libxaw-doc 2:1.0.12-2 / usr / share / doc / libxaw7-dev / Toggle.xml

<sect1 id="Toggle_Widget">
<title>Toggle Widget</title>
<literallayout class="monospaced">
Application Header file     &lt;Xaw/Toggle.h&gt;
Class Header file     &lt;Xaw/ToggleP.h&gt;
Class          toggleWidgetClass
Class Name     Toggle
Superclass      Command
</literallayout>

<para>
The Toggle widget is an area, often rectangular,
that displays a graphic.  The graphic may be a text
string containing multiple lines of characters in an 8
bit or 16 bit character set (to be displayed with a
<emphasis remap='I'>font</emphasis>), or in a multi-byte encoding (for use with
a <emphasis remap='I'>fontset</emphasis>).  The graphic may also be a bitmap or
pixmap.
</para>

<para>
This widget maintains a Boolean state (e.g.
True/False or On/Off) and changes state whenever it is selected.  When
the pointer is on the Toggle widget, the Toggle widget may become highlighted by
drawing a rectangle around its perimeter.  This highlighting indicates
that the Toggle widget is ready for selection.  When pointer button 1 is
pressed and released, the Toggle widget indicates that it has changed
state by reversing its foreground and background colors, and its
<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 Toggle widget reverts to its previous foreground and background
colors, and releasing the pointer button has no effect.  This behavior allows
the user to cancel the operation.
</para>

<para>
Toggle widgets may also be part of a ``radio group.''  A radio group is a
list of at least two Toggle widgets in which no more than one Toggle may
be set at
any time.  A radio group is identified by the widget ID of any one of
its members.  The convenience routine <xref linkend='XawToggleGetCurrent' xrefstyle='select: title'/> will
return information about the Toggle widget in the radio group.
</para>

<para>
Toggle widget state is preserved across changes in sensitivity.
</para>

<sect2 id='Toggle::Resources'>
<title>Resources</title>
<para>
When creating a Toggle widget instance, the following resources are
retrieved from the argument list or from the resource database:
</para>

<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>fontSet</entry>
      <entry>FontSet</entry>
      <entry>XFontSet</entry>
      <entry></entry>
      <entry>XtDefaultFontSet</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>radioData</entry>
      <entry>RadioData</entry>
      <entry>Pointer</entry>
      <entry></entry>
      <entry>Name of widget</entry>
    </row>
    <row>
      <entry>radioGroup</entry>
      <entry>Widget</entry>
      <entry>Widget</entry>
      <entry></entry>
      <entry>No radio group</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>shapeStype</entry>
      <entry>ShapeStyle</entry>
      <entry>ShapeStyle</entry>
      <entry></entry>
      <entry>Rectangle</entry>
    </row>
    <row>
      <entry>state</entry>
      <entry>State</entry>
      <entry>Boolean</entry>
      <entry></entry>
      <entry>Off</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>
  </tbody>
  </tgroup>
</informaltable>

<variablelist>
  <varlistentry>
    <term>
      <function>radioData</function>
    </term>
    <listitem>
      <para>
Specifies the data that will be returned by <xref linkend='XawToggleGetCurrent' xrefstyle='select: title'/>
when this is the currently <emphasis remap='I'>set</emphasis> widget in the radio group.  This
value is also used to identify the Toggle that will be set by a call to
<xref linkend='XawToggleSetCurrent' xrefstyle='select: title'/>.  The value NULL will be returned by
<xref linkend='XawToggleGetCurrent' xrefstyle='select: title'/> if no widget in a radio group is currently
set.  Programmers must not specify NULL (or Zero) as <function>radioData</function>.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>radioGroup</function>
    </term>
    <listitem>
      <para>
Specifies another Toggle widget that is in the radio group to which this
Toggle widget should be added.  A radio group is a group of at least two Toggle
widgets, only one of which may be <emphasis remap='I'>set</emphasis> at a time.  If this value is
NULL (the default) then the Toggle will not be part of any radio group
and can change state without affecting any other Toggle widgets.  If the
widget specified in this resource is not already in a radio group then a
new radio group will be created containing these two Toggle widgets.  No
Toggle widget can be in multiple radio groups.  The behavior of a radio
group of one toggle is undefined.  A converter is registered which will
convert widget names to widgets without caching.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>state</function>
    </term>
    <listitem>
      <para>
Specifies whether the Toggle widget is set (<function>True</function>) or unset
(<function>False</function>).
    </para>
  </listitem>
  </varlistentry>
</variablelist>
</sect2>

<sect2 id="Toggle_Actions">
<title>Toggle Actions</title>
<para>
The Toggle widget supports the following actions:
</para>

