Fixed Mac OS X control placement flipping. This is done by passing the height of the window around setRect() calls to avoid polling the content view frame each time.

button.go

@@ -62,11 +62,11 @@ func (b *Button) make(window *sysData) error {
 	return nil
 }
 
-func (b *Button) setRect(x int, y int, width int, height int) error {
+func (b *Button) setRect(x int, y int, width int, height int, winheight int) error {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 
-	return b.sysData.setRect(x, y, width, height)
+	return b.sysData.setRect(x, y, width, height, winheight)
 }
 
 func (b *Button) preferredSize() (width int, height int, err error) {

checkbox.go

@@ -68,11 +68,11 @@ func (c *Checkbox) make(window *sysData) error {
 	return nil
 }
 
-func (c *Checkbox) setRect(x int, y int, width int, height int) error {
+func (c *Checkbox) setRect(x int, y int, width int, height int, winheight int) error {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	return c.sysData.setRect(x, y, width, height)
+	return c.sysData.setRect(x, y, width, height, winheight)
 }
 
 func (c *Checkbox) preferredSize() (width int, height int, err error) {

combobox.go

@@ -113,11 +113,11 @@ func (c *Combobox) make(window *sysData) (err error) {
 	return nil
 }
 
-func (c *Combobox) setRect(x int, y int, width int, height int) error {
+func (c *Combobox) setRect(x int, y int, width int, height int, winheight int) error {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	return c.sysData.setRect(x, y, width, height)
+	return c.sysData.setRect(x, y, width, height, winheight)
 }
 
 func (c *Combobox) preferredSize() (width int, height int, err error) {

control.go

@@ -8,6 +8,6 @@ import (
 // A Control represents an UI control. Note that Control contains unexported members; this has the consequence that you can't build custom controls that interface directly with the system-specific code (fo rinstance, to import an unsupported control), or at least not without some hackery. If you want to make your own controls, embed Area and provide its necessities.
 type Control interface {
 	make(window *sysData) error
-	setRect(x int, y int, width int, height int) error
+	setRect(x int, y int, width int, height int, winheight int) error
 	preferredSize() (width int, height int, err error)
 }

delegate_darwin.go

@@ -88,7 +88,8 @@ func appDelegate_windowDidResize(self C.id, sel C.SEL, notification C.id) {
 	wincv := C.objc_msgSend_noargs(win, _contentView)		// we want the content view's size, not the window's; selector defined in sysdata_darwin.go
 	r := C.objc_msgSend_stret_rect_noargs(wincv, _frame)
 	if sysData.resize != nil {
-		err := sysData.resize(int(r.x), int(r.y), int(r.width), int(r.height))
+		// winheight is used here because (0,0) is the bottom-left corner, not the top-left corner
+		err := sysData.resize(int(r.x), int(r.y), int(r.width), int(r.height), int(r.height))
 		if err != nil {
 			panic("child resize failed: " + err.Error())
 		}

grid.go

@@ -109,7 +109,7 @@ func (g *Grid) make(window *sysData) error {
 	return nil
 }
 
-func (g *Grid) setRect(x int, y int, width int, height int) error {
+func (g *Grid) setRect(x int, y int, width int, height int, winheight int) error {
 	g.lock.Lock()
 	defer g.lock.Unlock()
 
@@ -165,7 +165,7 @@ func (g *Grid) setRect(x int, y int, width int, height int) error {
 				w = g.colwidths[col]
 				h = g.rowheights[row]
 			}
-			err := c.setRect(x, y, w, h)
+			err := c.setRect(x, y, w, h, winheight)
 			if err != nil {
 				return fmt.Errorf("error setting size of control (%d,%d) in Grid.setRect(): %v", row, col, err)
 			}

label.go

@@ -56,11 +56,11 @@ func (l *Label) make(window *sysData) error {
 	return nil
 }
 
