I'm invoking a NSOpenPanel from a thread created by boost C++.
the panel behaves erratically and doesn't respond well to mouse, that is clicking on objects does nothing sometime when clicking on top level combo box does improve response.
do i've to run a separate runloop I'm doing a runModalForDirectory which should take care of running its own loop.
I've also created a separate objc class which does performSelectorOnMainThread to show panel in main thread but still the behavior is same.
[ps performSelectorOnMainThread:#selector(showOpenPanel) withObject:nil
waitUntilDone:YES
modes:[NSArray arrayWithObject:NSRunLoopCommonModes]];
I've also tried with waitUntilDone:NO and running a CFRunLoopRunInMode which isn't helping either.
- (bool) showOpenPanel
{
NSOpenPanel *op = [NSOpenPanel openPanel];
[op setAllowsMultipleSelection:YES];
[op setTitle:#"Choose File"];
[op setMessage:#"Choose file for Importing."];
[op setFloatingPanel:true];
bool result =[op runModalForDirectory:NSHomeDirectory() file:nil types:self.fileTypes];
if (result == NSOKButton) {
[self setSelectedFiles:[op filenames]];
[self setLastShowResult:true];
}
else {
[self setLastShowResult:false];
}
[self setPanelIsDone:true];
return self.lastShowResult;
}
NSOpenPanel is part of AppKit. AppKit functions and classes can only be safely used on the main thread.
Show us the code you used with performSelectorOnMainThread so we can help figure out why you might still be seeing problems. I suspect you're calling individual methods with it--don't; it won't work the way you expect. Call back to the main thread for the totality of your interaction with NSOpenPanel.
Related
We are building a content editor that brings up a "cocos Player" in an NSWindow for test purposes. The user can test some content and then close the window.
So I need to be able to shutdown cocos and re-start within the same app.
Everything is working if I use the CC_MAC_USE_DISPLAY_LINK_THREAD threading model. I had to make a fix in CCDirectorMac to get this working. In CCDirectorMac | stopAnimation I had to set the _runningThread to nil since it is not set to nil by the #if and #elif when using CC_MAC_USE_DISPLAY_LINK_THREAD.
Anyway so now I am able to "end" a director and then re-start it later with no issues.
My question though is this: If I am building an AppKit editor with occasional use of cocos2D whould my threading model really be CC_MAC_USE_MAIN_THREAD as is suggested in the documentation?
When I do use CC_MAC_USE_MAIN_THREAD I get a HANG in in stopAnimation on the line:
CVDisplayLinkStop(displayLink);
I think the main thread would be fine and would avoid threading issues for our tool. Performance is not a concern. I can't find any sample code that shuts down and restarts cocos2d in an NSWindow ... so my assumption here is that I am in untested waters (or little tested waters).
My steps to shutdown/restart are:
Call [[CCDirector sharedDirector] end]
This calls stopAnimation
Then re-initialize cocos2d the same way I did originally
Any advice on threading models for a Mac desktop app ... and why CVDisplayLinkStop hangs would be greatly appreciated.
Thanks in advance.
Ok, I figured it out after reading this post and its answers on the Apple mailing list: http://lists.apple.com/archives/quartz-dev/2006/Oct/msg00056.html
When using CC_MAC_USE_MAIN_THREAD, the display link thread uses performSelector:onThread:waitUntilDone: to run drawScene: on the main thread. It passes YES for the waitUntilDone: parameter, so the display link thread blocks until the main thread can process the drawScene: call.
Here's the relevant fragment of the cocos2d code. MyDisplayLinkCallback is called on the display link thread.
static CVReturn MyDisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeStamp* now, const CVTimeStamp* outputTime, CVOptionFlags flagsIn, CVOptionFlags* flagsOut, void* displayLinkContext)
{
CVReturn result = [(CCDirectorDisplayLink*)displayLinkContext getFrameForTime:outputTime];
return result;
}
- (CVReturn) getFrameForTime:(const CVTimeStamp*)outputTime
{
#if (CC_DIRECTOR_MAC_THREAD == CC_MAC_USE_DISPLAY_LINK_THREAD)
...
