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NSMenu

Authors

Fred Kiefer (FredKiefer@gmx.de)
David Lazaro Saz (khelekir@encomix.es)
Michael Hanni (mhanni@sprintmail.com)
Felipe A. Rodriguez (far@ix.netcom.com)
Ovidiu Predescu (ovidiu@net-community.com)

Date: Generated at 2023-12-22 15:07:50 -0500

Copyright: (C) 1999,2016 Free Software Foundation, Inc.


Contents -

  1. Software documentation for the NSMenu class
  2. Software documentation for the NSMenu(GNUstepExtra) category
  3. Software documentation for the NSObject(NSMenuActionResponder) informal protocol
  4. Software documentation for the NSObject(NSMenuDelegate) informal protocol
  5. Software documentation for the NSMenuDelegate protocol
  6. Software documentation for the NSMenuValidation protocol
  7. Software documentation for the NSMenuView protocol

Software documentation for the NSMenu class

NSMenu : NSObject

Declared in:
AppKit/NSMenu.h
Conforms to:
NSCoding
NSCopying
Availability: OpenStep

Menus provide the user with a list of actions and/or submenus. Submenus themselves are full fledged menus and so a heirarchical structure of appears.

Every application has one special menu, the so called Application menu. This menu is always visible on the screen when the application is active. This menu normally contains items like, info, services, print, hide and quit.

After the info item normally some submenus follow containing the application specific actions.

On GNUstep the content of the menu is stacked vertically as oppossed to the Windows and Mac world, where they are stacked horizontally. Also because the menus are not part of any normal window they can be dragged around opened and closed independend of the application windows.

This can lead to a few menus being open simultanuously. The collection of open menus is remembered, when the program is started again, all the torn off menus aka detached menus, are displayed at their last known position.

The menu behaviour is richer than in most other environments and bear some explanation. This explanation is aimed at users of Menus but more so at the developer of custom menus.

Application menu
There alwasy at least one menu present and visible while the application is active. This is the application menu. This window can never be closed.
Attached menu
Normally when you click in a menu on a submenu item, the submenu is shown directly next to the menu you click in. The submenu is now called an attached menu. It is attached to the menu that was clicked in.
Detached menu
A menu is detached when it is not attached to its parent menu. A menu can become detached when the user drags a submenu away from its parents. A detached window contains in its title a close button.
Transient menu
A transient menu is a menu that dissappears as soon as the user stops interacting with the menus. Typically a transient menu is created when a right mouse click appears in an application window. The right mouse click will bring up the Application menu at the place the user clicks. While keeping the mouse button down the user can select items by moving around. When releasing the button, all transient menus will be removed from the screen and the action will be executed.

It is important to note that it is impossible to click in transient menus.

Attached transient menu
This is a menu that is attached and transient at the same time.
A single NSMenu instance can be displayed zero or one times when the user is not interaction with the menus. When the user is interaction with the menus it can occur that the same NSMenu is displayed in two locations at the same time. This is only possible when one of the displayed instances is a transient menu.
To understand how the diffent kind of menus are created lets look at some user actions:
Customizing the look of Menus
There are basically three ways of customizing the look of NSMenu
  1. Using custom NSMenuItemCell's. This you should do when you want to influence the look of the items displayed in the menu.
  2. Using custom NSMenuView. This is the class to modify if you want to change the way the menu is layout on the screen. So if you want to stack the menu items horizontally, you should change this class. This should be rarely needed.
  3. Reimplement NSMenu. This you should not do. But, if you implement everything yourself you can achieve anything.

Information for implementing custom NSMenuView class
When implementing a custom NSMenuView class it is important to keep the following information in mind. The displayed menus on the screen have the following structure:
  1. The ordered graph of displayed menus (note, NOT the set of NSMenus) form a collection of line graphs.
  2. The attached menus are precisely the non root vertices in this graph.
  3. An attached menu of a transient menu is itself a transient menu.
  4. The collection of transient menus form connect subgraph of the menu graph.

