I subclassed NSSecureTextField, and overrided -(BOOL)becomeFirstResponder,but it only works well when my custom NSSecureTextField get focus at the first time.
I think it is not a problem of NSSecureTextField. It is a problem of how a control get focused.
Create a new project and only drag two NSSecureTextField on your view. Set the custom class of one of them to MySecureTextField defined below and keep the other one default. Run the project and change focus between the two NSSecureTextField, you will see the "Get focus" printed when the custom one get focus each time.
Back to your program, please check if the NSSecureTextField is lost focus? Does the resignFirstResponser called?
#import "MySecureTextField.h"
#implementation MySecureTextField
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
// Drawing code here.
}
- (BOOL)becomeFirstResponder
{
NSLog(#"Get focus");
return [super becomeFirstResponder];
}
#end
Related
I'm trying to understand how Subclassing works in Cocoa.
I've created a new Cocoa Application Project in XCode 5.1.
I drag a new Custom View onto the main window.
I create a new Objective-C class CustomViewClass and set it as a Subclass of NSView. This generates the following :
CustomViewClass.h
#import <Cocoa/Cocoa.h>
#interface CustomViewClass : NSView
#end
CustomViewClass.m
#import "CustomViewClass.h"
#implementation CustomViewClass
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
NSLog(#"Custom View initialised");
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
[super drawRect:dirtyRect];
// Drawing code here.
}
#end
Note that I added the NSLog(#"Custom View initialised"); line so I can track what is going on.
In interface Builder, I select the Custom View and within the Idenditiy Inspecter set it's custom Class to CustomView. Then I run the Application.
As expected I get a Custom View initialised message in the Console.
I do exactly the same with an NSTextField adding it to the window, creating a new class TextFieldClass and the NSTextField custom Class is to TextFieldClass. I also add a NSLog(#"Text Field initialised"); in the same place as above to track things.
However when I run the App, I only get the Custom View initialised message in the Console and not the NSLog(#"Text Field initialised");message.
So initially I think that NSTextField doesn't recieve the initWithFrame message when it is created. So I add an initialiser to TextFieldClass :
- (id)init {
self = [super init];
if (self) {
// Initialization code here.
NSLog(#"Text Field initialised");
}
return self;
}
However this still doesn't seem to get called.
I assumed therefore that NSTextField just wasn't being subclassed. However, when I add this method to TextFieldClass :
-(void)textDidChange:(NSNotification *)notification {
NSLog(#"My text changed");
}
Run the app and lo and behold, every time I type in the text field I get the My text changed message in the Console.
So my question is, what is going on here? How does the NSTextField get initialized and how can you override it's initialiser?
Why does the Custom View seem to act differently to the NSTextField?
Source code here
For your first question, NSTextFiled gets initialised via
- (id)initWithCoder:(NSCoder *)aDecoder
In this case, you have dragged a NSTextField from the palette and then changed the class to your custom text field class in the identity inspector. Hence the initWithCoder: will be called instead of initWithFrame:. The same is true for any object (other than Custom View) dragged from the palette
Instead, if you drag "Custom View" from the palette and change the class to your custom text field class, the initWithFrame: will be invoked.
The CustomViewClass you have created is the second case, hence initWithFrame: is invoked. The TextFieldClass is the first case, hence initWithCoder: is invoked.
If you use the Interface Builder in XCode, you should use awakeFromNib to initialise your subclass.
- (void)awakeFromNib
{
// Your init code here.
}
If you want to use your subclass programatically and using the interface builder, then use code like this:
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self initView];
}
return self;
}
- (void)awakeFromNib
{
[self initView];
}
- (void)initView
{
// Your init code here
}
I just implemented following method that suppose to take some action after the value of a NSTextField is changed in my NSOutlineView
-(BOOL)control:(NSControl *)control textShouldEndEditing:(NSText *)fieldEditor
{
NSLog(#"end editing");
NSTextField* tf = (NSTextField*)control;
if(selectedItem && [selectedItem isKindOfClass:[HSCategoryClass class]])
{
HSCategoryClass* c = selectedItem;
c.name = tf.stringValue;
// request the update from DB
[[NSNotificationCenter defaultCenter] postNotificationName:#"updatingCategoryName"
object:c
userInfo:#{#"sender":self}];
}
return YES;
}
However, when I'm done editing and hit enter key or navigate anywhere outside of the text field this method is getting called twice instead of just once.
Does anyone know why is this?!
Any kind of help is highly appreciated!
That routine does not signify that editing has ended. Instead, it's called to find out if it should end (hence the name of the method). It can be called by the framework any number of times, and you shouldn't be relying on it for this purpose.
