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fb896a32 | 1 | ///////////////////////////////////////////////////////////////////////////// |
8898456d | 2 | // Name: src/cocoa/app.mm |
fb896a32 DE |
3 | // Purpose: wxApp |
4 | // Author: David Elliott | |
5 | // Modified by: | |
6 | // Created: 2002/11/27 | |
d89d4059 | 7 | // RCS-ID: $Id$ |
fb896a32 | 8 | // Copyright: (c) David Elliott |
047c1182 | 9 | // Software 2000 Ltd. |
bb27b372 | 10 | // Licence: wxWidgets licence |
fb896a32 DE |
11 | ///////////////////////////////////////////////////////////////////////////// |
12 | ||
fb896a32 | 13 | #include "wx/wxprec.h" |
8898456d | 14 | |
da80ae71 WS |
15 | #include "wx/app.h" |
16 | ||
fb896a32 | 17 | #ifndef WX_PRECOMP |
fb896a32 DE |
18 | #include "wx/intl.h" |
19 | #include "wx/log.h" | |
02761f6c | 20 | #include "wx/module.h" |
fb896a32 DE |
21 | #endif |
22 | ||
047c1182 | 23 | #include "wx/cocoa/ObjcRef.h" |
493902ac | 24 | #include "wx/cocoa/autorelease.h" |
af367f46 | 25 | #include "wx/cocoa/mbarman.h" |
bb27b372 | 26 | #include "wx/cocoa/NSApplication.h" |
fb45bb1f | 27 | |
938156b2 DE |
28 | #include "wx/cocoa/dc.h" |
29 | ||
fb896a32 DE |
30 | #import <AppKit/NSApplication.h> |
31 | #import <Foundation/NSRunLoop.h> | |
14fc7eb4 | 32 | #import <Foundation/NSThread.h> |
aaa5ab05 | 33 | #import <AppKit/NSEvent.h> |
eb537cfb | 34 | #import <Foundation/NSString.h> |
bb27b372 RN |
35 | #import <Foundation/NSNotification.h> |
36 | #import <AppKit/NSCell.h> | |
fb896a32 | 37 | |
879180b6 DE |
38 | bool wxApp::sm_isEmbedded = false; // Normally we're not a plugin |
39 | ||
047c1182 | 40 | // wxNSApplicationObserver singleton. |
a24aa427 | 41 | static wxObjcAutoRefFromAlloc<wxNSApplicationObserver*> sg_cocoaAppObserver = [[WX_GET_OBJC_CLASS(wxNSApplicationObserver) alloc] init]; |
047c1182 | 42 | |
ba808e24 DE |
43 | // ======================================================================== |
44 | // wxNSApplicationDelegate | |
45 | // ======================================================================== | |
ba808e24 DE |
46 | @implementation wxNSApplicationDelegate : NSObject |
47 | ||
2990ec97 | 48 | // NOTE: Terminate means that the event loop does NOT return and thus |
bb27b372 | 49 | // cleanup code doesn't properly execute. Furthermore, wxWidgets has its |
2990ec97 | 50 | // own exit on frame delete mechanism. |
fb896a32 DE |
51 | - (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)theApplication |
52 | { | |
2990ec97 | 53 | return NO; |
fb896a32 DE |
54 | } |
55 | ||
047c1182 | 56 | @end // implementation wxNSApplicationDelegate : NSObject |
a24aa427 | 57 | WX_IMPLEMENT_GET_OBJC_CLASS(wxNSApplicationDelegate,NSObject) |
047c1182 DE |
58 | |
59 | // ======================================================================== | |
60 | // wxNSApplicationObserver | |
61 | // ======================================================================== | |
62 | @implementation wxNSApplicationObserver : NSObject | |
63 | ||
0187ddb4 DE |
64 | - (void)applicationWillBecomeActive:(NSNotification *)notification |
65 | { | |
66 | wxTheApp->CocoaDelegate_applicationWillBecomeActive(); | |
67 | } | |
68 | ||
69 | - (void)applicationDidBecomeActive:(NSNotification *)notification | |
70 | { | |
71 | wxTheApp->CocoaDelegate_applicationDidBecomeActive(); | |
72 | } | |
73 | ||
74 | - (void)applicationWillResignActive:(NSNotification *)notification | |
