app/internal/window: macOS clipboard support

Updates gio#31

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

app/internal/window/os_darwin.go

@@ -3,9 +3,17 @@
 package window
 
 /*
+#include <Foundation/Foundation.h>
+
 __attribute__ ((visibility ("hidden"))) void gio_wakeupMainThread(void);
+__attribute__ ((visibility ("hidden"))) NSUInteger gio_nsstringLength(CFTypeRef str);
+__attribute__ ((visibility ("hidden"))) void gio_nsstringGetCharacters(CFTypeRef str, unichar *chars, NSUInteger loc, NSUInteger length);
 */
 import "C"
+import (
+	"unicode/utf16"
+	"unsafe"
+)
 
 var mainFuncs = make(chan func(), 1)
 
@@ -28,3 +36,14 @@ func gio_dispatchMainFuncs() {
 		}
 	}
 }
+
+// nsstringToString converts a NSString to a Go string, and
+// releases the original string.
+func nsstringToString(str C.CFTypeRef) string {
+	defer C.CFRelease(str)
+	n := C.gio_nsstringLength(str)
+	chars := make([]uint16, n)
+	C.gio_nsstringGetCharacters(str, (*C.unichar)(unsafe.Pointer(&chars[0])), 0, n)
+	utf8 := utf16.Decode(chars)
+	return string(utf8)
+}

app/internal/window/os_darwin.m

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 @import Dispatch;
+@import Foundation;
 
 #include "_cgo_export.h"
 
@@ -9,3 +10,13 @@ void gio_wakeupMainThread(void) {
 		gio_dispatchMainFuncs();
 	});
 }
+
+NSUInteger gio_nsstringLength(CFTypeRef cstr) {
+	NSString *str = (__bridge NSString *)cstr;
+	return [str length];
+}
+
+void gio_nsstringGetCharacters(CFTypeRef cstr, unichar *chars, NSUInteger loc, NSUInteger length) {
+	NSString *str = (__bridge NSString *)cstr;
+	[str getCharacters:chars range:NSMakeRange(loc, length)];
+}

app/internal/window/os_macos.go

@@ -11,6 +11,7 @@ import (
 	"sync"
 	"time"
 	"unicode"
+	"unicode/utf16"
 	"unsafe"
 
 	"gioui.org/f32"
@@ -24,7 +25,6 @@ import (
 /*
 #cgo CFLAGS: -DGL_SILENCE_DEPRECATION -Werror -Wno-deprecated-declarations -fmodules -fobjc-arc -x objective-c
 
-
 #include <AppKit/AppKit.h>
 
 #define GIO_MOUSE_MOVE 1
@@ -37,6 +37,8 @@ __attribute__ ((visibility ("hidden"))) CGFloat gio_viewHeight(CFTypeRef viewRef
 __attribute__ ((visibility ("hidden"))) void gio_setAnimating(CFTypeRef viewRef, BOOL anim);
 __attribute__ ((visibility ("hidden"))) void gio_updateDisplayLink(CFTypeRef viewRef, CGDirectDisplayID dispID);
 __attribute__ ((visibility ("hidden"))) CGFloat gio_getViewBackingScale(CFTypeRef viewRef);
+__attribute__ ((visibility ("hidden"))) CFTypeRef gio_readClipboard(void);
+__attribute__ ((visibility ("hidden"))) void gio_writeClipboard(unichar *chars, NSUInteger length);
 */
 import "C"
 
@@ -89,6 +91,24 @@ func (w *window) contextView() C.CFTypeRef {
 	return w.view
 }
 
+func (w *window) ReadClipboard() {
+	runOnMain(func() {
+		content := nsstringToString(C.gio_readClipboard())
+		w.w.Event(system.ClipboardEvent{Text: content})
+	})
+}
+
+func (w *window) WriteClipboard(s string) {
+	u16 := utf16.Encode([]rune(s))
+	runOnMain(func() {
+		var chars *C.unichar
+		if len(u16) > 0 {
+			chars = (*C.unichar)(unsafe.Pointer(&u16[0]))
+		}
+		C.gio_writeClipboard(chars, C.NSUInteger(len(u16)))
+	})
+}
+
 func (w *window) ShowTextInput(show bool) {}
 
 func (w *window) SetAnimating(anim bool) {

app/internal/window/os_macos.m

@@ -46,6 +46,26 @@
 }
 @end
 
+void gio_writeClipboard(unichar *chars, NSUInteger length) {
+	@autoreleasepool {
+		NSString *s = [NSString string];
+		if (length > 0) {
+			s = [NSString stringWithCharacters:chars length:length];
+		}
+		NSPasteboard *p = NSPasteboard.generalPasteboard;
+		[p declareTypes:@[NSPasteboardTypeString] owner:nil];
+		[p setString:s forType:NSPasteboardTypeString];
+	}
+}
+
+CFTypeRef gio_readClipboard(void) {
+	@autoreleasepool {
+		NSPasteboard *p = NSPasteboard.generalPasteboard;
+		NSString *content = [p stringForType:NSPasteboardTypeString];
+		return (__bridge_retained CFTypeRef)content;
+	}
+}
+
 CGFloat gio_viewHeight(CFTypeRef viewRef) {
 	NSView *view = (__bridge NSView *)viewRef;
 	return [view bounds].size.height;