Migrated Group on Windows over.

newctrl/container_windows.go

@@ -88,11 +88,6 @@ const (
 	// shared by multiple containers
 	marginDialogUnits  = 7
 	paddingDialogUnits = 4
-
-	// TODO move to group
-	groupXMargin       = 6
-	groupYMarginTop    = 11 // note this value /includes the groupbox label/
-	groupYMarginBottom = 7
 )
 
 func (w *window) beginResize() (d *sizing) {

newctrl/group_windows.go

@@ -0,0 +1,88 @@
+// 15 august 2014
+
+package ui
+
+// #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.preferredSize
+	g.fresize = g.resize
+	g.SetText(text)
+	C.controlSetControlFont(g.hwnd)
+	g.setParent(&controlParent{g.hwnd})
+	return g
+}
+
+func (g *group) Text() string {
+	return g.text()
+}
+
+func (g *group) SetText(text string) {
+	g.setText(text)
+}
+
+const (
+	groupXMargin       = 6
+	groupYMarginTop    = 11 // note this value /includes the groupbox label/
+	groupYMarginBottom = 7
+)
+
+func (g *group) preferredSize(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 {
+		// unforutnately, as mentioned above, the size of a groupbox includes the label and border
+		// 1DLU on each side should be enough to make up for that; if not, we can change it
+		// TODO make these named constants
+		marginRectDLU(&r, -1, -1, -1, -1, d)
+	} else {
+		marginRectDLU(&r, -groupYMarginTop, -groupYMarginBottom, -groupXMargin, -groupXMargin, d)
+	}
+	return int(r.right - r.left), int(r.bottom - r.top)
+}
+
+func (g *group) resize(x int, y int, width int, height int, d *sizing) {
+	// first, chain up to the container base to keep the Z-order correct
+	// TODO use a variable for this
+	g.controlSingleHWNDWithText.resize(x, y, width, height, d)
+
+	// now resize the child container
+	var r C.RECT
+
+	// pretend that the client area of the group box only includes the actual empty space
+	// container will handle the necessary adjustments properly
+	r.left = 0
+	r.top = 0
+	r.right = C.LONG(width)
+	r.bottom = C.LONG(height)
+	if g.margined {
+		// see above
+		marginRectDLU(&r, 1, 1, 1, 1, d)
+	} else {
+		marginRectDLU(&r, groupYMarginTop, groupYMarginBottom, groupXMargin, groupXMargin, d)
+	}
+	g.child.resize(int(r.left), int(r.top), int(r.right - r.left), int(r.bottom - r.top), d)
+}