1 files changed, 91 insertions, 0 deletions
diff --git a/prev/group_windows.go b/prev/group_windows.go
new file mode 100644
index 0000000..18a3cc6
--- /dev/null
+++ b/prev/group_windows.go
@@ -0,0 +1,91 @@
+// 15 august 2014
+
+package ui
+
+import (
+	"unsafe"
+)
+
+// #include "winapi_windows.h"
+import "C"
+
+type group struct {
+	*controlSingleHWNDWithText
+	child			Control
+	margined		bool
+}
+
+func newGroup(text string, control Control) Group {
+	hwnd := C.newControl(buttonclass,
+		C.BS_GROUPBOX,
+		C.WS_EX_CONTROLPARENT)
+	g := &group{
+		controlSingleHWNDWithText:		newControlSingleHWNDWithText(hwnd),
+		child:		control,
+	}
+	g.fpreferredSize = g.xpreferredSize
+	g.fnTabStops = control.nTabStops		// groupbox itself is not tabbable but the contents might be
+	g.SetText(text)
+	C.controlSetControlFont(g.hwnd)
+	C.setGroupSubclass(g.hwnd, unsafe.Pointer(g))
+	control.setParent(&controlParent{g.hwnd})
+	return g
+}
+
+func (g *group) Text() string {
+	return g.text()
+}
+
+func (g *group) SetText(text string) {
+	g.setText(text)
+}
+
+func (g *group) Margined() bool {
+	return g.margined
+}
+
+func (g *group) SetMargined(margined bool) {
+	g.margined = margined
+}
+
+const (
+	groupXMargin       = 6
+	groupYMarginTop    = 11 // note this value /includes the groupbox label/
+	groupYMarginBottom = 7
+)
+
+func (g *group) xpreferredSize(d *sizing) (width, height int) {
+	var r C.RECT
+
+	width, height = g.child.preferredSize(d)
+	if width < int(g.textlen) { // if the text is longer, try not to truncate
+		width = int(g.textlen)
+	}
+	r.left = 0
+	r.top = 0
+	r.right = C.LONG(width)
+	r.bottom = C.LONG(height)
+	// use negative numbers to increase the size of the rectangle
+	if g.margined {
+		marginRectDLU(&r, -groupYMarginTop, -groupYMarginBottom, -groupXMargin, -groupXMargin, d)
+	} else {
+		// unforutnately, as mentioned above, the size of a groupbox includes the label and border
+		// 1 character cell (4DLU x, 8DLU y) on each side (but only 3DLU on the bottom) should be enough to make up for that; TODO is not, we can change it
+		// TODO make these named constants
+		marginRectDLU(&r, -8, -3, -4, -4, d)
+	}
+	return int(r.right - r.left), int(r.bottom - r.top)
+}
+
+//export groupResized
+func groupResized(data unsafe.Pointer, r C.RECT) {
+	g := (*group)(unsafe.Pointer(data))
+	d := beginResize(g.hwnd)
+	if g.margined {
+		// see above
+		marginRectDLU(&r, groupYMarginTop, groupYMarginBottom, groupXMargin, groupXMargin, d)
+	} else {
+		marginRectDLU(&r, 8, 3, 4, 4, d)
+	}
+	g.child.resize(int(r.left), int(r.top), int(r.right - r.left), int(r.bottom - r.top), d)
+}