app: [macOS,iOS] don't use [NSString UTF8String]

UTF8String is lossy in the presence of nul (\x00) runes.

While here, don't CFRelease the input to nsstringToString; leave it
up to the caller.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/os_darwin.go

@@ -28,6 +28,16 @@ static void nsstringGetCharacters(CFTypeRef cstr, unichar *chars, NSUInteger loc
 	NSString *str = (__bridge NSString *)cstr;
 	[str getCharacters:chars range:NSMakeRange(loc, length)];
 }
+
+static CFTypeRef newNSString(unichar *chars, NSUInteger length) {
+	@autoreleasepool {
+		NSString *s = [NSString string];
+		if (length > 0) {
+			s = [NSString stringWithCharacters:chars length:length];
+		}
+		return CFBridgingRetain(s);
+	}
+}
 */
 import "C"
 import (
@@ -89,13 +99,11 @@ func gio_dispatchMainFuncs() {
 	}
 }
 
-// nsstringToString converts a NSString to a Go string, and
+// nsstringToString converts a NSString to a Go string.
-// releases the original string.
 func nsstringToString(str C.CFTypeRef) string {
 	if str == 0 {
 		return ""
 	}
-	defer C.CFRelease(str)
 	n := C.nsstringLength(str)
 	if n == 0 {
 		return ""
@@ -106,6 +114,16 @@ func nsstringToString(str C.CFTypeRef) string {
 	return string(utf8)
 }
 
+// stringToNSString converts a Go string to a retained NSString.
+func stringToNSString(str string) C.CFTypeRef {
+	u16 := utf16.Encode([]rune(str))
+	var chars *C.unichar
+	if len(u16) > 0 {
+		chars = (*C.unichar)(unsafe.Pointer(&u16[0]))
+	}
+	return C.newNSString(chars, C.NSUInteger(len(u16)))
+}
+
 func NewDisplayLink(callback func()) (*displayLink, error) {
 	d := &displayLink{
 		callback: callback,

app/os_ios.go

@@ -226,9 +226,9 @@ func onDeleteBackward(view C.CFTypeRef) {
 }
 
 //export onText
-func onText(view C.CFTypeRef, str *C.char) {
+func onText(view, str C.CFTypeRef) {
 	w := views[view]
-	w.w.EditorInsert(C.GoString(str))
+	w.w.EditorInsert(nsstringToString(str))
 }
 
 //export onTouch
@@ -259,7 +259,9 @@ func onTouch(last C.int, view, touchRef C.CFTypeRef, phase C.NSInteger, x, y C.C
 }
 
 func (w *window) ReadClipboard() {
-	content := nsstringToString(C.readClipboard())
+	cstr := C.readClipboard()
+	defer C.CFRelease(cstr)
+	content := nsstringToString(cstr)
 	w.w.Event(clipboard.Event{Text: content})
 }
 

app/os_ios.m

@@ -179,7 +179,7 @@ NSArray<UIKeyCommand *> *_keyCommands;
 }
 
 - (void)insertText:(NSString *)text {
-	onText((__bridge CFTypeRef)self, (char *)text.UTF8String);
+	onText((__bridge CFTypeRef)self, (__bridge CFTypeRef)text);
 }
 
 - (BOOL)canBecomeFirstResponder {

app/os_macos.go

@@ -11,8 +11,6 @@ import (
 	"runtime"
 	"time"
 	"unicode"
-	"unicode/utf16"
-	"unsafe"
 
 	"gioui.org/f32"
 	"gioui.org/io/clipboard"
@@ -36,14 +34,11 @@ import (
 
 __attribute__ ((visibility ("hidden"))) void gio_main(void);
 __attribute__ ((visibility ("hidden"))) CFTypeRef gio_createView(void);
-__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createWindow(CFTypeRef viewRef, const char *title, CGFloat width, CGFloat height, CGFloat minWidth, CGFloat minHeight, CGFloat maxWidth, CGFloat maxHeight);
+__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGFloat minWidth, CGFloat minHeight, CGFloat maxWidth, CGFloat maxHeight);
 
-static void writeClipboard(unichar *chars, NSUInteger length) {
+static void writeClipboard(CFTypeRef str) {
 	@autoreleasepool {
-		NSString *s = [NSString string];
+		NSString *s = (__bridge NSString *)str;
-		if (length > 0) {
-			s = [NSString stringWithCharacters:chars length:length];
-		}
 		NSPasteboard *p = NSPasteboard.generalPasteboard;
 		[p declareTypes:@[NSPasteboardTypeString] owner:nil];
 		[p setString:s forType:NSPasteboardTypeString];
@@ -144,9 +139,9 @@ static NSRect getScreenFrame(CFTypeRef windowRef) {
 	return [[window screen] frame];
 }
 
