all: replace unsafe slice operations with unsafe.Slice

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

app/internal/windows/windows.go

@@ -619,12 +619,12 @@ func GlobalFree(h syscall.Handle) {
 	_GlobalFree.Call(uintptr(h))
 }
 
-func GlobalLock(h syscall.Handle) (uintptr, error) {
+func GlobalLock(h syscall.Handle) (unsafe.Pointer, error) {
 	r, _, err := _GlobalLock.Call(uintptr(h))
 	if r == 0 {
-		return 0, fmt.Errorf("GlobalLock: %v", err)
+		return nil, fmt.Errorf("GlobalLock: %v", err)
 	}
-	return r, nil
+	return unsafe.Pointer(r), nil
 }
 
 func GlobalUnlock(h syscall.Handle) {

app/os_android.go

@@ -126,7 +126,6 @@ import (
 	"math"
 	"os"
 	"path/filepath"
-	"reflect"
 	"runtime"
 	"runtime/debug"
 	"sync"
@@ -1252,11 +1251,7 @@ func goString(env *C.JNIEnv, str C.jstring) string {
 	}
 	strlen := C.jni_GetStringLength(env, C.jstring(str))
 	chars := C.jni_GetStringChars(env, C.jstring(str))
-	var utf16Chars []uint16
-	hdr := (*reflect.SliceHeader)(unsafe.Pointer(&utf16Chars))
-	hdr.Data = uintptr(unsafe.Pointer(chars))
-	hdr.Cap = int(strlen)
-	hdr.Len = int(strlen)
+	utf16Chars := unsafe.Slice((*uint16)(unsafe.Pointer(chars)), strlen)
 	utf8 := utf16.Decode(utf16Chars)
 	return string(utf8)
 }

app/os_windows.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"fmt"
 	"image"
-	"reflect"
 	"runtime"
 	"sort"
 	"strings"
@@ -690,11 +689,7 @@ func (w *window) writeClipboard(s string) error {
 		windows.GlobalFree(mem)
 		return err
 	}
-	var u16v []uint16
-	hdr := (*reflect.SliceHeader)(unsafe.Pointer(&u16v))
-	hdr.Data = ptr
-	hdr.Cap = len(u16)
-	hdr.Len = len(u16)
+	u16v := unsafe.Slice((*uint16)(ptr), len(u16))
 	copy(u16v, u16)
 	windows.GlobalUnlock(mem)
 	if err := windows.SetClipboardData(windows.CF_UNICODETEXT, mem); err != nil {