I am working on a front end for a project in objective-c and I am having some trouble getting methods of my class Window which is a subclass of NSViewController to fully execute when called from a different class.
I have a method of the class Window that is called setColor which changes the color of my NSTableView variable which is linked to a bordered scroll view in my interface. I am able to successfully change the color by calling the setColor method like this from the init method in Window: [self setColor :self];
However when I do this [window1 setColor: window1] with window1 being an object of the class Window that I have declared in class Door, nothing seems to happen since the color of the boarded scroll view remains the same.
My Window.h file looks like this:
#interface Window : NSViewController {
#public
IBOutlet NSTableView *dataTableView;
}
#property (retain) IBOutlet NSTableView *tableView;
- (IBAction)SetColor:(id)sender;
#end
My Window.m looks like this:
#synthesize tableView;
- (void) awakeFromNib {
// [self SetColor :self];
}
- (IBAction)SetColor:(id)sender;
{
NSLog(#"changing the color");
[self->tableView setBackgroundColor: NSColor.blueColor];
}
Door.h looks like this
#interface Door : NSViewController {
Window* window1;
}
-(IBAction)buttonPress:(id)sender;
#property (retain) Window* window1;
#end
Door.m looks like this:
-(void) dealloc{
[window1 release];
}
-(id)init{
self = [super init];
if(self){
window1 = [Window alloc];
}
-(IBAction)buttonPress :(id)Sender;
{
[window1 setColor: window1];
}
I am using Xcode 3.2 so I cannot use ARC.
window1 = [Window alloc] will not load a Nib or storyboard and connect the outlet IBOutlet NSTableView *dataTableView to the table view inside it.
If "Window" is a view controller, you need to initialize it and the outlets in it a more standard way. View controllers need the proper initialization or the outlets are nil, and in Objective-C, if you send a method to nil, it just does nothing.
Related
I'm showing an NSPopover in an NSView, originating from a point on an NSBezierPath. I'm able to show the popover without a problem, but I can't seem to set the string value of the two text fields in it. The popover and the content view are both a custom subclass of NSPopover and NSViewController, respectively. The NSPopover subclass is also the NSPopover's delegate, although I don't implement any delegate methods, so I'm not sure I even need to do that.
Here is my subclass of NSViewController:
#import <Cocoa/Cocoa.h>
#interface WeightPopoverViewController : NSViewController
#end
#import "WeightPopoverViewController.h"
#interface WeightPopoverViewController ()
#end
#implementation WeightPopoverViewController
- (id)init {
self = [super initWithNibName:#"WeightPopoverViewController" bundle:nil];
if (self) {
}
return self;
}
#end
And my subclass of NSPopover:
#import <Cocoa/Cocoa.h>
#interface WeightPopoverController : NSPopover <NSPopoverDelegate> {
NSTextField *dateLabel;
NSTextField *weightLabel;
}
#property (strong) IBOutlet NSTextField *dateLabel;
#property (strong) IBOutlet NSTextField *weightLabel;
#end
#import "WeightPopoverController.h"
#implementation WeightPopoverController
#synthesize weightLabel;
#synthesize dateLabel;
#end
This is the code in my NSView subclass that opens up the popover:
#interface WeightGraphViewController () {
WeightPopoverController *popover;
WeightPopoverViewController *vc;
}
...
-(void)mouseEntered:(NSEvent *)theEvent {
// initialize the popover and its view controller
vc = [[WeightPopoverViewController alloc] init];
popover = [[WeightPopoverController alloc] init];
// configure popover
[popover setContentViewController:vc];
[popover setDelegate:popover];
[popover setAnimates:NO];
// set labels
for (id key in (id)[theEvent userData]) {
[popover.weightLabel setStringValue:[(NSDictionary*)[theEvent userData] objectForKey:key]];
[popover.dateLabel setStringValue:key];
}
// set the location
(redacted, irrelevant)
// show popover
[popover showRelativeToRect:rect ofView:[self window].contentView preferredEdge:NSMaxYEdge];
}
-(void)mouseExited:(NSEvent *)theEvent {
[popover close];
popover = nil;
}
In WeightPopoverViewController.xib, I've set the File's Owner to WeightPopoverViewController and connected the view to the custom NSView. In this xib I also have an Object set to WeightPopoverController with the dateLabel and weightLabel connected to their text fields and the contentViewController set to File's Owner.
