Newbie to ReactiveCocoa and ReactiveSwfit here... Sorry if the answer is obvious.
I am trying to adapt the Start Developing iOS Apps with Swift sample to ReactiveSwift / ReactiveCocoa, and I am running into an issue with "translating" the UITextField's Delegate method -- which gets rid of the keyboard and essentially ends the editing (so I can capture the text field in the mealNameLabel) :
func textFieldShouldReturn(_ textField: UITextField) -> Bool
I am using
nameTextField.reactive.textValues.observeValues { value in
viewModel.mealName.swap(value ?? "")
}
// Setup bindings to update the view's meal label
// based on data from the View Model
mealNameLabel.reactive.text <~ viewModel.mealLabel
to get the value from the text field into the view model and percolate the view model's label back to the UILabel (convoluted...)
That works fine, as long as I maintain the viewController as the UITextField's delegate and I still implement the method depicted in the tutorial and mentioned above. Essentially :
override func viewDidLoad() {
super.viewDidLoad()
nameTextField.delegate = self
// view controller logic
...
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
// Hide the keyboard.
textField.resignFirstResponder()
return true
}
I tried using
nameTextField.reactive.controlEvents
but that failed miserably due to my lack of understanding of controlEvents (docs anywhere ?).
So what do I need to do to make the keyboard disappear when the user is done editing, the "reactive way" ?
Thanks !!!
(Of course right after I post my question...)
It looks like this might actually do the trick :
nameTextField.reactive.controlEvents(UIControlEvents.primaryActionTriggered)
.observeValues { textField in
textField.resignFirstResponder()
}
After fiddling with the different event types, it looks like .primaryActionTriggered is what gets triggered when the "Done" button is pressed.
Any better way to do this ?
Related
I'd like to save the state of Check Box, quit application, then launch macOS app again to see restored state of my Check Box. But there's no restored state in UI of my app.
What am I doing wrong?
import Cocoa
class ViewController: NSViewController {
#IBOutlet weak var tick: NSButton!
override func viewDidLoad() {
super.viewDidLoad()
}
override func encodeRestorableState(with coder: NSCoder) {
super.encodeRestorableState(with: coder)
coder.encode(tick.state, forKey: "")
}
override func restoreState(with coder: NSCoder) {
super.restoreState(with: coder)
if let state = coder.decodeObject(forKey: "") as? NSControl.StateValue {
tick.state = state
}
}
}
To the best of my knowledge, this is the absolute minimum you need to implement custom UI state restoration of a window and/or its contents.
In this example, I have a window with a checkbox and that checkbox's state represents some custom view state that I want to restore when the app is relaunched.
The project contains a single window with a single checkbox button. The button's value is bound to the myState property of the window's content view controller. So, technically, the fact that this is a checkbox control is irrelevant; we're actually going to preserve and restore the myState property (the UI takes care of itself).
To make this work, the window's restorable property is set to true (in the window object inspector) and the window is assigned an identifier ("PersistentWindow"). NSWindow is subclassed (PersistentWindow) and the subclass implements the restorableStateKeyPaths property. This property lists the custom properties to be preserved/restored.
Note: if you can define your UI state restoration in terms of a list of key-value compliant property paths, that is (by far) the simplest solution. If not, you must implement encodeRestorableState / restoreState and are responsible for calling invalidateRestorableState.
Here's the custom window class:
class PersistentWindow: NSWindow {
// Custom subclass of window the perserves/restores UI state
// The simple way to preserve and restore state information is to just declare the key-value paths
// of the properties you want preserved/restored; Cocoa does the rest
override class var restorableStateKeyPaths: [String] {
return [ "self.contentViewController.myState" ]
}
// Alternatively, if you have complex UI state, you can implement these methods
// override func encodeRestorableState(with coder: NSCoder) {
// // optional method to encode special/complex view state here
// }
//
// override func restoreState(with coder: NSCoder) {
// // companion method to decode special/complex view state
// }
}
And here's the (relevant portion) of the content view controller
class ViewController: NSViewController {
#objc var myState : Bool = false
blah, blah, blah
}
(I built this as a Cocoa app project, which I could upload if someone tells me where I could upload it to.)
Actually you don't have to go through restorableStateKeyPaths / KVO / KVC if you don't want to.
I was stuck in the same state as you with the encodeRestorableState() & restoreState() methods not being called but found out what was missing.
In System Preferences > General, make sure "Close windows when quitting an app" is unchecked.
Make sure that the NSWindow containing your view has "Restorable" behavior enabled in IB.
Make sure that your NSViewController has a "Restoration ID" set.
Your NSViewController won't be encoded unless you call invalidateRestorableState(). You need to call this each time there's a state in your NSViewController that changes and that you want to have saved.
When no state changes in the NSViewController after having restored it, its state would not be encoded again when closing the app. Which would cause the custom states to not be restored when relaunching the app. The simplest way I found is to also call invalidateRestorableState() in viewDidLoad(), so that state is always saved.
After doing all that, I didn't even have to additionally implement NSApplicationDelegate or NSWindowRestoration protocol methods. So the state restoration of the NSViewController is pretty self-contained. Only external property is restorable NSWindow.
After losing a couple of hours of my life to this problem I finally got it working. Some of the information in the other answers was helpful, some was missing, some was not necessary.
