I am beginner of iPhone. I want to play two sound one by one. one stop and then second play.only one button click event play two sound one by one and using singleton object. give any source code and suggestion which apply in my apps...
You can use the delegate method
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag, which belongs to the protocol AVAudioPlayerDelegate.
You can read about it here.
Related
I'm using addGlobalMonitorForEventsMatchingMask to listen to events in Cocoa:
[NSEvent addGlobalMonitorForEventsMatchingMask:NSLeftMouseDraggedMask
handler:^(NSEvent *event) {
NSLog(#"Dragged...");
}];
Though I would like to know if I'm dragging/moving a window (and which window that is, I can find the focused window though when holding command and dragging a window it doesn't get focus as far as I know.)
So, can I detect whether or not I'm dragging a window?
Update:
I now have a class: "SATest : NSObject <NSWindowDelegate>" in which I implement the windowDidMove method (and later perhaps windowWillMove too.) Though, now the next step would be attaching this to a window, right? So my question now is: How do I attach the delegate to all windows of all apps?
Update 2:
I now can find a list of all open windows on the screen:
AXUIElementRef _systemWideElement;
_systemWideElement = AXUIElementCreateSystemWide();
CFArrayRef _windows;
AXUIElementCopyAttributeValues(_systemWideElement, kAXWindowsAttribute, 0, 100, &_windows);
Now I have to iterate over the windows, and of each get it's NSWindow so I can add my delegate to it: [window setDelegate:self];
Update 3: To be clear, this question is about detecting the dragging of ALL windows of ALL apps. Not only the windows of my own app.
Also, I'm very new to this event and window management stuff, so no need to keep your answer short I'm happy to read a lot :P
Thanks!
-P
To find out if a window is being dragged you need to have an object that acts as the delegate of the window by responding to the following messages of the NSWindowDelegate protocol:
windowWillMove - this tells the delegate that the window is about to move.
windowDidMove - this tells the delegate that the window has moved.
You can retrieve the NSWindow object in question by sending object to the notification parameter sent to these methods:
e.g.
NSWindow draggedWindow = [notification object];
More information can be found here.
Update:
In response to your request about getting this information for all windows the NSApplication class provides a method which returns an array of all windows owned by the application. The typical way of getting this information is to use one of the NSApplicationDelegate methods to get a reference to your application object.
For example, in your app delegate (pseudocode):
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
NSApplication * app = [aNotification object];
// you now have a reference to your application.
// and can iterate over the collection of windows and call
// [window setDelegate:self]; for each window.
}
Note that you will need to add / remove you delegates as windows are added and removed. The best method for doing this is – applicationDidUpdate:.
This should be enough to get you started solving your problem.
As suggested by Benjamin the answer lies in the accessibility API. I was looking around in this for a while, even before I asked this question, but never got it to do what I wanted. I now have found a pretty nice solution.
At a high-level I do the following:
Listen to the mouse down event and remember both on which window you clicked and it's location.
Listen to the mouse up event and check if the location has changed, if so you know you moved a window
You can do something similar for the size if you also want to know if you resized. There might be a better solution, but after days of trying stuff this is the only way I got it to work the way I wanted.
Hope this helps anyone who was looking for something similar.
-Pablo
i have been working on moving one of my apps away from the "shared appdelegate" process which seems to be frowned up, despite its over whelming use. i have been attempting to setup protocol methods for what i want to do but am having zero luck. my question is, can you even have lets say a single viewcontroller send delegate requests to multiple classes? from what im finding out it doesn't seem like you can. which doesn't make sense because i thought that was the whole point of delegates and protocols with mvc. now just to clarify, i know you can have a single viewcontroller act as the delegate for multiple other viewcontrollers. but that's not what i am asking. for a simple example, lets say you have apples flip-utility template. the "done" button just calls a delegate method to the mainvc to dismiss it. now lets say we added a new class called...
#interface NewClass : NSObject <TheOtherDelegate>
and it had a delegate method...
- (void)doSomething
{
NSLog(#"The Delegate did something...");
}
can we have a button on the flipsideviewcontroller, that we wanted to call that delegate method, but still keep the "done" button call to the delegate method on the mainviewcontroller that dismisses it?
that being said, i put together a quicky project just to see if it would work and it doesn't. i came across an "answer" that says you have to instantiate the class first you want to be the delegate...
NewClass *myDelegate = [NewClass alloc] init]
[fillInMethodHere setDelegate:myDelegate];
not sure why it got a correct answer check, because needless to say it doesn't work. is there something i am missing? i scoured ib to see if there is some "delegate" connection somewhere but i couldn't find anything.
on a side note, as i was working in my working project, i read a suggestion about removing the #import and adding #class. again, that broke all kinds of things. the strange thing is before doing that, what i had so far was working and building fine. when i removed the new #class and un-commented the #import. xcode all of a sudden gave me an error "cannot find protocol deceleration for..." but yet, it worked seconds earlier. i would up having to remove the protocol code and re-add it for it to work again. very starge.
any help would be appreciated. everything iv read in docs, google, stack, etc that say something should work, don't in an actual project.
A "delegate" isn't some fancy object. It's simply a synthesized property of type id called delegate. If you wanted to, you could have an arbitrary number of properties that all conformed to the same protocol. Then when you wanted to issue a callback, you would just address all of them:
[self.mydelegateA doSomething];
[self.mydelegateB doSomething];
etc.
