diff --git a/button.go b/button.go
index a0c4e67..630c684 100644
--- a/button.go
+++ b/button.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern void doButtonOnClicked(uiButton *, void *);
+// // see golang/go#19835
+// typedef void (*buttonCallback)(uiButton *, void *);
 import "C"
 
 // Button is a Control that represents a button that the user can
@@ -27,7 +29,7 @@ func NewButton(text string) *Button {
 	b.b = C.uiNewButton(ctext)
 	freestr(ctext)
 
-	C.uiButtonOnClicked(b.b, C.doButtonOnClicked, nil)
+	C.uiButtonOnClicked(b.b, C.buttonCallback(C.doButtonOnClicked), nil)
 
 	b.ControlBase = NewControlBase(b, uintptr(unsafe.Pointer(b.b)))
 	return b
diff --git a/checkbox.go b/checkbox.go
index d7fd949..8177226 100644
--- a/checkbox.go
+++ b/checkbox.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern void doCheckboxOnToggled(uiCheckbox *, void *);
+// // see golang/go#19835
+// typedef void (*checkboxCallback)(uiCheckbox *, void *);
 import "C"
 
 // Checkbox is a Control that represents a box with a text label at its
@@ -28,7 +30,7 @@ func NewCheckbox(text string) *Checkbox {
 	c.c = C.uiNewCheckbox(ctext)
 	freestr(ctext)
 
-	C.uiCheckboxOnToggled(c.c, C.doCheckboxOnToggled, nil)
+	C.uiCheckboxOnToggled(c.c, C.checkboxCallback(C.doCheckboxOnToggled), nil)
 
 	c.ControlBase = NewControlBase(c, uintptr(unsafe.Pointer(c.c)))
 	return c
diff --git a/combobox.go b/combobox.go
index 059422d..1e381de 100644
--- a/combobox.go
+++ b/combobox.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern void doComboboxOnSelected(uiCombobox *, void *);
+// // see golang/go#19835
+// typedef void (*comboboxCallback)(uiCombobox *, void *);
 import "C"
 
 // Combobox is a Control that represents a drop-down list of strings
@@ -25,7 +27,7 @@ func NewCombobox() *Combobox {
 
 	c.c = C.uiNewCombobox()
 
-	C.uiComboboxOnSelected(c.c, C.doComboboxOnSelected, nil)
+	C.uiComboboxOnSelected(c.c, C.comboboxCallback(C.doComboboxOnSelected), nil)
 
 	c.ControlBase = NewControlBase(c, uintptr(unsafe.Pointer(c.c)))
 	return c
diff --git a/control.go b/control.go
index 03cf181..23a8ddf 100644
--- a/control.go
+++ b/control.go
@@ -130,8 +130,12 @@ func (c *ControlBase) Disable() {
 // This function only works on Controls that use ControlBase.
 func ControlFromLibui(c uintptr) Control {
 	// comma-ok form to avoid creating nil entries
-	c, _ := controls[(*C.uiControl)(unsafe.Pointer(c))]
-	return c
+	cc, _ := controls[(*C.uiControl)(unsafe.Pointer(c))]
+	return cc
+}
+
+func touiControl(c uintptr) *C.uiControl {
+	return (*C.uiControl)(unsafe.Pointer(c))
 }
 
 // LibuiFreeText allows implementations of Control
diff --git a/datetimepicker.go b/datetimepicker.go
index 6e64e34..3436b3c 100644
--- a/datetimepicker.go
+++ b/datetimepicker.go
@@ -16,6 +16,8 @@ import (
 // 	return (struct tm *) pkguiAlloc(sizeof (struct tm));
 // }
 // extern void doDateTimePickerOnChanged(uiDateTimePicker *, void *);
+// // see golang/go#19835
+// typedef void (*dtpCallback)(uiDateTimePicker *, void *);
 import "C"
 
 // DateTimePicker is a Control that represents a field where the user
@@ -31,7 +33,7 @@ func finishNewDateTimePicker(dd *C.uiDateTimePicker) *DateTimePicker {
 
 	d.d = dd
 
-	C.uiDateTimePickerOnChanged(d.d, C.doDateTimePickerOnChanged, nil)
+	C.uiDateTimePickerOnChanged(d.d, C.dtpCallback(C.doDateTimePickerOnChanged), nil)
 
 	d.ControlBase = NewControlBase(d, uintptr(unsafe.Pointer(d.d)))
 	return d
@@ -40,7 +42,7 @@ func finishNewDateTimePicker(dd *C.uiDateTimePicker) *DateTimePicker {
 // NewDateTimePicker creates a new DateTimePicker that shows
 // both a date and a time.
 func NewDateTimePicker() *DateTimePicker {
-	return finishNewDateTImePicker(C.uiNewDateTimePicker())
+	return finishNewDateTimePicker(C.uiNewDateTimePicker())
 }
 
