Made planets selectable

src/Planet.cpp

@@ -3,17 +3,43 @@
 Planet::Planet(float xPos, float yPos, float radius, QColor color) :
 	position{ xPos, yPos }, radius(radius)
 {
-	circle = QBrush(color);
+	Initialize(color);
 }
 
 Planet::Planet(QPointF pos, float radius, QColor color) :
 	position(pos), radius(radius)
 {
-	circle = QBrush(color);
+	Initialize(color);
+}
+
+void Planet::Select(bool select)
+{
+	if (select)
+		outline.setColor(selectionColor);
+	else
+		outline.setColor(Qt::transparent);
 }
 
 void Planet::Draw(QPainter* painter)
 {
 	painter->setBrush(circle);
+	painter->setPen(outline);
 	painter->drawEllipse(position, radius, radius);
 }
+
+bool Planet::IsInside(QPointF point) const
+{
+	QPointF distance = point - position;
+	return (distance.x() * distance.x() + distance.y() * distance.y() < radius * radius);
+}
+
+void Planet::Initialize(QColor color)
+{
+	circle = QBrush(color);
+	outline = QPen(Qt::transparent);
+	outline.setWidthF(4.f);
+
+	int h, s, v, a;
+	color.getHsv(&h, &s, &v, &a);
+	selectionColor = QColor::fromHsv((h + 180) % 360, s, v, a);
+}

src/Planet.hpp

@@ -11,12 +11,21 @@ public:
 	Planet(QPointF pos, float radius, QColor color);
 
 	void Resize(float newRadius) { radius = newRadius; }
+	void Select(bool select);
 
 	void Draw(QPainter* painter);
 
+	bool IsInside(QPointF point) const;
+
+private:
+	void Initialize(QColor color);
+
 private:
 	QPointF position;
 	float radius;
 
+	QColor selectionColor;
+
 	QBrush circle;
+	QPen outline;
 };

src/Screen.cpp

@@ -8,9 +8,14 @@
 #include <QTimer>
 #include <QtMath>
 
+#define BIND_LMB(f) (lmbAction = std::bind(&Screen::f, this, std::placeholders::_1))
+
 Screen::Screen(QWidget* parent) :
 	QOpenGLWidget(parent)
 {
+	setMouseTracking(true);
+	BIND_LMB(lmb_MakePlanet);
+
 	srand(time(NULL));
 
 	background = QBrush(Qt::black);
@@ -25,23 +30,39 @@ Screen::Screen(QWidget* parent) :
 
 void Screen::mouseMoveEvent(QMouseEvent* event)
 {
-	if (mouseDown)
+	if (mouseDown && hovered == nullptr)
 	{
 		Planet* planet = planets.back();
 		QPointF distance = event->localPos() - mouseClickPos;
 		planet->Resize(qSqrt(distance.x()*distance.x() + distance.y() *distance.y()));
 	}
+	else
+	{
+		hovered = nullptr;
+		for (unsigned i = planets.size(); i-- > 0; )
+		{
+			if (planets[i]->IsInside(event->localPos()))
+			{
+				setCursor(Qt::OpenHandCursor);
+				BIND_LMB(lmb_SelectPlanet);
+				hovered = planets[i];
+				break;
+			}
+		}
+
+		if (hovered == nullptr)
+		{
+			setCursor(Qt::ArrowCursor);
+			BIND_LMB(lmb_MakePlanet);
+		}
+	}
 }
 
 void Screen::mousePressEvent(QMouseEvent* event)
 {
 	if (event->button() == Qt::MouseButton::LeftButton)
 	{
-		planets.push_back(new Planet(event->localPos(), 0,
-			QColor(rand() % 256, rand() % 256, rand() % 256)
-		));
-		mouseClickPos = event->localPos();
-		mouseDown = true;
+		lmbAction(event);
 	}
 
 	if (event->button() == Qt::MouseButton::RightButton)
@@ -65,6 +86,28 @@ void Screen::Render()
 	update();
 }
 
+void Screen::lmb_MakePlanet(QMouseEvent* event)
+{
+	planets.push_back(new Planet(event->localPos(), 0,
+		QColor(rand() % 256, rand() % 256, rand() % 256)
+	));
+	mouseClickPos = event->localPos();
+	mouseDown = true;
+}
+
+void Screen::lmb_SelectPlanet(QMouseEvent* event)
+{
+	if (hovered != nullptr)
+	{
+		if (selected != nullptr)
+			selected->Select(false);
+
+		hovered->Select(true);
+	}
+
+	selected = hovered;
+}
+
 void Screen::paintEvent(QPaintEvent* event)
 {
 	QPainter painter;

src/Screen.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <vector>
+#include <functional>
 
 #include <QOpenGLWidget>
 
@@ -18,15 +19,24 @@ public:
 private slots:
 	void Render();
 
+private:
+	void lmb_MakePlanet(QMouseEvent* event);
+	void lmb_SelectPlanet(QMouseEvent* event);
+
 protected:
 	void paintEvent(QPaintEvent* event) override;
 
 private:
 	bool mouseDown = false;
+
+	std::function<void(QMouseEvent*)> lmbAction;
+
 	QPointF mouseClickPos;
 
 	QBrush background;
 	QTimer* renderTimer;
 
 	std::vector<Planet*> planets;
+	Planet* selected = nullptr;
+	Planet* hovered = nullptr;
 };