andlabs-ui/uitask_darwin.go

109 lines
3.4 KiB
Go

// 28 february 2014
package ui
import (
"fmt"
"runtime"
"unsafe"
)
// #cgo LDFLAGS: -lobjc -framework Foundation -framework AppKit
// #include "objc_darwin.h"
import "C"
var uitask chan func()
var (
_NSAutoreleasePool = objc_getClass("NSAutoreleasePool")
_NSValue = objc_getClass("NSValue")
_valueWithPointer = sel_getUid("valueWithPointer:")
_performSelectorOnMainThread =
sel_getUid("performSelectorOnMainThread:withObject:waitUntilDone:")
_stop = sel_getUid("stop:")
_postEventAtStart = sel_getUid("postEvent:atStart:")
_pointerValue = sel_getUid("pointerValue")
_run = sel_getUid("run")
)
func ui(main func()) error {
runtime.LockOSThread()
uitask = make(chan func())
NSApp, err := initCocoa()
if err != nil {
return err
}
// Cocoa must run on the first thread created by the program, so we run our dispatcher on another thread instead
go func() {
for f := range uitask {
// we need to make an NSAutoreleasePool, otherwise we get leak warnings on stderr
pool := C.objc_msgSend_noargs(_NSAutoreleasePool, _new)
fp := C.objc_msgSend_ptr(_NSValue, _valueWithPointer,
unsafe.Pointer(&f))
C.objc_msgSend_sel_id_bool(
appDelegate,
_performSelectorOnMainThread,
_uitask,
fp,
C.BOOL(C.YES)) // wait so we can properly drain the autorelease pool; on other platforms we wind up waiting anyway (since the main thread can only handle one thing at a time) so
C.objc_msgSend_noargs(pool, _release)
}
}()
go func() {
main()
uitask <- func() {
// -[NSApplication stop:] stops the event loop; it won't do a clean termination, but we're not too concerned with that (at least not on the other platforms either so)
// we can't call -[NSApplication terminate:] because that will just quit the program, ensuring we never leave ui.Go()
C.objc_msgSend_id(NSApp, _stop, NSApp)
// simply calling -[NSApplication stop:] is not good enough, as the stop flag is only checked when an event comes in
// we have to create a "proper" event; a blank event will just throw an exception
C.objc_msgSend_id_bool(NSApp,
_postEventAtStart,
C.makeDummyEvent(),
C.BOOL(C.NO)) // not at start, just in case there are other events pending (TODO is this correct?)
}
}()
C.objc_msgSend_noargs(NSApp, _run)
return nil
}
// TODO move to init_darwin.go?
var (
_NSApplication = objc_getClass("NSApplication")
_sharedApplication = sel_getUid("sharedApplication")
_setActivationPolicy = sel_getUid("setActivationPolicy:")
_activateIgnoringOtherApps = sel_getUid("activateIgnoringOtherApps:")
)
func initCocoa() (NSApp C.id, err error) {
NSApp = C.objc_msgSend_noargs(_NSApplication, _sharedApplication)
r := C.objc_msgSend_int(NSApp, _setActivationPolicy,
0) // NSApplicationActivationPolicyRegular
if C.BOOL(uintptr(unsafe.Pointer(r))) != C.BOOL(C.YES) {
err = fmt.Errorf("error setting NSApplication activation policy (basically identifies our program as a separate program; needed for several things, such as Dock icon, application menu, window resizing, etc.) (unknown reason)")
return
}
C.objc_msgSend_bool(NSApp, _activateIgnoringOtherApps, C.BOOL(C.YES)) // TODO actually do C.NO here? Russ Cox does YES in his devdraw; the docs say the Finder does NO
err = mkAppDelegate()
if err != nil {
return
}
err = mkAreaClass()
return
}
//export appDelegate_uitask
func appDelegate_uitask(self C.id, sel C.SEL, arg C.id) {
p := C.objc_msgSend_noargs(arg, _pointerValue)
f := (*func ())(unsafe.Pointer(p))
(*f)()
}