75 | { | |
76 | wxTheApp->CocoaDelegate_applicationWillResignActive(); | |
77 | } | |
78 | ||
79 | - (void)applicationDidResignActive:(NSNotification *)notification | |
80 | { | |
81 | wxTheApp->CocoaDelegate_applicationDidResignActive(); | |
82 | } | |
83 | ||
047c1182 DE |
84 | - (void)applicationWillUpdate:(NSNotification *)notification; |
85 | { | |
86 | wxTheApp->CocoaDelegate_applicationWillUpdate(); | |
87 | } | |
88 | ||
bb27b372 RN |
89 | - (void)controlTintChanged:(NSNotification *)notification |
90 | { | |
422d306c | 91 | wxLogDebug(wxT("TODO: send EVT_SYS_COLOUR_CHANGED as appropriate")); |
bb27b372 RN |
92 | } |
93 | ||
047c1182 | 94 | @end // implementation wxNSApplicationObserver : NSObject |
a24aa427 | 95 | WX_IMPLEMENT_GET_OBJC_CLASS(wxNSApplicationObserver,NSObject) |
e2478fde | 96 | |
70fb935a DE |
97 | // ======================================================================== |
98 | // wxApp | |
99 | // ======================================================================== | |
fb896a32 DE |
100 | |
101 | // ---------------------------------------------------------------------------- | |
102 | // wxApp Static member initialization | |
103 | // ---------------------------------------------------------------------------- | |
fb896a32 | 104 | IMPLEMENT_DYNAMIC_CLASS(wxApp, wxEvtHandler) |
fb896a32 DE |
105 | |
106 | // ---------------------------------------------------------------------------- | |
05e2b077 | 107 | // wxApp initialization/cleanup |
fb896a32 | 108 | // ---------------------------------------------------------------------------- |
05e2b077 | 109 | bool wxApp::Initialize(int& argc, wxChar **argv) |
fb896a32 | 110 | { |
47f1ad6a | 111 | wxAutoNSAutoreleasePool pool; |
14fc7eb4 | 112 | m_cocoaMainThread = [NSThread currentThread]; |
05e2b077 VZ |
113 | // Mac OS X passes a process serial number command line argument when |
114 | // the application is launched from the Finder. This argument must be | |
115 | // removed from the command line arguments before being handled by the | |
116 | // application (otherwise applications would need to handle it) | |
117 | if ( argc > 1 ) | |
118 | { | |
9a83f860 | 119 | static const wxChar *ARG_PSN = wxT("-psn_"); |
b0c0a393 | 120 | if ( wxStrncmp(argv[1], ARG_PSN, wxStrlen(ARG_PSN)) == 0 ) |
05e2b077 VZ |
121 | { |
122 | // remove this argument | |
33f39af3 | 123 | --argc; |
b0c0a393 | 124 | memmove(argv + 1, argv + 2, argc * sizeof(wxChar *)); |
05e2b077 VZ |
125 | } |
126 | } | |
127 | ||
04453a9e DE |
128 | /* |
129 | Cocoa supports -Key value options which set the user defaults key "Key" | |
130 | to the value "value" Some of them are very handy for debugging like | |
131 | -NSShowAllViews YES. Cocoa picks these up from the real argv so | |
132 | our removal of them from the wx copy of it does not affect Cocoa's | |
133 | ability to see them. | |
134 | ||
135 | We basically just assume that any "-NS" option and its following | |
136 | argument needs to be removed from argv. We hope that user code does | |
137 | not expect to see -NS options and indeed it's probably a safe bet | |
138 | since most user code accepting options is probably using the | |
139 | double-dash GNU-style syntax. | |
140 | */ | |
141 | for(int i=1; i < argc; ++i) | |
142 | { | |
143 | static const wxChar *ARG_NS = wxT("-NS"); | |
144 | static const int ARG_NS_LEN = wxStrlen(ARG_NS); | |
