app/internal/window: x11 driver

This driver still lacks fling support and dp/sp configuration.

By default, linux builds will try to use the Wayland driver then
fallback to X11 if it fails. Drivers can be disabled by using either the
nowayland or nox11 build tags.

Signed-off-by: Denis Bernard <db047h@gmail.com>

app/internal/window/egl_wayland.go

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-// +build linux,!android
+// +build linux,!android,!nowayland
 
 package window
 
@@ -8,6 +8,8 @@ import (
 	"errors"
 	"sync"
 	"unsafe"
+
+	"gioui.org/app/internal/gl"
 )
 
 /*
@@ -63,4 +65,8 @@ func (w *window) eglWindow(visID int) (_EGLNativeWindowType, int, int, error) {
 	return _EGLNativeWindowType(uintptr(unsafe.Pointer(eglWin))), width, height, nil
 }
 
+func (w *window) NewContext() (gl.Context, error) {
+	return newContext(w)
+}
+
 func (w *window) needVSync() bool { return false }