Don't ask...

button.go

@@ -17,6 +17,7 @@ type Button struct {
 	checkedChangedPublisher EventPublisher
 	clickedPublisher        EventPublisher
 	textChangedPublisher    EventPublisher
+	image                   Image
 }
 
 func (b *Button) init() {
@@ -40,6 +41,36 @@ func (b *Button) init() {
 		b.textChangedPublisher.Event()))
 }
 
+func (b *Button) Image() Image {
+	return b.image
+}
+
+func (b *Button) SetImage(image Image) error {
+	var typ uintptr
+	var handle uintptr
+	switch img := image.(type) {
+	case nil:
+		// zeroes are good
+
+	case *Bitmap:
+		typ = win.IMAGE_BITMAP
+		handle = uintptr(img.hBmp)
+
+	case *Icon:
+		typ = win.IMAGE_ICON
+		handle = uintptr(img.hIcon)
+
+	default:
+		return newError("image must be either *walk.Bitmap or *walk.Icon")
+	}
+
+	b.SendMessage(win.BM_SETIMAGE, typ, handle)
+
+	b.image = image
+
+	return b.updateParentLayout()
+}
+
 func (b *Button) Text() string {
 	return windowText(b.hWnd)
 }

combobox.go

@@ -126,6 +126,18 @@ func newComboBoxWithStyle(parent Container, style uint32) (*ComboBox, error) {
 		},
 		cb.TextChanged()))
 
+	cb.MustRegisterProperty("HasCurrentItem", NewReadOnlyBoolProperty(
+		func() bool {
+			return cb.CurrentIndex() != -1
+		},
+		cb.CurrentIndexChanged()))
+
+	cb.MustRegisterProperty("TextNotEmpty", NewReadOnlyBoolProperty(
+		func() bool {
+			return cb.Text() != ""
+		},
+		cb.CurrentIndexChanged()))
+
 	cb.MustRegisterProperty("Value", NewProperty(
 		func() interface{} {
 			if cb.Editable() {
@@ -146,7 +158,11 @@ func newComboBoxWithStyle(parent Container, style uint32) (*ComboBox, error) {
 			}
 
 			if cb.bindingValueProvider == nil {
-				return newError("Data binding is only supported using a model that implements BindingValueProvider.")
+				if cb.model == nil {
+					return nil
+				} else {
+					return newError("Data binding is only supported using a model that implements BindingValueProvider.")
+				}
 			}
 
 			index := -1
@@ -180,7 +196,7 @@ func (cb *ComboBox) MinSizeHint() Size {
 	}
 
 	// FIXME: Use GetThemePartSize instead of guessing
-	w := maxi(defaultSize.Width, cb.maxItemTextWidth+26)
+	w := maxi(defaultSize.Width, cb.maxItemTextWidth+30)
 	h := defaultSize.Height + 1
 
 	return Size{w, h}
@@ -227,6 +243,8 @@ func (cb *ComboBox) resetItems() error {
 	cb.SetSuspended(true)
 	defer cb.SetSuspended(false)
 
+	cb.selChangeIndex = -1
+
 	if win.FALSE == cb.SendMessage(win.CB_RESETCONTENT, 0, 0) {
 		return newError("SendMessage(CB_RESETCONTENT)")
 	}
@@ -247,6 +265,8 @@ func (cb *ComboBox) resetItems() error {
 		}
 	}
 
+	cb.updateParentLayout()
+
 	return nil
 }
 
@@ -525,7 +545,9 @@ func (cb *ComboBox) WndProc(hwnd win.HWND, msg uint32, wParam, lParam uintptr) u
 
 		case win.CBN_SELENDCANCEL:
 			if cb.selChangeIndex != -1 {
-				cb.SetCurrentIndex(cb.selChangeIndex)
+				if cb.selChangeIndex < cb.model.ItemCount() {
+					cb.SetCurrentIndex(cb.selChangeIndex)
+				}
 
 				cb.selChangeIndex = -1
 			}
@@ -542,6 +564,11 @@ func (cb *ComboBox) WndProc(hwnd win.HWND, msg uint32, wParam, lParam uintptr) u
 
 			cb.selChangeIndex = -1
 		}
+
+	case win.WM_MOUSEWHEEL:
+		if !cb.Enabled() {
+			return 0
+		}
 	}
 
 	return cb.WidgetBase.WndProc(hwnd, msg, wParam, lParam)

container.go

@@ -35,7 +35,7 @@ func shouldLayoutWidget(widget Widget) bool {
 
 	_, isSpacer := widget.(*Spacer)
 
-	return isSpacer || widget.AsWindowBase().visible
+	return isSpacer || widget.AsWindowBase().visible || widget.AlwaysConsumeSpace()
 }
 
 func DescendantByName(container Container, name string) Widget {

databinding.go

@@ -31,6 +31,7 @@ type DataBinder struct {
 	autoSubmit                bool
 	canSubmit                 bool
 	inReset                   bool
+	dirty                     bool
 }
 
 func NewDataBinder() *DataBinder {
@@ -93,13 +94,15 @@ func (db *DataBinder) SetBoundWidgets(boundWidgets []Widget) {
 			db.property2Widget[prop] = widget
 
 			db.property2ChangedHandle[prop] = prop.Changed().Attach(func() {
+				db.dirty = true
+
 				if db.autoSubmit {
 					if prop.Get() == nil {
 						return
 					}
 
