Handled all controls's created field.

button.go

@@ -30,7 +30,9 @@ func (b *Button) SetText(text string) (err error) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 
-	// TODO handle created
+	if b.created {
+		return b.sysData.setText(text)
+	}
 	b.initText = text
 	return nil
 }
@@ -40,8 +42,12 @@ func (b *Button) make(window *sysData) error {
 	defer b.lock.Unlock()
 
 	b.sysData.event = b.Clicked
-	return b.sysData.make(b.initText, 300, 300, window)
-	// TODO size to parent size
+	err := b.sysData.make(b.initText, 300, 300, window)
+	if err != nil {
+		return err
+	}
+	b.created = true
+	return nil
 }
 
 func (b *Button) setRect(x int, y int, width int, height int) error {

checkbox.go

@@ -30,7 +30,9 @@ func (c *Checkbox) SetText(text string) (err error) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	// TODO handle created
+	if c.created {
+		return c.sysData.setText(text)
+	}
 	c.initText = text
 	return nil
 }
@@ -51,8 +53,12 @@ func (c *Checkbox) make(window *sysData) error {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	return c.sysData.make(c.initText, 300, 300, window)
-	// TODO size to parent size
+	err := c.sysData.make(c.initText, 300, 300, window)
+	if err != nil {
+		return err
+	}
+	c.created = true
+	return nil
 }
 
 func (c *Checkbox) setRect(x int, y int, width int, height int) error {

combobox.go

@@ -33,7 +33,10 @@ func (c *Combobox) Selection() (string, error) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	return c.sysData.text()
+	if c.created {
+		return c.sysData.text()
+	}
+	return "", nil
 }
 
 // TODO SelectedIndex
@@ -52,6 +55,7 @@ func (c *Combobox) make(window *sysData) (err error) {
 			return err
 		}
 	}
+	c.created = true
 	return nil
 }
 

label.go

@@ -29,7 +29,12 @@ func (l *Label) make(window *sysData) error {
 	l.lock.Lock()
 	defer l.lock.Unlock()
 
-	return l.sysData.make(l.initText, 300, 300, window)
+	err := l.sysData.make(l.initText, 300, 300, window)
+	if err != nil {
+		return err
+	}
+	l.created = true
+	return nil
 }
 
 func (l *Label) setRect(x int, y int, width int, height int) error {

listbox.go

@@ -46,6 +46,7 @@ func (l *Listbox) make(window *sysData) (err error) {
 			return err
 		}
 	}
+	l.created = true
 	return nil
 }
 

stack.go

@@ -40,6 +40,7 @@ func (s *Stack) make(window *sysData) error {
 			return err
 		}
 	}
+	s.created = true
 	return nil
 }