animated loader with circles

src/lib_gui/qt/view/QtViewOverlay.cpp

@@ -1,7 +1,11 @@
 #include "qt/view/QtViewOverlay.h"
 
-#include <QWidget>
+#include <cmath>
+
 #include <QEvent>
+#include <QPainter>
+#include <QPaintEvent>
+#include <QTimer>
 
 ResizeFilter::ResizeFilter(QWidget* widget)
 	: m_widget(widget)
@@ -20,21 +24,69 @@ bool ResizeFilter::eventFilter(QObject* obj, QEvent* event)
 }
 
 
+QtOverlay::QtOverlay(QWidget* parent)
+	: QWidget(parent)
+	, m_count(0)
+	, m_size(40)
+{
+}
+
+void QtOverlay::animate()
+{
+	m_count += 25;
+
+	QPoint center = geometry().center();
+	update(QRect(center.x() - m_size / 2, center.y() - m_size / 2, m_size, m_size));
+}
+
+void QtOverlay::paintEvent(QPaintEvent *event)
+{
+	QPainter painter(this);
+
+	painter.fillRect(geometry(), "#AAFFFFFF");
+
+	QPoint center = geometry().center();
+
+	size_t x = m_size / 2;
+	size_t y = m_size / 2;
+	size_t s = (m_count / 7) % 200;
+
+	if (s < 100)
+	{
+		x = std::cos(3.1415f * s / 100) * x;
+	}
+	else
+	{
+		y = std::cos(3.1415f * (s - 100) / 100) * y;
+	}
+
+	painter.translate(center.x(), center.y());
+	// painter.rotate(m_count / 8);
+
+	if (s > 50 && s < 150)
+	{
+		painter.setBrush(QBrush("#CC2E3C86"));
+	}
+	else
+	{
+		painter.setBrush(QBrush("#CC007AC2"));
+	}
+
+	painter.setPen(QPen(Qt::transparent));
+
+	painter.drawEllipse(-x, -y, 2 * x, 2 * y);
+}
+
+
 QtViewOverlay::QtViewOverlay(QWidget* parent)
 	: m_parent(parent)
 	, m_beforeFunctor(std::bind(&QtViewOverlay::doBefore, this))
 	, m_afterFunctor(std::bind(&QtViewOverlay::doAfter, this))
 {
-	m_overlay = new QWidget(m_parent);
+	m_overlay = new QtOverlay(m_parent);
 	m_parent->installEventFilter(new ResizeFilter(m_overlay));
-
-	std::string frameStyle =
-		"#overlay {"
-			"background: #55FF0000; "
-		"}";
-	m_overlay->setStyleSheet(frameStyle.c_str());
-	m_overlay->setObjectName("overlay");
 	m_overlay->hide();
+	m_timer = new QTimer(m_overlay);
 }
 
 void QtViewOverlay::handleMessage(MessageLoadBefore* message)
@@ -49,10 +101,16 @@ void QtViewOverlay::handleMessage(MessageLoadAfter* message)
 
 void QtViewOverlay::doBefore()
 {
+	QObject::connect(m_timer, SIGNAL(timeout()), m_overlay, SLOT(animate()));
+
+	m_timer->start(25);
+
 	m_overlay->show();
 }
 
 void QtViewOverlay::doAfter()
 {
+	m_timer->stop();
+
 	m_overlay->hide();
 }

src/lib_gui/qt/view/QtViewOverlay.h

@@ -1,14 +1,14 @@
 #ifndef QT_VIEW_OVERLAY
 #define QT_VIEW_OVERLAY
 
-#include <QObject>
+#include <QWidget>
 
 #include "qt/utility/QtThreadedFunctor.h"
 #include "utility/messaging/MessageListener.h"
 #include "utility/messaging/type/MessageLoadBefore.h"
 #include "utility/messaging/type/MessageLoadAfter.h"
 
-class QWidget;
+class QTimer;
 
 class ResizeFilter
 	: public QObject
@@ -29,6 +29,26 @@ private:
 };
 
 
+class QtOverlay
+	: public QWidget
+{
+	Q_OBJECT
+
+public:
+	QtOverlay(QWidget* parent = nullptr);
+
+public slots:
+	void animate();
+
+protected:
+	void paintEvent(QPaintEvent *event);
+
+private:
+	size_t m_count;
+	size_t m_size;
+};
+
+
 class QtViewOverlay
 	: public MessageListener<MessageLoadBefore>
 	, public MessageListener<MessageLoadAfter>
@@ -44,7 +64,9 @@ private:
 	void doAfter();
 
 	QWidget* m_parent;
-	QWidget* m_overlay;
+	QtOverlay* m_overlay;
+
+	QTimer* m_timer;
 
 	QtThreadedFunctor<void> m_beforeFunctor;
 	QtThreadedFunctor<void> m_afterFunctor;