-func (l *Label) setRect(x int, y int, width int, height int) error {
+func (l *Label) setRect(x int, y int, width int, height int, winheight int) error {
 	l.lock.Lock()
 	defer l.lock.Unlock()
 
-	return l.sysData.setRect(x, y, width, height)
+	return l.sysData.setRect(x, y, width, height, winheight)
 }
 
 func (l *Label) preferredSize() (width int, height int, err error) {

lineedit.go

@@ -68,11 +68,11 @@ func (l *LineEdit) make(window *sysData) error {
 	return nil
 }
 
-func (l *LineEdit) setRect(x int, y int, width int, height int) error {
+func (l *LineEdit) setRect(x int, y int, width int, height int, winheight int) error {
 	l.lock.Lock()
 	defer l.lock.Unlock()
 
-	return l.sysData.setRect(x, y, width, height)
+	return l.sysData.setRect(x, y, width, height, winheight)
 }
 
 func (l *LineEdit) preferredSize() (width int, height int, err error) {

listbox.go

@@ -104,11 +104,11 @@ func (l *Listbox) make(window *sysData) (err error) {
 	return nil
 }
 
-func (l *Listbox) setRect(x int, y int, width int, height int) error {
+func (l *Listbox) setRect(x int, y int, width int, height int, winheight int) error {
 	l.lock.Lock()
 	defer l.lock.Unlock()
 
-	return l.sysData.setRect(x, y, width, height)
+	return l.sysData.setRect(x, y, width, height, winheight)
 }
 
 func (l *Listbox) preferredSize() (width int, height int, err error) {

progressbar.go

@@ -49,11 +49,11 @@ func (p *ProgressBar) make(window *sysData) error {
 	return nil
 }
 
-func (p *ProgressBar) setRect(x int, y int, width int, height int) error {
+func (p *ProgressBar) setRect(x int, y int, width int, height int, winheight int) error {
 	p.lock.Lock()
 	defer p.lock.Unlock()
 
-	return p.sysData.setRect(x, y, width, height)
+	return p.sysData.setRect(x, y, width, height, winheight)
 }
 
 func (p *ProgressBar) preferredSize() (width int, height int, err error) {

stack.go

@@ -63,7 +63,7 @@ func (s *Stack) make(window *sysData) error {
 	return nil
 }
 
-func (s *Stack) setRect(x int, y int, width int, height int) error {
+func (s *Stack) setRect(x int, y int, width int, height int, winheight int) error {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
@@ -112,7 +112,7 @@ func (s *Stack) setRect(x int, y int, width int, height int) error {
 	}
 	// 3) now actually place controls
 	for i, c := range s.controls {
-		err := c.setRect(x, y, s.width[i], s.height[i])
+		err := c.setRect(x, y, s.width[i], s.height[i], winheight)
 		if err != nil {
 			return fmt.Errorf("error setting size of control %d in Stack.setRect(): %v", i, err)
 		}

stdwndclass_windows.go

@@ -51,7 +51,8 @@ func stdWndProc(s *sysData) func(hwnd _HWND, uMsg uint32, wParam _WPARAM, lParam
 				if r1 == 0 {
 					panic("GetClientRect failed: " + err.Error())
 				}
-				err = s.resize(int(r.Left), int(r.Top), int(r.Right), int(r.Bottom))
+				// top-left corner is (0,0) so no need for winheight
+				err = s.resize(int(r.Left), int(r.Top), int(r.Right), int(r.Bottom), 0)
 				if err != nil {
 					panic("child resize failed: " + err.Error())
 				}