Instance Variables

Method summary

menuBarVisible 

+ (BOOL) menuBarVisible;
Availability: MacOS-X 10.2.0

Description forthcoming.

menuZone 

+ (NSZone*) menuZone;
Availability: OpenStep

Returns the memory allocation zone used to create instances of this class.

popUpContextMenu: withEvent: forView: 

+ (void) popUpContextMenu: (NSMenu*)menu withEvent: (NSEvent*)event forView: (NSView*)view;
Availability: OpenStep

Description forthcoming.

popUpContextMenu: withEvent: forView: withFont: 

+ (void) popUpContextMenu: (NSMenu*)menu withEvent: (NSEvent*)event forView: (NSView*)view withFont: (NSFont*)font;
Availability: MacOS-X 10.3.0

Description forthcoming.

setMenuBarVisible: 

+ (void) setMenuBarVisible: (BOOL)flag;
Availability: MacOS-X 10.2.0

Description forthcoming.

setMenuZone: 

+ (void) setMenuZone: (NSZone*)zone;
Availability: OpenStep

Specifies the memory allocation zone used to create instances of this class.

addItem: 

- (void) addItem: (id<NSMenuItem>)newItem;
Availability: OpenStep

Add newItem to the menu.

addItemWithTitle: action: keyEquivalent: 

- (id<NSMenuItem>) addItemWithTitle: (NSString*)aString action: (SEL)aSelector keyEquivalent: (NSString*)keyEquiv;
Availability: OpenStep

Prefered method for inserting a menu item. This method calls [NSMenu-insertItemWithTitle:-action:-keyEquivalent:-atIndex:]
aString
The title of the specific menu item.
aSelector
The action taken by selecting this menu item, or NULL.
keyEquiv
The shortcut key for this menu item. If none is needed, specify and empty NSString, ie: @"".

See Also: -insertItemWithTitle:-action:-keyEquivalent:-atIndex


attachedMenu 

- (NSMenu*) attachedMenu;
Availability: OpenStep

Returns the menu that is attached to this menu.

If two instances of this menu are visible, return the attached window of the transient version of this menu.

If no menu is attached return nil.


autoenablesItems 

- (BOOL) autoenablesItems;
Availability: OpenStep

Returns YES if item does autoenable (default value) and NO otherwise.

See Also:


contextMenuRepresentation 

- (id) contextMenuRepresentation;
Availability: Not in OpenStep/MacOS-X removed at MacOS-X 10.1.0

Description forthcoming.

delegate 

- (id) delegate;
Availability: MacOS-X 10.3.0

Description forthcoming.

helpRequested: 

- (void) helpRequested: (NSEvent*)event;
Availability: OpenStep

Description forthcoming.

indexOfItem: 

- (NSInteger) indexOfItem: (id<NSMenuItem>)anObject;
Availability: OpenStep

Returns the index of item anObject.

indexOfItemWithRepresentedObject: 

- (NSInteger) indexOfItemWithRepresentedObject: (id)anObject;
Availability: OpenStep

Returns the index of an item with the represented object anObject.

indexOfItemWithSubmenu: 

- (NSInteger) indexOfItemWithSubmenu: (NSMenu*)anObject;
Availability: OpenStep

Returns the index of an item with the submenu anObject.

indexOfItemWithTag: 

- (NSInteger) indexOfItemWithTag: (NSInteger)aTag;
Availability: OpenStep

Returns the index of an item with the tag aTag.

indexOfItemWithTarget: andAction: 

- (NSInteger) indexOfItemWithTarget: (id)anObject andAction: (SEL)actionSelector;
Availability: OpenStep

Returns the index of an item with the target anObject and the actionSelector .

indexOfItemWithTitle: 

- (NSInteger) indexOfItemWithTitle: (NSString*)aTitle;
Availability: OpenStep

Returns the index of an item with the title aTitle.

initWithTitle: 