#else
// Display link thread blocks here:
[self performSelector:#selector(drawScene) onThread:_runningThread withObject:nil waitUntilDone:YES];
#endif
return kCVReturnSuccess;
}
The problem appears when the main thread tries to run CVDisplayLinkStop() which blocks until the display link callback in the display link thread finishes. Since the callback is at the same time waiting for the main thread to process its drawScene: call, both threads become deadlocked.
- (void) stopAnimation
{
...
if( displayLink ) {
// Main thread blocks here:
CVDisplayLinkStop(displayLink);
...
}
So, now for my workaround. I added a line to run the main thread's runloop in order to force the drawScene: call to be executed, which unblocks the display link thread. That way, when you call CVDisplayLinkStop() you're safe. Here's my addition (CCDirectorMac.m line 473 in cocos2d 2.1 release):
- (void) stopAnimation
{
...
if( displayLink ) {
#if (CC_DIRECTOR_MAC_THREAD != CC_MAC_USE_DISPLAY_LINK_THREAD)
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
#endif
CVDisplayLinkStop(displayLink);
...
}
I'm not sure this is the right thing to do, there's probably a better way to deal with this, but this workaround is good enough for me at the moment.
Thanks for this post, it helped me figure out how to solve the same deadlock, in a non-cocos2d app, by processing the display link callback on a separate thread, never on the main thread.
static CVReturn MyDisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeStamp* now, const CVTimeStamp* outputTime,
CVOptionFlags flagsIn, CVOptionFlags* flagsOut, void *userInfo)
{
static dispatch_queue_t sDisplayQueue;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sDisplayQueue = dispatch_queue_create("com.company.app.displayLink", NULL);
});
dispatch_sync(sDisplayQueue, ^{
<stuff>
});
return kCVReturnSuccess;
}
Problem Description
I have a function StdString ShowLockScreen() in this function I call activateViewController function which shows some UI where user must enter PIN, just after calling activateViewController function I want to lock all processes until user will enter his PIN and press OK button on opened UI. Below you can see code which I try
Source code in iOS
StdString ShowLockScreen()
{
// Create a lock.
NSLock* theLock = [[NSLock alloc] init];
// Create a UI in which user must enter his PIN.
PinLockController* controller = [[PinLockController alloc] initWithStyle:PinLockTypeSet];
// Set delegate.
controller.delegate = m_Context;
// !!! Here I show a UI and just after that I lock my lock in order code stop executing there.
[controller activateViewController:nil];
#synchronized(theLock) {
[theLock lock];
}
NSLog(#"User in UI unlock the lock");
}
I want that my code stops then I call [theLock lock]; and after I will call [theLock unlock]; from my UI and code will continue executing. But it doesn't work in my case.
Source code in Android
I have write similar application in Android and here is code. I want to write same in iOS but I can;t find solution
Intent intent = new Intent(mCtx, SoftPinActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
SharedObject lock = new SharedObject("");
int lockId = SharedObject.acquireLockId(lock);
Logger.i(TAG, "lockId = " + lockId);
intent.putExtra(SharedObject.LOCK_ID, lockId);
intent.putExtra(SoftPinActivity.UI_ID, style);
synchronized (lock) {
mCtx.startActivity(intent);
try {
Logger.i(TAG, "lock.wait()...");
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
Logger.i(TAG, "InterruptedException");
}
}
Logger.i(TAG, "lock.wait()...done");
SharedObject.releaseLockId(lockId);
String pin = lock.object();
Researches
I think I must use
NSCondition* condLock = [[NSCondition alloc] init];
[condLock wait];
and
[condLock signal];
but how to use this in my code ?
Answer to problem
You can lock threads using NSLock, but in your situation, this doesn't seem to be applicable. The reason being is that locking is primarily used to provide thread safety when data is accessed from multiple threads. What you're asking for is a domain level lock, which prevents the user from using the application unless they've typed in their PIN. These two concepts share the word "lock", but they're entirely different in their implementation. If you were to use NSLock and its related counterparts, you're forcing your implementation into separate threads purely to block user interaction, and risk complicating your project and pains in debugging (deadlocks much?).