sysdata.go

@@ -16,7 +16,7 @@ func Event() chan struct{} {
 type cSysData struct {
 	ctype	int
 	event	chan struct{}
-	resize	func(x int, y int, width int, height int) error
+	resize	func(x int, y int, width int, height int, winheight int) error
 	alternate	bool		// editable for Combobox, multi-select for listbox, password for lineedit
 }
 func (c *cSysData) make(initText string, window *sysData) error {
@@ -31,7 +31,7 @@ func (c *cSysData) hide() error {
 func (c *cSysData) setText(text string) error {
 	panic(runtime.GOOS + " sysData does not define setText()")
 }
-func (c *cSysData) setRect(x int, y int, width int, height int) error {
+func (c *cSysData) setRect(x int, y int, width int, height int, winheight int) error {
 	panic(runtime.GOOS + " sysData does not define setRect()")
 }
 func (c *cSysData) isChecked() bool {

sysdata_darwin.go

@@ -346,8 +346,10 @@ func (s *sysData) setText(text string) error {
 	return nil
 }
 
-func (s *sysData) setRect(x int, y int, width int, height int) error {
+func (s *sysData) setRect(x int, y int, width int, height int, winheight int) error {
-	objc_msgSend_rect(s.id, _setFrame, x, y, width, height)
+	// 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
+	objc_msgSend_rect(s.id, _setFrame, x, (winheight - y) - height, width, height)
 	return nil
 }
 

sysdata_unix.go

@@ -45,7 +45,8 @@ var classTypes = [nctypes]*classData{
 				return func() bool {
 					if s.container != nil && s.resize != nil {		// wait for init
 						width, height := gtk_window_get_size(s.widget)
-						err := s.resize(0, 0, width, height)
+						// top-left is (0,0) so no need for winheight
+						err := s.resize(0, 0, width, height, 0)
 						if err != nil {
 							panic("child resize failed: " + err.Error())
 						}
@@ -189,7 +190,7 @@ func (s *sysData) setText(text string) error {
 	return nil
 }
 
-func (s *sysData) setRect(x int, y int, width int, height int) error {
+func (s *sysData) setRect(x int, y int, width int, height int, winheight int) error {
 	gtk_fixed_move(s.container, s.widget, x, y)
 	gtk_widget_set_size_request(s.widget, width, height)
 	return nil

sysdata_windows.go

@@ -251,7 +251,7 @@ func (s *sysData) setText(text string) error {
 	return nil
 }
 
-func (s *sysData) setRect(x int, y int, width int, height int) error {
+func (s *sysData) setRect(x int, y int, width int, height int, winheight int) error {
 	r1, _, err := _moveWindow.Call(
 		uintptr(s.hwnd),
 		uintptr(x),
@@ -481,7 +481,8 @@ func (s *sysData) setWindowSize(width int, height int) error {
 	if r.ret == 0 {
 		return fmt.Errorf("error getting upper-left of window for resize: %v", r.err)
 	}
-	err := s.setRect(int(rect.Left), int(rect.Top), width, height)
+	// 0 because (0,0) is top-left so no winheight
+	err := s.setRect(int(rect.Left), int(rect.Top), width, height, 0)
 	if err != nil {
 		return fmt.Errorf("error actually resizing window: %v", err)
 	}

todo.md

@@ -27,7 +27,8 @@ so I don't forget:
 important things:
 - ui.Go() should exit when the main() you pass in exits
 - because the main event loop is not called if initialization fails, it is presently impossible for MsgBoxError() to work if UI initialization fails; this basically means we cannot allow initializiation to fail on Mac OS X if we want to be able to report UI init failures to the user with one
-- Cocoa coordinates have (0,0) at the bottom left: need to fix this somehow
+- figure out where to auto-place windows in Cocoa (also window coordinates are still not flipped properly so (0,0) on screen is the bottom-left)
+	- also provide a method to center windoes; Cocoa provides one for us but
 - I think Cocoa NSButton text is not vertically aligned properly...?
 - NSPopUpButton doesn't seem to allow no initial selection? need to be sure
 - NSComboBox scans the entered text to see if it matches one of the items and returns the index of that item if it does; find out how to suppress this so that it returns -1 unless the item was chosen from the list (like the other platforms)