- (id) initWithTitle: (NSString*)aTitle;
Availability: OpenStep

This is a designated initialiser for the class.
Description forthcoming.

insertItem: atIndex: 

- (void) insertItem: (id<NSMenuItem>)newItem atIndex: (NSInteger)index;
Availability: OpenStep

Insert newItem at position index.

insertItemWithTitle: action: keyEquivalent: atIndex: 

- (id<NSMenuItem>) insertItemWithTitle: (NSString*)aString action: (SEL)aSelector keyEquivalent: (NSString*)charCode atIndex: (NSInteger)index;
Availability: OpenStep

Inserts a new menu item at position index.

See Also:

  • -addItemWithTitle:-action:-keyEquivalent-atIndex:

isAttached 

- (BOOL) isAttached;
Availability: OpenStep

Returns if this menu is attached to its supermenu, return nil if it does not have a parent menu.

If two instances of this menu are visible, return the outcome of the check for the transient version of the menu.

Look for the semantics in the header. Note that this implementation works because there are... cases:

  1. This menu is transient, its supermenu is also transient. In this case we just do the check between the transient windows and everything is fine
  2. The menu is transient, its supermenu is not transient. This can go WRONG

isTornOff 

- (BOOL) isTornOff;
Availability: OpenStep

If there are two instances of this menu visible, return NO. Otherwise, return YES if we are a detached menu and visible.

itemArray 

- (NSArray*) itemArray;
Availability: OpenStep

Returns an array containing all menu items in this menu.

itemAtIndex: 

- (NSMenuItem*) itemAtIndex: (NSInteger)index;
Availability: OpenStep

Returns an item located at index.

itemChanged: 

- (void) itemChanged: (id<NSMenuItem>)anObject;
Availability: OpenStep

Informs the menu that the specified item has changed.

itemWithTag: 

- (id<NSMenuItem>) itemWithTag: (NSInteger)aTag;
Availability: OpenStep

Retuns an item referenced by aTag.

See Also:


itemWithTitle: 

- (id<NSMenuItem>) itemWithTitle: (NSString*)aString;
Availability: OpenStep

Returns an item with aString as its title.

locationForSubmenu: 

- (NSPoint) locationForSubmenu: (NSMenu*)aSubmenu;
Availability: OpenStep

Returns the position where submenu will be displayed when it will be displayed as an attached menu of this menu. The result is undefined when aSubmenu is not actually a submenu of this menu.

menuBarHeight 

- (float) menuBarHeight;
Availability: MacOS-X 10.4.0

Description forthcoming.

menuChangedMessagesEnabled 

- (BOOL) menuChangedMessagesEnabled;
Availability: OpenStep

Description forthcoming.

menuRepresentation 

- (id) menuRepresentation;
Availability: OpenStep

Return the NSView that is used for drawing the menu. It is the view set with [NSMenu -setMenuRepresentation:] and therefore it should be safe to assume it is an NSView implementing the NSMenuView protocol.

numberOfItems 

- (NSInteger) numberOfItems;
Availability: OpenStep

Returns the numbers of items on the menu

performActionForItemAtIndex: 

- (void) performActionForItemAtIndex: (NSInteger)index;
Availability: OpenStep

Simulates a mouse click on item located at index.

See Also:


performKeyEquivalent: 

- (BOOL) performKeyEquivalent: (NSEvent*)theEvent;
Availability: OpenStep

Looks for a menu item that responds to theEvent on the receiver. If the receiver is a submenu, the method is performed on it.

popUpMenuPositionItem: atLocation: inView: 

- (void) popUpMenuPositionItem: (NSMenuItem*)item atLocation: (NSPoint)point inView: (NSView*)view;
Availability: MacOS-X 10.6.0

Description forthcoming.

removeAllItems 

- (void) removeAllItems;
Availability: MacOS-X 10.6.0

Removes all items

removeItem: 