Suggested solution
As the concept is a domain level locking mechanism, I suggest we keep it this way for its implementation. If you want it to be analogous to Android, then you'd need to create your own concept of a 'SharedObject' that everything else queries. If this object were to say "The user hasn't unlocked the application", then nothing will process. This keeps you away from manually managing threads, and frees threads up for when you really need them most (asynchronous processing for example).
To implement this object, lets call it a UserContext, which is available as a singleton. How to implement this sharedInstance can be seen here.
Once you have that, then you can add various properties to it that are global throughout the application (and by the suggestion of the name, has all global properties that belong to a particular user). One of these properties is whether the user has the app locked or not:
[[UserContext sharedInstance] isLocked] // Returns BOOL
Using this throughout your application, you can then control (at the domain concept level), whether a method can compute something or not (naturally, you'll need to make UserContext thread safe, as it could be queried anywhere at any time). It would make it clear to the developer reading the code, that a certain method can not do anything unless the user has unlocked the app. To stop
Side notes
I want that my code stops then I call [theLock lock]; and after I will call [theLock unlock]; from my UI and code will continue executing.
Do not, under any circumstances, lock the UI thread. In a published app, the watchdog will kill your app, and it will effectively crash.
ViTo, as much I concerned with the NSLock, we use it in the case of multi-threading in which we lock a particular thread and force that upto that not unlock, none other thread become active or to do his required task.
So, may be what we can do that first of all we start all of your processes in the terms of thread and at that point when you try to open your UI we call 'lock' and when user pressed the button after inputting the text-box then we call 'unlock'.
But, for this we've to sure that this thread has high priority.
That's what I'm thinking right now, but really try this with my sample code and will update you accordingly.
Check that part of code:
+(void)aMethod:(id)param{
int x;
for(x=0;x<50;++x)
{enter code here
[lock lock];
printf("Object Thread says x is %i\n",x);
usleep(1);
[lock unlock];
}
}
- (void)viewDidLoad
{
int x;
lock = [[NSLock alloc] init];
[NSThread detachNewThreadSelector:#selector(aMethod:) toTarget:[MViewController class] withObject:nil];
for(x=0;x<50;++x)
{
[lock lock];
printf("Main thread says x is %i\n",x);
usleep(10000);
printf("Main thread lets go %i\n",x);
[lock unlock];
usleep(100);
}
printf("Now getting the process");
[super viewDidLoad];
}
Check the log you'll get what you want.
Hope, it's what you need. For any concern, shout-over me.
Okay I found solution to this issue, below you can see implemented function and line by line description.
StdString ShowLockScreen()
{
// Create NSCondition lock object.
NSCondition* conditionLock = [[NSCondition alloc] init];
// Here I create my UI which must ask user to enter PIN.
PinLockController* controller = [[PinLockController alloc] initWithStyle:PinLockTypeSet];
controller.delegate = m_Context;
// Here I lock the thread but not main thread (this is very important) I start
// ShowLockScreen function in new thread and lock it.
[conditionLock lock];
dispatch_sync(dispatch_get_main_queue(), ^{
// I call function which shows my UI in main thread as UI can be shown
// only in MAIN THREAD. (This is important too.)
[controller ShowLockController:conditionLock];
});
// Then I set lock to wait, how you can see I pass conditionLock as an
// argument to ShowLockController function in that function when user
// enter his PIN and press okay button I call [conditionLock signal];
// and my code code here after wait and continue executing.
[conditionLock wait];
NSLog(#"Come here then I call [conditionLock signal]!!!")
}
I have made a button so that when it's pressed by the user and a particular row(s) are selected it does something.
So far I have this:
if (pickerView selectedRowInComponent:0) {
[mailComposerTwo setToRecipients:[NSArray arrayWithObjects:#"email#blah.com",nil]];
}
It works on its own. But when I do the if statement multiple times it crashes.
An ways of making it work?
Any help appreciated, thanx.
The problem probably lies with your mail composer, not the picker view. When you show the composer, make sure that you only create it if it hasn't already created.
