I show my main window by calling
[window makeKeyAndOrderFront:self];
[NSApp activateIgnoringOtherApps:YES];
[window setIsVisible:YES];
[window display];
which works, but doesn't set the window to the key window right after this calls. I have to wait "some time" until [NSApp keyWindow] returns the actual window.
I'm wondering now, how long does this take and how can I force a window to become the key window immediately?
I think there are probably good reasons that makeKeyAndOrderFront isn't a synchronous call, namely there could be coordination involved with multiple windows and objects that NSApplication need to take care of to make it happen, so forcing window to become key immediately is probably not supported by Cocoa. This however may not be a problem depending on the problem you are trying to solve.
Now, my guess is that some of your methods depend on the window being key, and at the moment they are not happening properly because the window doesn't become key immediately. However, you can implement the NSWindowDelegate protocol, set yourself as window delegate, and override - (void)windowDidBecomeKey:(NSNotification *)notification method to find out when the window did become key. This should also be a global notification in case that works better for you.
For more details, check out apple docs at http://developer.apple.com/library/mac/#documentation/cocoa/reference/NSWindowDelegate_Protocol/Reference/Reference.html
Related
The problem: Attempting to display a window with text from applicationWillFinishLaunching will NOT draw itself if other processor-intensive non-UI code is immediately called.
Background: I have a helper app that when launched may or may not interact with the end user. While it is "deciding" if it needs to put up a window to ask user questions, there may be anywhere from 1 second to 10 seconds that elapse (after launch it's off in non-UI capable library code communicating over the internet).
So I wanted to be kind to the user and put up a "mini-alert"* window with "working, please wait...", prior to heading into that library code, which I will dismiss once that processing has elapsed.
It seems as if the app itself doesn't have time after launch to even draw this mini-alert (it's just an NSWindow, with an NSView, some text, and no buttons).
If after the library code returns and want to put up either an error alert or a query window for the user -- then at that point the mini-alert draws as expected. However, if I close the mini-alert (see below) and then put up an NSAlert -- the mini-alert doesn't have enough time to dismiss itself.
- (void)applicationWillFinishLaunching:(NSNotification *)notification
{
[NSApp activateIgnoringOtherApps:YES];
briefAlertWindowController = [[NSWindowController alloc] initWithWindowNibName:#"BriefAlertWindow"];
[[briefAlertWindowController window] center];
[briefAlertWindowController showWindow:self ];
[[briefAlertWindowController window] orderFront:self ];
[[briefAlertWindowController window] display];
[[briefAlertWindowController window] makeKeyAndOrderFront:nil];
}
and dismissing the mini-alert:
- (void)dismissMiniAlert
{
NSWindow * theWindow = [briefAlertWindowController window];
[theWindow orderOut:nil];
}
NOTE that neither NSWindow not NSWindowController have been derived/subclassed for this mini-alert.
I'm using the term "mini-alert", because I've noticed people get annoyed about the concept of a "splash screen". While the functionality IS similar -- I'm really just trying to let the user know that an unavoidably long operation is taking place.
It sounds like a threading problem. The splash window can't draw itself on the main thread because the main thread is busy doing the processor-intensive operation. Properly, your processor-intensive stuff should all be happening on a background thread. If you can't do that, you need at least to get off the main thread long enough to give the runloop a chance to draw your window. Just introduce a delay.
Apple makes NSTextView respond to page up, page down, arrow keys, etc. automatically, but the home and end keys are not automatically handled by NSTextView out of the box. There's no apparent reason for this; I just logged a Radar on it. Until they fix that Radar, the question is: how do I make my NSTextView handle those keys correctly?
I just spent a little while googling around about this, and didn't find a good modern answer on either SO or elsewhere, so I'm posting my own answer here just for other's reference.
The wrong way to do this is to implement keyDown: and check for the particular keys having been pressed. This circumvents Apple's key-binding mechanism, which as it happens does supply the needed selectors for the concepts of "scroll to beginning" and "scroll to end"; NSTextView just doesn't respond to those selectors.
All you need to do is to add, in your NSTextView subclass, the following:
- (void)scrollToBeginningOfDocument:(id)sender
{
[self scrollRangeToVisible:NSMakeRange(0, 0)];
}
- (void)scrollToEndOfDocument:(id)sender
{
[self scrollRangeToVisible:NSMakeRange([[self string] length], 0)];
}
This hooks up the NSResponder methods for the relevant key bindings to appropriate actions in your NSTextView. These methods on NSResponder appear to have been public since 10.6 or so, and may have actually existed for a while before that, so this solution should be good on all modern systems.
In my MAC app, in one use case, I prompt an window to the user and give him 2 options (say buttons Save and Cancel). I want to force the user to select either of the 2 buttons to close the window.
But currently I find that if the user hits "Command + w" key when window has the focus, the window gets closed. In the .xib resource file, I uncheck the "close" option but that only disables the close option in the window UI.
How do I make sure that my window ignores the "Command+w" key and stays as is without closing.
Have also tried removing the notification by adding below code in awakeFromNib method but did not help.
[[NSNotificationCenter defaultCenter] removeObserver:NSWindowWillCloseNotification ];
Have also tried to implement "windowShouldClose" delegate method and return NO, but this method is never called. The documentation too says that this method is not reliable.
You should use an NSAlert for this sort of prompt, probably run as a sheet on the window. That would avoid the problem of closing it.
