Qt: Allow use of modifier keys as input

CHANGES

@@ -60,6 +60,7 @@ Misc:
  - Util: Add MutexTryLock
  - Qt: Gray out "Skip BIOS intro" while "Use BIOS file" is unchecked
  - Qt: Add mute option to menu
+ - Qt: Allow use of modifier keys as input
 
 0.3.1: (2015-10-24)
 Bugfixes:

src/platform/qt/KeyEditor.cpp

@@ -22,6 +22,7 @@ KeyEditor::KeyEditor(QWidget* parent)
 {
 	setAlignment(Qt::AlignCenter);
 	setFocusPolicy(Qt::ClickFocus);
+	m_lastKey.setSingleShot(true);
 }
 
 void KeyEditor::setValue(int key) {
@@ -77,28 +78,47 @@ QSize KeyEditor::sizeHint() const {
 
 void KeyEditor::keyPressEvent(QKeyEvent* event) {
 	if (!m_button) {
-		if (m_key < 0) {
+		if (m_key < 0 || !m_lastKey.isActive()) {
 			m_key = 0;
 		}
-		if (ShortcutController::isModifierKey(event->key())) {
-			switch (event->key()) {
-			case Qt::Key_Shift:
-				setValue(m_key | Qt::ShiftModifier);
-				break;
-			case Qt::Key_Control:
-				setValue(m_key | Qt::ControlModifier);
-				break;
-			case Qt::Key_Alt:
-				setValue(m_key | Qt::AltModifier);
-				break;
-			case Qt::Key_Meta:
-				setValue(m_key | Qt::MetaModifier);
-				break;
-			default:
-				setValue(m_key);
+		m_lastKey.start(KEY_TIME);
+		if (m_key) {
+			if (ShortcutController::isModifierKey(m_key)) {
+				switch (event->key()) {
+				case Qt::Key_Shift:
+					setValue(Qt::ShiftModifier);
+					break;
+				case Qt::Key_Control:
+					setValue(Qt::ControlModifier);
+					break;
+				case Qt::Key_Alt:
+					setValue(Qt::AltModifier);
+					break;
+				case Qt::Key_Meta:
+					setValue(Qt::MetaModifier);
+					break;
+				}
+			}
+			if (ShortcutController::isModifierKey(event->key())) {
+				switch (event->key()) {
+				case Qt::Key_Shift:
+					setValue(m_key | Qt::ShiftModifier);
+					break;
+				case Qt::Key_Control:
+					setValue(m_key | Qt::ControlModifier);
+					break;
+				case Qt::Key_Alt:
+					setValue(m_key | Qt::AltModifier);
+					break;
+				case Qt::Key_Meta:
+					setValue(m_key | Qt::MetaModifier);
+					break;
+				}
+			} else {
+				setValue(event->key() | (m_key & (Qt::ShiftModifier | Qt::ControlModifier | Qt::AltModifier | Qt::MetaModifier)));
 			}
 		} else {
-			setValue(event->key() | (m_key & (Qt::ShiftModifier | Qt::ControlModifier | Qt::AltModifier | Qt::MetaModifier)));
+			setValue(event->key());
 		}
 	}
 	event->accept();

src/platform/qt/KeyEditor.h

@@ -7,7 +7,9 @@
 #define QGBA_KEY_EDITOR
 
 #include "GamepadAxisEvent.h"
+
 #include <QLineEdit>
+#include <QTimer>
 
 namespace QGBA {
 
@@ -41,12 +43,15 @@ protected:
 	virtual bool event(QEvent* event) override;
 
 private:
+	static const int KEY_TIME = 2000;
+
 	void updateButtonText();
 
 	int m_key;
 	int m_axis;
 	bool m_button;
 	GamepadAxisEvent::Direction m_direction;
+	QTimer m_lastKey;
 };
 
 }