Handle close event of the window in Swift - macos

How to handle close event of the window using swift, for example, to ask "Are you sure you want to close the form?"
The form will be closed in the case "yes" and not closed in the case "no". Showing message box is not a problem for me.
viewWillDisappear() works for minimizing also, but I need only close event.
Thanks.

Like said above, you should make the ViewController an NSWindowDelegate, but you should handle windowWillClose, not windowShouldClose. windowShouldClose is to determine if the window is able to close or not, not an event that the window is actually closing.
I also found that you need to set up the delegate in viewDidAppear, not viewDidLoad. For me self.view.window wasn't defined yet in viewDidLoad.
override func viewDidAppear() {
self.view.window?.delegate = self
}

I was having the same query too, solved it using the method explained in detail here: Quit Cocoa App when Window Close using XCode Swift 3
It needs three steps:
Conform toNSWindowDelegate in your ViewController class
Override viewDidAppear method
Add windowShouldClose method
The added code should look like this:
class ViewController: NSViewController, NSWindowDelegate {
// ... rest of the code goes here
override func viewDidAppear() {
self.view.window?.delegate = self
}
func windowShouldClose(_ sender: Any) {
NSApplication.shared().terminate(self)
}
}

You can use the NSWindowDelegate protocol in your ViewController class. (See the documentation here)
To make your class conform to the protocol:
class ViewController: NSObject, NSWindowDelegate
To detect when the window's close button has been clicked, use windowShouldClose:
From the doc:
Tells the delegate that the user has attempted to close a window [...]
In this method, you can use NSAlert to prompt the user on whether or not they really want to close the window.
EDIT (in response to #Mr Beardsley's comment)
To make your ViewController the delegate, use:
window.delegate = self
Where self is the ViewController and window is the window you're using. You can put this in viewDidLoad:.

Just add this function to AppDelegate ...
func applicationShouldTerminateAfterLastWindowClosed (_ theApplication: NSApplication) -> Bool {
return true
}

Related

How to get state restoration to restore all windows/tabs on macOS?

I have a non-document based macOS AppKit app. It has one window instantiated automatically by the storyboard. I have sub-classed NSWindowController and added a override func newWindowForTab(_ sender: Any?) to enable the + button on the tab-bar. My main view controller lets the user rename the tab title and the window title is set to the same. This is kind of like how Xcode tab renaming works.
Additionally I have sub-classed NSWindow and added a restorableStateKeyPaths to ensure tab and window titles are automatically restored on app restart.
This all works great.
But only for the first tab. The main window is loaded and it has the tab and window titles set automatically.
The other tabs (windows) are not restored.
Any hints on what I miss to make all tabs restored?
My NSWindowController:
class MyWindowController: NSWindowController {
var subview: MyWindowController?
#IBAction override func newWindowForTab(_ sender: Any?) {
let story = self.storyboard
let windowVC = story?.instantiateInitialController() as! Self
window?.addTabbedWindow(windowVC.window!, ordered: .above)
subview = windowVC
windowVC.window?.orderFront(self.window)
windowVC.window?.makeKey()
}
}
My NSWindow:
class MyWindow: NSWindow {
override class var restorableStateKeyPaths: [String] {
return [ "self.tab.title", "self.title" ]
}
}
First you need to make sure that state restoration is enabled for your user, you can do this by going to Preferences->General and unchecking "Close windows when quitting an app".
Then you should use a restoration class in order to restore all open windows.
Basically if an NSWindow doesn't have a restoration class it won't be preserved across launches, that includes your storyboard loaded window. In this case what is happening is Cocoa is ignoring all window preservation because you haven't defined a restoration class for any of your windows so it resorts to its default behavior which is loading the initial storyboard controller.
Implementing restoration class is easy, just create a restoration class that inherits from NSObject and conforms to NSWindowRestoration, then implement its only required type method restoreWindow(identifier:state:completionHandler) like so:
class MyAppWindowRestoration: NSObject, NSWindowRestoration {
static func restoreWindow(withIdentifier identifier: NSUserInterfaceItemIdentifier,
state: NSCoder,
completionHandler: #escaping (NSWindow?, Error?) -> Void) {
// 1.- Retrieve and show the window
// Retrieve a new instance of the only window
let window = (NSStoryboard.main?.instantiateInitialController() as? NSWindowController)?.window
// Call the completion handler with the window and no errors
completionHandler(window, nil)
}
}
Then just assign this class as the window restoration class on every window you want restored, you can do this everywhere after the window has loaded:
window.restorationClass = MyAppWindowRestoration.self
Unfortunately Apple's documentation on state restoration completely sucks so if you have any more questions let me know ;)

How to close window (NSWindowController) by hitting the ESC key?