I think where I am going wrong is likely related to how I have configured my class / instance variables for the NSPopover, but from the research I've done and documentation I've read I can't seem to crack where I've gone wrong. Any help would be appreciated.
UPDATE:
I removed the NSPopover subclass from code and from IB. I put my outlets in my NSViewController and connected them in IB. However, I'm still not able to set the string values. The following won't compile with the error "Property 'weightLabel' not found on object of type NSPopover*'".
#interface WeightGraphViewController () {
NSPopover *popover;
...
}
-(void)mouseEntered:(NSEvent *)theEvent {
vc = [[WeightPopoverViewController alloc] init];
popover = [[NSPopover alloc] init];
[popover setContentViewController:vc];
[popover.dateLabel setStringValue:#"test"];
}
I have the property definition exactly as I had it in my NSPopover subclass, but now in my NSViewController. This is actually what I had before, and since I wasn't able to set the properties from the NSViewController, I figured I needed to do it through a subclass of NSPopover. This is why I thought I am having an issue with how I have configured my class / instance variables.
You seem to be creating two popovers, one in code (popover = [[WeightPopoverController alloc] init]) and one in Interface Builder (In this xib I also have an Object set to WeightPopoverController). Have a think about what you’re trying to achieve.
I would also advise against subclassing NSPopover. I believe this is causing confusion and is unnecessary. Instead, put the outlets to your dateLabel and weightLabel in the popover’s content view controller.
I've experienced something that I think is similar. The root problem is that the "outlets" connecting your view (XIB) to your controller are not initialized until after the view has been displayed. If the controller tries to set properties on any UI controls in the view before the popover has been opened, those changes are ignored (since all the controls will be nil).
Luckily, there's an easy solution (as mentioned in this answer): just invoke the view getter on your controller, and it will force the view to initialize sooner.
In other words:
popover = [NSPopover new];
myController = [[MyViewController alloc] initWithNibName:#"MyView" bundle:nil];
popover.contentViewController = myController;
[myController view]; // force view to initialize
...set some values on myController... // works because view is now loaded
[popover showRelativeToRect: ...];
I'm new to objective-c and, maybe I haven't grassped the concept of delegation very clearly yet, but i hope to do it by using it. I'm trying to implement a delegation in my app.
Idea is that i have class TableViewController which has NSMutableArray used for TableView initialization. I need to reinitialize this Array from my DropDown class. I'v tried to do that using delegation but failed to do it yet, maybe there is something wrong with it. I could pass TableViewController to DropDown class and edit the table via object. But i'd like to get it done using delegation.
