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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 | |
fb896a32 | 7 | // Copyright: (c) David Elliott |
047c1182 | 8 | // Software 2000 Ltd. |
526954c5 | 9 | // Licence: wxWindows licence |
fb896a32 DE |
10 | ///////////////////////////////////////////////////////////////////////////// |
11 | ||
fb896a32 | 12 | #include "wx/wxprec.h" |
8898456d | 13 | |
da80ae71 WS |
14 | #include "wx/app.h" |
15 | ||
fb896a32 | 16 | #ifndef WX_PRECOMP |
fb896a32 DE |
17 | #include "wx/intl.h" |
18 | #include "wx/log.h" | |
02761f6c | 19 | #include "wx/module.h" |
fb896a32 DE |
20 | #endif |
21 | ||
047c1182 | 22 | #include "wx/cocoa/ObjcRef.h" |
493902ac | 23 | #include "wx/cocoa/autorelease.h" |
af367f46 | 24 | #include "wx/cocoa/mbarman.h" |
bb27b372 | 25 | #include "wx/cocoa/NSApplication.h" |
fb45bb1f | 26 | |
938156b2 DE |
27 | #include "wx/cocoa/dc.h" |
28 | ||
fb896a32 DE |
29 | #import <AppKit/NSApplication.h> |
30 | #import <Foundation/NSRunLoop.h> | |
14fc7eb4 | 31 | #import <Foundation/NSThread.h> |
aaa5ab05 | 32 | #import <AppKit/NSEvent.h> |
eb537cfb | 33 | #import <Foundation/NSString.h> |
bb27b372 RN |
34 | #import <Foundation/NSNotification.h> |
35 | #import <AppKit/NSCell.h> | |
fb896a32 | 36 | |
879180b6 DE |
37 | bool wxApp::sm_isEmbedded = false; // Normally we're not a plugin |
38 | ||
047c1182 | 39 | // wxNSApplicationObserver singleton. |
a24aa427 | 40 | static wxObjcAutoRefFromAlloc<wxNSApplicationObserver*> sg_cocoaAppObserver = [[WX_GET_OBJC_CLASS(wxNSApplicationObserver) alloc] init]; |
047c1182 | 41 | |
ba808e24 DE |
42 | // ======================================================================== |
43 | // wxNSApplicationDelegate | |
44 | // ======================================================================== | |
ba808e24 DE |
45 | @implementation wxNSApplicationDelegate : NSObject |
46 | ||
2990ec97 | 47 | // NOTE: Terminate means that the event loop does NOT return and thus |
bb27b372 | 48 | // cleanup code doesn't properly execute. Furthermore, wxWidgets has its |
2990ec97 | 49 | // own exit on frame delete mechanism. |
fb896a32 DE |
50 | - (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)theApplication |
51 | { | |
2990ec97 | 52 | return NO; |
fb896a32 DE |
53 | } |
54 | ||
047c1182 | 55 | @end // implementation wxNSApplicationDelegate : NSObject |
a24aa427 | 56 | WX_IMPLEMENT_GET_OBJC_CLASS(wxNSApplicationDelegate,NSObject) |
047c1182 DE |
57 | |
58 | // ======================================================================== | |
59 | // wxNSApplicationObserver | |
60 | // ======================================================================== | |
61 | @implementation wxNSApplicationObserver : NSObject | |
62 | ||
0187ddb4 DE |
63 | - (void)applicationWillBecomeActive:(NSNotification *)notification |
64 | { | |
65 | wxTheApp->CocoaDelegate_applicationWillBecomeActive(); | |
66 | } | |
67 | ||
68 | - (void)applicationDidBecomeActive:(NSNotification *)notification | |
69 | { | |
70 | wxTheApp->CocoaDelegate_applicationDidBecomeActive(); | |
71 | } | |
72 | ||
73 | - (void)applicationWillResignActive:(NSNotification *)notification | |
74 | { | |
75 | wxTheApp->CocoaDelegate_applicationWillResignActive(); | |
76 | } | |
77 | ||
78 | - (void)applicationDidResignActive:(NSNotification *)notification | |
79 | { | |
80 | wxTheApp->CocoaDelegate_applicationDidResignActive(); | |
81 | } | |
82 | ||
047c1182 DE |
83 | - (void)applicationWillUpdate:(NSNotification *)notification; |
84 | { | |
85 | wxTheApp->CocoaDelegate_applicationWillUpdate(); | |
86 | } | |
87 | ||
bb27b372 RN |
88 | - (void)controlTintChanged:(NSNotification *)notification |
89 | { | |
422d306c | 90 | wxLogDebug(wxT("TODO: send EVT_SYS_COLOUR_CHANGED as appropriate")); |
bb27b372 RN |
91 | } |
92 | ||
047c1182 | 93 | @end // implementation wxNSApplicationObserver : NSObject |
a24aa427 | 94 | WX_IMPLEMENT_GET_OBJC_CLASS(wxNSApplicationObserver,NSObject) |
