NSMenuDelegate methods not called for contextual menu - macos

I have a Document based application. I want to add a contextual menu that displays context-sensitive info when the user right-clicks selected text in an NSTextView.
I have followed the advice in the Apple documentation and
Added an NSMenu as a root object in my XIB file.
Connected the NSMenu instance to the menu outlet of the NSTextView.
Connected an IBAction to the NSMenuItem inside the NSMenu.
So far so good. Every thing works as expected: the menu item appears and the action is called when it is selected.
I need to get the selected text from the NSTextView before the menu appears so that I can configure my menu item appropriately. According to the docs
If you need to customize the contextual menu, you can do so by setting
an appropriate object as the menu’s delegate and implementing the
menuWillOpen: method to customize the menu as you see fit just before
it appears.
I connect the delegate of the NSMenu to File's Owner. None of the delegate methods are called. ( menuWillOpen: is the only one I need, but I've tried others, too).
I set a breakpoint inside the IBAction that gets called when the menu item is selected. If I inspect the menu with the debugger I can see that the delegate is correctly set to the object that implements the delegate method.
Is there anything else to check? Anything I'm doing blatantly wrong?
Xcode v4.6.3
SDK v10.8
Deployment target 10.7

After some digging, this is what I found: NSTextView builds a different NSMenu instance to use as the contextual menu, probably by overriding -menuForEvent: or some similar internal method. This new menu copies the menu items from the menu you created in Interface Builder (in fact, it creates new menu item instances whose attributes are copied from the original menu items) but it does not copy the menu delegate, which is why your menu delegate does not receive -menuWillOpen:. I am not sure whether this is intentional or not. Reading that documentation quote you posted, it seems to be a bug.
What you can do is to set the delegate of your NSTextView instance to an object whose class conforms to NSTextViewDelegate (maybe your File’s Owner, which already conforms to NSMenuDelegate) and implement the following method:
- (NSMenu *)textView:(NSTextView *)view menu:(NSMenu *)menu forEvent:(NSEvent *)event atIndex:(NSUInteger)charIndex
{
// if the menu delegate is not self, set another object
[menu setDelegate:self];
return menu;
}
This will make sure that the contextual menu created by the text view uses your delegate.
NB: since NSTextView creates a different contextual menu, it could be the case that it might want to set the menu delegate to itself or some other internal object. In my tests the delegate is nil, so it looks like it’s safe. Alternatively, you could discard the proposed menu argument and return your own NSMenu instance with the delegate correctly set.

Finding this thread saved me a lot of time...thanks! Here's an implementation that works in an NSView in Swift. myNSMenu is an outlet from Storyboard to appDelegate and a subclass of NSMenu. Without the assignment of the delegate in the code below, the NSMenuDelegate functions were not called.
let appDelegate = NSApplication.sharedApplication().delegate as! AppDelegate
appDelegate.myNSMenu.delegate = appDelegate.myNSMenu
NSMenu.popUpContextMenu(appDelegate.myNSMenu, withEvent: theEvent, forView: self)

Related

Control-drag to AppDelegate only

Xcode 6.1, OSX not ios, allows me to Control-drag from a button in MainMenu.xib to AppDelegate only. This is unfortunate for me because my IBAction must include view methods like [self setNeedsDisplay:YES] . I need to Control-drag it into my MyView file, which will tolerate them. This also makes more sense.
Control-dragging from the button to any file other than AppDelegate does nothing.
Identity Inspector > Class is set to MYView.
How can I make this work, and how does the fix work?
Also, why is it now restricted to AppDelegate? Perhaps a timing issue?
Thanks ahead,
Nick
Try dragging an empty object from the object library to the area where you see 'AppDelegate' then selecting it and setting its' class to 'MyView' then secondary dragging to that object to create the IBAction.

How to get notified when NSWindow opens?

How to take notice when an NSWindow is about to be opened or have just opened? That is, the opposite of windowWillClose: delegate method (likewise the opposite of NSWindowWillCloseNotification.)
This is related to this question, but from the other direction.
The background is, I'm looking to couple a window with a tickmark on the main menu (among other things). When the window is shown, the corresponding ̨ menu item should be checked and vice-versa.
It should not normally be a mystery when or how a window is made visible. It should only happen in response to something that your own code is doing. If the window is in a NIB and is marked Visible At Launch, then it shows when your code loads that NIB. Otherwise, it should only show if you call one of the -order... methods other than -orderOut: (e.g. -orderFront:) or -makeKeyAndOrderFront:. If the window is controlled by a window controller, then it would show if you invoke -[NSWindowController showWindow:]. Etc.
If you really feel the need to be notified, you can subclass NSWindow and override -orderWindow:relativeTo: and, if orderingMode is not NSWindowOut and the window was not already visible, post a notification of your own.
By macOS 10.10, this is somewhat solved by the call to NSViewController's viewWillAppear or viewDidAppear. Have an NSViewController subclass and set it as the contentViewController of the window. Then its viewWillAppear/ viewDidAppear implementation can post a notification that the window will (or did) open.
You can bind your NSMenuItem value to the NSWindows visible binding Zero lines of code if you do it in IB.
visible:
A Boolean value that specifies if the NSWindow is visible.
If visible evaluates to YES, the NSWindow is visible.
Availability:
Available in OS X v10.3 and later.
See the NSWindow Binding Documentation for more info.
You can either bind the NSMenuItem value binding to an existing NSWindow property on one of your existing classes, or add an NSObjectController to your nib and set its content to the NSWindow instance then bind to the controller.
Tested and confirmed on Mac OS 10.9. Works for window minimization and restoration too.

