app/internal/window: implement key.Press and key.Release on macOS

Update key.State documentation and add State.String while here. Also
update Event.String to include State.

Signed-off-by: Raffaele Sena <raff367@gmail.com>

app/internal/window/gl_macos.m

@@ -76,9 +76,13 @@ 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]);
+	gio_onKeys((__bridge CFTypeRef)self, (char *)[keys UTF8String], [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);
+}
 - (void)insertText:(id)string {
 	const char *utf8 = [string UTF8String];
 	gio_onText((__bridge CFTypeRef)self, (char *)utf8);

app/internal/window/os_macos.go

@@ -151,15 +151,20 @@ 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) {
+func gio_onKeys(view C.CFTypeRef, cstr *C.char, ti C.double, mods C.NSUInteger, keyDown C.bool) {
 	str := C.GoString(cstr)
 	kmods := convertMods(mods)
+	ks := key.Release
+	if keyDown {
+		ks = key.Press
+	}
 	w := mustView(view)
 	for _, k := range str {
 		if n, ok := convertKey(k); ok {
 			w.w.Event(key.Event{
 				Name:      n,
 				Modifiers: kmods,
+				State:     ks,
 			})
 		}
 	}

io/key/key.go

@@ -10,6 +10,7 @@ events.
 package key
 
 import (
+	"fmt"
 	"strings"
 
 	"gioui.org/internal/opconst"
@@ -64,7 +65,7 @@ const (
 	// Release is the state of a key that has been released.
 	//
 	// Note: release events are only implemented on the following platforms:
-	// Linux, Windows, WebAssembly.
+	// macOS, Linux, Windows, WebAssembly.
 	Release
 )
 
@@ -129,7 +130,7 @@ func (Event) ImplementsEvent()      {}
 func (FocusEvent) ImplementsEvent() {}
 
 func (e Event) String() string {
-	return "{" + string(e.Name) + " " + e.Modifiers.String() + "}"
+	return fmt.Sprintf("%v %v %v}", e.Name, e.Modifiers, e.State)
 }
 
 func (m Modifiers) String() string {
@@ -151,3 +152,14 @@ func (m Modifiers) String() string {
 	}
 	return strings.Join(strs, "|")
 }
+
+func (s State) String() string {
+	switch s {
+	case Press:
+		return "Press"
+	case Release:
+		return "Release"
+	default:
+		panic("invalid State")
+	}
+}