Tribblix: manual page: XmCascadeButton.3

XmCascadeButton(library call) XmCascadeButton(library call)

NAME

XmCascadeButton -- The CascadeButton widget class

SYNOPSIS

#include <Xm/CascadeB.h>

DESCRIPTION

CascadeButton links two menu panes or a MenuBar to a menu pane.

It is used in menu systems and must have a RowColumn parent with its
XmNrowColumnType resource set to XmMENU_BAR, XmMENU_POPUP or
XmMENU_PULLDOWN.

It is the only widget that can have a Pulldown menu pane attached to
it as a submenu. The submenu is displayed when this widget is
activated within a MenuBar, a PopupMenu, or a PulldownMenu. Its
visuals can include a label or pixmap and a cascading indicator when
it is in a Popup or Pulldown menu pane; or it can include only a
label or a pixmap when it is in a MenuBar. The positioning of the
PulldownMenu with respect to the CascadeButton depends on the
XmNlayoutDirection resource of the MenuShell.

The default behavior associated with a CascadeButton depends on the
type of menu system in which it resides. By default, BSelect
controls the behavior of the CascadeButton. In addition, BMenu
controls the behavior of the CascadeButton if it resides in a
PopupMenu system. The actual mouse button used is determined by its
RowColumn parent. BMenu also performs the BSelect actions in all
types of menu systems.

A CascadeButton's visuals differ from most other button gadgets. When
the button becomes armed, its visuals change from a 2-D to a 3-D
look, and it displays the submenu that has been attached to it. If no
submenu is attached, it simply changes its visuals.

When a CascadeButton within a Pulldown or Popup menu pane is armed as
the result of the user moving the mouse pointer into the widget, it
does not immediately display its submenu. Instead, it waits a short
amount of time to see if the arming was temporary (that is, the user
was simply passing through the widget), or whether the user really
wanted the submenu posted. This time delay is configurable using
XmNmappingDelay.

CascadeButton provides a single mechanism for activating the widget
from the keyboard. This mechanism is referred to as a keyboard
mnemonic. If a mnemonic has been specified for the widget, the user
may activate the CascadeButton by simply typing the mnemonic while
the CascadeButton is visible. If the CascadeButton is in a MenuBar
and the MenuBar does not have the focus, the MAlt modifier must be
pressed with the mnemonic. Mnemonics are typically used to interact
with a menu using the keyboard interface.

If the Cascadebutton is in a Pulldown or Popup menu pane and there is
a submenu attached, the XmNmarginBottom, XmNmarginLeft,
XmNmarginRight, and XmNmarginTop resources may enlarge to accommodate
XmNcascadePixmap. XmNmarginWidth defaults to 6 if this resource is
in a MenuBar; otherwise, it takes Label's default, which is 2.

CascadeButton uses the XmQTmenuSystem and XmQTspecifyRenderTable
traits.

Classes

CascadeButton inherits behavior, resources, and traits from Core,
XmPrimitive, and XmLabel classes.

The class pointer is xmCascadeButtonWidgetClass.

The class name is XmCascadeButton.

New Resources

The following table defines a set of widget resources used by the
programmer to specify data. The programmer can also set the resource
values for the inherited classes to set attributes for this widget.
To reference a resource by name or by class in a .Xdefaults file,
remove the XmN or XmC prefix and use the remaining letters. To
specify one of the defined values for a resource in a .Xdefaults
file, remove the Xm prefix and use the remaining letters (in either
lowercase or uppercase, but include any underscores between words).
The codes in the access column indicate if the given resource can be
set at creation time (C), set by using XtSetValues (S), retrieved by
using XtGetValues (G), or is not applicable (N/A).