145 | if( wxStrncmp(argv[i], ARG_NS, ARG_NS_LEN) == 0 ) | |
146 | { | |
147 | // Only eat this option if it has an argument | |
148 | if( (i + 1) < argc ) | |
149 | { | |
150 | argc -= 2; | |
151 | memmove(argv + i, argv + i + 2, argc * sizeof(wxChar*)); | |
152 | // drop back one position so the next run through the loop | |
153 | // reprocesses the argument at our current index. | |
154 | --i; | |
155 | } | |
156 | } | |
157 | } | |
158 | ||
94826170 | 159 | return wxAppBase::Initialize(argc, argv); |
fb896a32 DE |
160 | } |
161 | ||
94826170 | 162 | void wxApp::CleanUp() |
fb896a32 | 163 | { |
0187ddb4 DE |
164 | wxAutoNSAutoreleasePool pool; |
165 | ||
938156b2 | 166 | wxCocoaDCImpl::CocoaShutdownTextSystem(); |
af367f46 | 167 | wxMenuBarManager::DestroyInstance(); |
94826170 | 168 | |
879180b6 DE |
169 | [[NSNotificationCenter defaultCenter] removeObserver:sg_cocoaAppObserver]; |
170 | if(!sm_isEmbedded) | |
171 | { | |
172 | [m_cocoaApp setDelegate:nil]; | |
173 | [m_cocoaAppDelegate release]; | |
174 | m_cocoaAppDelegate = NULL; | |
175 | } | |
0187ddb4 | 176 | |
94826170 | 177 | wxAppBase::CleanUp(); |
fb896a32 DE |
178 | } |
179 | ||
180 | // ---------------------------------------------------------------------------- | |
181 | // wxApp creation | |
182 | // ---------------------------------------------------------------------------- | |
fb896a32 DE |
183 | wxApp::wxApp() |
184 | { | |
185 | m_topWindow = NULL; | |
fb896a32 | 186 | |
fb896a32 | 187 | argc = 0; |
b95d7ac9 | 188 | #if !wxUSE_UNICODE |
fb896a32 | 189 | argv = NULL; |
b95d7ac9 | 190 | #endif |
fb896a32 | 191 | m_cocoaApp = NULL; |
0187ddb4 | 192 | m_cocoaAppDelegate = NULL; |
fb896a32 DE |
193 | } |
194 | ||
0187ddb4 DE |
195 | void wxApp::CocoaDelegate_applicationWillBecomeActive() |
196 | { | |
197 | } | |
198 | ||
199 | void wxApp::CocoaDelegate_applicationDidBecomeActive() | |
200 | { | |
201 | } | |
202 | ||
203 | void wxApp::CocoaDelegate_applicationWillResignActive() | |
204 | { | |
39050120 | 205 | wxTopLevelWindowCocoa::DeactivatePendingWindow(); |
0187ddb4 DE |
206 | } |
207 | ||
208 | void wxApp::CocoaDelegate_applicationDidResignActive() | |
209 | { | |
210 | } | |
211 | ||
fb896a32 DE |
212 | bool wxApp::OnInitGui() |
213 | { | |
47f1ad6a | 214 | wxAutoNSAutoreleasePool pool; |
fb896a32 | 215 | if(!wxAppBase::OnInitGui()) |
8898456d | 216 | return false; |
fb896a32 DE |
217 | |
218 | // Create the app using the sharedApplication method | |
219 | m_cocoaApp = [NSApplication sharedApplication]; | |
047c1182 | 220 | |
879180b6 DE |
221 | if(!sm_isEmbedded) |
222 | { | |
223 | // Enable response to application delegate messages | |
a24aa427 | 224 | m_cocoaAppDelegate = [[WX_GET_OBJC_CLASS(wxNSApplicationDelegate) alloc] init]; |
879180b6 DE |
225 | [m_cocoaApp setDelegate:m_cocoaAppDelegate]; |
226 | } | |
047c1182 DE |
227 | |
228 | // Enable response to "delegate" messages on the notification observer | |
229 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
230 | selector:@selector(applicationWillBecomeActive:) | |
231 | name:NSApplicationWillBecomeActiveNotification object:nil]; | |
232 | ||
233 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
234 | selector:@selector(applicationDidBecomeActive:) | |
235 | name:NSApplicationDidBecomeActiveNotification object:nil]; | |
236 | ||
237 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
238 | selector:@selector(applicationWillResignActive:) | |
