I subclassed NSFontManager and overrode "modifyFont:(id)sender)
Then I changed the NSFontManager class in my xib files to the new class.
I can see, that the class is initialized, but the overwritten method is never called. Though the NSFontManager method works normal.
What do I wrong?
#import "GFFontManager.h"
#implementation GFFontManager
-(id)init{
if (self = [super init]) {
//this is called
NSLog(#"GFFontManager init");
}
return self;
}
-(void)modifyFont:(id)sender{
//this is never called
NSLog(#"Do something");
[super modifyFont:sender];
}
#end
OK - here is how it works:
I added the following to the main.c and it worked like a charm!
#import <Cocoa/Cocoa.h>
#import "GFFontManager.h"
int main(int argc, char *argv[])
{
[NSFontManager setFontManagerFactory: [GFFontManager class]];
return NSApplicationMain(argc, (const char **) argv);
}
Best regards - Gerald
Related
I'm developing an app in Objective-c for OSX.
I have write a first class and try to call this class in my MainThread.
The build succeed but the app crash
DeviceManager.h
#import <Foundation/Foundation.h>
#interface DeviceManager : NSObject
+(void)DeviceManager:OpenDevice;
#end
DeviceManager.m
#import "DeviceManager.h"
#implementation DeviceManager
- (id)init{
self = [super init];
if(self){
NSLog(#"Init");
}
return self;
}
+ (void)DeviceManager:OpenDevice {
NSLog(#"Opening Device");
}
#end
The main.m is calling it:
#import "DeviceManager.h"
int main(int argc, const char * argv[]) {
[DeviceManager OpenDevice];
return NSApplicationMain(argc, argv);
}
At build, I have Not known class method for selector OpenDevice
Thx
Seb
#import <Foundation/Foundation.h>
#interface DeviceManager : NSObject
+ (void) openDevice;
#end
DeviceManager.m
#import "DeviceManager.h"
#implementation DeviceManager
+ (void) openDevice {
NSLog(#"Opening Device");
}
#end
main.m
#import "DeviceManager.h"
int main(int argc, const char * argv[]) {
[DeviceManager openDevice];
return NSApplicationMain(argc, argv);
}
The above works for me. What does DeviceManager:OpenDevice mean? Because unless it's a new way to define methods it's gibberish. It looks like you want a class method for Device Manager called openDevice... so use + (void) openDevice {...}.
I am learning Objective-C inheritance and my program is getting lost in a recursive loop and won't come out. It gets hung up when calling a getter function.
I am using XCode version: Version 6.2 (6C101)
My program is given below
Vehicle.h
#ifndef exercise_2_Vehicle_h
#define exercise_2_Vehicle_h
#import <Foundation/Foundation.h>
#interface Vehicle : NSObject
#property float speed;
-(void) start;
-(void) stop;
-(void) park;
#end
#endif
Vehicle.m
#import "Vehicle.h"
#implementation Vehicle
-(void) setSpeed:(float)speed {
self.speed = speed;
}
-(float) speed {
return self.speed;
}
-(void) start {
NSLog(#"Starting the vehicle");
}
-(void) stop {
NSLog(#"Stopping the vehicle");
}
-(void) park {
NSLog(#"Parking the vehicle");
}
#end
Car.h
#ifndef exercise_2_Car_h
#define exercise_2_Car_h
#import "Vehicle.h"
#interface Car : Vehicle
#property (nonatomic) NSString* make;
-(Car*) initMake: (NSString*) make;
-(NSString*) make;
#end
#endif
Car.m
#import "Car.h"
#implementation Car
-(Car*) initMake:(NSString *)make {
self = [super init];
if (self) {
self.make = make;
}
return self;
}
-(NSString*) make {
return self.make;
}
#end
main.m
#import <Foundation/Foundation.h>
#import "Car.h"
#import "Vehicle.h"
int main(int argc, const char * argv[]) {
#autoreleasepool {
// insert code here...
Car* car = [[[Car alloc] init] initMake: #"Camry"];
//[car setSpeed:45];
NSLog(#"The model initialized is ");
[car make];
// [car speed];
}
return 0;
}
The issue you have is caused by creating the property for speed:
#property float speed;
and overriding setSpeed: method.
When you create #property compiler adds two methods for you, in your example setSpeed and speed.
This command:
self.speed = speed;
is equal to:
[self setSpeed: speed];
and inside setSpeed you have this command again which cause the loop. In your example you can remove both methods (setSpeed and speed) because compiler will add it for you. If you need it because you want to do some customisation you should use _speed instead self.speed.
_speed is backed variable added by compiler when using #property.