In any case, the window's delegate can implement -windowShouldClose: to control if a window is allowed to close. You can make an object (often the window controller) be its delegate by declaring that it adopts the NSWindowDelegate protocol and connecting the window's delegate outlet to that object.
I recently had to solve a similar problem. I'm not sure that this is the 'right' way to do it. But it worked for my purposes, and might work for you.
By default, I think, the 'Close Window' (CMD+W) menu item is bound to the action 'performClose' on first-responder. If you remove this binding and instead bind to a custom IBAction on your application delegate or main window controller, it allows you to conditionally call the close method of the current key-window if it is not matching the instance that you want to keep alive.
#property (strong, nonatomic) MyWindowController *unstoppable;
-(IBAction)killActiveWindow:(id)sender
{
NSWindow *keyWindow = [[NSApplication sharedApplication]keyWindow];
if ([keyWindow isNotEqualTo: unstoppable.window]){
NSLog(#" CMD+W Closing Window %#",keyWindow.title);
[keyWindow close];
}
}
I would like to track each time a certain window appears (becomes visible to the user) in a OS X app. Where would be the most adequate place to call the tracker?
windowWillLoad, maybe?
I expected to find something like windowWillAppear but it seems I'm thinking too much iOS.
How about getting notification such as NSWindowDidBecomeMainNotification, By main I guess the one which is top most on screen directly visible by user.
see : Apple Documentation
Yes, one would expect that a window would notify its delegate or its controller with a windowWillAppear or windowDidAppear message, or post a documented notification like NSWindowDidAppearNotification. But alas, none of those exist. I filed a bug report with Apple and was given the advice to use a storyboard and a view controller instead. This is unhelpful in legacy apps that already use a bunch of window controllers and xibs.
You could subclass NSWindow and override orderWindow:relativeTo: to send a notification. Most, but not quite all, of the messages that make a window show itself ultimately go through this method, including orderBack:, orderFront:, makeKeyAndOrderFront:, and -[NSWindowController showWindow:]. But orderFrontRegardless does not go through orderWindow:relativeTo:, so you would also want to override that for completeness.
Another way to be notified is to make a subclass of NSViewController that controls some view that's always visible in the window. The view controller will receive viewWillAppear and viewDidAppear.
If you're subclassing NSWindow or NSViewController already for some other reason, either of these is a reasonable solution.
If you're not subclassing NSWindow already, and don't have an NSViewController subclass for a view that's always visible in the window, then another way is to use Cocoa bindings to connect the window's visible binding to a property one of your objects. For example, I have a custom NSWindowController subclass. I gave it a windowIsVisible property:
#interface MyWindowController ()
#property (nonatomic) BOOL windowIsVisible;
#end
and I implemented the accessors like this:
- (BOOL)windowIsVisible { return self.window.visible; }
- (void)setWindowIsVisible:(BOOL)windowIsVisible {
NSLog(#"window %# became %s", self.window, windowIsVisible ? "visible" : "hidden");
}
and in awakeFromNib, I bind the window's visible binding to the property like this:
- (void)awakeFromNib {
[super awakeFromNib];
[self.window bind:NSVisibleBinding toObject:self withKeyPath:NSStringFromSelector(#selector(windowIsVisible)) options:nil];
}
When the window becomes visible, the setWindowIsVisible: setter is called with an argument of YES. Note that if the whole app is hidden and reappears, the setter is called again, even though it wasn't called with argument NO when the app was hidden. So be careful not to assume the window was previously hidden.
Also, the binding might create a retain cycle, so you should probably unbind it when the window is closed, unless you want to keep the window and controller around. Note that the window does post NSWindowWillCloseNotification when it's closing, so you don't need any special magic to detect that.
I have a NSWindow that hosts a WebView that Ive hooked up to a script handler.
Now, when the user clicks a button on a control on the WebView it calls a Objective C method on my object.
In this specific case, the action of the button is to try and close the window hosting the WebView
[[webView window] close];
This usually works, but sometimes i get a SEGFAULT or some other access violation as a result of the event loop trying to dispatcha mouse message to the now destroyed view.
The callstack is horrible when I try to close the window, the even loop has called the window has called the webView, has called my script delegate when I try and close the window. Destruction of an object from a callback from that object is generally, well, dangerous, but I can't figure out how windows should safely be closed as a result of users interacting with views on them.
Istead of closing, can't you try out the API
- (void)orderOut:(id)sender
just check whether your window is visible and orderout that window
if([[webView window] isVisible])
[[webView window] orderOut:self];
The callstack is horrible when I try to close the window, the even loop has called the window has called the webView, has called my script delegate when I try and close the window. Destruction of an object from a callback from that object is generally, well, dangerous, but I can't figure out how windows should safely be closed as a result of users interacting with views on them.
You can use performSelector:withObject:afterDelay: to put off closing the window until 0.0 seconds after the button hit.
In this specific case, the action of the button is to try and close the window hosting the WebView
[[webView window] close];
This usually works, but sometimes i get a SEGFAULT or some other access violation as a result of the event loop trying to dispatcha mouse message to the now destroyed view.
That's not likely. The event loop will only dispatch an event for a window that exists; if you have closed and thereby destroyed a window, no event can arrive at that window, nor at any view that may once have been in it.
It would help if you would edit your question to include the stack trace for that crash.
I know this is an old question, but I'm having a similar issue and I suspect the accepted answer is missing the point. I believe the window hosting the WebView is still one or more of the delegates of the WebView, and delegate methods are being called after the WebView finishes loading, which is after the window is closed.
I was looking for the right way to resolve this… I'll keep looking. :-)