XmCascadeButtonGadget --
the CascadeButtonGadget widget class
Synopsis
#include <Xm/CascadeBG.h>
Description
CascadeButtonGadget links two MenuPanes, a MenuBar to a MenuPane, or an
OptionMenu to a MenuPane.
It is used in menu systems and must have a RowColumn parent
with its XmNrowColumnType resource set to XmMENU_BAR,
XmMENU_POPUP, XmMENU_PULLDOWN, or XmMENU_OPTION.
It is the only gadget that can have a Pulldown MenuPane attached to it as
a submenu. The submenu is displayed when this gadget is activated within
a PopupMenu, a PulldownMenu, or an OptionMenu. Its visuals can
include a label or pixmap and a cascading indicator when it is in a
Popup or Pulldown MenuPane; or it can include only a label or a pixmap
when it is in an OptionMenu.
The default behavior associated with a CascadeButtonGadget depends on the type
of menu system in which it resides.
By default, BSelect controls the behavior of the CascadeButtonGadget.
In addition, BMenu controls the behavior of the CascadeButtonGadget if
it resides in a PopupMenu system.
The actual mouse button used is determined by its RowColumn parent.
A CascadeButtonGadget'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 CascadeButtonGadget
within a Pulldown or Popup MenuPane is armed as the result of the user
moving the mouse pointer into the gadget, it does not immediately display its
submenu. Instead, it waits a short time to see if the arming
was temporary (that is, the user was simply passing through the gadget), or
the user really wanted the submenu posted. This delay is
configurable via XmNmappingDelay.
CascadeButtonGadget provides a single mechanism for
activating the gadget from the keyboard. This mechanism is referred to as
a keyboard mnemonic.
If a mnemonic has been
specified for the gadget, the user may activate it
by simply typing the mnemonic while the CascadeButtonGadget is visible.
If the CascadeButtonGadget 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
via the keyboard.
If a CascadeButtonGadget is in a Pulldown or Popup MenuPane 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 LabelGadget's default, which
is 2.
Classes
CascadeButtonGadget inherits behavior and resources
from Object, RectObj, XmGadget,
and XmLabelGadget classes.
The class pointer is xmCascadeButtonGadgetClass.
The class name is XmCascadeButtonGadget.
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).
xmCascadeButtonGadget
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 CascadeButtonGadget,
and there is no submenu attached to pop up. The activation occurs by
releasing a mouse button
or by typing the mnemonic associated with the gadget. 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 gadget when
a CascadeButtonGadget is used within a Popup or Pulldown MenuPane
and a submenu is attached.
The LabelGadget class resources XmNmarginBottom,
XmNmarginLeft, XmNmarginRight, and
XmNmarginTop may be modified to
ensure that room is left for the cascade pixmap.
The default cascade pixmap in menus other than option menus is an arrow
pointing to the side of the menu where the submenu will appear.
The default for the CascadeButtonGadget in an option menu is
XmUNSPECIFIED_PIXMAP.
XmNcascadingCallback
Specifies the list of callbacks that is called just prior to
the mapping of the submenu associated with the CascadeButtonGadget.
The reason sent by the callback is XmCR_CASCADING.
XmNmappingDelay
Specifies the amount of time, in milliseconds, between when a
CascadeButtonGadget
becomes armed and when it maps its submenu. This delay is used only when the
gadget is within a Popup or Pulldown MenuPane.
The value must not be negative.
XmNsubMenuId
Specifies the widget ID for the Pulldown MenuPane to be
associated with this CascadeButtonGadget. The specified MenuPane is
displayed when the CascadeButtonGadget becomes armed. The MenuPane must
have been created with the appropriate parentage depending on the type
of menu used. See
XmCreatePulldownMenu(X3mot),
XmCreatePopupMenu(X3mot),
and
XmCreateOptionMenu(X3mot)
for
more information on the menu systems.
Inherited resources
CascadeButtonGadget inherits behavior and resources from the following
superclasses. For a complete description of each resource, refer to the
man page for that superclass.