239 | name:NSApplicationWillResignActiveNotification object:nil]; | |
240 | ||
241 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
242 | selector:@selector(applicationDidResignActive:) | |
243 | name:NSApplicationDidResignActiveNotification object:nil]; | |
244 | ||
245 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
246 | selector:@selector(applicationWillUpdate:) | |
247 | name:NSApplicationWillUpdateNotification object:nil]; | |
248 | ||
249 | // Enable response to system notifications | |
250 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
bb27b372 RN |
251 | selector:@selector(controlTintChanged:) |
252 | name:NSControlTintDidChangeNotification object:nil]; | |
af367f46 | 253 | |
879180b6 DE |
254 | if(!sm_isEmbedded) |
255 | wxMenuBarManager::CreateInstance(); | |
af367f46 | 256 | |
938156b2 | 257 | wxCocoaDCImpl::CocoaInitializeTextSystem(); |
8898456d | 258 | return true; |
fb896a32 DE |
259 | } |
260 | ||
047c1182 DE |
261 | wxApp::~wxApp() |
262 | { | |
263 | if(m_cfRunLoopIdleObserver != NULL) | |
264 | { | |
265 | // Invalidate the observer which also removes it from the run loop. | |
266 | CFRunLoopObserverInvalidate(m_cfRunLoopIdleObserver); | |
267 | // Release the ref as we don't need it anymore. | |
268 | m_cfRunLoopIdleObserver.reset(); | |
269 | } | |
270 | } | |
271 | ||
47f1ad6a DE |
272 | bool wxApp::CallOnInit() |
273 | { | |
bd3e8827 | 274 | // wxAutoNSAutoreleasePool pool; |
47f1ad6a DE |
275 | return OnInit(); |
276 | } | |
277 | ||
fb896a32 DE |
278 | bool wxApp::OnInit() |
279 | { | |
280 | if(!wxAppBase::OnInit()) | |
8898456d | 281 | return false; |
fb896a32 | 282 | |
8898456d | 283 | return true; |
fb896a32 DE |
284 | } |
285 | ||
70fb935a DE |
286 | void wxApp::Exit() |
287 | { | |
288 | wxApp::CleanUp(); | |
289 | ||
290 | wxAppConsole::Exit(); | |
291 | } | |
292 | ||
eb537cfb DE |
293 | void wxApp::WakeUpIdle() |
294 | { | |
30cfcda5 DE |
295 | /* When called from the main thread the NSAutoreleasePool managed by |
296 | the [NSApplication run] method would ordinarily be in place and so | |
297 | one would think a pool here would be unnecessary. | |
298 | ||
299 | However, when called from a different thread there is usually no | |
300 | NSAutoreleasePool in place because wxThread has no knowledge of | |
301 | wxCocoa. The pool here is generally only ever going to contain | |
302 | the NSEvent we create with the factory method. As soon as we add | |
303 | it to the main event queue with postEvent:atStart: it is retained | |
304 | and so safe for our pool to release. | |
305 | */ | |
306 | wxAutoNSAutoreleasePool pool; | |
307 | /* NOTE: This is a little heavy handed. What this does is cause an | |
308 | AppKit NSEvent to be added to NSApplication's queue (which is always | |
309 | on the main thread). This will cause the main thread runloop to | |
310 | exit which returns control to nextEventMatchingMask which returns | |
311 | the event which is then sent with sendEvent: and essentially dropped | |
312 | since it's not for a window (windowNumber 0) and NSApplication | |
313 | certainly doesn't understand it. | |
314 | ||
315 | With the exception of wxEventLoop::Exit which uses us to cause the | |
316 | runloop to exit and return to the NSApplication event loop, most | |
317 | callers only need wx idle to happen, or more specifically only really | |