Instead override the NSOutlineView's textDidEndEditing: method.
Be sure to call super.
So you'd subclass the NSOutlineView and in your subclass:
- (void)textDidEndEditing:(NSNotification *)aNotification
{
// do your stuff
[super textDidEndEditing:aNotification];
}
I found some answer that quite solve my questions, but seems that I'm missing some steps. I'm just trying to intercept the "ViewDidBlablabla" events of a ScrollView, so I created a custom UIScrollView class.
MyScrollView.m
#import "MyScrollView.h"
#implementation MyScrollView
- (id)initWithFrame:(CGRect)frame{
NSLog(#"initWithFrame");
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
-(void)scrollViewWillBeginDragging:(UIScrollView*)scrollView{
NSLog(#"scrollViewWillBeginDragging");
//scrollView.contentOffset
}
-(void)scrollViewDidScroll:(UIScrollView*)scrollView{
NSLog(#"scrollViewDidScroll");
}
-(void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView{
NSLog(#"scrollViewDidEndScrollingAnimation");
}
#end
MyScrollView.h
#import <UIKit/UIKit.h>
#interface MyScrollView : UIScrollView <UIScrollViewDelegate>
#end
When I alloc my custom Scroll View I do get the console message "initWithFrame", but there's no way to get to the other events. What am I missing?
If you need some other pieces of code feel free to ask, but since I get to my custom "initWithFrame" method, I suppose that the error should be here.
Try setting your view as the delegate of itself:
if (self) {
// Initialization code
self.delegate = self;
}
Technically, you do not need to inherit UIScrollView to respond to scrolling events: it is sufficient to set the delegate to an implementation of <UIScrollViewDelegate>.
Also, the scrollViewDidEndScrollingAnimation: method has been gone for about two years, so it is not going to be called on modern iOS installations.
I am not sure I am doing things the right way, or if I have it all hacked up.
I have a really simple test application (not document-based) I created for learning how to work with application-modal dialogs in Cocoa applications.
With the application project "TestModalDialog", I have a simple MainMenu.xib with the default view and a button, "Show Dialog", I added. I created a second XIB called TheDialog.xib that has "Cancel" and "OK" buttons. That xib has as its owner a class derived from NSWindowController called "TheDialogController"; the window outlet and delegate are connected to the controller.
Selection of "Show Dialog" on the main view will launch the dialog. Selection of "Cancel" or "OK" will dismiss the dialog. Here is the pretty simple code:
// TestModalDialogAppDelegate.h
// TestModalDialog
#import <Cocoa/Cocoa.h>
#class TheDialogController;
#interface TestModalDialogAppDelegate : NSObject <NSApplicationDelegate>
{
NSWindow *window;
TheDialogController* theDialogController;
}
#property (assign) IBOutlet NSWindow *window;
- (IBAction)showDialog:(id)sender;
#end
// TestModalDialogAppDelegate.m
// TestModalDialog
#import "TestModalDialogAppDelegate.h"
#import "TheDialogController.h"
#implementation TestModalDialogAppDelegate
#synthesize window;
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
theDialogController= [[TheDialogController alloc] init];
}
- (void)dealloc
{
if(nil != theDialogController)
[theDialogController release];
[super dealloc];
}
- (IBAction)showDialog:(id)sender
{
if(nil == theDialogController)
{
NSAlert* alert= [NSAlert alertWithMessageText:#"Dialog Error" defaultButton:nil alternateButton:nil otherButton:nil informativeTextWithFormat:#"The dialog controller was not allocated."];
[alert runModal];
return;
}
NSInteger result= [NSApp runModalForWindow:[theDialogController window]];
// Do something with result....
}
#end
// TheDialogController.h
// TestModalDialog
#import <Cocoa/Cocoa.h>
#interface TheDialogController : NSWindowController
{
// BOOL userClickedCloseOrOk; // Removed based on answer.
// Should declare a common define - just being lazy.
NSInteger userClickedOk; // Added based on answer.
UInt16 timesShown;
}
- (IBAction)showWindow:(id)sender;
- (IBAction)closeDialog:(id)sender;
- (IBAction)okDialog:(id)sender;
//- (BOOL)windowShouldClose:(id)sender; // Removed based on answer.
- (void)windowWillClose:(NSNotification*)notification; // Added based on answer.
- (void)windowDidBecomeKey:(NSNotification*)notification; // To set title when modal.
#end
// TheDialogController.m
// TestModalDialog
#import "TheDialogController.h"
#implementation TheDialogController
- (id)init
{
self = [super initWithWindowNibName:#"TheDialog"];
userClickedOk= 0; // Added based on answer.