Issue
I would like the user being able to close a window by hitting the ESC key but I can't get it to work in this specific case, hitting ESC triggers an error sound (the "no you can't do that" macOS bloop) and nothing happens.
Context
I'm making a subclass of NSWindowController which itself creates an instance of a subclass of NSViewController and sets it in a view. Both controllers have their own xib file.
NSWindowController:
final class MyWindowController: NSWindowController, NSWindowDelegate {
#IBOutlet weak var targetView: MainView!
let myVC: MyViewController!
var params: SomeParams!
override func windowDidLoad() {
super.windowDidLoad()
myVC = MyViewController(someParams: params)
myVC.view.setFrameSize(targetView.frame.size)
myVC.view.setBoundsSize(targetView.bounds.size)
targetView.addSubview(myVC.view)
}
override var windowNibName: String! {
return "MyWindowController"
}
convenience init(someParams params: SomeType) {
self.init(window: nil)
self.params = params
}
}
NSViewController:
final class MyViewController: NSViewController {
convenience init(someParams params: SomeType) {
// do stuff with the params
}
override func viewDidLoad() {
super.viewDidLoad()
// configure stuff for the window
}
}
What I've tried
I suppose that my issue is that the MyWindowController NSWindow is the .initialFirstResponder when I would want the content of the targetView (an NSTableView) to be the first responder - this way I could use keyDown, I guess, and send the close command to the window from there. This doesn't seem optimal, though.
I've tried forcing the view controller views into being the first responder by using window?.makeFirstResponder(theView) in the windowDidLoad of MyWindowController but nothing ever changes.
I've also tried adding this to MyWindowController:
override func cancelOperation(_ sender: Any?) {
print("yeah, let's close!")
}
But this only works if the user clicks first on the background of the window then hits ESC, and it still emits the error sound anyway. Which is actually what made me think that the issue was about the first responder being on the window.
Question
How would you achieve that? Of course, I know that the user can already close the window with CMD+W, but I'd really like to sort out this issue nonetheless.
Note that the code example is in Swift but I can also accept explanations using Objective-C.
The documentation of cancelOperation explains how cancelOperation should work:
This method is bound to the Escape and Command-. (period) keys. The key window first searches the view hierarchy for a view whose key equivalent is Escape or Command-., whichever was entered. If none of these views handles the key equivalent, the window sends a default action message of cancelOperation: to the first responder and from there the message travels up the responder chain.
If no responder in the responder chain implements cancelOperation:, the key window searches the view hierarchy for a view whose key equivalent is Escape (note that this may be redundant if the original key equivalent was Escape). If no such responder is found, then a cancel: action message is sent to the first responder in the responder chain that implements it.
NSResponder declares but does not implement this method.
NSWindow implements cancelOperation: and the next responder, the window controller, isn't checked for an implementation of cancelOperation:. The cancel: message does arrive at the window controller. Implementing
- (void)cancel:(id)sender
{
NSLog(#"cancel");
}
will work. The cancel: message isn't inherited from a superclass so autocompletion doesn't suggest it.
This worked for me in Xcode 10 and Swift 4.2:
#objc func cancel(_ sender: Any?) {
close()
}
I tried it before but without the #objc part and it didn't work. So don't omit it.
When I needed such behavior I implemented it by overriding keyDown: of the NSWindow object.
I.e. something like the following:
- (void)keyDown:(NSEvent *)theEvent
{
int k = [theEvent keyCode];
if (k == kVK_Escape)
{
[self close];
return;
}
[super keyDown:theEvent];
}

How do you re-open a closed window created in the storyboard in OS X

My question is essential this question, but the answer doesn't seem to work with Swift/Storyboards.
Cocoa: programmatically show the main window after closing it with X
Basically, I have a more or less default application with a menu, a window, and a ViewController. If the user closes the window while the application is running, how do I reopen it?
I have created an action in the app delegate the connects to the "Open" Menu Item. Within this function, I would like to ensure that the window is visible. So if the user has closed it, it should reappear. But I cannot figure out how to access the closed window. Storyboard does not seem to allow me to create an outlet for my Window in my app delegate.
This is quite simple to archive, even it is not an elegant solution. Add a new property to your app delegate for your main window controller. In the following example, I call the controller MainWindowController.
#NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {
var mainWindowController: MainWindowController? = nil
func applicationShouldHandleReopen(sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
mainWindowController?.window?.makeKeyAndOrderFront(self)
return false
}
}
In the initialisation of the main window controller I register the controller in the app delegate:
class MainWindowController: NSWindowController {
override func windowDidLoad() {
super.windowDidLoad()
// ...initialisation...
// Register the controller in the app delegate
let appDelegate = NSApp.delegate as! AppDelegate
appDelegate.mainWindowController = self
}
}
That is all, works perfectly for me.