-static void setTitle(CFTypeRef windowRef, const char *title) {
+static void setTitle(CFTypeRef windowRef, CFTypeRef titleRef) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
+	NSWindow *window = (__bridge NSWindow *)windowRef;
-	window.title = [NSString stringWithUTF8String: title];
+	window.title = (__bridge NSString *)titleRef;
 }
 
 static CFTypeRef layerForView(CFTypeRef viewRef) {
@@ -229,17 +224,16 @@ func (w *window) contextView() C.CFTypeRef {
 }
 
 func (w *window) ReadClipboard() {
-	content := nsstringToString(C.readClipboard())
+	cstr := C.readClipboard()
+	defer C.CFRelease(cstr)
+	content := nsstringToString(cstr)
 	w.w.Event(clipboard.Event{Text: content})
 }
 
 func (w *window) WriteClipboard(s string) {
-	u16 := utf16.Encode([]rune(s))
+	cstr := stringToNSString(s)
-	var chars *C.unichar
+	defer C.CFRelease(cstr)
-	if len(u16) > 0 {
+	C.writeClipboard(cstr)
-		chars = (*C.unichar)(unsafe.Pointer(&u16[0]))
-	}
-	C.writeClipboard(chars, C.NSUInteger(len(u16)))
 }
 
 func (w *window) updateWindowMode() {
@@ -338,8 +332,8 @@ func (w *window) Configure(options []Option) {
 func (w *window) setTitle(prev, cnf Config) {
 	if prev.Title != cnf.Title {
 		w.config.Title = cnf.Title
-		title := C.CString(cnf.Title)
+		title := stringToNSString(cnf.Title)
-		defer C.free(unsafe.Pointer(title))
+		defer C.CFRelease(title)
 		C.setTitle(w.window, title)
 	}
 }
@@ -391,8 +385,8 @@ func (w *window) setStage(stage system.Stage) {
 }
 
 //export gio_onKeys
-func gio_onKeys(view C.CFTypeRef, cstr *C.char, ti C.double, mods C.NSUInteger, keyDown C.bool) {
+func gio_onKeys(view, cstr C.CFTypeRef, ti C.double, mods C.NSUInteger, keyDown C.bool) {
-	str := C.GoString(cstr)
+	str := nsstringToString(cstr)
 	kmods := convertMods(mods)
 	ks := key.Release
 	if keyDown {
@@ -411,8 +405,8 @@ func gio_onKeys(view C.CFTypeRef, cstr *C.char, ti C.double, mods C.NSUInteger,
 }
 
 //export gio_onText
-func gio_onText(view C.CFTypeRef, cstr *C.char) {
+func gio_onText(view, cstr C.CFTypeRef) {
-	str := C.GoString(cstr)
+	str := nsstringToString(cstr)
 	w := mustView(view)
 	w.w.EditorInsert(str)
 }
@@ -579,7 +573,7 @@ func newWindow(win *callbacks, options []Option) error {
 		}
 		errch <- nil
 		w.w = win
-		w.window = C.gio_createWindow(w.view, nil, 0, 0, 0, 0, 0, 0)
+		w.window = C.gio_createWindow(w.view, 0, 0, 0, 0, 0, 0)
 		win.SetDriver(w)
 		w.Configure(options)
 		if nextTopLeft.x == 0 && nextTopLeft.y == 0 {

app/os_macos.m

@@ -117,16 +117,15 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 }
 - (void)keyDown:(NSEvent *)event {
 	NSString *keys = [event charactersIgnoringModifiers];
-	gio_onKeys((__bridge CFTypeRef)self, (char *)[keys UTF8String], [event timestamp], [event modifierFlags], true);
+	gio_onKeys((__bridge CFTypeRef)self, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], true);
 	[self interpretKeyEvents:[NSArray arrayWithObject:event]];
 }
 - (void)keyUp:(NSEvent *)event {
 	NSString *keys = [event charactersIgnoringModifiers];
-	gio_onKeys((__bridge CFTypeRef)self, (char *)[keys UTF8String], [event timestamp], [event modifierFlags], false);
+	gio_onKeys((__bridge CFTypeRef)self, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], false);
 }
 - (void)insertText:(id)string {
-	const char *utf8 = [string UTF8String];
+	gio_onText((__bridge CFTypeRef)self, (__bridge CFTypeRef)string);
-	gio_onText((__bridge CFTypeRef)self, (char *)utf8);
 }
 - (void)doCommandBySelector:(SEL)sel {
 	// Don't pass commands up the responder chain.
@@ -210,7 +209,7 @@ void gio_setCursor(NSUInteger curID) {
 	}
 }
 
-CFTypeRef gio_createWindow(CFTypeRef viewRef, const char *title, CGFloat width, CGFloat height, CGFloat minWidth, CGFloat minHeight, CGFloat maxWidth, CGFloat maxHeight) {
+CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGFloat minWidth, CGFloat minHeight, CGFloat maxWidth, CGFloat maxHeight) {
 	@autoreleasepool {
 		NSRect rect = NSMakeRect(0, 0, width, height);
 		NSUInteger styleMask = NSTitledWindowMask |
@@ -229,9 +228,6 @@ CFTypeRef gio_createWindow(CFTypeRef viewRef, const char *title, CGFloat width,
 			window.contentMaxSize = NSMakeSize(maxWidth, maxHeight);
 		}
 		[window setAcceptsMouseMovedEvents:YES];
-		if (title != nil) {
-			window.title = [NSString stringWithUTF8String: title];
-		}
 		NSView *view = (__bridge NSView *)viewRef;
 		[window setContentView:view];
 		[window makeFirstResponder:view];