<itemizedlist>
  <listitem>
    <para>
Switching the Toggle widget between the foreground and background
colors with <function>set</function> and <function>unset</function> and <function>toggle</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>
The following are the default translation bindings used by the
Toggle widget:
</para>

<literallayout class="monospaced">
     &lt;EnterWindow&gt;:     highlight(Always)
     &lt;LeaveWindow&gt;:     unhighlight()
     &lt;Btn1Down&gt;,&lt;Btn1Up&gt;:     toggle() notify()
</literallayout>
</sect2>

<sect2 id='Toggle_Actions_b'>
<title>Toggle Actions</title>
<para>
The full list of actions supported by Toggle is:
</para>
<variablelist>
  <varlistentry>
    <term>
      <function>highlight</function>(<emphasis remap='I'>condition</emphasis>)
    </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
Toggle widget.  The conditions <function>WhenUnset</function> and <function>Always</function> are
understood by this action procedure.  If no argument is passed then
<function>WhenUnset</function> is assumed.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>unhighlight</function>()
    </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
Toggle widget.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>set</function>()
    </term>
    <listitem>
      <para>
Enters the <emphasis remap='I'>set</emphasis> state, in which <function>notify</function> is possible.  This
action causes the Toggle widget 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>()
    </term>
    <listitem>
      <para>
Cancels the <emphasis remap='I'>set</emphasis> state and displays the interior of the Toggle widget in the
<function>background</function> color.  The label or bitmap is displayed in the
<function>foreground</function> color.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>toggle</function>()
    </term>
    <listitem>
      <para>
Changes the current state of the Toggle widget, causing to be set
if it was previously unset, and unset if it was previously set.
If the widget is to be set, and is in a radio group then this procedure may
unset another Toggle widget causing all routines on its callback list
to be invoked.  The callback routines for the Toggle that
is to be unset will be called before the one that is to be set.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>reset</function>()
    </term>
    <listitem>
      <para>
Cancels any <function>set</function> or <function>highlight</function> and displays the interior of the
Toggle widget in the <function>background</function> color, with the label displayed in the
<function>foreground</function> color.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <function>notify</function>()
    </term>
    <listitem>
      <para>
When the Toggle widget 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 call_data argument in these callback functions is undefined.
    </para>
  </listitem>
  </varlistentry>
</variablelist>

<para>
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.
</para>
</sect2>

<sect2 id="Radio_Groups">
<title>Radio Groups</title>
<para>
There are typically two types of radio groups desired by applications.
The default translations for the Toggle widget implement a "zero or one
<!-- .IN "Radio groups" "zero or one of many" -->
of many" radio group.  This means that there may be no more than one
Toggle widget active, but there need not be any Toggle widgets active.
</para>

<para>
The other type of radio group is "one of many" and has the more strict
policy that there will always be exactly one radio button active.
Toggle widgets can be used to provide this interface with a slight
modification to the translation table of each Toggle in the group.
</para>

<literallayout class="monospaced">
     &lt;EnterWindow&gt;:     highlight(Always)
     &lt;LeaveWindow&gt;:     unhighlight()
     &lt;Btn1Down&gt;,&lt;Btn1Up&gt;:     set() notify()
</literallayout>

<para>
This translation table will not allow any Toggle to be <emphasis remap='I'>unset</emphasis>
except as a result of another Toggle becoming <emphasis remap='I'>set</emphasis>.  It is
the application programmer's responsibility to choose an initial
state for the radio group by setting the <function>state</function> resource of one of
its member widgets to <function>True</function>.
</para>
</sect2>

<sect2 id='Toggle::Convenience_Routines'>
<title>Convenience Routines</title>
<para>
The following functions allow easy access to the Toggle widget's radio
group functionality.
</para>

<sect3 id='Changing_the_Toggles_Radio_Group'>
<title>Changing the Toggle's Radio Group.</title>
<para>
To enable an application to change the Toggle's radio group, add
the Toggle to a radio group, or remove the Toggle from a radio group, use
<xref linkend='XawToggleChangeRadioGroup' xrefstyle='select: title'/>.
</para>

<funcsynopsis id='XawToggleChangeRadioGroup'>
<funcprototype>
  <funcdef>void<function> XawToggleChangeRadioGroup</function></funcdef>
  <paramdef>Widgetw,<parameter> radio_group</parameter></paramdef>
</funcprototype>
</funcsynopsis>

<para>
<variablelist>
  <varlistentry>
    <term>
      <emphasis remap='I'>w</emphasis>
    </term>
    <listitem>
      <para>
Specifies the Toggle widget.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <emphasis remap='I'>radio_group</emphasis>
    </term>
    <listitem>
      <para>
Specifies any Toggle in the new radio group.  If NULL then the Toggle
will be removed from any radio group of which it is a member.
    </para>
  </listitem>
  </varlistentry>
</variablelist>
</para>

