Add a space pressable pushbutton with focus highlight indicator

data/gui/normalStyle.css

@@ -336,8 +336,10 @@ QPushButton {
         font-size: 100%;
 	background-color: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1, stop: 0 rgb(183, 184, 185), stop: 1 rgb(111, 113, 114));
 }
-
-QPushButton:focus {
+/*
+ * Only the space-pressable pushbutton should show a focus highlight!
+ */
+SpacePushButton:focus {
 	border: 2px solid rgb(161, 161, 161);
 }
 

src/CMakeLists.txt

@@ -348,6 +348,8 @@ IF(STELLARIUM_GUI_MODE STREQUAL "Standard")
           gui/ObsListCreateEditDialog.cpp
           gui/SpaceCheckBox.hpp
           gui/SpaceCheckBox.cpp
+          gui/SpacePushButton.hpp
+          gui/SpacePushButton.cpp
           gui/StelDialog.hpp
           gui/StelDialog_p.hpp
           gui/StelDialog.cpp

src/gui/SpacePushButton.cpp

@@ -0,0 +1,37 @@
+/***************************************************************************
+ *   Copyright (C) 2021 Georg Zotti                                        *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Suite 500, Boston, MA  02110-1335, USA.           *
+ ***************************************************************************/
+
+#include "SpacePushButton.hpp"
+#include <QKeyEvent>
+
+SpacePushButton::SpacePushButton(QWidget* parent)
+	: QPushButton(parent)
+{
+}
+
+void SpacePushButton::keyPressEvent(QKeyEvent *e)
+{
+	switch (e->key()) {
+	case Qt::Key_Space:
+		animateClick();
+		break;
+	default:
+		QPushButton::keyPressEvent(e);
+    }
+}

src/gui/SpacePushButton.hpp

@@ -0,0 +1,42 @@
+/*
+ * Stellarium
+ * Copyright (C) 2021 Georg Zotti
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA  02110-1335, USA.
+ */
+
+#ifndef SPACEPUSHBUTTON_HPP
+#define SPACEPUSHBUTTON_HPP
+
+#include <QPushButton>
+
+//! @class SpacePushButton
+//! A QPushButton which can be triggered by pressing Space when it has focus.
+//! To use this class in the QtCreator UI designer, add a regular QPushButton to the UI,
+//! then right-click on it and change its type to SpacePushButton.
+//! Then it makes sense to put this button into a useful GUI tab order.
+class SpacePushButton : public QPushButton
+{
+	Q_OBJECT
+public:
+	SpacePushButton(QWidget* parent=Q_NULLPTR);
+	~SpacePushButton() Q_DECL_OVERRIDE {}
+
+protected:
+    //! This triggers the button on pressing the Space bar.
+    virtual void keyPressEvent(QKeyEvent *e) Q_DECL_OVERRIDE;
+};
+
+#endif // SPACEPUSHBUTTON_HPP