Here is my minimal example based on a new Xcode 13 project:
in AppDelegate add (this is missing in the other examples):
func applicationSupportsSecureRestorableState(_ app: NSApplication) -> Bool { return true }
in ViewController add:
#objc var myState : Bool = false
override class var restorableStateKeyPaths: [String] {
return [ "myState" ]
}
set up some UI and bind it to myState to see what is going on
make sure System Preferences > General > "Close windows when quitting an app" is unchecked
Things that I did not need to do:
create a custom window subclass
set a custom restoration id
it worked fine just with Xcode start/stop
I'm trying to find how to bring up a second view/window after pushing a button on my primary window. I have read about segues and I can get the first window to display the second but the second is not connected to a view controller so I can't add any code to any controls on the second view. Try as I might I cannot create a SecondViewController.swift file and connect it to a window controller or a view controller. The tutorials I have found all deal with iOS and I want OS X which means there are just enough differences to keep me from figuring this out.
Can anyone show me how to do this?
Ta,
A.
First make new file like:
After that, put these codes in your classes and that should do it.
class SecondWindowController: NSWindowController {
convenience init() {
self.init(windowNibName: "SecondWindowController")
}
}
class ViewController: NSViewController {
private var secondWindowController: SecondWindowController?
#IBAction func showSecondWindow(sender: AnyObject) {
if secondWindowController == nil {
secondWindowController = SecondWindowController()
}
secondWindowController?.showWindow(self)
}
}
I am simply trying to get undo working for the actions a user performs in my app. By default, any text editing the user does has the benefit of undo, but any actions that are done otherwise (from my code) does not.
I can see the documentation explains that I need to get an instance of NSUndoManager and call registerUndoWithTarget, but I am stumped with the first step: getting the undoManager from within my ViewController. Since ViewController is a UIResponder, I tried this:
if let undoManager = self.undoManager {
undoManager.registerUndoWithTarget(self, selector: Selector("removeLatestEntry:"), object: "test")
}
Since that binding returns nil, I thought maybe the ViewController doesn't have the undoManager, so I looked for it in the window:
if let window = NSApplication.sharedApplication().mainWindow {
if let undoManager = window.undoManager {
undoManager.registerUndoWithTarget(self, selector: Selector("removeLatestEntry:"), object: "test")
}
}
Alas, the window binding also returns nil. Sorry, I am very new to this. Can anyone point me in the right direction? Am I supposed to implement my own undoManager or something? There is clearly an undoManager somewhere because anything a user does manually in my textField is getting undo behavior. It seems like this would be a singleton that I could access easily from a ViewController.
--
Edit: BTW, the code above was placed in viewDidLoad and removeLatestEntry is just a function in my ViewController that takes a string and prints it at this point.
To use undoManager, the ViewController needs to be first responder. So:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
becomeFirstResponder()
}
Then, from wherever your action is defined that needs to be reversed, you register your undo and pass it whatever it needs to undo that action. So in my case:
func addEntry(activity: String) {
// some other stuff…
undoManager!.registerUndoWithTarget(self, selector: Selector("removeLatestEntry:"), object: activity)
}
I'm using Xcode 6 and Swift to develop an OS X app, not iOS.
Let's say we have two toggle buttons and each one controls a combobox. Everytime press the button, it will enable or disable the combobox it controls. I can definately set up separate actions for each button. Since I have ten buttons, this approach seems to contain a lot of redundant code.
#IBAction func clickBtn1 (sender: NSButton){
if combobox1.enabled == true
{
combobox1.enabled = faulse;
}
else
{
combobox1.enabled = true;
}
}
#IBAction func clickBtn2 (sender: NSButton){
//same codes for combobox 2
}
Is there any way to make this simpler, such as share the action code by identify different sender, Similar to VB.NET?
UPDATE:
I found a imcomplete solution for it from https://stackoverflow.com/a/24842728/2784097
now I control+drag the two buttons to the same action in ViewController.swift and also give those two buttons different tag. button1.tag=1, button2.tag = 2. The code now looks like,
//button1.tag=1, button2.tag = 2.
#IBAction func clickButton(sender:NSButton) {
switch(sender.tag){
case 0:
combobox1.enabled = !combobox1.enabled;
break;
case 1:
combobox2.enabled = !combobox2.enabled;
break;
default:
break;
}
}
This solves a part of my problem. Next, I wonder is there any way to access/find the controls/components by reference, for example a string or tag or name anything. Pseudo code would like following,
//button1.tag=1, button2.tag = 2.
#IBAction func clickButton(sender:NSButton) {
//pseudo code
combobox[button.tag].enabled = !combobox[button.tag].enabled;
}
You should be able to bind all of the NSButton (and NSComboBox) control events to the same buttonClicked: method. You can achieve this through Interface Builder or programmatically via the setAction: method.
Selectors in Swift are just strings, like "buttonClicked:", but I prefer to wrap them in Selector initializers for clarity (e.g. Selector("buttonClicked:")).
There are many ways to do this, here's one:
Extend the NSButton class to include a property for the combo box that it controls. That way, when in the action method, you can get a reference to the correct combo box from the instance of the button that is passed in.
Create a new class MyButton that extends NSButton
Add a public property to that class to hold an reference to a combo box.
Replace your NSButtons with MyButtons.
After the view loads, set the combo box property on each of your buttons to the correct combo box.
Write a new action method that accepts a MyButton object as the sender. Get the combo box property from the sender and call combobox.enabled = !combobox.enabled.
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: