I think this should be quite simple, but I cannot make it work.
I want to detect mouse clicks on a WebView...
I've subclassed WebView, here is the code
#import <AppKit/AppKit.h>
#import <Foundation/Foundation.h>
#import <WebKit/WebKit.h>
#interface ResultsWebView : WebView {
}
#end
and
#import "ResultsWebView.h"
#implementation ResultsWebView
- (void)mouseDown:(NSEvent *)theEvent {
NSLog(#"%#", theEvent);
}
#end
In my xib file, I added a WebView and then changed the class to ResultsWebView.
I've checked in runtime and the object is a ResultsWebView, but the mouseDown event is never called...
What am I missing?
WebUIDelegate comes into rescue.
Supposing that you have a WebView instance in your NSWindowController:
WebView *aWebView;
You can set your controller as UIDelegate, as follow:
[aWebView setUIDelegate:self];
implementing the following method within your controller, you will have a form of control over mouse click events:
- (void)webView:(WebView *)sender mouseDidMoveOverElement:
(NSDictionary *)elementInformation modifierFlags:(NSUInteger)
modifierFlags
{
if ([[NSApp currentEvent] type] == NSLeftMouseUp)
NSLog(#"mouseDown event occurred");
}
as a bonus, playing with the elementInformation dictionary you can get additional informations about the DOM element in which click event occurred.
The problem is that the message isn't being sent to the WebView. Instead it is being sent to the private WebHTMLView inside your WebView, which actually processes the mouse events.
http://trac.webkit.org/browser/trunk/Source/WebKit/mac/WebView/WebHTMLView.mm#L3555
You might just want to look into using javascript in your WebView to send the onmousedown events back to your objective-c class.
Maybe this helps:
[window setAcceptsMouseMovedEvents:YES];
Related
I have the problem that touchesEnded (on iOS) or mouseUp (on macOS) is still called on released objects when the touch/click was started before the release. This behavior is causing crashes in my project. I made a stripped down program with SceneKit and a SpriteKit overlay but I am not sure what I am doing wrong.
I've started with the SceneKit game template (iOS or macOS) and I've added two classes:
In GameViewController.m at the end of -(void)awakeFromNib I added this:
OverlayScene *overlay=[OverlayScene sceneWithSize:self.gameView.frame.size];// init the overlay
[overlay setupButtons];// create a small GUI menu
[self.gameView setOverlaySKScene:overlay];// add the overlay to the SceneKit view
Then the two classes
OverlayScene.m:
#import <SpriteKit/SpriteKit.h>
#import "Button.h"
#interface OverlayScene : SKScene
-(void)setupButtons;
#end
OverlayScene.m:
#import "OverlayScene.h"
#implementation OverlayScene
-(void)setupButtons{//showing a menu mockup
NSLog(#"setupButtons");
srand((unsigned)time(NULL));// seed the RNG
[self removeAllChildren];//remove all GUI element (only one button or nothing (in the first call)
Button *b=[[Button alloc] initWithSelector:#selector(setupButtons) onObject:self];// a new button
b.position=CGPointMake(rand()%300, rand()%300);// just a random position so we can see the change
[self addChild:b];// finally attach the button to the scene
}
#end
Button.h:
#import <SpriteKit/SpriteKit.h>
#interface Button : SKSpriteNode{
SEL selector;//the method which is supposed to be called by the button
__weak id selectorObj;//the object on which the selector is called
}
-(id)initWithSelector:(SEL)s onObject:(__weak id)o;
#end
Button.m:
#import "Button.h"
#implementation Button
-(id)initWithSelector:(SEL)s onObject:(__weak id)o{
//self=[super initWithColor:[UIColor purpleColor] size:CGSizeMake(200, 60)];//this is the code for iOS
self=[super initWithColor:[NSColor purpleColor] size:CGSizeMake(200, 60)];// this is for macOS
selector=s;//keep the selector with the button
selectorObj=o;
[self setUserInteractionEnabled:YES];//enable touch handling
return self;
}
//-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{//called on iOS
-(void)mouseDown:(NSEvent *)event{//called on macOS
[selectorObj performSelector:selector];//we are calling the method which was given during the button initialization
}
#end
When you click on the button it gets removed (and dealloced by arc) as expected and a new one is created. Everything is fine as long as you keep holding down the mouse button. When you release it the app crashes because that mouseUp event is sent to the removed button:
I'm going through this book called "cocoa programming for mac os x" and I just started with delegates. This whole thing with delegates is still a little bit wacky to me but I think I just need to let it settle.
However there was this one exercise where I should implement a delegate of the main window so that if resized height is always 2xwidth.
So I got 4 files:
AppDelegate.h
AppDelegate.m
WindowDelegate.h
WindowDelegate.m
AppDelegate are just the two standard files that get created when you open a new Cocoa project. I had to look up the solution because I didn't quite know how to accomplish this task.
The solution was just to create a new cocoa class, "WindowDelegat.h/.m" and add this to it's implementation file:
- (NSSize)windowWillResize:(NSWindow *)sender toSize:(NSSize)frameSize {
NSSize newSize = frameSize;
newSize.height = newSize.width * 2;
return newSize;
}
Then I opened the interface builder, added a new object and made it my WindowDelegate. I then had to ctrl drag from the WindowDelegate to the actual window and made it the window's delegate.
Clicked run and it worked. Yay! But why?
First I thought that "windowWillResize" is just one of these callback functions that get's called as soon as the window is resized but it isn't. Normally methods get invoked because the general lifecycle of an program invokes them or because they are an #IBAction, a button or different control elements.
But "windowWillResize" is non of them. So why is it called?
EDIT: Problem solved! Thanks a lot!
Now I'm trying to connect the delegate to the window programmatically. Therefore I deleted the referencing outlet from WindowDelegate to the actual window in interface builder. It works but I just want to verify that this it the correct way how it's done:
AppDelegate.h
#import <Cocoa/Cocoa.h>
#import "WindowDelegate.h"
#interface AppDelegate : NSObject <NSApplicationDelegate>
#end
AppDelegate.m
#import "AppDelegate.h"
#interface AppDelegate ()
#property (weak) IBOutlet NSWindow *window;
#property (strong) WindowDelegate *winDeleg;
#end
#implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
}
- (void)applicationWillTerminate:(NSNotification *)aNotification {
// Insert code here to tear down your application
}
- (void)awakeFromNib {
[_window setOpaque:NO];
NSColor *transparentColor = [NSColor colorWithDeviceRed:0.0 green:0.0 blue:0.0 alpha:0.5];
[_window setBackgroundColor:transparentColor];
NSSize initialSize = NSMakeSize(100, 200);
[_window setContentSize:initialSize];
_winDeleg = [[WindowDelegate alloc] init];
[_window setDelegate: _winDeleg];
}
#end
WindowDelegate.h
#import <Foundation/Foundation.h>
#import <Cocoa/Cocoa.h>
#interface WindowDelegate : NSObject <NSWindowDelegate>
#end
WindowDelegate.m
#import "WindowDelegate.h"
#implementation WindowDelegate
- (NSSize)windowWillResize:(NSWindow *)sender toSize:(NSSize)frameSize {
NSSize newSize = frameSize;
newSize.height = newSize.width * 2;
return newSize;
}
- (id)init {
self = [super init];
return self;
}
#end
Why does the #property of WindowDelegate need to be strong?
And isn't my winDeleg an object? Why do I have to access it through _winDeleg when it's an object. I though the underscore is used to access variables?
Thank you for your help!
Clicked run and it worked. Yay! But why?
Because instances of NSWindow have a delegate property that can point to any object that implements the NSWindowDelegate protocol, and that protocol includes the -windowWillResize:toSize: method.
Read that a few times. The reason it's important is that you can create your own object, say that it implements NSWindowDelegate, implement -windowWillResize:toSize:, and set that object as your window's delegate. Then, whenever the user resizes the window, your method will be called and can modify the proposed new size.
Normally methods get invoked because the general lifecycle of an program invokes them or because they are an #IBAction, a button or different control elements. But "windowWillResize" is non of them. So why is it called?
This really isn't so different. Think of delegates as "helper objects." They let you customize the behavior of an object without having to create a whole new subclass. The NSWindowDelegate object is essentially a contract that the NSWindow promises to follow: whenever certain things happen, such as the user resizing the window, the window will call certain methods in its delegate object, if the delegate exists and implements those methods. In the case of NSApplication, a lot of those delegate methods are application lifecycle events, like the app starting up or quitting or getting a message from the operating system. In the case of NSWindow, delegate methods correspond to interesting events that can happen to a window, like the user moving it, hiding it, showing it, maximizing it, moving it to a different screen, etc. Other classes, like text views or network connections or movie players, have their own sets of interesting events and their own delegate protocols to match.
Note that methods marked IBAction really aren't delegate methods, they're just methods that get called by objects like controls that use a target/action paradigm. The IBAction keyword lets the IDE know which methods it should present as possible actions for things like buttons. You often find actions in window controllers and view controllers, and those objects frequently act as a delegate for some other object, but the actions themselves aren't part of the delegate protocol. For example, NSTableView takes a delegate object that determines how the table will act and what's displayed in it. It often makes sense for the view controller that manages the table to be the table's delegate, and that same view controller might also manage some buttons and contain the action methods that said buttons trigger, but the actions aren't part of the NSTableViewDelegate protocol and you therefore wouldn't call them delegate methods.
I did find an answer to this title and I did do a little research but I'm still not getting the flow. Here is what I want to happen:
1) click a button on the presenter view to open a modal view. 2) retrieve some value and click a button to close the modal view....sending the value to the presentor view and execute a method.
I get that this works like a callback but I still can't figure out where to put the callback stuff.
So, how exactly do I do this? A) In the presentViewController completion block, should I include the presenter view method to execute when modal view is completed?
Or: B) In the modal view's dismissViewControllerAnimated completion block, should I include the presenter view method to execute when modal view is completed?
Can somebody help me with some sample code? Or at least help me get the flow of which block to put the code in?
Thank you, P
You talk about completion blocks so I am assuming you do not want to use delegates.
In the viewController that will be presented modally you need to provide a public completion handler, that will be called when it is dismissed.
#interface PresentedViewController : UIViewController
#property (nonatomic, strong) void (^onCompletion)(id result);
#end
Then in the implementation you need to call this completion block on dismissal. Here I assume the viewController is dismissed on a button click
- (IBAction)done:(id)sender
{
if (self.onCompletion) {
self.onCompletion(self.someRetrievedValue);
}
}
Now back in the viewController that presented the modal you need to provide the actual completion block - normally when you create the viewController
- (IBAction)showModal;
{
PresentedViewController *controller = [[PresentedViewController alloc] init];
controller.onCompletion = ^(id result) {
[self doSomethingWithTheResult:result]
[self dismissViewControllerAnimated:YES completion:nil];
}
[self presentViewController:controller animated:YES completion:nil];
}
This will create the new viewController to be presented modally and define what needs to happen on completion.
You can do this with delegates, that's the way Apple seems to recommend, but that seems like overkill to me. You have a reference to the presenter with the presentingViewController property, so you can just set the value of a property in the presenter from the presented controller in the button click method:
self.presentingViewController.someProp = self.theValueToPass;
[self dismissViewControllerAnimated:YES];
Using delegates is a good way to handle this:
In your PresentedViewController.h
#protocol PresentedViewControllerDelegate <NSObject>
-(void) viewWillDismiss;
#end
#property (nonatomic, weak) id <PresentedViewController> delegate;
Then in your PresentingViewController.h, you would subscribe to this delegate
#interface PresentingViewController : UIViewController <PresentedViewControllerDelegate>
in the .m you must implement the delegate method
- (void) viewWillDismiss {
}
and before you present the view controller set the delegate property you made as self.
presentingViewController.delegate = self;
Obviously not every implementation detail has been done here, but this should get you started.
How do I handle a mousedown event inside a window in Cocoa?
My code:
-(void)mouseDown:(NSEvent *)event {
NSLog(#"yay");
}
I am using Mac OS10.6, in xcode 4.0.1.
EDIT:
Yes, this is in the app delegate, but this is my .h:
#interface jumperAppDelegate : NSWindow {
Which I have done before in app delegates (just not for mouse events). This is really annoying me
Make sure you inherit from NSWindow, as well as conform to the <NSWindowDelegate> protocol. Like this:
#interface YourWindow : NSWindow <NSWindowDelegate> {}
#end
Then you should receive the event notification.
-(void)mouseDown:(NSEvent *)event {
}
For this method to be called the class it is being called in needs to inherit from NSResponder. Windows and views are all subclasses of NSResponder. If the class you are calling this from is not a subclass of NSResponder then the method will not fire.
* Update *
Also be sure to override acceptsFirstResponder to return yes.