318 | need to ensure that ProcessPendingEvents is called which is currently | |
319 | done without exiting the runloop. | |
320 | ||
321 | Be careful if you decide to change the implementation of this method | |
322 | as wxEventLoop::Exit depends on the current behavior. | |
323 | */ | |
eb537cfb DE |
324 | [m_cocoaApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined |
325 | location:NSZeroPoint modifierFlags:NSAnyEventMask | |
326 | timestamp:0 windowNumber:0 context:nil | |
327 | subtype:0 data1:0 data2:0] atStart:NO]; | |
328 | } | |
329 | ||
047c1182 DE |
330 | extern "C" static void ObserveMainRunLoopBeforeWaiting(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info); |
331 | extern "C" static void ObserveMainRunLoopBeforeWaiting(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info) | |
332 | { | |
333 | static_cast<wxApp*>(info)->CF_ObserveMainRunLoopBeforeWaiting(observer, activity); | |
334 | } | |
335 | ||
336 | #if 0 | |
337 | static int sg_cApplicationWillUpdate = 0; | |
338 | #endif | |
339 | ||
30cfcda5 DE |
340 | /*! |
341 | Invoked from the applicationWillUpdate notification observer. See the | |
342 | NSApplication documentation for the official statement on when this | |
343 | will be called. Since it can be hard to understand for a Cocoa newbie | |
344 | I'll try to explain it here as it relates to wxCocoa. | |
345 | ||
346 | Basically, we get called from within nextEventMatchingMask if and only | |
347 | if any user code told the application to send the update notification | |
348 | (sort of like a request for idle events). However, unlike wx idle events, | |
349 | this notification is sent quite often, nearly every time through the loop | |
350 | because nearly every control tells the application to send it. | |
351 | ||
352 | Because wx idle events are only supposed to be sent when the event loop | |
353 | is about to block we instead schedule a function to be called just | |
354 | before the run loop waits and send the idle events from there. | |
355 | ||
356 | It also has the desirable effect of only sending the wx idle events when | |
357 | the event loop is actualy going to block. If the event loop is being | |
358 | pumped manualy (e.g. like a PeekMessage) then the kCFRunLoopBeforeWaiting | |
359 | observer never fires. Our Yield() method depends on this because sending | |
360 | idle events from within Yield would be bad. | |
361 | ||
362 | Normally you might think that we could just set the observer up once and | |
363 | leave it attached. However, this is problematic because our run loop | |
364 | observer calls user code (the idle handlers) which can actually display | |
365 | modal dialogs. Displaying a modal dialog causes reentry of the event | |
366 | loop, usually in a different run loop mode than the main loop (e.g. in | |
367 | modal-dialog mode instead of default mode). Because we only register the | |
368 | observer with the run loop mode at the time of this call, it won't be | |
369 | called from a modal loop. | |
370 | ||
371 | We want it to be called and thus we need a new observer. | |
372 | */ | |
047c1182 DE |
373 | void wxApp::CocoaDelegate_applicationWillUpdate() |
374 | { | |
375 | wxLogTrace(wxTRACE_COCOA,wxT("applicationWillUpdate")); | |
376 | ||
377 | // CFRunLoopRef cfRunLoop = [[NSRunLoop currentRunLoop] getCFRunLoop]; | |
378 | CFRunLoopRef cfRunLoop = CFRunLoopGetCurrent(); | |