- (void) removeItem: (id<NSMenuItem>)anItem;
Availability: OpenStep

Calls -removeItemAtIndex: for anItem.

removeItemAtIndex: 

- (void) removeItemAtIndex: (NSInteger)index;
Availability: OpenStep

Removes item at position index.

setAutoenablesItems: 

- (void) setAutoenablesItems: (BOOL)flag;
Availability: OpenStep

Sets if a menu does autoenable.

setContextMenuRepresentation: 

- (void) setContextMenuRepresentation: (id)representation;
Availability: Not in OpenStep/MacOS-X removed at MacOS-X 10.1.0

Description forthcoming.

setDelegate: 

- (void) setDelegate: (id)delegate;
Availability: MacOS-X 10.3.0

Description forthcoming.

setMenuChangedMessagesEnabled: 

- (void) setMenuChangedMessagesEnabled: (BOOL)flag;
Availability: OpenStep

Description forthcoming.

setMenuRepresentation: 

- (void) setMenuRepresentation: (id)menuRep;
Availability: OpenStep

Set the View that should be used to display the menu.

The default is NSMenuView, but a user can supply its own NSView object as long as it

  • Inherits from NSView
  • Implements NSMenuView protocol

setSubmenu: forItem: 

- (void) setSubmenu: (NSMenu*)aMenu forItem: (id<NSMenuItem>)anItem;
Availability: OpenStep

Set a submenu of a menu.
aMenu
The submenu to be inserted.
anItem
Item to be turned into a submenu.

See Also:


setSupermenu: 

- (void) setSupermenu: (NSMenu*)supermenu;
Availability: OpenStep

Set the supermenu of this menu. TODO: add explanation if this will change remove this menu from the old supermenu or if it does not.

setTearOffMenuRepresentation: 

- (void) setTearOffMenuRepresentation: (id)representation;
Availability: Not in OpenStep/MacOS-X removed at MacOS-X 10.1.0

Description forthcoming.

setTitle: 

- (void) setTitle: (NSString*)aTitle;
Availability: OpenStep

Change the title of the menu.

sizeToFit 

- (void) sizeToFit;
Availability: OpenStep

Description forthcoming.

submenuAction: 

- (void) submenuAction: (id)sender;
Availability: OpenStep

Description forthcoming.

supermenu 

- (NSMenu*) supermenu;
Availability: OpenStep

Returns the supermenu of this menu. Return nil if this is the application menu.

tearOffMenuRepresentation 

- (id) tearOffMenuRepresentation;
Availability: Not in OpenStep/MacOS-X removed at MacOS-X 10.1.0

Description forthcoming.

title 

- (NSString*) title;
Availability: OpenStep

Returns the current title.

update 

- (void) update;
Availability: OpenStep

Description forthcoming.



Instance Variables for NSMenu Class

_attachedMenu

@protected NSMenu* _attachedMenu;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

_delegate

@protected id _delegate;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

_items

@protected NSMutableArray* _items;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

_notifications

@protected NSMutableArray* _notifications;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

_popUpButtonCell

@protected NSPopUpButtonCell* _popUpButtonCell;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

_superMenu

@protected NSMenu* _superMenu;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

_title

@protected NSString* _title;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

_view

@protected NSView* _view;
Availability: OpenStep

Warning the underscore at the start of the name of this instance variable indicates that, even though it is not technically private, it is intended for internal use within the package, and you should not use the variable in other code.

struct GSMenuFlags

@protected struct GSMenuFlags struct GSMenuFlags;
Availability: OpenStep

Description forthcoming.




Software documentation for the NSMenu(GNUstepExtra) category

NSMenu(GNUstepExtra)

Declared in:
AppKit/NSMenu.h
Availability: Not in OpenStep/MacOS-X

This interface exist contains methods that are meant for the NSMenuView. If you write your own implementation of the NSMenuView interface you can use these methods to popup other menus or close them.
Method summary

_ownedByPopUp 

- (BOOL) _ownedByPopUp;
Availability: Not in OpenStep/MacOS-X

Warning the underscore at the start of the name of this method indicates that it is private, for internal use only, and you should not use the method in your code.