You could also have an NSMutableArray property that you could add objects to, and then use [self.myMutableArrayOfDelegates makeObjectsPerformSelector:#selector(doSomething)].
Finally, there's always the route of NSNotificationCenter (not to be confused with push notifications) is a class that provides an inter-object messaging system. Many objects can register for a message that any other object can send.
Please see the Apple's documentation for more information. Click Here.
Regardless of the fact that this is OS X documentation, it's still quite good at explaining things visually: click here.
Here's an example of simply changing the name of the delegate property: click here
And here's an example of adding another protocol and a second delegate: click here
Finally, here's an example that builds on the previous two and has a third delegate that also conforms to the same protocol: click here
I use sharekit with mail/twitter/facebook and I am really new to objective-c. sharekit works well and sends my images like it should.
in my app I have a screenshot function. I want the app to 'freeze' when a screenshot is taken, stopping to send any shake- or touch-event to the scene behind the sharekit-action.
in my screenshot-layer I have three buttons which call the shareItem-methods of their specified service, like
[SHKTwitter shareItem:item];
vereything works fine 'till here. but now when the sending is finished (or canceled or errored) I need the app to 'unfreeze', sharekit should tell my app that it is allowed to listen to any touch- or shake-action again.
I am sorry but I think I don't understand the concept of using the delegate here. I mean, is 'sendDidFinish' meant to be inside a delegate? and if so, how could I tell sharekit who is its delegate? or do I have to edit the send-service classes (like SHKItem or SHKFacebook) itself?
please don't downrate me for this question. I really want to get behind this mystery...
SHKTwitter inherit from SHKOAuthSharer, who inherit from SHKSharer. SHKSharer has a delegate protocol called "SharerDelegate".
So you can use an instance of SHKTwitter, then set it's delegate as :
shkTwitterInstance.shareDelegate = yourDelegateObject.
And implement the delegate method
- (void)sharerFinishedSending:(SHKSharer *)sharer;.
Try that.
EDIT (OTHER, AND MORE POPULAR, SOLUTION)
Also, you can suscribe your object to "SHKSendDidFinish" notification from SHKTwitter object.
[[NSNotificationCenter defaultCenter] addObserver:yourObject selector:#selector(theMethodthatYouWantToExecuteWhenTheNotificationIsRaised:) name:#"SHKSendDidFinish" object:shkTwitterObject];
In my app, every time a user switches to a new view a sound will be played. Also, every time a button is tapped, a sound will be played.
The sounds to be played are the same for each case, so for example, sound.caf will be used many times and will be the same for every view.
My problem is that I cant think of a clever place to alloc these sounds, thats visible to all views. Is this possible? I dont want to alloc the sound everytime a view is created because I think it's a waste of time.
Is there someplace where I can alloc these sounds, and play them from any view in my program? Thanks!
The simplest solution would probably be to use the app delegate for that purpose because it's a singleton class (there is only one instance of it per application) and it can be accessed by any class easily: [UIApplication sharedApplication].delegate
You could set up the sound(s) in the applicationDidFinishLaunching: method so they're ready to go when your app is.
I'm slowly learning Objective-C and Cocoa, and the only way I see so far to capture key events in Text Views is to use delegation, but I'm having trouble finding useful documentation and examples on how to implement such a solution. Can anyone point me in the right direction or supply some first-hand help?
Generally, the way you implement it is simply to add the required function to your view's controller, and set its delegate. For example, if you want code to run when the view loads, you just delegate your view to the controller, and implement the awakeFromNib function.
So, to detect a key press in a text view, make sure your controller is the text view's delegate, and then implement this:
- (void)keyUp:(NSEvent *)theEvent
Note that this is an inherited NSResponder method, not a NSTextView method.
Just a tip for syntax highlighting:
Don't highlight the whole text view at once - it's very slow. Also don't highlight the last edited text using -editedRange - it's very slow too if the user pastes a large body of text into the text view.
Instead you need to highlight the visible text which is done like this:
NSRect visibleRect = [[[textView enclosingScrollView] contentView] documentVisibleRect];
NSRange visibleRange = [[textView layoutManager] glyphRangeForBoundingRect:visibleRect inTextContainer:[textView textContainer]];
Then you feed visibleRange to your highlighting code.
It's important to tell us what you're really trying to accomplish — the higher-level goal that you think capturing key events in an NSTextView will address.
For example, when someone asks me how to capture key events in an NSTextField what they really want to know is how to validate input in the field. That's done by setting the field's formatter to an instance of NSFormatter (whether one of the formatters included in Cocoa or a custom one), not by processing keystrokes directly.
So given that example, what are you really trying to accomplish?
I've done some hard digging, and I did find an answer to my own question. I'll get at it below, but thanks to the two fellas who replied. I think that Stack Overflow is a fantastic site already--I hope more Mac developers find their way in once the beta is over--this could be a great resource for other developers looking to transition to the platform.
So, I did, as suggested by Danny, find my answer in delegation. What I didn't understand from Danny's post was that there are a set of delegate-enabled methods in the delegating object, and that the delegate must implement said events. And so for a TextView, I was able to find the method textDidChange, which accomplished what I wanted in an even better way than simply capturing key presses would have done. So if I implement this in my controller:
- (void)textDidChange:(NSNotification *)aNotification;
I can respond to the text being edited. There are, of course, other methods available, and I'm excited to play with them, because I know I'll learn a whole lot as I do. Thanks again, guys.