Also, make sure you release it after you show it:
MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
picker.mailComposeDelegate = self;
...[configure the picker]
[rootContainer presentModalViewController:picker animated:YES];
[picker release];
NSArray *finalList = [[NSArray alloc]init];
//put all your if statements
if (pickerView selectedRowInComponent:0)
{
[finalList arrayByAddingObjectsFromArray:#[#"email#address.com",#"second#address.com",...];
}
if (pickerView selectedRowInComponent:1)
{
[finalList arrayByAddingObjectsFromArray:#[#"another#address.com",#"fourth#address.com",...];
}
//end of if statements
[mailComposerTwo setToRecipients:finalList];
[self presentViewController:yourInitializedMessageController animated:YES completion:^{NSLog(#"message controller is presented");}];
This will do a single method call rather than continually reassigning which for some odd reason is causing your exception. presentModalViewController:animated: has been deprecated as of iOS 6.0? if not 7.0 I believe.
NOTE! Make the message controller a property of the main view controller. It is good practice so that it is not auto-released by iOS if you need to bring it back up. However if you use MFMessageComposer iOS will keep messenger allocated or running in a thread somewhere so initializing a view controller for it is quick.
I'm having a strange problem with wxWidgets. I have the following code
MyFrame::OnDoSomeLongThing(...) {
progScreen = new wxProgressDialog(text,text,number,this,wxPD_AUTO_HIDE); // wxProgressDialog *progScreen is class member
doPartOfThing() // calls the update method at the end of it
....
doLastPartOfThing() // again calls update method that pushes value to 100/100
progScreen->Destroy();
}
MyFrame::update() {
progScreen->Update(newValue);
}
Now here's the thing. I can literally comment out the lines relating to progScreen, just let the process go without using a progress dialog, after all is said and done, my apps exits gracefully when I close the main window.
However, just the use of the progress dialog is somehow extending the life of the application. I've tried Destroy(), I've tried simply 'delete progScreen', and both, every time: I'll close the main frame, the process keeps running, and at some point exits with some astronomical number. The only thing I could think might be relevant, is that the doPartsOfThings methods may call boost::this_thread::sleep, because it involves waiting and whatnot down in my model class. But this shouldn't have anything to do with my problem. Or maybe it does... EDIT: I do want to emphasize that progScreen->Update() IS being called from the main (GUI) thread.
So I ask, am I using a wxProgressDialog correctly? If not, how should it be used?
Thanks for your help!
EDIT:
Well... it turns out that removing wxPD_AUTO_HIDE fixed the problem. I'm still not quite sure what the problem is, but the dialog even still behaves as before. App closes as expected.
I think that you need to override the wxApp method that closes the application so that it closes the wxProgressDialog object before it quits.
wxApp::OnExit
virtual int OnExit()
Override this member function for any processing which needs to be
done as the application is about to exit. OnExit is called after
destroying all application windows and controls, but before wxWidgets
cleanup. Note that it is not called at all if OnInit failed.
The return value of this function is currently ignored, return the
same value as returned by the base class method if you override it.
You will need something like, assuming progScreen is a public attribute of your frame
int myApp::OnExit()
{
(MyFrame*)(GetTopWindow())->progScreen->Destroy()
return wxApp::OnExit();
}
I am developing a C++ app and I need to display a NSWindow with a WebKit WebView inside it. I've coded up the Objective-C class which will manage creating and displaying the window but the WebView contained inside it does not display. Here is my code. Any idea on what is wrong and how I can fix it?
