1 files changed, 178 insertions, 0 deletions
diff --git a/experiments/hscrolllistbox.go b/experiments/hscrolllistbox.go
new file mode 100644
index 0000000..3975a56
--- /dev/null
+++ b/experiments/hscrolllistbox.go
@@ -0,0 +1,178 @@
+// WINDOWS (works)
+
+		style:			_LBS_NOTIFY | _LBS_NOINTEGRALHEIGHT | _WS_HSCROLL | _WS_VSCROLL | controlstyle,
+		xstyle:			_WS_EX_CLIENTEDGE | controlxstyle,
+		altStyle:			_LBS_EXTENDEDSEL | _LBS_NOTIFY | _LBS_NOINTEGRALHEIGHT | _WS_HSCROLL | _WS_VSCROLL | controlstyle,
+
+(call recalcListboxWidth() from sysData.append(), sysData.insertBefore(), and sysData.delete())
+
+// List Boxes do not dynamically handle horizontal scrollbars.
+// We have to manually handle this ourselves.
+// TODO make this run on the main thread when we switch to uitask taking function literals
+// TODO this is inefficient; some caching would be nice
+func recalcListboxWidth(hwnd _HWND) {
+	var size _SIZE
+
+	ret := make(chan uiret)
+	defer close(ret)
+	uitask <- &uimsg{
+		call:		_sendMessage,
+		p:		[]uintptr{
+			uintptr(hwnd),
+			uintptr(_LB_GETCOUNT),
+			uintptr(0),
+			uintptr(0),
+		},
+		ret:		ret,
+	}
+	r := <-ret
+	if r.ret == uintptr(_LB_ERR) {		// failure
+		panic(fmt.Errorf("error getting number of items for Listbox width calculations: %v", r.err))
+	}
+	n := int(r.ret)
+	uitask <- &uimsg{
+		call:		_getWindowDC,
+		p:		[]uintptr{uintptr(hwnd)},
+		ret:		ret,
+	}
+	r = <-ret
+	if r.ret == 0 {		// failure
+		panic(fmt.Errorf("error getting DC for Listbox width calculations: %v", r.err))
+	}
+	dc := _HANDLE(r.ret)
+	uitask <- &uimsg{
+		call:		_selectObject,
+		p:		[]uintptr{
+			uintptr(dc),
+			uintptr(controlFont),
+		},
+		ret:		ret,
+	}
+	r = <-ret
+	if r.ret == 0  {		// failure
+		panic(fmt.Errorf("error loading control font into device context for Listbox width calculation: %v", r.err))
+	}
+	hextent := uintptr(0)
+	for i := 0; i < n; i++ {
+		uitask <- &uimsg{
+			call:		_sendMessage,
+			p:		[]uintptr{
+				uintptr(hwnd),
+				uintptr(_LB_GETTEXTLEN),
+				uintptr(_WPARAM(i)),
+				uintptr(0),
+			},
+			ret:		ret,
+		}
+		r := <-ret
+		if r.ret == uintptr(_LB_ERR) {
+			panic("UI library internal error: LB_ERR from LB_GETTEXTLEN in what we know is a valid listbox index (came from LB_GETSELITEMS)")
+		}
+		str := make([]uint16, r.ret)
+		uitask <- &uimsg{
+			call:		_sendMessage,
+			p:		[]uintptr{
+				uintptr(hwnd),
+				uintptr(_LB_GETTEXT),
+				uintptr(_WPARAM(i)),
+				uintptr(_LPARAM(unsafe.Pointer(&str[0]))),
+			},
+			ret:		ret,
+		}
+		r = <-ret
+		if r.ret == uintptr(_LB_ERR) {
+			panic("UI library internal error: LB_ERR from LB_GETTEXT in what we know is a valid listbox index (came from LB_GETSELITEMS)")
+		}
+		// r.ret is still the length of the string; this time without the null terminator
+		uitask <- &uimsg{
+			call:		_getTextExtentPoint32,
+			p:		[]uintptr{
+				uintptr(dc),
+				uintptr(unsafe.Pointer(&str[0])),
+				r.ret,
+				uintptr(unsafe.Pointer(&size)),
+			},
+			ret:		ret,
+		}
+		r = <-ret