Here is my TableViewController.h
#protocol TableViewControllerdelegate;
#interface TableViewController : UIViewController<UITableViewDataSource,UITableViewDelegate,MFMessageComposeViewControllerDelegate>
{
ControllerType controllerType;
}
#property (retain, nonatomic) IBOutlet UITableView *tableView;
#property (retain, nonatomic) NSMutableArray *dataArray;
#property (retain, nonatomic) NSArray *imageArray;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil andType:(ControllerType)type;
- (void)sendSMS: (NSString *) sms;
#end;
Here is my DropDown.h
#import "TableViewController.h"
#interface DropDownExample : UITableViewController <VPPDropDownDelegate, UIActionSheetDelegate> {
#private
VPPDropDown *_dropDownSelection;
VPPDropDown *_dropDownSelection1;
VPPDropDown *_dropDownSelection2;
VPPDropDown *_dropDownSelection3;
VPPDropDown *_dropDownSelection4;
VPPDropDown *_dropDownDisclosure;
VPPDropDown *_msg;
VPPDropDown *_dropDownCustom;
NSIndexPath *_ipToDeselect;
}
+ (bool) uncheck:(UITableViewCell *) cell andData:(NSString *) data;
- (void)reloadData;
#end
And this is how i try to edit my tableview object array
TableViewController *newControll = (TableViewController*)[UIApplication sharedApplication].delegate;
NSMutableArray *arrayWithInfo = [[NSMutableArray alloc] initWithObjects:AMLocalizedString(#"Status", nil),AMLocalizedString(#"Call", nil),AMLocalizedString(#"Location", nil),AMLocalizedString(#"Control", nil),AMLocalizedString(#"Sim", nil),AMLocalizedString(#"Object", nil),AMLocalizedString(#"Info", nil),nil];
newControll.dataArray = arrayWithInfo;
[arrayWithInfo release];
[newControll.tableView reloadData];
I get it running, but it get's '-[AppDelegate setDataArray:]: unrecognized selector sent to instance after reaching this code.
OK, I am not sure if I got this right but it finally clicked for me what delegation is and why I need it. Hopefully you'll understand too once you read through my scenario.
History
Previously, in my UITabBar app, I wanted to show a custom form view overlaid on top of my view controller to enter name and email.
Later I also needed to show the same custom overlay on top of another view controller on another tab.
At the time I didn't really know what delegation was for, so the first method I used to tackle this problem was NSNotificationCenter. I duplicated the same code to my second view controller and hooked it up to a button press event.
On pressing a button on the second view controller on another tab, it certainly showed my custom overlay, just like my first view controller.
However, this is where the problem starts.
The Problem
I needed to close my custom form view. So using NSNotificationCenter, I posted a notification and the listener callback method for the notification was told to close my custom view.
The problem was, using NSNotificationCenter, all listeners both in my first tab and my second tab responded to the posted notification and as a result, instead of closing just the custom form view overlaid on top of my second view controller, it closed ALL my custom view, regardless of where the custom view was opened from.
What I wanted was when I tap on the "X" button to close my custom form view, I only want it to close it for that single instance of the custom view, not all the other ones I had opened.
The Solution: Delegation
This is where it finally clicked for me - delegation.
With delegation, I tell each instance of my custom form view who the delegate was, and if I was to tap on the "X" button to close my custom view, it only close it for that single instance that was opened, all the other view controllers were untouched.
Some Code
Right, down to some code.
Not sure if this is the best way to do it (correct me if I am wrong) but this is how I do it:
// ------------------------------------------------------------
// Custom Form class .h file
// ------------------------------------------------------------
#protocol MyCustomFormDelegate <NSObject>
// if you don't put a #optional before any method, then they become required
// in other words, you must implement these methods
-(void)sendButtonPressed;
-(void)closeButtonPressed;
// example: these two methods here does not need to be implemented
#optional
-(void)optionalMethod1;
-(void)optioinalMethod2;
#end
#interface MyCustomFormView : UIView
{
...
id<MyCustomFormDelegate> delegate;
}
...
#property (nonatomic, retain) id<MyCustomFormDelegate> delegate;
#end
// ------------------------------------------------------------
// Custom Form class .m file
// ------------------------------------------------------------
...
#implementation TruckPickerView
#synthesize delegate;
-(id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if(self)
{
...
[btnSend addTarget:self selector:#selector(sendEmail) forControlEvent:UIControlEventTouchUpInside];
...
[btnClose addTarget:self selector:#selector(closeForm) forControlEvent:UIControlEventTouchUpInside];
}
return self;
}
-(void)sendEmail
{
// code sends email
...