e2478fde | 95 | |
70fb935a DE |
96 | // ======================================================================== |
97 | // wxApp | |
98 | // ======================================================================== | |
fb896a32 DE |
99 | |
100 | // ---------------------------------------------------------------------------- | |
101 | // wxApp Static member initialization | |
102 | // ---------------------------------------------------------------------------- | |
fb896a32 | 103 | IMPLEMENT_DYNAMIC_CLASS(wxApp, wxEvtHandler) |
fb896a32 DE |
104 | |
105 | // ---------------------------------------------------------------------------- | |
05e2b077 | 106 | // wxApp initialization/cleanup |
fb896a32 | 107 | // ---------------------------------------------------------------------------- |
05e2b077 | 108 | bool wxApp::Initialize(int& argc, wxChar **argv) |
fb896a32 | 109 | { |
47f1ad6a | 110 | wxAutoNSAutoreleasePool pool; |
14fc7eb4 | 111 | m_cocoaMainThread = [NSThread currentThread]; |
05e2b077 VZ |
112 | // Mac OS X passes a process serial number command line argument when |
113 | // the application is launched from the Finder. This argument must be | |
114 | // removed from the command line arguments before being handled by the | |
115 | // application (otherwise applications would need to handle it) | |
116 | if ( argc > 1 ) | |
117 | { | |
9a83f860 | 118 | static const wxChar *ARG_PSN = wxT("-psn_"); |
b0c0a393 | 119 | if ( wxStrncmp(argv[1], ARG_PSN, wxStrlen(ARG_PSN)) == 0 ) |
05e2b077 VZ |
120 | { |
121 | // remove this argument | |
33f39af3 | 122 | --argc; |
b0c0a393 | 123 | memmove(argv + 1, argv + 2, argc * sizeof(wxChar *)); |
05e2b077 VZ |
124 | } |
125 | } | |
126 | ||
04453a9e DE |
127 | /* |
128 | Cocoa supports -Key value options which set the user defaults key "Key" | |
129 | to the value "value" Some of them are very handy for debugging like | |
130 | -NSShowAllViews YES. Cocoa picks these up from the real argv so | |
131 | our removal of them from the wx copy of it does not affect Cocoa's | |
132 | ability to see them. | |
133 | ||
134 | We basically just assume that any "-NS" option and its following | |
135 | argument needs to be removed from argv. We hope that user code does | |
136 | not expect to see -NS options and indeed it's probably a safe bet | |
137 | since most user code accepting options is probably using the | |
138 | double-dash GNU-style syntax. | |
139 | */ | |
140 | for(int i=1; i < argc; ++i) | |
141 | { | |
142 | static const wxChar *ARG_NS = wxT("-NS"); | |
143 | static const int ARG_NS_LEN = wxStrlen(ARG_NS); | |
144 | if( wxStrncmp(argv[i], ARG_NS, ARG_NS_LEN) == 0 ) | |
145 | { | |
146 | // Only eat this option if it has an argument | |
147 | if( (i + 1) < argc ) | |
148 | { | |
149 | argc -= 2; | |
150 | memmove(argv + i, argv + i + 2, argc * sizeof(wxChar*)); | |
151 | // drop back one position so the next run through the loop | |
152 | // reprocesses the argument at our current index. | |
153 | --i; | |
154 | } | |
155 | } | |
156 | } | |
157 | ||
94826170 | 158 | return wxAppBase::Initialize(argc, argv); |
fb896a32 DE |
159 | } |
160 | ||
94826170 | 161 | void wxApp::CleanUp() |
fb896a32 | 162 | { |
0187ddb4 DE |
163 | wxAutoNSAutoreleasePool pool; |
164 | ||
938156b2 | 165 | wxCocoaDCImpl::CocoaShutdownTextSystem(); |
af367f46 | 166 | wxMenuBarManager::DestroyInstance(); |
94826170 | 167 | |
879180b6 DE |
168 | [[NSNotificationCenter defaultCenter] removeObserver:sg_cocoaAppObserver]; |
169 | if(!sm_isEmbedded) | |
170 | { | |
171 | [m_cocoaApp setDelegate:nil]; | |
172 | [m_cocoaAppDelegate release]; | |
173 | m_cocoaAppDelegate = NULL; | |
174 | } | |
0187ddb4 | 175 | |
94826170 | 176 | wxAppBase::CleanUp(); |
fb896a32 DE |
177 | } |
178 | ||
179 | // ---------------------------------------------------------------------------- | |
180 | // wxApp creation | |
181 | // ---------------------------------------------------------------------------- | |