How do I subscribe to TextField's TextChanged event in Xcode

I've recently started working on some test projects to get the feel for OS X development with Xcode. I come from Windows, so I might not be making much sense here.
How would I subscribe to certain "events" in Swift? I have just learned how to connect actions to UI objects. For example, I can now click a button, and change the text of a label programatically. However, and this may just be a case of lack of knowledge on my part - I am not able to find a way to subscribe to a TextField's "Text Changed" event.
Let's say that I have a TextField, and when I change the text at runtime (i.e. type something), I want to do something in the textChanged event for that particular TextField.
Is there even such a thing as a TextChanged event in OS X development?
Update
I am now using the following code:
import Cocoa
class ViewController: NSViewController {
class textField:NSTextField, NSTextFieldDelegate
{
override func awakeFromNib() {
delegate = self;
}
override func controlTextDidChange(obj: NSNotification)
{
println("Text changed.")
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override var representedObject: AnyObject? {
didSet {
// Update the view, if already loaded.
}
}
}
And I have added a ClassName to the TextField control in the Identity Inspector, but it isn't responding to the text changing. The message given is:
Failed to connect (textField) outlet from
(Xcode_Action_Basics.ViewController) to (NSTextField): missing setter
or instance variable
I just googled that error and came across this page: Failed to connect (storyboard) outlet from (NSApplication) to (NSNibExternalObjectPlaceholder) error in Cocoa and storyboard which states that this is a known issue in Xcode and that it does not mean there is a problem with your code - but I'm not so sure about that, because the code isn't working. Not sure if I've missed out on something.
Create a class that implements the protocol NSTextFieldDelegate like
class MyTextField:NSTextField, NSTextFieldDelegate {
override func awakeFromNib() {
delegate = self // tell that we care for ourselfs
}
override func controlTextDidChange(obj: NSNotification) {
// .... handle change, there are a lot of other similar methods. See help
}
}
In IB assign this class here:

Use NSToolBar Outlet xcode 6 and Storyboard?

I am trying to add an outlet into my viewcontroller for a toolbar item in my window controller. I have tried playing around with first responder and bindings but have not been able to find any solutions.
A similar question that was answered provided some insight but no one has mentioned anything about IBOutlets other than still asking how to add them in the comments. The answer has been accepted so i am assuming no one will add to it.
How to use NSToolBar in Xcode 6 and Storyboard?
Incase my question is unclear at all, i would like to be able to add this to my storyboard program
#IBOutlet weak var Mytoolbar: NSToolbarItem!
func enabletoolbar()
{
Mytoolbar.action = "FunctionIn.ViewController.swift"
Mytoolbar.enabled = true
}
I found a decent workaround by adding IBOutlets to my custom NSWindow class and using the storyboard to connect my views to the IBOutlets. Then, I accessed these views from my NSViewController class by getting them from the custom NSWindow.
Basically you need to set the action and other properties to the toolbaritem but not in the toolbar. So try the same.
i ended up doing this in my view controller which seems to work
override func viewDidLayout() {
var x = self.view.window?.toolbar?.items[1].label
println(x)
if(self.view.window?.toolbar?.items[0].label! != "Check")
{
toobarediting()
}
println("didlay")
}
func toobarediting() {
self.view.window?.toolbar?.insertItemWithItemIdentifier("Check", atIndex: 0)
}
func toolbarcheck(functiontoset: Selector) {
var y = self.view.window?.toolbar?.items[0] as NSToolbarItem
y.action = functiontoset
if(functiontoset != nil)
{
y.enabled = true
}
}
It seems to allow me to make the tool bar button clickable/unclickable when ever i require it to change it just seems so much more bulky and error prone than
myitem.enable = fale
myitem.action = nil
is this really the best way for a storyboard based application in osx?
While connectiong IBActions works by using either the First Responder or by adding an "Object" to the scene, then changing its class to the window's view controller class, this doesn't help with IBOutlets and delegates that you'd like to point to the view controller.
Here's a work-around for that:
Add the Toolbar to the View Controller, not to its Window. That way, you can make all the IBOutlet connections in the View Controller Scene easily. I've done that for years and found no issues with it, even when using Tabs.
You'll have to assign the window's toolbar in code, then. E.g. like this:
#interface ViewController ()
#property (weak) IBOutlet NSToolbar *toolbar; // connect this in your storyboard to the Toolbar that you moved to the View Controller Scene
#end
- (void)viewWillAppear {
[super viewWillAppear];
self.view.window.toolbar = self.toolbar;
}

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