// ------------------------------------------------------------
// tell the delegate to execute the delegate callback method
//
// note: the implementation will be defined in the
// view controller (see below)
// ------------------------------------------------------------
[delegate sendButtonPressed];
}
-(void)closeForm
{
// ------------------------------------------------------------
// tell the delegate to execute the delgate callback method
//
// note: the implementation will be defined in the
// view controller (see below)
// ------------------------------------------------------------
[delegate closeButtonPressed];
}
// ------------------------------------------------------------
// view controller .h file
// ------------------------------------------------------------
#import "MyCustomFormView.h"
// conform to our delegate protocol
#interface MyViewController <MyCustomFormDelegate>
{
...
// create a single instance of our custom view
MyCustomFormView *customForm;
}
#property (nonatomic, retain) MyCustomFormView *customForm;
// ------------------------------------------------------------
// view controller .m file
// ------------------------------------------------------------
#synthesize customForm;
-(void)viewDidLoad
{
customForm = [[MyCustomFormView alloc] initWithFrame:....];
// tell our custom form this view controller is the delegate
customForm.delegate = self;
// only show the custom form when user tap on the designated button
customForm.hidden = YES;
[self.view addSubview:customForm];
}
-(void)dealloc
{
...
[customForm release];
[super dealloc];
}
// helper method to show and hide the custom form
-(void)showForm
{
customForm.hidden = NO;
}
-(void)hideForm
{
customForm.hidden = YES;
}
// ------------------------------------------------------------
// implement the two defined required delegate methods
// ------------------------------------------------------------
-(void)sendButtonPressed
{
...
// email has been sent, do something then close
// the custom form view afterwards
...
[self hideForm];
}
-(void)closeButtonPressed
{
// Don't send email, just close the custom form view
[self hideForm];
}
You get that error, because (as the error says) you're sending a setDataArray: message to your app delegate (the AppDelegate class).
[UIApplication sharedApplication].delegate;
This will return the delegate of you app. There are a couple of ways to find out which class is your app's delegate, but usually it's called AppDelegate (as in your case) and it's implementing the UIApplicationDelegate protocol too.
You can't simply cast that to a completely different class. If your app delegate has an ivar or property of type TableViewController you have to use accessors to get it. If it's a property, you can use the dot notation. If it's an ivar, you can either implement a getter method that returns the ivar, or make it a property instead.
// assuming your app delegate has a TableViewController property called myTableViewController.
AppDelegate *appDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
TableViewController *tableViewController = appDelegate.myTableViewController;
This will fix the error, but your use of the delegate pattern is wrong too. I don't see where you're using any custom delegates. You forward declare a TableViewControllerdelegate protocol, but I don't see any declaration of it, or I don't see where you're trying to use it.
I have a Subclass of NSObject in which I want to call IMMEDIATELY (a sort of -(void)viewDidLoad) a method (in this case to load a MkMapView): what's the better way to do this? I think I cant use viewDidLoad, so can I use performSelector?
SubClass.h
#interface Mysubclass : NSObject <MKMapViewDelegate> {
}
SubClass.m (1st alternative)
-(id)init{
self = [super init];
if ( self != nil ) {
// THE CODE TO INITIALIZE MKMAPVIEW
}
return self
}
OR
SubClass.m (2nd alternative)
-(id)init{
[self performSelector:#selector(myMethod)];
return self;
}
-myMethod{
// THE CODE TO INITIALIZE MKMAPVIEW
}
What's the better (or correct) alternative? Its possible to avoid -(id)init? Or everytime I add a subclass, to call a method I have to write it into -(id)init? Thank you!
There is no reason to use -performSelector: in this context. If you want to add a method that initializes the MKMapView when your object is created, call the method from within the if (self) block:
- (id)init
{
self = [super init];
if (self) {
[self setupMapView];
}
return self;
}
- (void)setupMapView
{
// THE CODE TO INITIALIZE MKMAPVIEW
}
It is a matter of personal preference/style whether to have a second method -setupMapView or to simply leave the code for setting up the MKMapView in the if (self) block of the -init method or to break the code off into a second method -setupMapView called from -init.