fb896a32 DE |
182 | wxApp::wxApp() |
183 | { | |
184 | m_topWindow = NULL; | |
fb896a32 | 185 | |
fb896a32 | 186 | argc = 0; |
b95d7ac9 | 187 | #if !wxUSE_UNICODE |
fb896a32 | 188 | argv = NULL; |
b95d7ac9 | 189 | #endif |
fb896a32 | 190 | m_cocoaApp = NULL; |
0187ddb4 | 191 | m_cocoaAppDelegate = NULL; |
fb896a32 DE |
192 | } |
193 | ||
0187ddb4 DE |
194 | void wxApp::CocoaDelegate_applicationWillBecomeActive() |
195 | { | |
196 | } | |
197 | ||
198 | void wxApp::CocoaDelegate_applicationDidBecomeActive() | |
199 | { | |
200 | } | |
201 | ||
202 | void wxApp::CocoaDelegate_applicationWillResignActive() | |
203 | { | |
39050120 | 204 | wxTopLevelWindowCocoa::DeactivatePendingWindow(); |
0187ddb4 DE |
205 | } |
206 | ||
207 | void wxApp::CocoaDelegate_applicationDidResignActive() | |
208 | { | |
209 | } | |
210 | ||
fb896a32 DE |
211 | bool wxApp::OnInitGui() |
212 | { | |
47f1ad6a | 213 | wxAutoNSAutoreleasePool pool; |
fb896a32 | 214 | if(!wxAppBase::OnInitGui()) |
8898456d | 215 | return false; |
fb896a32 DE |
216 | |
217 | // Create the app using the sharedApplication method | |
218 | m_cocoaApp = [NSApplication sharedApplication]; | |
047c1182 | 219 | |
879180b6 DE |
220 | if(!sm_isEmbedded) |
221 | { | |
222 | // Enable response to application delegate messages | |
a24aa427 | 223 | m_cocoaAppDelegate = [[WX_GET_OBJC_CLASS(wxNSApplicationDelegate) alloc] init]; |
879180b6 DE |
224 | [m_cocoaApp setDelegate:m_cocoaAppDelegate]; |
225 | } | |
047c1182 DE |
226 | |
227 | // Enable response to "delegate" messages on the notification observer | |
228 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
229 | selector:@selector(applicationWillBecomeActive:) | |
230 | name:NSApplicationWillBecomeActiveNotification object:nil]; | |
231 | ||
232 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
233 | selector:@selector(applicationDidBecomeActive:) | |
234 | name:NSApplicationDidBecomeActiveNotification object:nil]; | |
235 | ||
236 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
237 | selector:@selector(applicationWillResignActive:) | |
238 | name:NSApplicationWillResignActiveNotification object:nil]; | |
239 | ||
240 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
241 | selector:@selector(applicationDidResignActive:) | |
242 | name:NSApplicationDidResignActiveNotification object:nil]; | |
243 | ||
244 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
245 | selector:@selector(applicationWillUpdate:) | |
246 | name:NSApplicationWillUpdateNotification object:nil]; | |
247 | ||
248 | // Enable response to system notifications | |
249 | [[NSNotificationCenter defaultCenter] addObserver:sg_cocoaAppObserver | |
bb27b372 RN |
250 | selector:@selector(controlTintChanged:) |
251 | name:NSControlTintDidChangeNotification object:nil]; | |
af367f46 | 252 | |
879180b6 DE |
253 | if(!sm_isEmbedded) |
254 | wxMenuBarManager::CreateInstance(); | |
af367f46 | 255 | |
938156b2 | 256 | wxCocoaDCImpl::CocoaInitializeTextSystem(); |
8898456d | 257 | return true; |
fb896a32 DE |
258 | } |
259 | ||
047c1182 DE |
260 | wxApp::~wxApp() |
261 | { | |
262 | if(m_cfRunLoopIdleObserver != NULL) | |
263 | { | |
264 | // Invalidate the observer which also removes it from the run loop. | |
265 | CFRunLoopObserverInvalidate(m_cfRunLoopIdleObserver); | |
266 | // Release the ref as we don't need it anymore. | |
267 | m_cfRunLoopIdleObserver.reset(); | |
268 | } | |
269 | } | |
270 | ||
47f1ad6a DE |
271 | bool wxApp::CallOnInit() |
272 | { | |
bd3e8827 | 273 | // wxAutoNSAutoreleasePool pool; |
47f1ad6a DE |
274 | return OnInit(); |
275 | } | |
276 | ||
fb896a32 DE |
277 | bool wxApp::OnInit() |
278 | { | |
279 | if(!wxAppBase::OnInit()) | |
8898456d | 280 | return false; |
fb896a32 | 281 | |
8898456d | 282 | return true; |
fb896a32 DE |
283 | } |
284 | ||
70fb935a DE |
285 | void wxApp::Exit() |
286 | { | |
287 | wxApp::CleanUp(); | |
288 | ||