_owningPopUp 

- (NSPopUpButtonCell*) _owningPopUp;
Availability: Not in OpenStep/MacOS-X

Warning the underscore at the start of the name of this method indicates that it is private, for internal use only, and you should not use the method in your code.

_setOwnedByPopUp: 

- (void) _setOwnedByPopUp: (NSPopUpButtonCell*)popUp;
Availability: Not in OpenStep/MacOS-X

Warning the underscore at the start of the name of this method indicates that it is private, for internal use only, and you should not use the method in your code.

close 

- (void) close;
Availability: Not in OpenStep/MacOS-X

Remove the window from the screen. This method can/should be used by the menurepresentation to remove a submenu from the screen.

closeTransient 

- (void) closeTransient;
Availability: Not in OpenStep/MacOS-X

Remove the transient version of the window from the screen. This method is used by NSMenuView implementations that need to open/close transient menus.

display 

- (void) display;
Availability: Not in OpenStep/MacOS-X

Show menu on the screen. This method can/should be used by the menurepresentation to display a submenu on the screen.

displayTransient 

- (void) displayTransient;
Availability: Not in OpenStep/MacOS-X

Display the transient version of the menu.

isPartlyOffScreen 

- (BOOL) isPartlyOffScreen;
Availability: Not in OpenStep/MacOS-X

Description forthcoming.

isTransient 

- (BOOL) isTransient;
Availability: Not in OpenStep/MacOS-X

Returns YES if there is a transient version of this menu displayed on the screen.

nestedSetFrameOrigin: 

- (void) nestedSetFrameOrigin: (NSPoint)aPoint;
Availability: Not in OpenStep/MacOS-X

Set the frame origin of the receiver to aPoint. If a submenu of the receiver is attached. The frame origin of the submenu is set appropriately.

setMain: 

- (void) setMain: (BOOL)isMain;
Availability: Not in OpenStep/MacOS-X

Flag this menu to be the main menu of the application, when isMain is YES. Flag it as no longer being the main menu when NO is handed in.

This method also checks the user defaults to determine how the menu is to be displayed (eg vertical or horizontal) and can therefore be used to change window geometry.


setTornOff: 

- (void) setTornOff: (BOOL)flag;
Availability: Not in OpenStep/MacOS-X

When the flag is YES this method will detach the receiver from its parent and update the menurepresentation so it will display a close button if appropriate.

If the flag is NO this method will update the menurepresentation so it will be able to remove the close button if needed. Note that it will not reattach to its parent menu.


shiftOnScreen 

- (void) shiftOnScreen;
Availability: Not in OpenStep/MacOS-X

Description forthcoming.

window 

- (NSWindow*) window;
Availability: Not in OpenStep/MacOS-X

Returns the window in which this menu is displayed. If there is a transient version it will return the window in which the transient version is displayed. If the Menu is not displayed at all the result is meaningless.

Software documentation for the NSObject(NSMenuActionResponder) informal protocol

NSObject(NSMenuActionResponder)

Declared in:
AppKit/NSMenu.h
Availability: Not in OpenStep/MacOS-X

Description forthcoming.
Method summary

validateMenuItem: 

- (BOOL) validateMenuItem: (id<NSMenuItem>)aMenuItem;
Availability: Not in OpenStep/MacOS-X

Description forthcoming.