+---------------------------------------------------------------------------+
| XmCascadeButton Resource Set |
|Name | Class | Type | Default | Access |
+---------------------+-----------------+----------------+---------+--------+
|XmNactivateCallback | XmCCallback | XtCallbackList | NULL | C |
+---------------------+-----------------+----------------+---------+--------+
|XmNcascadePixmap | XmCPixmap | Pixmap | dynamic | CSG |
+---------------------+-----------------+----------------+---------+--------+
|XmNcascadingCallback | XmCCallback | XtCallbackList | NULL | C |
+---------------------+-----------------+----------------+---------+--------+
|XmNmappingDelay | XmCMappingDelay | int | 180 ms | CSG |
+---------------------+-----------------+----------------+---------+--------+
|XmNsubMenuId | XmCMenuWidget | Widget | NULL | CSG |
+---------------------+-----------------+----------------+---------+--------+
+---------------------+-----------------+----------------+---------+--------+
XmNactivateCallback
Specifies the list of callbacks that is called when the
user activates the CascadeButton widget and there is no
submenu attached to pop up. The activation occurs when a
mouse button is released or when the mnemonic associated
with the widget is typed. The specific mouse button depends
on information in the RowColumn parent. The reason sent by
the callback is XmCR_ACTIVATE.

XmNcascadePixmap
Specifies the cascade pixmap displayed on one end of the
widget when a CascadeButton is used within a Popup or
Pulldown menu pane and a submenu is attached. The Label
class resources XmNmarginBottom, XmNmarginLeft,
XmNmarginRight, and XmNmarginTop may be modified to ensure
that room is left for the cascade pixmap. The default
cascade pixmap is an arrow pointing to the side of the menu
where the submenu will appear. The positioning of the
cascade pixmap to either the left of right of the widget,
and the direction of the arrow, depend on the
XmNlayoutDirection resource of the MenuShell.

XmNcascadingCallback
Specifies the list of callbacks that is called just prior
to the mapping of the submenu associated with
CascadeButton. The reason sent by the callback is
XmCR_CASCADING.

XmNmappingDelay
Specifies the amount of time, in milliseconds, between when
a CascadeButton becomes armed and when it maps its submenu.
This delay is used only when the widget is within a Popup
or Pulldown menu pane. The value must not be negative.

XmNsubMenuId
Specifies the widget ID for the Pulldown menu pane to be
associated with this CascadeButton. The specified menu pane
is displayed when the CascadeButton becomes armed. The menu
pane must have been created with the appropriate parentage
depending on the type of menu used. See XmCreateMenuBar(3),
XmCreatePulldownMenu(3), and XmCreatePopupMenu(3) for more
information on the menu systems.

Inherited Resources

Callback Information

A pointer to the following structure is passed to each callback:

typedef struct
{
int reason;
XEvent * event;
} XmAnyCallbackStruct;

reason Indicates why the callback was invoked

event Points to the XEvent that triggered the callback or is NULL
if this callback was not triggered due to an XEvent

Translations

XmCascadeButton includes translations from XmPrimitive.
XmCascadeButton includes the menu traversal translations from
XmLabel.

Note that altering translations in #override or #augment mode is
undefined.

The following list describes the translations for a CascadeButton in
a MenuBar. The following key names are listed in the X standard key
event translation table syntax. This format is the one used by Motif
to specify the widget actions corresponding to a given key. A brief
overview of the format is provided under VirtualBindings(3). For a
complete description of the format, please refer to the X Toolkit
Instrinsics Documentation.

<EnterWindow>Normal:
MenuBarEnter()

<LeaveWindow>Normal:
MenuBarLeave()

<Btn2Down>:
ProcessDrag()

c<BtnDown>:
MenuButtonTakeFocusUp()

c<BtnUp>: MenuButtonTakeFocusUp()

~c<BtnDown>:
MenuBarSelect()

~c<BtnUp>:
DoSelect()

:<Key><osfSelect>:
KeySelect()

:<Key><osfActivate>:
KeySelect()

:<Key><osfHelp>:
Help()

:<Key><osfCancel>:
CleanupMenuBar()

~s<Key>Return:
KeySelect()

~s<Key>space:
KeySelect()

The following list describes the translations for a CascadeButton in
a PullDown or Popup MenuPane. In a Popup menu system, <Btn3> also
performs the <Btn1> actions.