 // NewDatePicker creates a new DateTimePicker that shows
@@ -72,7 +74,7 @@ func (d *DateTimePicker) Time() time.Time {
 }
 
 // SetTime sets the time in the DateTimePicker to t.
-// t's components are read as-is via t.Date() and t.Time();
+// t's components are read as-is via t.Date() and t.Clock();
 // no time zone manipulations are done.
 func (d *DateTimePicker) SetTime(t time.Time) {
 	tm := C.allocTimeStruct()
@@ -81,7 +83,7 @@ func (d *DateTimePicker) SetTime(t time.Time) {
 	tm.tm_year = C.int(year - 1900)
 	tm.tm_mon = C.int(mon - 1)
 	tm.tm_mday = C.int(mday)
-	hour, min, sec := t.Time()
+	hour, min, sec := t.Clock()
 	tm.tm_hour = C.int(hour)
 	tm.tm_min = C.int(min)
 	tm.tm_sec = C.int(sec)
diff --git a/editablecombobox.go b/editablecombobox.go
index 31db150..1242928 100644
--- a/editablecombobox.go
+++ b/editablecombobox.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern void doEditableComboboxOnChanged(uiEditableCombobox *, void *);
+// // see golang/go#19835
+// typedef void (*editableComboboxCallback)(uiEditableCombobox *, void *);
 import "C"
 
 // EditableCombobox is a Control that represents a drop-down list
@@ -25,7 +27,7 @@ func NewEditableCombobox() *EditableCombobox {
 
 	c.c = C.uiNewEditableCombobox()
 
-	C.uiEditableComboboxOnChanged(c.c, C.doEditableComboboxOnChanged, nil)
+	C.uiEditableComboboxOnChanged(c.c, C.editableComboboxCallback(C.doEditableComboboxOnChanged), nil)
 
 	c.ControlBase = NewControlBase(c, uintptr(unsafe.Pointer(c.c)))
 	return c
@@ -48,7 +50,7 @@ func (e *EditableCombobox) Text() string {
 }
 
 // SetText sets the text in the entry of the EditableCombobox.
-func (e *EditableCombobox) SetText(index int) {
+func (e *EditableCombobox) SetText(text string) {
 	ctext := C.CString(text)
 	C.uiEditableComboboxSetText(e.c, ctext)
 	freestr(ctext)
@@ -58,7 +60,7 @@ func (e *EditableCombobox) SetText(index int) {
 // item or changes the text in the EditableCombobox. Only one
 // function can be registered at a time.
 func (e *EditableCombobox) OnChanged(f func(*EditableCombobox)) {
-	c.onChanged = f
+	e.onChanged = f
 }
 
 //export doEditableComboboxOnChanged
diff --git a/entry.go b/entry.go
index 2b6cc11..52da537 100644
--- a/entry.go
+++ b/entry.go
@@ -12,6 +12,8 @@ import (
 
 // #include "ui.h"
 // extern void doEntryOnChanged(uiEntry *, void *);
+// // see golang/go#19835
+// typedef void (*entryCallback)(uiEntry *, void *);
 import "C"
 
 // Entry is a Control that represents a space that the user can
@@ -27,7 +29,7 @@ func finishNewEntry(ee *C.uiEntry) *Entry {
 
 	e.e = ee
 
-	C.uiEntryOnChanged(e.e, C.doEntryOnChanged, nil)
+	C.uiEntryOnChanged(e.e, C.entryCallback(C.doEntryOnChanged), nil)
 
 	e.ControlBase = NewControlBase(e, uintptr(unsafe.Pointer(e.e)))
 	return e
diff --git a/main.go b/main.go
index 1ba6d05..6500345 100644
--- a/main.go
+++ b/main.go
@@ -12,7 +12,9 @@ import (
 // #include "ui.h"
 // extern void doQueueMain(void *);
 // extern int doOnShouldQuit(void *);
-// extern int doOnTimer(void *);
+// // see golang/go#19835
+// typedef void (*queueMainCallback)(void *);
+// typedef int (*onShouldQuitCallback)(void *);
 import "C"
 
