// guiLoop runs the main GUI thread event loop in C++ land.
func guiLoop() {
runtime.LockOSThread()
guiLoopRef = tref.Ref()
C.newGuiApplication()
C.idleTimerInit(&hookWaiting)
guiLoopReady.Unlock()
C.applicationExec()
}
// 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 := tref.Ref() == atomic.LoadUintptr(&guiPaintRef)
prev, ok := engine.values[gvalue]
if ok && (prev.owner == owner || 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 {
prev.next = fold
fold.prev = prev
} else {
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
}
//export hookGoValuePaint
func hookGoValuePaint(enginep, foldp unsafe.Pointer, reflectIndex C.intptr_t) {
fold := ensureEngine(enginep, foldp)
v := reflect.ValueOf(fold.gvalue)
// 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, tref.Ref())
painter := &Painter{fold.engine, &Common{fold.cvalue, fold.engine}}
method := v.Method(int(reflectIndex))
method.Call([]reflect.Value{reflect.ValueOf(painter)})
atomic.StoreUintptr(&guiPaintRef, 0)
}
// gui runs f in the main GUI thread and waits for f to return.
func gui(f func()) {
ref := tref.Ref()
if ref == guiLoopRef || 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((*int32)(unsafe.Pointer(&hookWaiting)), 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
}