289 | wxAppConsole::Exit(); | |
290 | } | |
291 | ||
eb537cfb DE |
292 | void wxApp::WakeUpIdle() |
293 | { | |
30cfcda5 DE |
294 | /* When called from the main thread the NSAutoreleasePool managed by |
295 | the [NSApplication run] method would ordinarily be in place and so | |
296 | one would think a pool here would be unnecessary. | |
297 | ||
298 | However, when called from a different thread there is usually no | |
299 | NSAutoreleasePool in place because wxThread has no knowledge of | |
300 | wxCocoa. The pool here is generally only ever going to contain | |
301 | the NSEvent we create with the factory method. As soon as we add | |
302 | it to the main event queue with postEvent:atStart: it is retained | |
303 | and so safe for our pool to release. | |
304 | */ | |
305 | wxAutoNSAutoreleasePool pool; | |
306 | /* NOTE: This is a little heavy handed. What this does is cause an | |
307 | AppKit NSEvent to be added to NSApplication's queue (which is always | |
308 | on the main thread). This will cause the main thread runloop to | |
309 | exit which returns control to nextEventMatchingMask which returns | |
310 | the event which is then sent with sendEvent: and essentially dropped | |
311 | since it's not for a window (windowNumber 0) and NSApplication | |
312 | certainly doesn't understand it. | |
313 | ||
314 | With the exception of wxEventLoop::Exit which uses us to cause the | |
315 | runloop to exit and return to the NSApplication event loop, most | |
316 | callers only need wx idle to happen, or more specifically only really | |
317 | need to ensure that ProcessPendingEvents is called which is currently | |
318 | done without exiting the runloop. | |
319 | ||
320 | Be careful if you decide to change the implementation of this method | |
4c51a665 | 321 | as wxEventLoop::Exit depends on the current behaviour. |
30cfcda5 | 322 | */ |
eb537cfb DE |
323 | [m_cocoaApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined |
324 | location:NSZeroPoint modifierFlags:NSAnyEventMask | |
325 | timestamp:0 windowNumber:0 context:nil | |
326 | subtype:0 data1:0 data2:0] atStart:NO]; | |
327 | } | |
328 | ||
047c1182 DE |
329 | extern "C" static void ObserveMainRunLoopBeforeWaiting(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info); |
330 | extern "C" static void ObserveMainRunLoopBeforeWaiting(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info) | |
331 | { | |
332 | static_cast<wxApp*>(info)->CF_ObserveMainRunLoopBeforeWaiting(observer, activity); | |
333 | } | |
334 | ||
335 | #if 0 | |
336 | static int sg_cApplicationWillUpdate = 0; | |
337 | #endif | |
338 | ||
30cfcda5 DE |
339 | /*! |
340 | Invoked from the applicationWillUpdate notification observer. See the | |
341 | NSApplication documentation for the official statement on when this | |
342 | will be called. Since it can be hard to understand for a Cocoa newbie | |
343 | I'll try to explain it here as it relates to wxCocoa. | |
344 | ||
345 | Basically, we get called from within nextEventMatchingMask if and only | |
346 | if any user code told the application to send the update notification | |
347 | (sort of like a request for idle events). However, unlike wx idle events, | |
348 | this notification is sent quite often, nearly every time through the loop | |
349 | because nearly every control tells the application to send it. | |
350 | ||
351 | Because wx idle events are only supposed to be sent when the event loop | |
352 | is about to block we instead schedule a function to be called just | |
353 | before the run loop waits and send the idle events from there. | |
354 | ||
355 | It also has the desirable effect of only sending the wx idle events when | |
d13b34d3 | 356 | the event loop is actually going to block. If the event loop is being |
30cfcda5 DE |
357 | pumped manualy (e.g. like a PeekMessage) then the kCFRunLoopBeforeWaiting |
358 | observer never fires. Our Yield() method depends on this because sending | |