XmLabelGadget resource set
Name
Class
Type
Default
Access
XmNaccelerator
XmCAccelerator
String
NULL
N/A
XmNacceleratorText
XmCAcceleratorText
XmString
NULL
N/A
XmNalignment
XmCAlignment
unsigned char
dynamic
CSG
XmNfontList
XmCFontList
XmFontList
dynamic
CSG
XmNlabelInsensitivePixmap
XmCLabelInsensitivePixmap
Pixmap
XmUNSPECIFIED_PIXMAP
CSG
XmNlabelPixmap
XmCLabelPixmap
Pixmap
XmUNSPECIFIED_PIXMAP
CSG
XmNlabelString
XmCXmString
XmString
dynamic
CSG
XmNlabelType
XmCLabelType
unsigned char
XmSTRING
CSG
XmNmarginBottom
XmCMarginBottom
Dimension
dynamic
CSG
XmNmarginHeight
XmCMarginHeight
Dimension
2
CSG
XmNmarginLeft
XmCMarginLeft
Dimension
0
CSG
XmNmarginRight
XmCMarginRight
Dimension
dynamic
CSG
XmNmarginTop
XmCMarginTop
Dimension
dynamic
CSG
XmNmarginWidth
XmCMarginWidth
Dimension
dynamic
CSG
XmNmnemonic
XmCMnemonic
KeySym
NULL
CSG
XmNmnemonicCharSet
XmCMnemonicCharSet
String
dynamic
CSG
XmNrecomputeSize
XmCRecomputeSize
Boolean
True
CSG
XmNstringDirection
XmCStringDirection
XmStringDirection
dynamic
CSG
XmGadget resource set
Name
Class
Type
Default
Access
XmNbottomShadowColor
XmCBottomShadowColor
Pixel
dynamic
G
XmNhelpCallback
XmCCallback
XtCallbackList
NULL
C
XmNhighlightColor
XmCHighlightColor
Pixel
dynamic
G
XmNhighlightOnEnter
XmCHighlightOnEnter
Boolean
False
CSG
XmNhighlightThickness
XmCHighlightThickness
Dimension
0
CSG
XmNnavigationType
XmCNavigationType
XmNavigationType
XmNONE
CSG
XmNshadowThickness
XmCShadowThickness
Dimension
2
CSG
XmNtopShadowColor
XmCTopShadowColor
Pixel
dynamic
G
XmNtraversalOn
XmCTraversalOn
Boolean
True
CSG
XmNunitType
XmCUnitType
unsigned char
dynamic
CSG
XmNuserData
XmCUserData
XtPointer
NULL
CSG
RectObj resource set
Name
Class
Type
Default
Access
XmNancestorSensitive
XmCSensitive
Boolean
dynamic
G
XmNborderWidth
XmCBorderWidth
Dimension
0
CSG
XmNheight
XmCHeight
Dimension
dynamic
CSG
XmNsensitive
XmCSensitive
Boolean
True
CSG
XmNwidth
XmCWidth
Dimension
dynamic
CSG
XmNx
XmCPosition
Position
0
CSG
XmNy
XmCPosition
Position
0
CSG
Object resource set
Name
Class
Type
Default
Access
XmNdestroyCallback
XmCCallback
XtCallbackList
NULL
C
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 by an XEvent.
Behavior
XmCascadeButtonGadget includes behavior from XmGadget.
XmCascadeButton includes the menu traversal behavior from XmLabel.
Additional XmCascadeButtonGadget behavior is described below (in a Popup
menu system, BMenu also performs the BSelect actions):
BSelect Press:
Unposts any menus posted by the parent menu.
Arms the CascadeButtonGadget,
posts the associated submenu,
enables mouse traversal,
and, in a MenuBar, arms the MenuBar.
If the menu is already active, this event
disables keyboard traversal for the menu and returns
the menu to mouse traversal mode.
BSelect Release:
Calls the callbacks in XmNcascadingCallback,
posts the submenu attached to the CascadeButtonGadget and
enables keyboard traversal within the menu.
If the CascadeButtonGadget does not have a submenu attached,
calls the callbacks in XmNactivateCallback,
the CascadeButtonGadget is activated and all posted menus in the cascade are
unposted.
KActivate:
Calls the callbacks in XmNcascadingCallback,
and
posts the submenu attached to the CascadeButtonGadget if keyboard
traversal is enabled in the menu.
If the CascadeButtonGadget does not have a submenu attached,
calls the callbacks in XmNactivateCallback,
the CascadeButtonGadget is activated and all posted menus in the cascade are
unposted. This action applies only to gadgets in MenuBars, PulldownMenus, and
PopupMenus. For a CascadeButtonGadget in an OptionMenu, if the parent
is a manager, this action passes the event to the parent.
KSelect:
Calls the callbacks in XmNcascadingCallback,
and
posts the submenu attached to the CascadeButtonGadget if keyboard
traversal is enabled in the menu.
If the CascadeButtonGadget does not have a submenu attached,
calls the callbacks in XmNactivateCallback,
the CascadeButtonGadget is activated and all posted menus in the cascade are
unposted.
KHelp:
Unposts all menus in the menu hierarchy and,
when the shell's keyboard focus policy is XmEXPLICT,
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.
MAny KCancel:
In a MenuBar, disarms the CascadeButtonGadget and the menu and,
when the shell's keyboard focus policy is XmEXPLICT,
restores
keyboard focus to the widget that had the focus before the menu was
entered.
For a CascadeButtonGadget in an OptionMenu, if the parent is a manager, this
action passes the event to the parent.
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 XmEXPLICT,
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 restores keyboard focus to the
widget from which the menu was posted.
<Enter>:
If keyboard traversal is enabled does nothing.
Otherwise, in a MenuBar,
unposts any MenuPanes associated with another MenuBar entry,
arms the CascadeButtonGadget, and posts the associated submenu.
In other menus,
arms the CascadeButtonGadget and posts the associated submenu after
the delay specified by XmNmappingDelay.
<Leave>:
If keyboard traversal is enabled does nothing.
Otherwise, in a MenuBar,
disarms the CascadeButtonGadget
if the submenu associated with the CascadeButtonGadget is not currently
posted or if there is no submenu associated with the CascadeButtonGadget.
In other menus, if the pointer moves anywhere except into a submenu
associated with the CascadeButtonGadget, the CascadeButtonGadget 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(X3mot).