it has been selected by reversing its foreground and background colors.
When the mouse button is released, the Command widget's <function>notify</function>
action is invoked, calling all functions on its callback list.  If
the pointer is moved off of the widget before the pointer button is
released, the widget reverts to its normal foreground and background
colors, and releasing the pointer button has no effect.  This behavior
allows the user to cancel an action.
</para>
<sect2 id="Resources">
<title>Resources</title>
<para>
<!-- .LP -->
When creating a Command widget instance, the following resources are
retrieved from the argument list or from the resource database:
</para>
<para>
<!-- .LP -->
<indexterm><primary>Command 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>bitmap</entry>
      <entry>Bitmap</entry>
      <entry>Pixmap</entry>
      <entry></entry>
      <entry>None</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>callback</entry>
      <entry>Callback</entry>
      <entry>XtCallbackList</entry>
      <entry></entry>
      <entry>NULL</entry>
    </row>
    <row>
      <entry>colormap</entry>
      <entry>Colormap</entry>
      <entry>Colormap</entry>
      <entry></entry>
      <entry>Parent's Colormap</entry>
    </row>
    <row>
      <entry>cornerRoundPercent</entry>
      <entry>CornerRoundPercent</entry>
      <entry>Dimension</entry>
      <entry></entry>
      <entry>25</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>encoding</entry>
      <entry>Encoding</entry>
      <entry>UnsignedChar</entry>
      <entry></entry>
      <entry>XawTextEncoding8bit</entry>
    </row>
    <row>
      <entry>font</entry>
      <entry>Font</entry>
      <entry>XFontStruct</entry>
      <entry></entry>
      <entry>XtDefaultFont</entry>
    </row>
    <row>
      <entry>foreground</entry>
      <entry>Foreground</entry>
      <entry>Pixel</entry>
      <entry></entry>
      <entry>XtDefaultForeground</entry>
    </row>
    <row>
      <entry>height</entry>
      <entry>Height</entry>
      <entry>Dimension</entry>
      <entry>A</entry>
      <entry>graphic height + 2 * <function>internalHeight</function></entry>
    </row>
    <row>
      <entry>highlightThickness</entry>
      <entry>Thickness</entry>
      <entry>Dimension</entry>
      <entry>A</entry>
      <entry>2 (0 if Shaped)</entry>
    </row>
    <row>
      <entry>insensitiveBorder</entry>
      <entry>Insensitive</entry>
      <entry>Pixmap</entry>
      <entry></entry>
      <entry>GreyPixmap</entry>
    </row>
    <row>
      <entry>internalHeight</entry>
      <entry>Height</entry>
      <entry>Dimension</entry>
      <entry></entry>
      <entry>2</entry>
    </row>
    <row>
      <entry>internalWidth</entry>
      <entry>Width</entry>
      <entry>Dimension</entry>
      <entry></entry>
      <entry>4</entry>
    </row>
    <row>
      <entry>international</entry>
      <entry>International</entry>
      <entry>Boolean</entry>
      <entry>C</entry>
      <entry>False</entry>
    </row>
    <row>
      <entry>justify</entry>
      <entry>Justify</entry>
      <entry>Justify</entry>
      <entry></entry>
      <entry>XtJustifyCenter (center)</entry>
    </row>
    <row>
      <entry>label</entry>
      <entry>Label</entry>
      <entry>String</entry>
      <entry></entry>
      <entry>name of widget</entry>
    </row>
    <row>
      <entry>leftBitmap</entry>
      <entry>LeftBitmap</entry>
      <entry>Bitmap</entry>
      <entry></entry>
      <entry>None</entry>
    </row>
    <row>
      <entry>mappedWhenManaged</entry>
      <entry>MappedWhenManaged</entry>
      <entry>Boolean</entry>
      <entry></entry>
      <entry>True</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>resize</entry>
      <entry>Resize</entry>
      <entry>Boolean</entry>
      <entry></entry>
      <entry>True</entry>
    </row>
    <row>
      <entry>screen</entry>
      <entry>Screen</entry>
      <entry>Screen</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>shapeStyle</entry>
      <entry>ShapeStyle</entry>
      <entry>ShapeStyle</entry>
      <entry></entry>
      <entry>Rectangle</entry>
    </row>
    <row>
      <entry>translations</entry>
      <entry>Translations</entry>
      <entry>TranslationTable</entry>
      <entry></entry>
      <entry>See below</entry>
    </row>
    <row>
      <entry>width</entry>
      <entry>Width</entry>
      <entry>Dimension</entry>
      <entry>A</entry>
      <entry>graphic width + 2 * <function>internalWidth</function></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>
    <row>
      <entry>_</entry>
    </row>
  </tbody>
  </tgroup>
</informaltable>
<!-- \" Resource Descriptions -->
<!-- .Ac -->
<!-- .As -->
<!-- .Bg -->
<!-- .Gp -->
<!-- .Bm -->
<!-- .Bc -->
<!-- .Bp -->
<!-- .Bw -->
<!-- .Cb Bold -->
<!-- .Cm -->
<!-- .Cr Bold -->
<!-- .Cu -->
<!-- .Cn -->
<!-- .Dp -->
<!-- .Dc -->
<!-- .Le -->
<!-- .Lf -->
<!-- .Ls -->
<!-- .Lg -->
<!-- .Hw -->
<!-- .Ht Bold -->
<!-- .Ib -->
<!-- .Ih -->
<!-- .In -->
<!-- .Ju -->
<!-- .La -->
<!-- .Ll -->
<!-- .Mm -->
<!-- .Pf -->
<!-- .Pb -->
<!-- .Re -->
<!-- .Sc -->
<!-- .Se -->
<!-- .Ss Bold -->
<!-- .Tr -->
<!-- .Xy -->
</para>
</sect2>
<sect2 id="Command_Actions">
<title>Command Actions</title>
<indexterm><primary>Command widget</primary><secondary>actions</secondary></indexterm>
<para>
<!-- .LP -->
The Command widget supports the following actions:
</para>
<itemizedlist>
  <listitem>
    <para>
Switching the button's interior between the foreground and background
colors with <function>set</function>, <function>unset</function>, and <function>reset</function>.