379 | wxCFRef<CFStringRef> cfRunLoopMode(CFRunLoopCopyCurrentMode(cfRunLoop)); | |
380 | ||
30cfcda5 DE |
381 | /* If we have an observer and that observer is for the wrong run loop |
382 | mode then invalidate it and release it. | |
383 | */ | |
047c1182 DE |
384 | if(m_cfRunLoopIdleObserver != NULL && m_cfObservedRunLoopMode != cfRunLoopMode) |
385 | { | |
386 | CFRunLoopObserverInvalidate(m_cfRunLoopIdleObserver); | |
387 | m_cfRunLoopIdleObserver.reset(); | |
388 | } | |
389 | #if 0 | |
390 | ++sg_cApplicationWillUpdate; | |
391 | #endif | |
30cfcda5 DE |
392 | /* This will be true either on the first call or when the above code has |
393 | invalidated and released the exisiting observer. | |
394 | */ | |
047c1182 DE |
395 | if(m_cfRunLoopIdleObserver == NULL) |
396 | { | |
397 | // Enable idle event handling | |
398 | CFRunLoopObserverContext observerContext = | |
399 | { 0 | |
400 | , this | |
401 | , NULL | |
402 | , NULL | |
403 | , NULL | |
404 | }; | |
30cfcda5 DE |
405 | /* NOTE: I can't recall why we don't just let the observer repeat |
406 | instead of invalidating itself each time it fires thus requiring | |
407 | it to be recreated for each shot but there was if I remember | |
408 | some good (but very obscure) reason for it. | |
409 | ||
410 | On the other hand, I could be wrong so don't take that as gospel. | |
411 | */ | |
047c1182 DE |
412 | m_cfRunLoopIdleObserver.reset(CFRunLoopObserverCreate(kCFAllocatorDefault, kCFRunLoopBeforeWaiting, /*repeats*/FALSE, /*priority*/0, ObserveMainRunLoopBeforeWaiting, &observerContext)); |
413 | m_cfObservedRunLoopMode = cfRunLoopMode; | |
414 | CFRunLoopAddObserver(cfRunLoop, m_cfRunLoopIdleObserver, m_cfObservedRunLoopMode); | |
415 | } | |
416 | } | |
417 | ||
418 | static inline bool FakeNeedMoreIdle() | |
419 | { | |
420 | #if 0 | |
421 | // Return true on every 10th call. | |
422 | static int idleCount = 0; | |
423 | return ++idleCount % 10; | |
424 | #else | |
425 | return false; | |
426 | #endif | |
427 | } | |
428 | ||
30cfcda5 DE |
429 | /*! |
430 | Called by CFRunLoop just before waiting. This is the appropriate time to | |
431 | send idle events. Unlike other ports, we don't peek the queue for events | |
432 | and stop idling if there is one. Instead, if the user requests more idle | |
433 | events we tell Cocoa to send us an applicationWillUpdate notification | |
434 | which will cause our observer of that notification to tell CFRunLoop to | |
435 | call us before waiting which will cause us to be fired again but only | |
436 | after exhausting the event queue. | |
437 | ||
438 | The reason we do it this way is that peeking for an event causes CFRunLoop | |
439 | to reenter and fire off its timers, observers, and sources which we're | |
440 | better off avoiding. Doing it this way, we basically let CFRunLoop do the | |
441 | work of peeking for the next event which is much nicer. | |
442 | */ | |
047c1182 DE |
443 | void wxApp::CF_ObserveMainRunLoopBeforeWaiting(CFRunLoopObserverRef observer, int activity) |
444 | { | |
30cfcda5 DE |
445 | // Ensure that CocoaDelegate_applicationWillUpdate will recreate us. |
446 | // We've already been invalidated by CFRunLoop because we are one-shot. | |
047c1182 DE |
447 | m_cfRunLoopIdleObserver.reset(); |
448 | #if 0 | |
449 | wxLogTrace(wxTRACE_COCOA,wxT("Idle BEGIN (%d)"), sg_cApplicationWillUpdate); | |
450 | sg_cApplicationWillUpdate = 0; | |
451 | #else | |