That being said, it sounds like other things may be off with your setup. Your MKMapView should [most likely] be within a UIViewController subclass (which will probably have an associated XIB), so you will be have access to -viewDidLoad. Note that your UIViewController subclass will serve as the delegate to your MKMapView.
Update 1
In your UIViewController subclass instance (I'll assume you called it ViewController, you should have an IBOutlet to an MKMapView object. Do this in ViewController.h either by (1) adding an instance variable
#interface ViewController : UIViewController
{
IBOutlet MKMapView *myMap;
}
#end
or by (2) adding a property
#interface ViewController : UIViewController
#property (nonatomic, strong, readwrite) IBOutlet MKMapView *myMap;
#end
Now open ViewController.xib in Interface Builder. You should have an MKMapView inside the view. If you don't already, add one from the Object Library. Right click on File's Owner. Locate the row with the item myMap. Drag from the circle on the right end of the row to the MKMapView in the visible view.
Your ViewController class now has an outlet to the MKMapView. You will be able to send messages to the MKMapView subview of your view controllers view after it has been loaded.
You should have a property or an instance variable for your SubClass instance so that it doesn't get destroyed as soon as -viewDidLoad returns. Do this again by either adding an instance variable to ViewController.h
#interface ViewController : UIViewController
{
IBOutlet MKMapView *myMap;
SubClass *istance;
}
#end
or by adding a property
#interface ViewController : UIViewController
#property (nonatomic, strong, readwrite) IBOutlet MKMapView *myMap;
#property (nonatomic, strong, readwrite) SubClass *istance;
#end
Now, in ViewController.m, you need to define -viewDidLoad so that self.istance is set as the delegate of self.myMap. In the comments, I had suggested creating your own initializer -initWithMapView:. If you plan on having SubClass do some extensive set-up of your MKMapView, that makes sense. If you just want SubClass to be the delegate of the MKMapView, there's no need for such a method.
Let's consider both cases:
(1) using a method -[SubClass initWithMapView:]:
In ViewController.m you'll have (within the #implementation of ViewController)
- (void)viewDidLoad
{
self.istance = [[SubClass alloc] initWithMapView:self.myMap];
}
In SubClass.h you'll have (within the #interface of SubClass)
- (id)initWithMapView:(MKMapView *)mapView;
#property (nonatomic, weak, readwrite) MKMapView *mapView;
In SubClass.m you'll have (within the #implementation of SubClass)
- (id)initWithMapView:(MKMapView *)mapView
{
self = [super init];
if (self) {
self.mapView = mapView;
self.mapView.delegate = self;
//more setup of mapView.
}
return self;
}
(2) using -[SubClass init]:
Instead, in ViewController.m you'll have
- (void)viewDidLoad
{
self.istance = [[SubClass alloc] init];
self.myMap.delegate = self.istance;
}
I have an NSImageView subclass that I use for dragging and dropping Files onto in my app.
To do this I created a subclass of NSImageView and also dragged the NSImageView onto my XIB, I then set the class of the XIB NSImageView Object to my custom subclass.
Everything works well with the drag and drop and I know I have the correct file after the drag.
The problem comes in when I want to update a textfield on the MainViewController based on the file dragged in.