Receive window notifications

I have an NSWindow set up in Interface Builder. I have set the class of File's Owner to my NSWindowController and linked the window property of the controller to my NSWindow.
My controller implements NSWindowDelegate.
Now, in my controller, I have added the following:
- (void)windowDidLoad
{
[super windowDidLoad];
[self.window setDelegate:self];
}
- (void)windowDidBecomeMain:(NSNotification *)notification
{
NSLog(#"Did become main.");
}
Still, -windowDidBecomeMain: isn't called. Does anyone know why this is?
EDIT:
Trying to show a window from AppDelegate on launch. The main nib (declared in Info.plist) contains a menu item only which is linked to the AppDelegate. In the application delegate, I show an icon on the status bar and when this icon is clicked, I display the menu from the main nib.
In the application delegate, I also want to display a window which should have a window controller assigned to take care of the logic.
I believe that when this works, I will receive my window notifications.
Now, the following code doesn't show the window and I can't figure out why.
DemoWindowController *dwc = [[DemoWindowController alloc] initWithWindowNibName:#"DemoWindowController"];
[dwc showWindow:self];
Note that self is the application delegate.
I suspect your problem is due to the fact that your window controller is not actually the object that is the nibs file owner.
When you change the class in interface builder you are telling it what outlets and actions are available (which is why you are able to drag to the window outlet) but you are still responsible for passing in this object yourself.
In the case of a non-document based application, you will have a main method which calls NSApplicationMain. What this does is basically look up and load the window nib that is specified in your info.plist file and pass the current NSApplication instance to this nib as the files owner (so even though you changed the class type to NSWindowController, the object being passed in is actually of type NSApplication).
The easiest way to fix your problem is to get rid of your window controller for now (as it isn't actually doing anything yet).
You should implement the -windowDidBecomeMain: method in your app delegate. Then Ctrl+drag from your window to your appDelegate to set it as the delegate of the window to get your notifications.
Update
To answer your question regarding the WindowController beware of the following two issues:
You are creating your window controller variable (dwc) in your applicationDidFinishLaunching: method. This is released the moment you leave the method taking your window with it. Create an instance variable to hold onto the window controller instead.
Ensure that your second window nib has its file owner set to NSWindowController (or your window controller type) and that its window outlet is connected to the window in the nib file.
Your window should now display.

Setting NSDocument as delegate of NSMenu

I have a menu item whose state should depend on whichever NSDocument is open. From my understanding, to make its state change dynamically I should use the NSMenu delegate method menuNeedsUpdate:.
It seems like I would want to have the menu's delegate be the First Responder in MainMenu.xib. However, Interface Builder won't let me set it as the Main Menu's delegate. How can I make a delegate which will be able to access the currently active document?
I generally make such changes in the validateMenuItem: method being called before the menu is shown. The receiver of the action is asked whether the item is to be enabled or not. But you can do pretty much any change there. Since 10.5 it is also safe to add and remove items during such a call.

Accessing IBOutlet from other classes

I have a document based cocoa application with an item in the application menu hooked up to an IBAction. Clicking the item needs to perform a task that uses an IBOutlet in the main nib file which is using another class, MyDocument. Creating 2 objects of the same class, one in each nib seems to not be working. How can I access the outlet?
Actions for menu items are often sent to the first responder so that whatever is currently selected can act on it.
It sounds like this action is something that works on the current document, then it should be implemented by the document. In this case have the menu send it's action to the first responder and then put the action method in the MyDocument class.
If the action you are trying to send is a custom one: in the Main Menu nib select the First Responder item, add your method name, then connect the menu item's selector to the action.
Read the Responders section of the Cocoa Event-Handling Guide for more info.
To summarize the above, in your NIB/XIB file, in interface builder make the connection to the First Responder object, not to Files Owner or anything else. You'll still be offered a lit of actions across potential first responders.
Cocoa then takes that selector and looks for it, starting with the NSView (if any) that's currently the first responder, then with the NSDocument that's currently in use, then with it's window controller etc etc all the way up to the Application delegate. The first object it checks that actually implements that method, it will use that object (after validating it with that same object).
So:
#interface MyDocumentTypeA : NSDocument {
}
-(void)myMenuAction:(id)sender;
-
#interface MyDocumntTypeB : NSDocument {
}
// -myMenuAction: not implemented here
-
#interface MyApplicationDelegate ... {
}
-(void)myMenuAction:(id)sender;
-
In Interface builder (or even programmatically), if you've linked the "action" of the menu item to a selector named "myMenuAction:" on the First Responder (which equates to not specifying a target when done programmatically), for the above two document subclasses the following will happen.
For MyDocumentTypeA, when the user selects that menu item, MyDocumentTypeA's -myMenuAction: will be invoked. Since MyDocumentTypeB does not implement this action, Cocoa will continue to look up the responder chain until it gets to your application delegate, which does implement it, so it will be invoked here instead.
If Cocoa finds no objects in the responder chain that implement the method, the menu item remains disabled.
There is a way how to do this, I've posted the answer in a similar thread: Access IBOutlet from other class (ObjC)

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