From fa6761afbf8c2658782e0c7fc5d51063679b7ae4 Mon Sep 17 00:00:00 2001
From: Sylvain Munaut <tnt@246tNt.com>
Date: Mon, 2 Dec 2019 20:14:22 +0100
Subject: [PATCH] gr-fosphor/qt: Qt5 - Track visibility of the widget

When not visible, doing GL operations is not supported

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
---
 lib/QGLSurface.cc | 13 +++++++++++++
 lib/QGLSurface.h  |  2 ++
 2 files changed, 15 insertions(+)

diff --git a/lib/QGLSurface.cc b/lib/QGLSurface.cc
index 7abdcd3..3c588ec 100644
--- a/lib/QGLSurface.cc
+++ b/lib/QGLSurface.cc
@@ -40,6 +40,19 @@ QGLSurface::QGLSurface(QWidget *parent, qt_sink_c_impl *block)
 	this->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 }
 
+
+void
+QGLSurface::hideEvent(QHideEvent *he)
+{
+	this->d_block->cb_visibility(this->isVisible());
+}
+
+void
+QGLSurface::showEvent(QShowEvent *he)
+{
+	this->d_block->cb_visibility(this->isVisible());
+}
+
 void
 QGLSurface::paintEvent(QPaintEvent *pe)
 {
diff --git a/lib/QGLSurface.h b/lib/QGLSurface.h
index 65afd8a..a10b2a1 100644
--- a/lib/QGLSurface.h
+++ b/lib/QGLSurface.h
@@ -38,6 +38,8 @@ namespace gr {
       QThread *d_gui_thread;
 
      protected:
+      void hideEvent(QHideEvent *he);
+      void showEvent(QShowEvent *he);
       void paintEvent(QPaintEvent *pe);
       void resizeEvent(QResizeEvent *re);
       void keyPressEvent(QKeyEvent *ke);