I manually bind the value of a NSTextView to a property of an object. When I call unbind, the window becomes first responder ... Why?
I don't want that!
Well there isn't a lot of information here, but you might want to check the responder chain to see if the window is next in line and being passed the focus.
Related
I just started to suspect that calling resignFirstResponder directly is not actually allowed. Unlike NSResponder, it's allowed to call becomeFirstResponder directly in UIKit. So far I was making assumption that calling resignFirstResponder would be okay too. But in fact, the manual says resignFirstResponder method is there to get notified, and mentions nothing about direct calling.
Notifies this object that it has been asked to relinquish its status
as first responder in its window.
If it's designed in same way of how NSResponder works, direct calling to resignFirstResponder wouldn't be allowed though there's no obvious way to figure out validity of the call in the manual...
If it's been designed not to be called directly, directly calling to the method would be harmful or make code harder to maintain.
Is it okay to call UIResponder.resignFirstResponder method directly?
It seems to be okay because on another part of the manual, it says
...
To dismiss the keyboard, you call the resignFirstResponder method of
the text-based view that is currently the first responder. When a text
view resigns its first responder status, it ends its current editing
session, notifies its delegate of that fact, and dismisses the
keyboard. In other words, if you have a variable called myTextField
that points to the UITextField object that is currently the first
responder, dismissing the keyboard is as simple as doing the
following:
[myTextField resignFirstResponder];
Everything from that point on is handled for you automatically by the text object.
I just spent ages trying to work out how to keep the focus in an NSTableView column after deleting a row, rather than just keeping a selection. I did it like this:
[[myTableView window]makeFirstResponder:myTableView];
Why does the code above work, but the code below doesn't?
[myTableView becomeFirstResponder];
-makeFirstResponder: is a request to the window that it make the specified responder its first responder. -becomeFirstResponder is a notification to a responder that it is about to become the first responder. It doesn't inherently cause a state change; it gives the receiver a chance to react to a state change that was caused by -makeFirstResponder:.
You should not call -becomeFirstResponder (except, possibly, to call through to super in an override). The framework calls it as necessary.
I'm trying to detect when user finishes editing a NSTextField by implementing NSTextFieldDelegate's controlTextDidEndEditing: method. However the problem is that upon initially making the NSTextField first responder of the window, immediately the controlTextDidEndEditing: notification gets fired. I tried this in an extremely simple test app and confirms the result. Would really appreciate some pointers on why this is the case and how to detect when textField loses focus.
As the text field is first Responder, selectText: message will also sent to textField, which will cause it to end editing. If you don't want this behavior set NO to selectable property of textField.
- (void)selectText:(id)sender;
Ends editing and selects the entire contents of the receiver if it’s selectable.
I have a Core Data project.
Basically I have an NSTableView where I add some entities (using the "add:" selector), double clicking on the TableView opens a new NSWindow where is possible to edit the entity using some NSTextFields.
Each text field is binded to an attribute of the entity.
Everything is working fine, except the fact that the entity's attributes are updated only when a textfield lose the focus.
If I write on the first text field and then I move to the second one my entry is saved, but if I write on the first text field and I close the window I lose my changes.
How can I update my core data entity as soon as I write something in the text field? Should I use textDidChange:?
--- UPDATE ---
Unfortunately [context save] doesn't work. If I understand correctly the entity is not modified until the NSTextField resign first responder.
The only working solution for now is something like:
(void)controlTextDidChange:(NSNotification *)aNotification
{
NSTextField *tf = [aNotification object];
[self.window makeFirstResponder:tf];
}
but this is quite inelegant, and in any case I also still need to re-set the cursor at the end of the NSTextField.
Setting NSContinuouslyUpdatesValueBindingOption will cause the model to update every time the text field changes, which sets the dirty flag properly and causes the document to save on quit.
I think you could use DidEndEditing or TextDidChange, another way of doing this is handeling in the window close event, but I would not recommend it.
If you don't have one already, you can set a delegate on the window and use -windowWillClose: or observe the NSWindowWillCloseNotification. You can then call [[notification object] makeFirstResponder:[window initialFirstResponder]] to set the window's first responder to its initial first responder as the window is closing. This will cause the control that is first responder (e.g. NSTextField) to resign the first responder status and the binding will save the changes.
So I'm building a program that features the use of the IKImageBrowserView component as a subview in an NSWindow. As a side note, I have a controller object called ImageBrowserController which subclasses NSWindow and is set as the delegate of the NSWindow object of my app.
I have sent IKImageBrowserView the message setCanControlQuickLookPanel:YES to enable it to automatically use the QuickLook functionality to preview image files when the IKImageBrowserView is a first responder to receive key events. Then it took me a while to figure out how to make the IKImageBrowserView a first responder which I finally got working by overriding acceptsFirstResponder inside my ImageBrowserController.
Now I understand that as the delegate to the NSWindow, ImageBrowserController has a place in the responder chain after the event gets triggered on NSWindow. And I understand that as a subview of NSWindow, IKImageBrowserView is in line to be passed events for event handling. What I don't get is where the connection is between the ImageBrowserController being a first responder and the event somehow making it to the IKImageBrowserView. I didn't set NSWindow or IKImageBrowserView as first responders explicitly. So why isn't it necessary for me to implement event handling inside my ImageBrowserController?
EDIT: So after reading the accepted answer and going back to my code I tried removing the acceptsFirstResponder override in my ImageBrowserController and the QuickLook functionality still triggered just like the accepted answer said it would. Commenting out the setCanControlQuickLookPanel:YES made the app beep at me when I tried to invoke QuickLook functionality via the spacebar. I'm getting the feeling that my troubles were caused by user error of XCode in hitting the RUN button instead of the BUILD button after making changes to my code (sigh).
Some of what you are saying regarding the interactions between your objects does not make sense, and it is hard to address your stated question without some background.
As you say, your window delegate has a place at the end of the responder chain, after the window itself. The key point I think you are missing is that GUI elements, such as your IKImageBrowserView, will be at the beginning of the chain, and any one of them in a given window could be the current firstResponder.
When your application gets an event, it passes it off to the key window (which is just the window which currently accepts "key" (i.e., "keystroke") events). That window begins by asking its firstResponder to handle the event. If that object refuses, it passes the event to its own nextResponder, usually its superview, which either handles it or passes it on, until the event has either been handled or passed all the way up to the window object itself. Only then will the window (if it does not handle the event itself) ask its delegate to handle the event.
This means that the connection between the window delegate and the IKImageBrowserView is only through the Responder Chain, and its nature is simply that if the view declines to handle any given event, the delegate may eventually be asked to handle it, if no other object in between them handles it first.
Your window delegate does not need to be a firstResponder. Nor does overriding acceptsFirstResponder on the window delegate have any effect on one of the window's subviews.*
Your window delegate also does not need to (and, indeed should not) be a subclass of NSWindow. All it needs is to be a subclass of NSObject which implements whatever methods from the NSWindowDelegate Protocol you are interested in, and methods to handle any events you might want to catch if they are not handled by other objects.
So, the answer to your explicit question at the end is (and I do not mean this sarcastically): you only need to implement event handling in your window delegate if you want it to handle events itself.
*: IKImageBrowserView already responds YES to acceptsFirstResponder. If there are no other subviews in your window, it will automatically be the firstResponder when your application starts. You can set this initialFirstResponder explicitly in Interface Builder by connecting that outlet on the window to whatever object you want.