Software documentation for the NSObject(NSMenuDelegate) informal protocol

NSObject(NSMenuDelegate)

Declared in:
AppKit/NSMenu.h
Availability: MacOS-X 10.3.0

Description forthcoming.
Method summary

menu: updateItem: atIndex: shouldCancel: 

- (BOOL) menu: (NSMenu*)menu updateItem: (NSMenuItem*)item atIndex: (NSInteger)index shouldCancel: (BOOL)shouldCancel;
Availability: MacOS-X 10.3.0

Description forthcoming.

menuHasKeyEquivalent: forEvent: target: action: 

- (BOOL) menuHasKeyEquivalent: (NSMenu*)menu forEvent: (NSEvent*)event target: (id*)target action: (SEL*)action;
Availability: MacOS-X 10.3.0

Description forthcoming.

menuNeedsUpdate: 

- (void) menuNeedsUpdate: (NSMenu*)menu;
Availability: MacOS-X 10.3.0

Description forthcoming.

numberOfItemsInMenu: 

- (NSInteger) numberOfItemsInMenu: (NSMenu*)menu;
Availability: MacOS-X 10.3.0

Description forthcoming.

Software documentation for the NSMenuDelegate protocol

NSMenuDelegate

Declared in:
AppKit/NSMenu.h
Conforms to:
NSObject
Availability: OpenStep

The NSMenuDelegate protocol defines optional methods implemented by delegates of NSMenu objects.
Method summary

confinementRectForMenu: onScreen: 

- (NSRect) confinementRectForMenu: (NSMenu*)menu onScreen: (NSScreen*)screen;
Availability: OpenStep

Specify a display location for the menu

menu: updateItem: atIndex: shouldCancel: 

- (BOOL) menu: (NSMenu*)menu updateItem: (NSMenuItem*)item atIndex: (NSInteger)index shouldCancel: (BOOL)shouldCancel;
Availability: OpenStep

Invoked to allow the delegate to update an item before it is displayed.

menu: willHighlightItem: 

- (void) menu: (NSMenu*)menu willHighlightItem: (NSMenuItem*)item;
Availability: OpenStep

Invoked too notify the delegate that the item will be highlighted.

menuDidClose: 

- (void) menuDidClose: (NSMenu*)menu;
Availability: OpenStep

Invoked to inform the delegate that the menu did close.

menuHasKeyEquivalent: forEvent: target: action: 

- (BOOL) menuHasKeyEquivalent: (NSMenu*)menu forEvent: (NSEvent*)event target: (id*)target action: (SEL*)action;
Availability: OpenStep

Allows the delegate to return the target and action for a key-down event.

menuNeedsUpdate: 

- (void) menuNeedsUpdate: (NSMenu*)menu;
Availability: OpenStep

Invoked to indicate that the menu is about to be updated.

menuWillOpen: 

- (void) menuWillOpen: (NSMenu*)menu;
Availability: OpenStep

Invoked on the delegate to allow changes before the menu opens.

numberOfItemsInMenu: 

- (NSInteger) numberOfItemsInMenu: (NSMenu*)menu;
Availability: OpenStep

Invoked when the menu is about to be displayed.

Software documentation for the NSMenuValidation protocol

NSMenuValidation

Declared in:
AppKit/NSMenu.h
Availability: OpenStep

Specifies the protocol to which an object must confirm if it is to be used to validate menu items (in order to implement automatic enabling and disabling of menu items).
Method summary

validateMenuItem: 

- (BOOL) validateMenuItem: (id<NSMenuItem>)menuItem;
Availability: OpenStep

The receiver should return YES if the menuItem is valid... and should be enabled in the menu, NO if it is invalid and the user should not be able to select it.

This method is invoked automatically to determine whether menu items should be enabled or disabled automatically whenever [NSMenu -update] is invoked (usually by the applications event loop).


