andlabs-ui/uitask_darwin.go

116 lines
3.4 KiB
Go

// 28 february 2014
package ui
import (
"fmt"
"runtime"
"unsafe"
)
/*
We will create an Objective-C class goAppDelegate. It contains two methods:
- (void)applicationDidFinishLoading:(NSNotification *)unused
will signal to ui() that we are now in the Cocoa event loop; we make our goAppDelegate instance the NSApplication delegate
- (void)uitask:(NSValue *)functionPointer
the function that actually performs our UI task functions; it is called with NSObject's performSelectorOnMainThread system
*/
// #cgo LDFLAGS: -lobjc -framework Foundation -framework AppKit
// #include "objc_darwin.h"
// extern void appDelegate_applicationDidFinishLaunching(id, SEL, id);
// extern void appDelegate_uitask(id, SEL, id);
import "C"
var uitask chan func()
var mtret chan interface{}
var (
_NSAutoreleasePool = objc_getClass("NSAutoreleasePool")
_NSValue = objc_getClass("NSValue")
_uitask = sel_getUid("uitask:")
_valueWithPointer = sel_getUid("valueWithPointer:")
_performSelectorOnMainThread =
sel_getUid("performSelectorOnMainThread:withObject:waitUntilDone:")
_pointerValue = sel_getUid("pointerValue")
)
func ui(initDone chan error) {
runtime.LockOSThread()
uitask = make(chan func())
mtret = make(chan interface{})
go mainThread()
v := <-mtret
if err, ok := v.(error); err {
initDone <- fmt.Errorf("error initializing Cocoa: %v", err)
return
}
appDelegate := v.(C.id)
for f := range uitask {
// we need to make an NSAutoreleasePool, otherwise we get leak warnings on stderr
pool := objc_new(_NSAutoreleasePool)
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
objc_release(pool)
}
}
const (
_goAppDelegate = "goAppDelegate"
)
var (
_NSApplication = objc_getClass("NSApplication")
_sharedApplication = sel_getUid("sharedApplication")
_applicationDidFinishLaunching = sel_getUid("applicationDidFinishLaunching:")
_run = sel_getUid("run")
)
func mainThread() {
runtime.LockOSThread()
_NSApp := C.objc_msgSend_noargs(_NSApplication, _sharedApplication)
appdelegateclass, err := makeDelegateClass(_goAppDelegate)
if err != nil {
mtret <- fmt.Errorf("error creating NSApplication delegate: %v", err)
return
}
err = addDelegateMethod(appdelegateclass, _applicationDidFinishLaunching,
C.appDelegate_applicationDidFinishLaunching)
if err != nil {
mtret <- fmt.Errorf("error adding NSApplication delegate applicationDidFinishLaunching: method (to start UI loop): %v", err)
return
}
err = addDelegateMethod(appdelegateclass, _uitask, C.appDelegate_uitask)
if err != nil {
mtret <- fmt.Errorf("error adding NSApplication delegate uitask: method (to do UI tasks): %v", err)
return
}
appDelegate := objc_new(objc_getClass(_goAppDelegate))
objc_setDelegate(_NSApp, appDelegate)
// and that's it, really
C.objc_msgSend_noargs(_NSApp, _run)
}
//export appDelegate_applicationDidFinishLaunching
func appDelegate_applicationDidFinishLaunching(self C.id, sel C.SEL, arg C.id) {
mtret <- self
}
//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)()
}