 // make sure main() runs on the first thread created by the OS
@@ -39,7 +41,7 @@ func Main(f func()) error {
 		C.uiFreeInitError(estr)
 		return err
 	}
-	C.uiOnShouldQuit(C.doOnShouldQuit, nil)
+	C.uiOnShouldQuit(C.onShouldQuitCallback(C.doOnShouldQuit), nil)
 	QueueMain(f)
 	C.uiMain()
 	return nil
@@ -88,7 +90,7 @@ func QueueMain(f func()) {
 		}
 	}
 	qmmap[n] = f
-	C.uiQueueMain(C.doQueueMain, unsafe.Pointer(n))
+	C.uiQueueMain(C.queueMainCallback(C.doQueueMain), unsafe.Pointer(n))
 }
 
 //export doQueueMain
diff --git a/radiobuttons.go b/radiobuttons.go
index 59b5665..5f7505d 100644
--- a/radiobuttons.go
+++ b/radiobuttons.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern void doRadioButtonsOnSelected(uiRadioButtons *, void *);
+// // see golang/go#19835
+// typedef void (*radioButtonsCallback)(uiRadioButtons *, void *);
 import "C"
 
 // RadioButtons is a Control that represents a set of checkable
@@ -24,7 +26,7 @@ func NewRadioButtons() *RadioButtons {
 
 	r.r = C.uiNewRadioButtons()
 
-	C.uiRadioButtonsOnSelected(r.r, C.doRadioButtonsOnSelected, nil)
+	C.uiRadioButtonsOnSelected(r.r, C.radioButtonsCallback(C.doRadioButtonsOnSelected), nil)
 
 	r.ControlBase = NewControlBase(r, uintptr(unsafe.Pointer(r.r)))
 	return r
diff --git a/slider.go b/slider.go
index 68218bc..91656cf 100644
--- a/slider.go
+++ b/slider.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern void doSliderOnChanged(uiSlider *, void *);
+// // see golang/go#19835
+// typedef void (*sliderCallback)(uiSlider *, void *);
 import "C"
 
 // Slider is a Control that represents a horizontal bar that represents
@@ -25,7 +27,7 @@ func NewSlider(min int, max int) *Slider {
 
 	s.s = C.uiNewSlider(C.int(min), C.int(max))
 
-	C.uiSliderOnChanged(s.s, C.doSliderOnChanged, nil)
+	C.uiSliderOnChanged(s.s, C.sliderCallback(C.doSliderOnChanged), nil)
 
 	s.ControlBase = NewControlBase(s, uintptr(unsafe.Pointer(s.s)))
 	return s
diff --git a/spinbox.go b/spinbox.go
index a1dfc3b..27dd287 100644
--- a/spinbox.go
+++ b/spinbox.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern void doSpinboxOnChanged(uiSpinbox *, void *);
+// // see golang/go#19835
+// typedef void (*spinboxCallback)(uiSpinbox *, void *);
 import "C"
 
 // Spinbox is a Control that represents a space where the user can
@@ -25,7 +27,7 @@ func NewSpinbox(min int, max int) *Spinbox {
 
 	s.s = C.uiNewSpinbox(C.int(min), C.int(max))
 
-	C.uiSpinboxOnChanged(s.s, C.doSpinboxOnChanged, nil)
+	C.uiSpinboxOnChanged(s.s, C.spinboxCallback(C.doSpinboxOnChanged), nil)
 
 	s.ControlBase = NewControlBase(s, uintptr(unsafe.Pointer(s.s)))
 	return s
diff --git a/window.go b/window.go
index 784d485..a40ddd9 100644
--- a/window.go
+++ b/window.go
@@ -8,6 +8,8 @@ import (
 
 // #include "ui.h"
 // extern int doWindowOnClosing(uiWindow *, void *);
+// // see golang/go#19835
+// typedef int (*windowOnClosingCallback)(uiWindow *, void *);
 import "C"
 
 // Window is a Control that represents a top-level window.
@@ -29,7 +31,7 @@ func NewWindow(title string, width int, height int, hasMenubar bool) *Window {
 	w.w = C.uiNewWindow(ctitle, C.int(width), C.int(height), frombool(hasMenubar))
 	freestr(ctitle)
 
-	C.uiWindowOnClosing(w.w, C.doWindowOnClosing, nil)
+	C.uiWindowOnClosing(w.w, C.windowOnClosingCallback(C.doWindowOnClosing), nil)
 
 	w.ControlBase = NewControlBase(w, uintptr(unsafe.Pointer(w.w)))
 	return w