Change your method to:
-(void) setSpeed:(float)speed {
_speed = speed;
}
to remove the infinite loop.
In the
- (NSString*)make;
use
return _make
instead. The same with the speed.
If you return "self.x" in a getter method, then it's going to try and call the method again because you're requesting it on self. XCode will automatically convert the properties into variables that can be accessed with an '_' character, so you don't need to do any extra work.
You could also ignore our advice and remove both the "speed" and "make" getter methods you have made, because XCode automagically creates them for you.
So I am quite new on OC programming, I come from Front-end background (i.e. HTML/CSS/JavaScript ...), so I understand basic concepts of programming :)
Basically I created a console application, with a simple FooClass.
FooClass.h
#import <Foundation/Foundation.h>
#interface FooClass : NSObject
#property (strong, nonatomic) NSString *username;
- (NSString *) username;
- (void) setUsername:(NSString *)username;
#end
FooClass.m
#import "FooClass.h"
#implementation FooClass
#synthesize username = _username;
- (instancetype) init
{
self = [super init];
if (self) {
}
return self;
}
- (NSString *) username
{
return _username;
}
- (void) setUsername:(NSString *)username
{
_username = username;
}
#end
And in the main.m file, where the app bootstraps.
#import <Foundation/Foundation.h>
#include "FooClass.h"
int main(int argc, const char * argv[])
{
#autoreleasepool {
// insert code here...
NSLog(#"Hello, World!");
FooClass *foo = [[FooClass alloc] init];
foo.username = #"a";
}
return 0;
}
XCode tells me that it cannot find property username on object of type FooClass. And I don't really have idea about it. Any one could help?
I am a bit late in posting the answer. Here are few things that you should consider.
Since you have a property username. You are not required to create methods for setters and getters. The compiler will create them for you. Simply remove the two statements.
No need to synthesize in .m as well.
Instead of #include use #import. import takes only one copy even if you try to add the file(s) directly or indirectly from other files as compared to include.
I've dived into learning Objective-C and hit a little snag in when calling a method. Here's my simple code snippets:
Player.h code snippet:
#interface Player : NSObject{
}
-(void) performAction;
-(int) addNumber:(int) a toNumber:(int) b;
#end
Player.m code snippet:
#implementation Player
-(void)performAction{
NSLog(#"Here it is!");
}
-(int)addNumber:(int)a toNumber:(int)b{
return a+b;
}
#end
Calling method from main.m:
int val = [playerOne addNumber:(int)3 toNumber:(int)3];
In the above line of code, i keep getting an 'Expected expression' error.
Any ideas ?
This code works for me.
Player.h
#import <Foundation/Foundation.h>
#interface Player : NSObject
- (void)performAction;
- (int)addNumber:(int)a toNumber:(int)b;
#end
Player.m
#import "Player.h"
#implementation Player
- (void)performAction {
NSLog(#"Here it is!");
}
- (int)addNumber:(int)a toNumber:(int)b {
return a+b;
}
#end
main.m
#import <UIKit/UIKit.h>
#import "AppDelegate.h"
#import "Player.h"
int main(int argc, char *argv[])
{
#autoreleasepool {
Player *playerOne = [Player new];
int val = [playerOne addNumber:(int)3 toNumber:(int)3];
NSLog(#"%d", val);
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
}
}
I want to have an ivar of type Class, and to keep the pointer around after it is passed in. But no matter what I do, arc will not let me do that. For instance, if I declare
#property (nonatomic, strong) Class myClass;
the compiler decides that myClass should be unsafe_unretained. And if I try this:
-(id) initWithClass: (Class) passedInClass {
if ((self = [super init])) {
self.myClass = passedInClass;
}
return self;
}
what happens is that even if the class is non-nil in the calling code, it is nil within the init method.
Short of turning off arc, is there any way to get around this?
EDIT: This question is just wrong. It does work. See the accepted answer.
Works as advertised with Xcode 4.3.2 targeting 10.7 and 5.1:
#interface MOYNObject : NSObject
#property (nonatomic, strong, readwrite) Class myClass;
#end
#implementation MOYNObject
#synthesize myClass;
- (id)initWithClass:(id)pClass
{
self = [super init];
if (self != nil)
self.myClass = pClass;
assert(self.myClass);
CFShow((__bridge const void*)self.myClass);
return self;
}
#end
int main(int argc, const char* argv[]) {
#autoreleasepool {
MOYNObject * o = [[MOYNObject alloc] initWithClass:[NSString class]];
// ...
}
return 0;
}
Are you ahead of or behind 4.3.2?