From 2b4f36e26fee16f1cea831e5f7003acd9f9115f6 Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander.neumann@picos-software.com>
Date: Mon, 25 Feb 2019 16:45:48 +0100
Subject: [PATCH] Add two-way binding for checked menu item to bool property
 via Action.Checked

---
 action.go                   | 42 +++++++++++++++++++++++++++++++++++++
 declarative/action.go       |  9 ++++++--
 examples/actions/actions.go | 13 ++++++++++++
 menu.go                     | 33 +++++++++++++++++++++++++----
 4 files changed, 91 insertions(+), 6 deletions(-)

diff --git a/action.go b/action.go
index 4c106dd9..554cdc3f 100644
--- a/action.go
+++ b/action.go
@@ -27,6 +27,8 @@ type Action struct {
 	text                          string
 	toolTip                       string
 	image                         *Bitmap
+	checkedCondition              Condition
+	checkedConditionChangedHandle int
 	enabledCondition              Condition
 	enabledConditionChangedHandle int
 	visibleCondition              Condition
@@ -114,6 +116,16 @@ func (a *Action) Checked() bool {
 }
 
 func (a *Action) SetChecked(value bool) (err error) {
+	if a.checkedCondition != nil {
+		if bp, ok := a.checkedCondition.(*boolProperty); ok {
+			if err := bp.Set(value); err != nil {
+				return err
+			}
+		} else {
+			return newError("CheckedCondition != nil")
+		}
+	}
+
 	if value != a.checked {
 		old := a.checked
 
@@ -128,6 +140,32 @@ func (a *Action) SetChecked(value bool) (err error) {
 	return
 }
 
+func (a *Action) CheckedCondition() Condition {
+	return a.checkedCondition
+}
+
+func (a *Action) SetCheckedCondition(c Condition) {
+	if a.checkedCondition != nil {
+		a.checkedCondition.Changed().Detach(a.checkedConditionChangedHandle)
+	}
+
+	a.checkedCondition = c
+
+	if c != nil {
+		a.checked = c.Satisfied()
+
+		a.checkedConditionChangedHandle = c.Changed().Attach(func() {
+			if a.checked != c.Satisfied() {
+				a.checked = !a.checked
+
+				a.raiseChanged()
+			}
+		})
+	}
+
+	a.raiseChanged()
+}
+
 func (a *Action) Enabled() bool {
 	return a.enabled
 }
@@ -341,6 +379,10 @@ func (a *Action) Triggered() *Event {
 }
 
 func (a *Action) raiseTriggered() {
+	if a.Checkable() {
+		a.SetChecked(!a.Checked())
+	}
+
 	a.triggeredPublisher.Publish()
 }
 
diff --git a/declarative/action.go b/declarative/action.go
index ef489e2d..ca8e2465 100644
--- a/declarative/action.go
+++ b/declarative/action.go
@@ -25,6 +25,7 @@ type Action struct {
 	AssignTo    **walk.Action
 	Text        string
 	Image       interface{}
+	Checked     Property
 	Enabled     Property
 	Visible     Property
 	Shortcut    Shortcut
@@ -45,10 +46,10 @@ func (a Action) createAction(builder *Builder, menu *walk.Menu) (*walk.Action, e
 	if err := setActionImage(action, a.Image); err != nil {
 		return nil, err
 	}
-	if err := action.SetCheckable(a.Checkable); err != nil {
+
+	if err := setActionBoolOrCondition(action.SetChecked, action.SetCheckedCondition, a.Checked, "Action.Checked", builder); err != nil {
 		return nil, err
 	}
-
 	if err := setActionBoolOrCondition(action.SetEnabled, action.SetEnabledCondition, a.Enabled, "Action.Enabled", builder); err != nil {
 		return nil, err
 	}
@@ -56,6 +57,10 @@ func (a Action) createAction(builder *Builder, menu *walk.Menu) (*walk.Action, e
 		return nil, err
 	}
 
+	if err := action.SetCheckable(a.Checkable || action.CheckedCondition() != nil); err != nil {
+		return nil, err
+	}
+
 	s := a.Shortcut
 	if err := action.SetShortcut(walk.Shortcut{s.Modifiers, s.Key}); err != nil {
 		return nil, err
diff --git a/examples/actions/actions.go b/examples/actions/actions.go
index 7ed411c0..df0ff505 100644
--- a/examples/actions/actions.go
+++ b/examples/actions/actions.go
@@ -55,6 +55,19 @@ func main() {
 					},
 				},
 			},
+			Menu{
+				Text: "&View",
+				Items: []MenuItem{
+					Action{
+						Text:    "Open / Special Enabled",
+						Checked: Bind("enabledCB.Visible"),
+					},
+					Action{
+						Text:    "Open Hidden",
+						Checked: Bind("openHiddenCB.Visible"),
+					},
+				},
+			},
 			Menu{
 				Text: "&Help",
 				Items: []MenuItem{
diff --git a/menu.go b/menu.go
index 54473289..58493c00 100644
--- a/menu.go
+++ b/menu.go
@@ -10,9 +10,7 @@ import (
 	"fmt"
 	"syscall"
 	"unsafe"
-)
 
-import (
 	"github.com/lxn/win"
 )
 
@@ -83,9 +81,9 @@ func (m *Menu) initMenuItemInfoFromAction(mii *win.MENUITEMINFO, action *Action)
 		mii.HbmpItem = action.image.handle()
 	}
 	if action.IsSeparator() {
-		mii.FType = win.MFT_SEPARATOR
+		mii.FType |= win.MFT_SEPARATOR
 	} else {
-		mii.FType = win.MFT_STRING
+		mii.FType |= win.MFT_STRING
 		var text string
 		if s := action.shortcut; s.Key != 0 {
 			text = fmt.Sprintf("%s\t%s", action.text, s.String())
@@ -109,6 +107,9 @@ func (m *Menu) initMenuItemInfoFromAction(mii *win.MENUITEMINFO, action *Action)
 	if action.Checked() {
 		mii.FState |= win.MFS_CHECKED
 	}
+	if action.Exclusive() {
+		mii.FType |= win.MFT_RADIOCHECK
+	}
 
 	menu := action.menu
 	if menu != nil {
@@ -130,6 +131,30 @@ func (m *Menu) onActionChanged(action *Action) error {
 		return newError("SetMenuItemInfo failed")
 	}
 
+	if action.Exclusive() && action.Checked() {
+		var first, last int
+
+		index := m.actions.Index(action)
+
+		for i := index; i >= 0; i-- {
+			first = i
+			if !m.actions.At(i).Exclusive() {
+				break
+			}
+		}
+
+		for i := index; i < m.actions.Len(); i++ {
+			last = i
+			if !m.actions.At(i).Exclusive() {
+				break
+			}
+		}
+
+		if !win.CheckMenuRadioItem(m.hMenu, uint32(first), uint32(last), uint32(index), win.MF_BYPOSITION) {
+			return newError("CheckMenuRadioItem failed")
+		}
+	}
+
 	return nil
 }