Implemented tabbing properly. Tab order still backwards.

newctrl/control.go

@@ -8,12 +8,14 @@ type Control interface {
 //	nChildren() int		// TODO
 	preferredSize(d *sizing) (width, height int)
 	resize(x int, y int, width int, height int, d *sizing)
+	nTabStops() int
 }
 
 type controlbase struct {
 	fsetParent			func(p *controlParent)
 	fpreferredSize		func(d *sizing) (width, height int)
 	fresize			func(x int, y int, width int, height int, d *sizing)
+	fnTabStops		func() int
 }
 
 func (c *controlbase) setParent(p *controlParent) {
@@ -27,3 +29,7 @@ func (c *controlbase) preferredSize(d *sizing) (width, height int) {
 func (c *controlbase) resize(x int, y int, width int, height int, d *sizing) {
 	c.fresize(x, y, width, height, d)
 }
+
+func (c *controlbase) nTabStops() int {
+	return c.fnTabStops()
+}

newctrl/control_windows.go

@@ -21,6 +21,10 @@ func newControlSingleHWND(hwnd C.HWND) *controlSingleHWND {
 	c.controlbase = &controlbase{
 		fsetParent:	c.setParent,
 		fresize:		c.resize,
+		fnTabStops:	func() int {
+			// most controls count as one tab stop
+			return 1
+		},
 	}
 	c.hwnd = hwnd
 	return c

newctrl/grid.go

@@ -423,3 +423,11 @@ func (g *grid) preferredSize(d *sizing) (width, height int) {
 	return colwidth + (g.xmax-1)*d.xpadding,
 		rowheight + (g.ymax-1)*d.ypadding
 }
+
+func (g *grid) nTabStops() int {
+	n := 0
+	for _, c := range g.controls {
+		n += c.control.nTabStops()
+	}
+	return n
+}

newctrl/group_windows.go

@@ -21,6 +21,7 @@ func newGroup(text string, control Control) Group {
 	}
 	g.fpreferredSize = g.preferredSize
 	g.fresize = g.resize
+	g.fnTabStops = control.nTabStops		// groupbox itself is not tabbable but the contents might be
 	g.SetText(text)
 	C.controlSetControlFont(g.hwnd)
 	control.setParent(&controlParent{g.hwnd})

newctrl/label_windows.go

@@ -22,6 +22,10 @@ func newLabel(text string) Label {
 		controlSingleHWNDWithText:		newControlSingleHWNDWithText(hwnd),
 	}
 	l.fpreferredSize = l.preferredSize
+	l.fnTabStops = func() int {
+		// labels are not tab stops
+		return 0
+	}
 	l.SetText(text)
 	C.controlSetControlFont(l.hwnd)
 	return l

newctrl/simplegrid.go

@@ -215,3 +215,13 @@ func (g *simpleGrid) preferredSize(d *sizing) (width int, height int) {
 	}
 	return width, height
 }
+
+func (g *simpleGrid) nTabStops() int {
+	n := 0
+	for _, cc := range g.controls {
+		for _, c := range cc {
+			n += c.nTabStops()
+		}
+	}
+	return n
+}

newctrl/stack.go

@@ -180,6 +180,14 @@ func (s *stack) preferredSize(d *sizing) (width int, height int) {
 	return
 }
 
+func (s *stack) nTabStops() int {
+	n := 0
+	for _, c := range s.controls {
+		n += c.nTabStops()
+	}
+	return n
+}
+
 // TODO the below needs to be changed
 
 // Space returns a null Control intended for padding layouts with blank space.

newctrl/tab_windows.go

@@ -30,6 +30,7 @@ func newTab() Tab {
 	}
 	t.fpreferredSize = t.preferredSize
 	t.fresize = t.resize
+	// count tabs as 1 tab stop; the actual number of tab stops varies
 	C.controlSetControlFont(t.hwnd)
 	C.setTabSubclass(t.hwnd, unsafe.Pointer(t))
 	return t
@@ -67,12 +68,10 @@ func tabTabHasChildren(data unsafe.Pointer, which C.LRESULT) C.BOOL {
 	if len(t.tabs) == 0 { // currently no tabs
 		return C.FALSE
 	}
-return C.TRUE/*TODO
+	if t.children[int(which)].nTabStops() > 0 {
-	if t.tabs[int(which)].nchildren > 0 {
 		return C.TRUE
 	}
 	return C.FALSE
-*/
 }
 
 func (t *tab) preferredSize(d *sizing) (width, height int) {