<EnterWindow>:
DelayedArm()

<LeaveWindow>:
CheckDisarm()

<Btn2Down>:
ProcessDrag()

c<BtnDown>:
MenuButtonTakeFocus()

c<BtnUp>: MenuButtonTakeFocusUp()

~c<BtnDown>:
StartDrag()

~c<BtnUp>:
DoSelect()

:<Key><osfSelect>:
KeySelect()

:<Key><osfActivate>:
KeySelect()

:<Key><osfHelp>:
Help()

:<Key><osfCancel>:
CleanupMenuBar()

~s<Key>Return:
KeySelect()

~s<Key>space:
KeySelect()

Action Routines

The XmCascadeButton action routines are

CleanupMenuBar():
In a MenuBar, disarms the CascadeButton and the menu and,
when the shell's keyboard focus policy is XmEXPLICIT,
restores keyboard focus to the widget that had the focus
before the menu was entered.

In a toplevel Pulldown MenuPane from a MenuBar, unposts the
menu, disarms the MenuBar CascadeButton and the MenuBar,
and, when the shell's keyboard focus policy is XmEXPLICIT,
restores keyboard focus to the widget that had the focus
before the MenuBar was entered. In other Pulldown
MenuPanes, unposts the menu.

In a Popup MenuPane, unposts the menu and, when the shell's
keyboard focus policy is XmEXPLICIT, restores keyboard
focus to the widget from which the menu was posted.

DoSelect():
Calls the callbacks in XmNcascadingCallback, posts the
submenu attached to the CascadeButton and enables keyboard
traversal within the menu. If the CascadeButton does not
have a submenu attached, this action calls the callbacks in
XmNactivateCallback, activates the CascadeButton, and
unposts all posted menus in the cascade.

Help(): Unposts all menus in the menu hierarchy and, when the
shell's keyboard focus policy is XmEXPLICIT, restores
keyboard focus to the widget that had the focus before the
menu system was entered. Calls the callbacks for
XmNhelpCallback if any exist. If there are no help
callbacks for this widget, this action calls the help
callbacks for the nearest ancestor that has them.

KeySelect():
Calls the callbacks in XmNcascadingCallback, and posts the
submenu attached to the CascadeButton if keyboard traversal
is enabled in the menu. If the CascadeButton does not have
a submenu attached, this action calls the callbacks in
XmNactivateCallback, activates the CascadeButton, and
unposts all posted menus in the cascade.

MenuBarSelect():
Unposts any menus posted by the parent menu. Arms both the
CascadeButton and the MenuBar, posts the associated
submenu, and enables mouse traversal. If the menu is
already active, this event disables keyboard traversal for
the menu and returns the menu to mouse traversal mode.

StartDrag():
Arms the CascadeButton, posts the associated submenu, and
enables mouse traversal. If the menu is already active,
this event disables keyboard traversal for the menu and
returns the menu to mouse traversal mode.

Additional Behavior

Posting a submenu calls the XmNcascadingCallback callbacks. This
widget has the following additional behavior:

<EnterWindow>:
If keyboard traversal is enabled, does nothing. Otherwise,
in a MenuBar that is armed, unposts any MenuPanes
associated with another MenuBar entry, arms the
CascadeButton, and posts the associated submenu. In other
menus, arms the CascadeButton and posts the associated
submenu after the delay specified by XmNmappingDelay.

<LeaveWindow>:
If keyboard traversal is enabled does nothing. Otherwise,
in a MenuBar that is armed, disarms the CascadeButton if
the submenu associated with the CascadeButton is not
currently posted or if there is no submenu associated with
the CascadeButton.

In other menus, if the pointer moves anywhere except into a
submenu associated with the CascadeButton, the
CascadeButton is disarmed and its submenu is unposted.

Virtual Bindings

The bindings for virtual keys are vendor specific. For information
about bindings for virtual buttons and keys, see VirtualBindings(3).

Core(3), XmCascadeButtonHighlight(3), XmCreateCascadeButton(3),
XmCreateMenuBar(3), XmCreatePulldownMenu(3), XmCreatePopupMenu(3),
XmLabel(3), XmPrimitive(3), XmRowColumn(3),
XmVaCreateCascadeButton(3), XmVaCreateManagedCascadeButton(3).

XmCascadeButton(library call)