func initGoType(fold *valueFold) {
if cdata.Ref() == atomic.LoadUintptr(&guiPaintRef) {
go RunMain(func() { _initGoType(fold, true) })
} else {
_initGoType(fold, false)
}
}
// wrapGoValue creates a new GoValue object in C++ land wrapping
// the Go value contained in the given interface.
//
// This must be run from the main GUI thread.
func wrapGoValue(engine *Engine, gvalue interface{}, owner valueOwner) (cvalue unsafe.Pointer) {
gvaluev := reflect.ValueOf(gvalue)
gvaluek := gvaluev.Kind()
if gvaluek == reflect.Struct && !hashable(gvalue) {
name := gvaluev.Type().Name()
if name != "" {
name = " (" + name + ")"
}
panic("cannot hand an unhashable struct value" + name + " to QML logic; use its address instead")
}
if gvaluek == reflect.Ptr && gvaluev.Elem().Kind() == reflect.Ptr {
panic("cannot hand pointer of pointer to QML logic; use a simple pointer instead")
}
painting := cdata.Ref() == atomic.LoadUintptr(&guiPaintRef)
// Cannot reuse a jsOwner because the QML runtime may choose to destroy
// the value _after_ we hand it a new reference to the same value.
// See issue #68 for details.
prev, ok := engine.values[gvalue]
if ok && (prev.owner == cppOwner || painting) {
return prev.cvalue
}
if painting {
panic("cannot allocate new objects while painting")
}
parent := nilPtr
if owner == cppOwner {
parent = engine.addr
}
fold := &valueFold{
engine: engine,
gvalue: gvalue,
owner: owner,
}
fold.cvalue = C.newGoValue(unsafe.Pointer(fold), typeInfo(gvalue), parent)
if prev != nil {
// Put new fold first so the single cppOwner, if any, is always the first entry.
fold.next = prev
prev.prev = fold
}
engine.values[gvalue] = fold
//fmt.Printf("[DEBUG] value alive (wrapped): cvalue=%x gvalue=%x/%#v\n", fold.cvalue, addrOf(fold.gvalue), fold.gvalue)
stats.valuesAlive(+1)
C.engineSetContextForObject(engine.addr, fold.cvalue)
switch owner {
case cppOwner:
C.engineSetOwnershipCPP(engine.addr, fold.cvalue)
case jsOwner:
C.engineSetOwnershipJS(engine.addr, fold.cvalue)
}
return fold.cvalue
}
// Run runs the main QML event loop, runs f, and then terminates the
// event loop once f returns.
//
// Most functions from the qml package block until Run is called.
//
// The Run function must necessarily be called from the same goroutine as
// the main function or the application may fail when running on Mac OS.
func Run(f func() error) error {
if cdata.Ref() != guiMainRef {
panic("Run must be called on the initial goroutine so apps are portable to Mac OS")
}
if !atomic.CompareAndSwapInt32(&initialized, 0, 1) {
panic("qml.Run called more than once")
}
C.newGuiApplication()
C.idleTimerInit((*C.int32_t)(&guiIdleRun))
done := make(chan error, 1)
go func() {
RunMain(func() {}) // Block until the event loop is running.
done <- f()
C.applicationExit()
}()
C.applicationExec()
return <-done
}
// RunMain runs f in the main QML thread and waits for f to return.
//
// This is meant to be used by extensions that integrate directly with the
// underlying QML logic.
func RunMain(f func()) {
ref := cdata.Ref()
if ref == guiMainRef || ref == atomic.LoadUintptr(&guiPaintRef) {
// Already within the GUI or render threads. Attempting to wait would deadlock.
f()
return
}
// Tell Qt we're waiting for the idle hook to be called.
if atomic.AddInt32(&guiIdleRun, 1) == 1 {
C.idleTimerStart()
}
// Send f to be executed by the idle hook in the main GUI thread.
guiFunc <- f
// Wait until f is done executing.
<-guiDone
}
//export hookGoValuePaint
func hookGoValuePaint(enginep, foldp unsafe.Pointer, reflectIndex C.intptr_t) {
// Besides a convenience this is a workaround for http://golang.org/issue/8588
defer printPaintPanic()
defer atomic.StoreUintptr(&guiPaintRef, 0)
// The main GUI thread is mutex-locked while paint methods are called,
// so no two paintings should be happening at the same time.
atomic.StoreUintptr(&guiPaintRef, cdata.Ref())
fold := ensureEngine(enginep, foldp)
if fold.init.IsValid() {
return
}
painter := &Painter{engine: fold.engine, obj: &Common{fold.cvalue, fold.engine, newConnections()}}
v := reflect.ValueOf(fold.gvalue)
method := v.Method(int(reflectIndex))
method.Call([]reflect.Value{reflect.ValueOf(painter)})
}
func init() {
runtime.LockOSThread()
guiMainRef = cdata.Ref()
}