- (BOOL)acceptsFirstResponder {
return YES;
}
I don't know for sure, but I have heard that in your header file (.h) that you need to replace the "NSObject" with "NSWindow". I would test it but I am not at my computer right now.
Also, make sure that you put the following code into your header file:
- (void) mouseDown:(NSEvent*)event;
EDIT: I have done some tests and research, but I cannot get it to work. I have two tips though.
Use the '-acceptsFirstMouse method.
Try creating an NSEvent:
NSEvent * someEvent;
-(void)mouseDown:(NSEvent*)someEvent;
This probably won't work, but I will have more information tomarrow
I know this question has been asked several times and I did read existing posts on this topic but I still need help.
I have 2 UIViewControllers - parent and child. I display the child UIViewController using the presentModalViewController as below:
ChildController *child =
[[ChildController alloc] initWithNibName:#"ChildView" bundle:nil];
[self presentModalViewController:child animated:YES];
[child release];
The child view has a UIPickerView. When user selects an item from UIPickerView and clicks done, I have to dismiss the modal view and display the selected item on a UITextField in the parent view.
In child's button click delegate, I do the following:
ParentController *parent =
(ParentController *)[self.navigationController parentViewController];
[parent.myTextField setText:selectedText];
[self dismissModalViewControllerAnimated:YES];
Everything works without errors. But I don't know how to load the parent view so that it displays the updated UITextField.
I tried
[parent reloadInputViews];
doesn' work. Please help.
Delegation is the way to go. I know some people that may be looking for an easier solution but trust me I have tried others and nothing works better than delegation. So anyone having the same problem, go read up on delegation and follow it step by step.
In your subviewcontroller.h - declare a protocol and declare delegate mthods in it.
#protocol myDelegate
-(void)clickedButton:(subviewcontroller *)subController;
#end
In your subviewcontroller.h, within #interface:
id<myDelegate> delegate;
#property (nonatomic, assign) id<myDelegate> delegate;
NSString *data;
-(NSString *)getData;
In your subviewcontroller.m, synthesize myDelegate. Add the following code to where you want to notify your parentviewcontroller that the subview is done doing whatever it is supposed to do:
[delegate clickedButton:self];
and then handle getData to return whatever data you want to send to your parentviewcontroller
In your parentviewcontroller.h, import subviewcontroller.h and use it's delegate
#import "subviewcontroller.h"
#interface parentviewcontroller : VUIViewController <myDelegate>
{}
In your parentviewcontroller.m, implement the delegate method
- (void)clickedButton:(subviewcontroller *)subcontroller
{
NSString *myData = [subcontroller getData];
[self dimissModalViewControllerAnimated:YES];
[self reloadInputViews];
}
Don't forget memory management!
If a low-memory warning comes in during your modal view's display, the parent's view will be unloaded. Then parent.myTextField is no longer referring to the right text field until the view is reloaded. You can force a reload of the view just by calling parent.view;
However, a better idea might be to have the parent view have a String property that can be set by the child view. Then, when the parent view reappears, put that data into the text field, inside viewWillAppear: for example. You'd want to have the value set to some default value for when the parent view initially shows up too.
-(void) viewWillAppear:(BOOL) animated doesn't get called for me either, exactly when it's a modal view controller. No idea why. Not incorrectly overridden anywhere in this app, and the same problem occurs on the other 2 apps I'm working on. I really don't think it works.
I've used the delegate approach before, but I think that following approach is pretty good as well.
I work around this by adding a private category to UIViewController, like so:
.h file:
#interface UIViewController(Extras)
// returns true if this view was presented via presentModalViewController:animated:, false otherwise.
#property(readonly) BOOL isModal;
// Just like the regular dismissModalViewController, but actually calls viewWillAppear: on the parent, which hasn't been working for me, ever, for modal dialogs.
- (void)dismissModal: (BOOL) animated;
#end
and .m file:
#implementation UIView(Extras)
-(BOOL) isModal
{
return self == self.parentViewController.modalViewController;
}
- (void)dismissModal: (BOOL) animated
{
[self.parentViewController viewWillAppear: animated];
[self dismissModalViewControllerAnimated: animated];
}
#end
which I can now call like this when I want to dismiss the dialog box:
// If presented as a modal view, dismiss yourself.
if(self.isModal)
[self dismissModal: YES];
and now viewWillAppear is correctly called.
And yes, I'm donating a bonus 'isModal' property, so that the modal view can tell how it was being presented, and dismiss itself appropriately.