<para>
If a Toggle is already <emphasis remap='I'>set</emphasis> in the new radio group,
and the Toggle to be added is also <emphasis remap='I'>set</emphasis> then the previously
<emphasis remap='I'>set</emphasis> Toggle in the radio group is <emphasis remap='I'>unset</emphasis> and its callback
procedures are invoked.
Finding the Currently selected Toggle in a radio group of Toggles
</para>

<para>
To find the currently selected Toggle in a radio group of Toggle widgets
use <xref linkend='XawToggleGetCurrent' xrefstyle='select: title'/>.
</para>

<funcsynopsis id='XawToggleGetCurrent'>
<funcprototype>
  <funcdef>XtPointer<function> XawToggleGetCurrent</function></funcdef>
  <paramdef>XtPointer<parameter> XawToggleGetCurrent(radio_group)</parameter></paramdef>
  <paramdef>Widget<parameter> radio_group</parameter></paramdef>
</funcprototype>
</funcsynopsis>

<variablelist>
  <varlistentry>
    <term>
      <emphasis remap='I'>radio_group</emphasis>
    </term>
    <listitem>
      <para>
Specifies any Toggle widget in the radio group.
    </para>
  </listitem>
  </varlistentry>
</variablelist>

<para>
The value returned by this function is the
<function>radioData</function>
of the Toggle in this radio group that is currently set.  The default
value for <function>radioData</function>
is the name of that Toggle widget.  If no Toggle is set in the radio
group specified then NULL is returned.
Changing the Toggle that is set in a radio group.
</para>

<para>
To change the Toggle that is currently set in a radio group use
<xref linkend='XawToggleSetCurrent' xrefstyle='select: title'/>.
</para>

<funcsynopsis id='XawToggleSetCurrent'>
<funcprototype>
  <funcdef>void<function> XawToggleSetCurrent</function></funcdef>
  <paramdef>voidXawToggleSetCurrent(radio_group,<parameter> radio_data)</parameter></paramdef>
  <paramdef>Widget<parameter> radio_group</parameter></paramdef>
  <paramdef>XtPointer<parameter> radio_data</parameter></paramdef>
</funcprototype>
</funcsynopsis>

<variablelist>
  <varlistentry>
    <term>
      <emphasis remap='I'>radio_group</emphasis>
    </term>
    <listitem>
      <para>
Specifies any Toggle widget in the radio group.
      </para>
    </listitem>
  </varlistentry>
  <varlistentry>
    <term>
      <emphasis remap='I'>radio_data</emphasis>
    </term>
    <listitem>
      <para>
Specifies the
<function>radioData</function>
identifying the Toggle that should be set in the radio group specified
by the <emphasis remap='I'>radio_group</emphasis> argument.
    </para>
  </listitem>
  </varlistentry>
</variablelist>


<para>
<xref linkend='XawToggleSetCurrent' xrefstyle='select: title'/> locates the Toggle widget to be set by
matching <emphasis remap='I'>radio_data</emphasis> against the <function>radioData</function> for each Toggle in
the radio group.  If none match, <xref linkend='XawToggleSetCurrent' xrefstyle='select: title'/> returns
without making any changes.  If more than one Toggle matches,
<xref linkend='XawToggleSetCurrent' xrefstyle='select: title'/> will choose a Toggle to set arbitrarily.  If
this causes any Toggle widgets to change state, all routines in their
callback lists will be invoked.  The callback routines for a Toggle that
is to be unset will be called before the one that is to be set.
Unsetting all Toggles in a radio group.
</para>

<para>
To unset all Toggle widgets in a radio group use
<xref linkend='XawToggleUnsetCurrent' xrefstyle='select: title'/>.
</para>

<funcsynopsis id='XawToggleUnsetCurrent'>
<funcprototype>
  <funcdef>void<function> XawToggleUnsetCurrent</function></funcdef>
  <paramdef>void<parameter> XawToggleUnsetCurrent(radio_group)</parameter></paramdef>
  <paramdef>Widget<parameter> radio_group</parameter></paramdef>
</funcprototype>
</funcsynopsis>

<variablelist>
  <varlistentry>
    <term>
      <emphasis remap='I'>radio_group</emphasis>
    </term>
    <listitem>
      <para>
Specifies any Toggle widget in the radio group.
    </para>
  </listitem>
  </varlistentry>
</variablelist>

<para>
If this causes a Toggle widget to change state, all routines on its
callback list will be invoked.
</para>
</sect3>
</sect2>
</sect1>