+		if r.ret == 0 {		// failure
+			panic(fmt.Errorf("error getting width of item %d text for Listbox width calculation: %v", i, r.err))
+		}
+		if hextent < uintptr(size.cx) {
+			hextent = uintptr(size.cx)
+		}
+	}
+	uitask <- &uimsg{
+		call:		_releaseDC,
+		p:		[]uintptr{
+			uintptr(hwnd),
+			uintptr(dc),
+		},
+		ret:		ret,
+	}
+	r = <-ret
+	if r.ret == 0 {		// failure
+		panic(fmt.Errorf("error releasing DC for Listbox width calculations: %v", r.err))
+	}
+	uitask <- &uimsg{
+		call:		_sendMessage,
+		p:		[]uintptr{
+			uintptr(hwnd),
+			uintptr(_LB_SETHORIZONTALEXTENT),
+			hextent,
+			uintptr(0),
+		},
+		ret:		ret,
+	}
+	<-ret
+}
+
+// DARWIN (does not work)
+
+// NSTableView is actually in a NSScrollView so we have to get it out first
+// NSTableView and NSTableColumn both provide sizeToFit methods, but they don't do what we want (NSTableView's sizes to fit the parent; NSTableColumn's sizes to fit the column header)
+// We have to get the width manually; see also http://stackoverflow.com/questions/4674163/nstablecolumn-size-to-fit-contents
+// We can use the NSTableView sizeToFit to get the height, though.
+// TODO this is inefficient!
+// TODO move this to listbox_darwin.go
+var (
+	_dataCellForRow = sel_getUid("dataCellForRow:")
+	_cellSize = sel_getUid("cellSize")
+	_setMinWidth = sel_getUid("setMinWidth:")
+	_setWidth = sel_getUid("setWidth:")
+)
+
+func listboxPrefSize(control C.id) (width int, height int) {
+	var maxwidth C.int64_t
+
+	listbox := listboxInScrollView(control)
+	_, height = controlPrefSize(listbox)
+	column := listboxTableColumn(listbox)
+	n := C.objc_msgSend_intret_noargs(listbox, _numberOfRows)
+	for i := C.intptr_t(0); i < n; i++ {
+		cell := C.objc_msgSend_int(column, _dataCellForRow, i)
+		csize := C.objc_msgSend_stret_size_noargs(cell, _cellSize)
+		if maxwidth < csize.width {
+			maxwidth = csize.width
+		}
+	}
+	// and in order for horizontal scrolling to work, we need to set the column width to this
+	C.objc_msgSend_cgfloat(column, _setMinWidth, C.double(maxwidth))
+	C.objc_msgSend_cgfloat(column, _setWidth, C.double(maxwidth))
+	return int(maxwidth), height
+}
+
+func (s *sysData) setRect(x int, y int, width int, height int, winheight int) error {
+	// winheight - y because (0,0) is the bottom-left corner of the window and not the top-left corner
+	// (winheight - y) - height because (x, y) is the bottom-left corner of the control and not the top-left
+	C.objc_msgSend_rect(s.id, _setFrame,
+		C.int64_t(x), C.int64_t((winheight - y) - height), C.int64_t(width), C.int64_t(height))
+	// TODO having this here is a hack; split it into a separate function in listbox_darwin.go
+	// the NSTableView:NSTableColumn ratio is what determines horizontal scrolling; see http://stackoverflow.com/questions/7050497/enable-scrolling-for-nstableview
+	if s.ctype == c_listbox {
+		listbox := listboxInScrollView(s.id)
+		C.objc_msgSend_rect(listbox, _setFrame,
+			0, 0, C.int64_t(width), C.int64_t(height))
+	}
+	return nil
+}