NSToolbarItemValidation Protocol Reference

(informal protocol)

Framework
/System/Library/Frameworks/AppKit.framework
Companion guide
Toolbar Programming Topics for Cocoa
Declared in
NSToolbarItem.h

Overview

A toolbar item with a valid target and action is enabled by default. To allow a toolbar item to be disabled in certain situations, a toolbar item’s target can implement the validateToolbarItem: method.

Tasks

Validating Toolbar Items

Instance Methods

validateToolbarItem:

If this method is implemented and returns NO, NSToolbar will disable theItem; returning YES causes theItem to be enabled.

- (BOOL)validateToolbarItem:(NSToolbarItem *)theItem
Discussion

NSToolbar only calls this method for image items.

If the receiver is the target for the actions of multiple toolbar items, it’s necessary to determine which toolbar item theItem refers to by testing the itemIdentifier.

-(BOOL)validateToolbarItem:(NSToolbarItem *)toolbarItem
{
    BOOL enable = NO;
    if ([[toolbarItem itemIdentifier] isEqual:SaveDocToolbarItemIdentifier]) {
        // We will return YES (enable the save item)
        // only when the document is dirty and needs saving
        enable = [self isDocumentEdited];
    } else if ([[toolbarItem itemIdentifier] isEqual:NSToolbarPrintItemIdentifier]) {
        // always enable print for this window
        enable = YES;
    }
    return enable;
}
Availability
  • Available in OS X v10.0 and later.
See Also
Declared In
NSToolbarItem.h


© 2009 Apple Inc. All Rights Reserved. (Last updated: 2009-11-13)

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