    </para>
  </listitem>
  <listitem>
    <para>
Processing application callbacks with <function>notify</function>
    </para>
  </listitem>
  <listitem>
    <para>
Switching the internal border between highlighted
and unhighlighted states with <function>highlight</function> and <function>unhighlight</function>
    </para>
  </listitem>
</itemizedlist>
<para>
<!-- .LP -->
<indexterm><primary>Command widget</primary><secondary>translation bindings</secondary></indexterm>
The following are the default translation bindings used by the
Command widget:
</para>
<para>
<!-- .LP -->
<literallayout class="monospaced">
<!-- .TA .5i 2.25i -->
<!-- .ta .5i 2.25i -->
	&lt;EnterWindow&gt;:	highlight(&#x2006;)
	&lt;LeaveWindow&gt;:	reset(&#x2006;)
	&lt;Btn1Down&gt;:	set(&#x2006;)
	&lt;Btn1Up&gt;:	notify(&#x2006;) unset(&#x2006;)
</literallayout>
</para>
<para>
<!-- .LP -->
The full list of actions supported by Command is:
<variablelist>
  <varlistentry>
    <term>
      <function>highlight</function>(<function>condition</function>)
    </term>
    <listitem>
      <para>
Displays the internal highlight border in the color (<function>foreground</function>
or <function>background</function> ) that contrasts with the interior color of the
Command widget.  The conditions <function>WhenUnset</function> and <function>Always</function> are
understood by this action procedure.  If no argument is passed,
<function>WhenUnset</function> is assumed.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>unhighlight</function>(&#x2006;)
    </term>
    <listitem>
      <para>
Displays the internal highlight border in the color (<function>foreground</function>
or <function>background</function> ) that matches the interior color of the
Command widget.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>set</function>(&#x2006;)
    </term>
    <listitem>
      <para>
Enters the <function>set</function> state, in which <function>notify</function> is possible.  This
action causes the button to display its interior in the
<function>foreground</function> color.  The label or bitmap is displayed in the
<function>background</function> color.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>unset</function>(&#x2006;)
    </term>
    <listitem>
      <para>
Cancels the <emphasis remap='I'>set</emphasis> state and displays the interior of the button in the
<function>background</function> color.  The label or bitmap is displayed in the
<function>foreground</function> color.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>reset</function>(&#x2006;)
    </term>
    <listitem>
      <para>
Cancels any <emphasis remap='I'>set</emphasis> or <emphasis remap='I'>highlight</emphasis> and displays the interior of the
button in the <function>background</function> color, with the label or bitmap displayed
in the <function>foreground</function> color.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>notify</function>(&#x2006;)
    </term>
    <listitem>
      <para>
When the button is in the <function>set</function> state this action calls all functions in
the callback list named by the <function>callback</function> resource.  The value of
the <emphasis remap='I'>call_data</emphasis> argument passed to these functions is undefined.
    </para>
  </listitem>
  </varlistentry>
</variablelist>
</para>
<para>
<!-- .LP -->
A very common alternative to registering callbacks is to augment a
Command's translations with an action performing the desired
function.  This often takes the form of:
</para>
<para>
<!-- .LP -->
<literallayout class="monospaced">
<!-- .TA .5i 2.25i -->
<!-- .ta .5i 2.25i -->
*Myapp*save.translations: #augment &lt;Btn1Down&gt;,&lt;Btn1Up&gt;: Save()
</literallayout>
</para>
<para>
<!-- .LP -->
<!-- .NT -->
When a bitmap of depth greater that one (1) is specified the
<emphasis remap='I'>set</emphasis>(), <emphasis remap='I'>unset</emphasis>(), and <emphasis remap='I'>reset</emphasis>() actions have no effect,
since there are no foreground and background colors used in a
multi-plane pixmap.
<!-- .NE -->

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