I'm compiling the below code with
$g++ -x objective-c++ -framework Cocoa -framework WebKit Foo.m main.m -o test
Foo.h
#import <Cocoa/Cocoa.h>
#import <WebKit/WebKit.h>
#interface Foo :NSObject {
NSWindow *window;
WebView *view;
}
- (void)displayWindow;
#end
Foo.m
#import "Foo.h"
#implementation Foo
- (id)init {
self = [super init];
// Window Container
window = [[NSWindow alloc] initWithContentRect:NSMakeRect(500.0f,500.0f,250.0f,250.0f)
styleMask:NSBorderlessWindowMask
backing:NSBackingStoreNonretained
defer:NO];
// WebView
view = [[WebView alloc] initWithFrame:NSMakeRect(0, 0, 250.0f, 250.0f)
frameName:#"Frame"
groupName:nil];
[[view mainFrame] loadHTMLString:#"<html><head></head><body><h1>Hello</h1></body></html>"
baseURL:nil];
return self;
}
- (void)displayWindow {
NSLog(#"In Display window");
[window setContentView:view];
[window setLevel:NSStatusWindowLevel];
[window orderFrontRegardless];
sleep(5); // leave it up for 5 seconds
}
- (void)dealloc {
[window release];
[super dealloc];
}
#end
main.m
#import "Foo.h"
int main() {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
[NSApplication sharedApplication];
Foo *foo = [[Foo alloc] init];
[foo displayWindow];
[foo release];
[pool release];
return 0;
}
You need to run the run loop. If you just order the window in and then exit, that's exactly what will happen: The window will appear, and then (five seconds later) your program will exit. You can run the run loop by telling the application (which you create but don't otherwise use) to run.
On the main thread of a Cocoa app, sleep is always the wrong answer. The same goes for its Cocoa cousins, +[NSThread sleepUntilDate:] and +[NSThread sleepForTimeInterval:]. The run loop will let you tell it to run for a fixed amount of time, but that won't get the application running; you do need to send the application the run message, which provides no opportunity to exit after a fixed interval.
The solution there is to first create an NSTimer object whose target is the application and whose selector is #selector(terminate:). Create it scheduled and non-repeating, with the interval set to five seconds. (Creating it scheduled means you don't need to schedule it separately—it is already ready to go from the moment you create it.) Then, send the application the run message. Five seconds later, the run loop will fire the timer, which will tell the application to terminate itself. This is assuming that you actually have a good reason to make your application quit after five seconds.
As noted by Yuji, every window in modern Cocoa should use NSBackingStoreBuffered.
And don't forget to release what you have created; you currently are forgetting that in the case of the view. See the Memory Management Programming Guide for Cocoa.
Once you have this working, I suggest moving toward a more typical architecture for this application:
Create a subclass of NSObject, and make an instance of that class your application's delegate.
Put the window and its WebView into a nib, and have the app delegate create a window controller to load and own the contents of that nib.
The app delegate should also be responsible for loading the page into the WebView and for setting up the self-termination timer.
Finally, create a nib to hold your application's main menu (the contents of the menu bar) and the application delegate. Interface Builder has a template for the first part; you create the app delegate object by dragging a blank Object in from the Library, setting its class on the ⌘6 Inspector, and dragging the connection from the application to the object. Then, you can reduce main to the single line that Xcode's project templates put in it: return NSApplicationMain(argc, argv);.
Doing all this will help your understanding of Cocoa, as well as your maintenance of the application—cramming everything into main will not scale.
You should also read the Cocoa Fundamentals Guide, if you haven't already.
Don't make it sleep. It stops the execution of the main thread, in which the GUI is dealt with. Instead, you need to run the run loop. Also, Cocoa needs to set itself up. So, call [[NSApplication sharedApplication] run] to set it up correctly and run the event loop.
Also, don't use backing mode other than buffered mode. Other modes are remnants from the time immemorial, and only NSBackingStoreBuffered should be used. As discussed in this Apple document, the non-retained mode is a remnant to support Classic Blue Box (OS 9 virtualizer), and newer classes like WebKit just can't operate within it.
So, what you need to do is practically:
change NSBackingStoreNonretained to NSBackingStoreBuffered.
Remove the line
sleep(5);
add a line
[[NSApplication sharedApplication] run];
after
[foo displayWindow];
Also, in order for an app to receive events from the window server correctly, you need to pack it into an app bundle. Compile it into a binary called foo, and create the following structure:
foo.app/
foo.app/Contents/
foo.app/Contents/MacOS/
foo.app/Contents/MacOS/foo <--- this is the executable
Then you can double-click foo.app from the Finder, or just call ./foo from the command line.