359 | idle events from within Yield would be bad. | |
360 | ||
361 | Normally you might think that we could just set the observer up once and | |
362 | leave it attached. However, this is problematic because our run loop | |
363 | observer calls user code (the idle handlers) which can actually display | |
364 | modal dialogs. Displaying a modal dialog causes reentry of the event | |
365 | loop, usually in a different run loop mode than the main loop (e.g. in | |
366 | modal-dialog mode instead of default mode). Because we only register the | |
367 | observer with the run loop mode at the time of this call, it won't be | |
368 | called from a modal loop. | |
369 | ||
370 | We want it to be called and thus we need a new observer. | |
371 | */ | |
047c1182 DE |
372 | void wxApp::CocoaDelegate_applicationWillUpdate() |
373 | { | |
374 | wxLogTrace(wxTRACE_COCOA,wxT("applicationWillUpdate")); | |
375 | ||
376 | // CFRunLoopRef cfRunLoop = [[NSRunLoop currentRunLoop] getCFRunLoop]; | |
377 | CFRunLoopRef cfRunLoop = CFRunLoopGetCurrent(); | |
378 | wxCFRef<CFStringRef> cfRunLoopMode(CFRunLoopCopyCurrentMode(cfRunLoop)); | |
379 | ||
30cfcda5 DE |
380 | /* If we have an observer and that observer is for the wrong run loop |
381 | mode then invalidate it and release it. | |
382 | */ | |
047c1182 DE |
383 | if(m_cfRunLoopIdleObserver != NULL && m_cfObservedRunLoopMode != cfRunLoopMode) |
384 | { | |
385 | CFRunLoopObserverInvalidate(m_cfRunLoopIdleObserver); | |
386 | m_cfRunLoopIdleObserver.reset(); | |
387 | } | |
388 | #if 0 | |
389 | ++sg_cApplicationWillUpdate; | |
390 | #endif | |
30cfcda5 DE |
391 | /* This will be true either on the first call or when the above code has |
392 | invalidated and released the exisiting observer. | |
393 | */ | |
047c1182 DE |
394 | if(m_cfRunLoopIdleObserver == NULL) |
395 | { | |
396 | // Enable idle event handling | |
397 | CFRunLoopObserverContext observerContext = | |
398 | { 0 | |
399 | , this | |
400 | , NULL | |
401 | , NULL | |
402 | , NULL | |
403 | }; | |
30cfcda5 DE |
404 | /* NOTE: I can't recall why we don't just let the observer repeat |
405 | instead of invalidating itself each time it fires thus requiring | |
406 | it to be recreated for each shot but there was if I remember | |
407 | some good (but very obscure) reason for it. | |
408 | ||
409 | On the other hand, I could be wrong so don't take that as gospel. | |
410 | */ | |
047c1182 DE |
411 | m_cfRunLoopIdleObserver.reset(CFRunLoopObserverCreate(kCFAllocatorDefault, kCFRunLoopBeforeWaiting, /*repeats*/FALSE, /*priority*/0, ObserveMainRunLoopBeforeWaiting, &observerContext)); |
412 | m_cfObservedRunLoopMode = cfRunLoopMode; | |
413 | CFRunLoopAddObserver(cfRunLoop, m_cfRunLoopIdleObserver, m_cfObservedRunLoopMode); | |
414 | } | |
415 | } | |
416 | ||
417 | static inline bool FakeNeedMoreIdle() | |
418 | { | |
419 | #if 0 | |
420 | // Return true on every 10th call. | |
421 | static int idleCount = 0; | |
422 | return ++idleCount % 10; | |
423 | #else | |
424 | return false; | |
425 | #endif | |
426 | } | |
427 | ||
30cfcda5 DE |
428 | /*! |
429 | Called by CFRunLoop just before waiting. This is the appropriate time to | |
430 | send idle events. Unlike other ports, we don't peek the queue for events | |
431 | and stop idling if there is one. Instead, if the user requests more idle | |
432 | events we tell Cocoa to send us an applicationWillUpdate notification | |
433 | which will cause our observer of that notification to tell CFRunLoop to | |
434 | call us before waiting which will cause us to be fired again but only | |
435 | after exhausting the event queue. | |
436 | ||
437 | The reason we do it this way is that peeking for an event causes CFRunLoop | |
438 | to reenter and fire off its timers, observers, and sources which we're | |
439 | better off avoiding. Doing it this way, we basically let CFRunLoop do the | |
440 | work of peeking for the next event which is much nicer. | |