I created the following subclass and protocol
#import <Cocoa/Cocoa.h>
#import <Quartz/Quartz.h>
#protocol PDFDraggedIntoWell <NSObject>
#required
-(void)PDFDraggedIntoWellWithURL:(NSURL*) importedURL;
#end
#interface DragAndDropImageView : NSImageView
#property (strong) id <PDFDraggedIntoWell> delegate;
#end
Then in my implementation in the subclass I try to call the delegate method
-(void) finishedDragginInFileWithURL:(NSURL*) importedURL{
if( self.delegate != nil && [ self.delegate respondsToSelector: #selector(PDFDraggedIntoWellWithURL:)]) {
[self.delegate performSelector:#selector(PDFDraggedIntoWellWithURL:) withObject:importedURL];
}
}
The problem I run into is how do you assign the delegate. From the XIB NSImageView to my MainviewController I connect up an IBOutlet
#property (weak) IBOutlet DragAndDropImageView *draggedFileImageView;
And I have declared that my ViewController will receive the delegate
#interface MyMainUIViewController ()<PDFDraggedIntoWell>
with the appropriate method implemented
-(void) PDFDraggedIntoWellWithURL:(NSURL *)importedURL{ }
Now I have tried in various places to assign delegate to self (in viewDidLoad - which doesn’t get called since the view is being loaded in a XIB??) and also in
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
but all I get back is the delegate is still nil when debugging.
What am I doing wrong? Thanks for the help!!
If you are using xibx the initWithCoder method is called for initialization. Set your delegate there.
- (id)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
UIView *myView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 10, 10)];
myView.delegate = self;
}
return self;
}
Alternatively set the delegate via interface builder by dragging wile holding ctrl from the File's Owner to your view. Like this:
I was able to add add the delegate to the awakefromnib(in mymainviewcontroller) method and things are working fine now. Thanks
I've only programmed on the iPhone so far, so Cocoa is sort of confusing in certain ways for me. Here's where I've hit a snag. I wanted my window so that the background was invisible, and without a title-bar. Something like this:
Here's how I'm doing it:
I set my window's class to a custom window, which I've created like this:
CustomWindow.h
#import <Foundation/Foundation.h>
#import <Cocoa/Cocoa.h>
#interface CustomWindow : NSWindow {
#private
NSPoint initialLocation;
}
#property(assign)NSPoint initialLocation;
#end
CustomWindow.m
//trimmed to show important part
#import "CustomWindow.h"
#implementation CustomWindow
#synthesize initialLocation;
- (id)initWithContentRect:(NSRect)contentRect styleMask:(NSUInteger)aStyle backing:(NSBackingStoreType)bufferingType defer:(BOOL)flag {
// Removes the window title bar
self = [super initWithContentRect:contentRect styleMask:NSBorderlessWindowMask backing:NSBackingStoreBuffered defer:NO];
if (self != nil) {
[self setAlphaValue:1.0];
[self setOpaque:NO];
}
return self;
}
#end
Now, in my .xib file for this window I've added a custom view onto the window. I've set the view class to a custom class I've created that inherits from NSView. Here's how I'm setting that up:
MainView.h
#import <Cocoa/Cocoa.h>
#interface MainView : NSView {
#private
//nothing to see here, add later
}
#end
MainView.m
//trimmed greatly again to show important part
#import "MainView.h"
#implementation MainView
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
}
return self;
}
- (void)drawRect:(NSRect)rect {
// Clear the drawing rect.
[[NSColor clearColor] set];
NSRectFill([self frame]);
}
#end
So here's my question. I've added a NSImageView to my custom view (MainView) in Interface Builder. However, for some reason I can't figure out how to connect this image view to an instance variable in my custom view. They seem like they can't be connected like I normally would if I was creating an iPhone app. Any ideas how this would be done?
You connect objects created in your XIB in Mac OS X the same way you do for iOS programs. Just add an NSImageView property to your main view, mark it as an IBOutlet and connect it up.
For example,
In MainView.h create a property for your NSImageView and make it an IBOutlet:
#import <Cocoa/Cocoa.h>
#interface MainView : NSView {
NSImageView *imageView;
}
#property(retain) IBOutlet NSImageView *imageView;
#end
In interface builder, make sure the class for the custom view is set to MainView, to do this click on the File's Owner object in the custom view XIB and then select the identity option in the inspector and enter MainView as the class type.
Next, CTRL+click File's owner and drag the arrow to the NSImageView and select the imageView outlet.
That's all there is to it. You should be able to reference the image view from code now.