-					p, s := db.reflectValuesFromDataSource()
-					field := db.fieldBoundToProperty(p, s, prop)
+					v := reflect.ValueOf(db.dataSource)
+					field := db.fieldBoundToProperty(v, prop)
 					if !field.IsValid() {
 						return
 					}
@@ -230,6 +233,8 @@ func (db *DataBinder) Reset() error {
 
 	db.validateProperties()
 
+	db.dirty = false
+
 	return nil
 }
 
@@ -244,12 +249,23 @@ func (db *DataBinder) Submit() error {
 		return err
 	}
 
+	db.dirty = false
+
 	db.submittedPublisher.Publish()
 
 	return nil
 }
 
+func (db *DataBinder) Dirty() bool {
+	return db.dirty
+}
+
 func (db *DataBinder) submitProperty(prop Property, field reflect.Value) error {
+	if !field.CanSet() {
+		// FIXME: handle properly
+		return nil
+	}
+
 	value := prop.Get()
 	if value == nil {
 		// This happens e.g. if CurrentIndex() of a ComboBox returns -1.
@@ -284,13 +300,13 @@ func (db *DataBinder) submitProperty(prop Property, field reflect.Value) error {
 }
 
 func (db *DataBinder) forEach(f func(prop Property, field reflect.Value) error) error {
-	p, s := db.reflectValuesFromDataSource()
-	if p.IsNil() {
+	dsv := reflect.ValueOf(db.dataSource)
+	if dsv.Kind() == reflect.Ptr && dsv.IsNil() {
 		return nil
 	}
 
 	for _, prop := range db.properties {
-		field := db.fieldBoundToProperty(p, s, prop)
+		field := db.fieldBoundToProperty(dsv, prop)
 
 		if err := f(prop, field); err != nil {
 			return err
@@ -300,40 +316,78 @@ func (db *DataBinder) forEach(f func(prop Property, field reflect.Value) error)
 	return nil
 }
 
-func (db *DataBinder) reflectValuesFromDataSource() (p, s reflect.Value) {
-	p = reflect.ValueOf(db.dataSource)
-	if p.IsNil() {
-		return
+func (db *DataBinder) fieldBoundToProperty(v reflect.Value, prop Property) reflect.Value {
+	source := prop.Source().(string)
+	path := strings.Split(source, ".")
+
+	vv, err := reflectValueFromPath(v, path)
+	if err != nil {
+		panic(fmt.Sprintf("invalid source '%s'", source))
 	}
 
-	s = p.Elem()
+	return vv
+}
 
-	return
+func validateBindingMemberSyntax(member string) error {
+	// FIXME
+	return nil
 }
 
-func (db *DataBinder) fieldBoundToProperty(p, s reflect.Value, prop Property) reflect.Value {
-	var v reflect.Value
-	source := prop.Source().(string)
-	path := strings.Split(source, ".")
+func reflectValueFromPath(root reflect.Value, path []string) (reflect.Value, error) {
+	v := root
 
-	for i, name := range path {
-		v = s.FieldByName(name)
-		if !v.IsValid() {
-			panic(fmt.Sprintf("invalid element '%s' in source '%s'", name, source))
-		}
-		if i < len(path)-1 {
+	for _, name := range path {
+		var p reflect.Value
+		for v.Kind() == reflect.Ptr {
 			p = v
-			if p.IsNil() {
-				return reflect.Value{}
+			v = v.Elem()
+		}
+
+		// Try as field first.
+		var f reflect.Value
+		if v.Kind() == reflect.Struct {
+			f = v.FieldByName(name)
+		}
+		if f.IsValid() {
+			v = f
+		} else {
+			// No field, so let's see if we got a method.
+			var m reflect.Value
+			if p.IsValid() {
+				// Try pointer receiver first.
+				m = p.MethodByName(name)
+			}
+
+			if !m.IsValid() {
+				// No pointer, try directly.
+				m = v.MethodByName(name)
+			}
+			if !m.IsValid() {
+				return v, fmt.Errorf("bad member: '%s'", strings.Join(path, "."))
+			}
+
+			// We assume it takes no args and returns one mandatory value plus
+			// maybe an error.
+			rvs := m.Call(nil)
+			switch len(rvs) {
+			case 1:
+				v = rvs[0]
+
+			case 2:
+				rv2 := rvs[1].Interface()
+				if err, ok := rv2.(error); ok {
+					return v, err
+				} else if rv2 != nil {
+					return v, fmt.Errorf("Second method return value must implement error.")
+				}
+
+				v = rvs[0]
+
+			default:
+				return v, fmt.Errorf("Method must return a value plus optionally an error: %s", name)
 			}
-			s = p.Elem()
 		}
 	}
 
-	return v
-}
-
-func validateBindingMemberSyntax(member string) error {
-	// FIXME
-	return nil
+	return v, nil
 }