441 | */ | |
047c1182 DE |
442 | void wxApp::CF_ObserveMainRunLoopBeforeWaiting(CFRunLoopObserverRef observer, int activity) |
443 | { | |
30cfcda5 DE |
444 | // Ensure that CocoaDelegate_applicationWillUpdate will recreate us. |
445 | // We've already been invalidated by CFRunLoop because we are one-shot. | |
047c1182 DE |
446 | m_cfRunLoopIdleObserver.reset(); |
447 | #if 0 | |
448 | wxLogTrace(wxTRACE_COCOA,wxT("Idle BEGIN (%d)"), sg_cApplicationWillUpdate); | |
449 | sg_cApplicationWillUpdate = 0; | |
450 | #else | |
451 | wxLogTrace(wxTRACE_COCOA,wxT("Idle BEGIN")); | |
452 | #endif | |
453 | if( ProcessIdle() || FakeNeedMoreIdle() ) | |
454 | { | |
455 | wxLogTrace(wxTRACE_COCOA, wxT("Idle REQUEST MORE")); | |
456 | [NSApp setWindowsNeedUpdate:YES]; | |
457 | } | |
458 | else | |
459 | { | |
460 | wxLogTrace(wxTRACE_COCOA, wxT("Idle END")); | |
461 | } | |
462 | } | |
463 | ||
30cfcda5 DE |
464 | /* A note about Cocoa's event loops vs. run loops: |
465 | ||
466 | It's important to understand that Cocoa has a two-level event loop. The | |
467 | outer level is run by NSApplication and can only ever happen on the main | |
468 | thread. The nextEventMatchingMask:untilDate:inMode:dequeue: method returns | |
469 | the next event which is then given to sendEvent: to send it. These | |
470 | methods are defined in NSApplication and are thus part of AppKit. | |
471 | ||
472 | Events (NSEvent) are only sent due to actual user actions like clicking | |
473 | the mouse or moving the mouse or pressing a key and so on. There are no | |
474 | paint events; there are no timer events; there are no socket events; there | |
475 | are no idle events. | |
476 | ||
477 | All of those types of "events" have nothing to do with the GUI at all. | |
478 | That is why Cocoa's AppKit doesn't implement them. Instead, they are | |
479 | implemented in Foundation's NSRunLoop which on OS X uses CFRunLoop | |
480 | to do the actual work. | |
481 | ||
482 | How NSApplication uses NSRunLoop is rather interesting. Basically, it | |
483 | interacts with NSRunLoop only from within the nextEventMatchingMask | |
484 | method. It passes its inMode: argument almost directly to NSRunLoop | |
485 | and thus CFRunLoop. The run loop then runs (e.g. loops) until it | |
486 | is told to exit. The run loop calls the callout functions directly. | |
487 | From within those callout functions the run loop is considered to | |
488 | be running. Presumably, the AppKit installs a run loop source to | |
489 | receive messages from the window server over the mach port (like a | |
490 | socket). For some messages (e.g. need to paint) the AppKit will | |
491 | call application code like drawRect: without exiting the run loop. | |
492 | For other messages (ones that can be encapsulated in an NSEvent) | |
493 | the AppKit tells the run loop to exit which returns control to | |
494 | the nextEventMatchingMask method which then returns the NSEvent | |
495 | object. It's important to note that once the runloop has exited | |
496 | it is no longer considered running and thus if you ask it which | |
497 | mode it is running in it will return nil. | |
498 | ||
499 | When manually pumping the event loop care should be taken to | |
500 | tell it to run in the correct mode. For instance, if you are | |
501 | using it to run a modal dialog then you want to run it in | |
502 | the modal panel run loop mode. AppKit presumably has sources | |
503 | or timers or observers that specifically don't listen on this | |
504 | mode. Another interesting mode is the connection reply mode. | |
505 | This allows Cocoa to wait for a response from a distributed | |
506 | objects message without firing off user code that may result | |
507 | in a DO call being made thus recursing. So basically, the | |
508 | mode is a way for Cocoa to attempt to avoid run loop recursion | |
509 | but to allow it under certain circumstances. | |
510 | */ | |
511 |