From 56a1eb65e2f82c36d5f63e1182ebf78680a0adba Mon Sep 17 00:00:00 2001
From: Carlos Rafael Giani <dv@pseudoterminal.org>
Date: Sun, 4 Mar 2018 15:14:08 +0100
Subject: [PATCH] qt: Get EGL native display from QPA if platform header is
 available

https://bugzilla.gnome.org/show_bug.cgi?id=792378
---
 configure.ac             |  1 +
 ext/qt/gstqtglutility.cc | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/configure.ac b/configure.ac
index 800b356150..3503ed9f2a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -892,6 +892,7 @@ AG_GST_CHECK_FEATURE(QT, [Qt elements], qt, [
         AS_IF([test -f "$PKG_CONFIG_SYSROOT_DIR/$QPA_INCLUDE_PATH/qpa/qplatformnativeinterface.h"], [
           QT_CFLAGS="$QT_CFLAGS -I$PKG_CONFIG_SYSROOT_DIR/$QPA_INCLUDE_PATH"
           HAVE_QT_QPA_HEADER="yes"
+          AC_DEFINE([HAVE_QT_QPA_HEADER], [], [Define if the Qt QPA header is installed])
         ], [AC_MSG_NOTICE([Cannot find QPA])])
         if test "x$GST_GL_HAVE_WINDOW_X11" = "x1" -a "x$GST_GL_HAVE_PLATFORM_GLX" = "x1" || test "x$GST_GL_HAVE_WINDOW_X11" = "x1" -a "x$GST_GL_HAVE_PLATFORM_EGL" = "x1"; then
           PKG_CHECK_MODULES(QT_X11, Qt5X11Extras, [
diff --git a/ext/qt/gstqtglutility.cc b/ext/qt/gstqtglutility.cc
index ee9d04b8ff..cc84c8340c 100644
--- a/ext/qt/gstqtglutility.cc
+++ b/ext/qt/gstqtglutility.cc
@@ -42,6 +42,9 @@
 #else
 #include <gst/gl/egl/gstegl.h>
 #include <gst/gl/egl/gstgldisplay_egl.h>
+#ifdef HAVE_QT_QPA_HEADER
+#include <qpa/qplatformnativeinterface.h>
+#endif
 #endif
 #endif
 
@@ -110,6 +113,13 @@ gst_qt_get_gl_display ()
     }
 
     display = (GstGLDisplay *) gst_gl_display_viv_fb_new (disp_idx);
+#elif defined(HAVE_QT_QPA_HEADER)
+    QPlatformNativeInterface *native =
+        QGuiApplication::platformNativeInterface();
+    EGLDisplay egl_display = (EGLDisplay)
+        native->nativeResourceForWindow("egldisplay", NULL);
+    if (egl_display != EGL_NO_DISPLAY)
+      display = (GstGLDisplay *) gst_gl_display_egl_new_with_egl_display (egl_display);
 #else
     EGLDisplay egl_display = (EGLDisplay) gst_gl_display_egl_get_from_native (GST_GL_DISPLAY_TYPE_ANY, 0);
     display = (GstGLDisplay *) gst_gl_display_egl_new_with_egl_display (egl_display);