Software documentation for the NSMenuView protocol

NSMenuView

Declared in:
AppKit/NSMenu.h
Availability: OpenStep

Description forthcoming.
Method summary

detachSubmenu 

- (void) detachSubmenu;
Availability: OpenStep

This should ensure that if there is an attached submenu this submenu will be detached. Detaching means that this particular menu representation should be removed from the screen. It should implement a deep detach, that is, all attached submenus of this menu should also be detached.

highlightedItemIndex 

- (NSInteger) highlightedItemIndex;
Availability: OpenStep

Returns the currently highlighted item. Returns -1 if no item is highlighted.

imageAndTitleOffset 

- (float) imageAndTitleOffset;
Availability: OpenStep

Method used by NSMenuItemCell to draw itself correctly and nicely lined up with the other menu items

imageAndTitleWidth 

- (float) imageAndTitleWidth;
Availability: OpenStep

Methos used by NSMenuItemCell to draw itself correctly and nicely lined up with the other menu items.

keyEquivalentOffset 

- (float) keyEquivalentOffset;
Availability: OpenStep

Methos used by NSMenuItemCell to draw itself correctly and nicely lined up with the other menu items.

keyEquivalentWidth 

- (float) keyEquivalentWidth;
Availability: OpenStep

Used by NSItemCell to...

locationForSubmenu: 

- (NSPoint) locationForSubmenu: (NSMenu*)aSubmenu;
Availability: OpenStep

Used by the NSMenu to determine where to position a submenu.

performActionWithHighlightingForItemAtIndex: 

- (void) performActionWithHighlightingForItemAtIndex: (NSInteger)index;
Availability: OpenStep

Description forthcoming.

setHighlightedItemIndex: 

- (void) setHighlightedItemIndex: (NSInteger)index;
Availability: OpenStep

Set the currently highlighted item. This is used by the NSMenu class to restore the selected item when it is temporary set to another item. This happens when both the regular version and the transient version are on the screen. A value of -1 means that no item will be highlighted.

setMenu: 

- (void) setMenu: (NSMenu*)menu;
Availability: OpenStep

Set the menu that this view object will be drawing. This method will NOT retain the menu. In normal usage an instance of NSMenu will use this method to supply the NSMenuView with reference to itself. The NSMenu will retain the NSMenuView.

sizeToFit 

- (void) sizeToFit;
Availability: OpenStep

Hm, why is this method needed? Shouldn't this be done by the update method?

stateImageWidth 

- (float) stateImageWidth;
Availability: OpenStep

Method used by NSMenuItemCell to draw itself correctly and nicely lined up with the other menu items.

trackWithEvent: 

- (BOOL) trackWithEvent: (NSEvent*)event;
Availability: OpenStep

This is method is responsible for handling all events while the user is interacting with this menu. It should pass on this call to another menurepresentation when the user moves the mouse cursor over either a submenu or over the supermenu.

The method returns when the interaction from the user with the menu system is over.

The method returns NO when the user releases the mouse button above a submenu item and YES in all other cases.

This return value can be used to determine if submenus should be removed from the screen or that they are supposed to stay.

The implementation should roughly follow the following logic:

{while (have not released mouse button) {if (mouse hovers over submenu, or supermenu) {if ([(menurepresentation under mouse) trackWithEvent: the event]) { [self detachSubmenu]; return YES;} return NO;} //highlight item under mouse if (highlighting submenu item) {[self attachSubmenuAtIndex:..];} else {[self detachSubmenu];} get next event.} execute the menu action if applicable; return YES | NO depending on the situation;} Note that actual implementations tend to be more complicated because because of all kind of useability issues. Useabilities issues to look out for are:

  • Menus that are only partly on the screen. Those need to be moved while navigation the menu.
  • Submenus that are hard to reach. If the natural route to the content of a submenu travels through other menu items you do not want to remove the submenu immediately.
  • Transient menus require slightly different behaviour from the normal menus. For example, when selecting a action from a transient menu that brings up a modal panel you would expect the transient menu to dissappear. However in the normal menu system you want it to stay, so you still have feedback on which menu action triggered the modal panel.

update 

- (void) update;
Availability: OpenStep

This will relayout the NSMenuView. It should be called when the menu changes. Changes include becoming detached, adding or removing submenu items etcetera. However, normally it does not need to be called directly because Because the NSMenuView is supposed to listen to the NSMenu notifications for the item added, removed and change notifications. It should be called explicitly when other changes occur, such as becoming detached or changing the title.


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