452 | wxLogTrace(wxTRACE_COCOA,wxT("Idle BEGIN")); | |
453 | #endif | |
454 | if( ProcessIdle() || FakeNeedMoreIdle() ) | |
455 | { | |
456 | wxLogTrace(wxTRACE_COCOA, wxT("Idle REQUEST MORE")); | |
457 | [NSApp setWindowsNeedUpdate:YES]; | |
458 | } | |
459 | else | |
460 | { | |
461 | wxLogTrace(wxTRACE_COCOA, wxT("Idle END")); | |
462 | } | |
463 | } | |
464 | ||
30cfcda5 DE |
465 | /* A note about Cocoa's event loops vs. run loops: |
466 | ||
467 | It's important to understand that Cocoa has a two-level event loop. The | |
468 | outer level is run by NSApplication and can only ever happen on the main | |
469 | thread. The nextEventMatchingMask:untilDate:inMode:dequeue: method returns | |
470 | the next event which is then given to sendEvent: to send it. These | |
471 | methods are defined in NSApplication and are thus part of AppKit. | |
472 | ||
473 | Events (NSEvent) are only sent due to actual user actions like clicking | |
474 | the mouse or moving the mouse or pressing a key and so on. There are no | |
475 | paint events; there are no timer events; there are no socket events; there | |
476 | are no idle events. | |
477 | ||
478 | All of those types of "events" have nothing to do with the GUI at all. | |
479 | That is why Cocoa's AppKit doesn't implement them. Instead, they are | |
480 | implemented in Foundation's NSRunLoop which on OS X uses CFRunLoop | |
481 | to do the actual work. | |
482 | ||
483 | How NSApplication uses NSRunLoop is rather interesting. Basically, it | |
484 | interacts with NSRunLoop only from within the nextEventMatchingMask | |
485 | method. It passes its inMode: argument almost directly to NSRunLoop | |
486 | and thus CFRunLoop. The run loop then runs (e.g. loops) until it | |
487 | is told to exit. The run loop calls the callout functions directly. | |
488 | From within those callout functions the run loop is considered to | |
489 | be running. Presumably, the AppKit installs a run loop source to | |
490 | receive messages from the window server over the mach port (like a | |
491 | socket). For some messages (e.g. need to paint) the AppKit will | |
492 | call application code like drawRect: without exiting the run loop. | |
493 | For other messages (ones that can be encapsulated in an NSEvent) | |
494 | the AppKit tells the run loop to exit which returns control to | |
495 | the nextEventMatchingMask method which then returns the NSEvent | |
496 | object. It's important to note that once the runloop has exited | |
497 | it is no longer considered running and thus if you ask it which | |
498 | mode it is running in it will return nil. | |
499 | ||
500 | When manually pumping the event loop care should be taken to | |
501 | tell it to run in the correct mode. For instance, if you are | |
502 | using it to run a modal dialog then you want to run it in | |
503 | the modal panel run loop mode. AppKit presumably has sources | |
504 | or timers or observers that specifically don't listen on this | |
505 | mode. Another interesting mode is the connection reply mode. | |
506 | This allows Cocoa to wait for a response from a distributed | |
507 | objects message without firing off user code that may result | |
508 | in a DO call being made thus recursing. So basically, the | |
509 | mode is a way for Cocoa to attempt to avoid run loop recursion | |
510 | but to allow it under certain circumstances. | |
511 | */ | |
512 |