// userClickedCloseOrOk= FALSE; // Removed based on answer.
return self;
}
-(void)dealloc
{
// Do member cleanup if needed.
[super dealloc];
}
- (void)windowDidLoad
{
[super windowDidLoad];
// Initialize as needed....
[[self window] center]; // Center the window.
}
// Does not show with runModalForWindow.
- (IBAction)showWindow:(id)sender
{
// Just playing with the window title....
++timesShown;
NSString* newTitle= [NSString stringWithFormat:#"Shown %d Times", timesShown];
[[self window] setTitle:newTitle];
return [super showWindow:sender];
}
// This method no longer used for this solution based on the answer.
//- (BOOL)windowShouldClose:(id)sender
//{
// if(!userClickedCloseOrOk) // The user did not click one of our buttons.
// [NSApp abortModal];
// else
// userClickedCloseOrOk= FALSE; // Clear for next time.
//
// return TRUE;
//}
// Added based on answer.
- (void)windowWillClose:(NSNotification*)notification
{
[NSApp stopModalWithCode:userClickedOk];
userClickedOk= 0; // Reset for next time.
}
// Note - the title will update every time the window becomes key. To do the
// update only once per modal session, a flag can be added. There might be a better
// notification to catch.
- (void)windowDidBecomeKey:(NSNotification*)notification
{
++timesShown;
NSString* newTitle= [NSString stringWithFormat:#"Shown %d Times", timesShown];
[[self window] setTitle:newTitle];
}
- (IBAction)closeDialog:(id)sender
{
//userClickedCloseOrOk= TRUE; // Removed based on answer.
//[NSApp abortModal]; // Removed based on answer.
//[[self window] performClose:self]; // Removed based on answer.
[[self window] close]; // Know we want to close - based on answer.
}
- (IBAction)okDialog:(id)sender
{
userClickedOk= 1; // Added based on answer.
//userClickedCloseOrOk= TRUE; // Removed based on answer.
//[NSApp stopModal]; // Removed based on answer.
//[[self window] performClose:self]; // Removed based on answer.
[[self window] close]; // Know we want to close - based on answer.
}
#end
I had trouble with the modality - before I put in userClickedCloseOrOk and tests, if the user hit the close button (upper-left red dot), the dialog would close but the modal session was still running.
I realize I could just leave the close-button off the dialog to start with, but with it there, is what I have demonstrated a good way to catch that scenario, or is there a better way? Or, am I doing something wrong to start with, which creates that problem for me?
Any advice would be appreciated.
NOTE - Code from the original example commented out and replaced with code based on the answer. Also added a new notification handler.
In the okDialog: and closeDialog: methods call close instead of performClose: to avoid the window calling the windowShouldClose: delegate method. That way you don't need userClickedCloseOrOk.
Also I think you want to be calling stopModalWithCode: instead of stopModal since in the app delegate you seem to be interested in the result. And you can call stopModal or stopModalWithCode: instead of abortModal because you are always in the runloop when you call it (abort is for when you are outside of the modal runloop, like in another thread or timer's runloop).
In windowShouldClose: you are doing an action (abortModal) when you should only be answering the question "should this window close". The windowWillClose: delegate method is where you should do actions if you need to.
Sheets are useful when there is one window and it tells the user they can't do anything with it until they complete whatever is in the sheet. Application-modal windows are useful when you have multiple windows that the user can't interact with until they complete whatever is in the modal window or where there is an error that involves the whole application but is not tied to the content of one window. In their HIG Apple suggests avoiding the use of Application-modal windows whenever possible.
I have actually just been struggling with the same problem and found this link :
Stopping modal when window is closed (Cocoa)
I have an NSSlider (slider) and an NSLabel (label) on a window. I also have a class "Controller" that updates the label whenever the slider's value is changed.
The default position of the slider is 0.5, I'm trying to get is where Controller's constructor updates the label upon program launch.
The following is the implementation file for my attempt to do this. Everything works fine except the label is always 0 when I start the program.
#implementation Controller
{
}
-(id)init
{
NSLog(#"initializing...");
[self updateLabel];
return self;
}
- (IBAction)sliderChanged:(id)sender
{
[self updateLabel];
}
- (void)updateLabel
{
label.text = [NSString stringWithFormat:#"%.1f", slider.value];
}
#end
In the console I see the text "initializing...", but the label is never updated. What am I missing?
The controller may be getting initialized (where is your call to [super init]?), but that doesn't mean the outlets are hooked up. The proper way to do that would be to rely on a viewDidLoad, windowDidLoad, or awakeFromNib method.
you should achieve this with bindings and without any "glue code" in controllers.
Here's some reference on how to use them: http://cocoadevcentral.com/articles/000080.php