Add basic platform

src/mainwindow.cpp

@@ -1,10 +1,13 @@
 #include "mainwindow.h"
 #include "./ui_mainwindow.h"
 #include <QDebug>
+#include <memory>
 
 MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent), ui(new Ui::MainWindow) {
     ui->setupUi(this);
 
+    platform = std::make_shared<Platform>(this);
+
     auto ball = std::make_shared<Ball>(this);
     connect(ball.get(), &Ball::deleted, this, &MainWindow::onDeleteBall);
     balls.append(ball);
@@ -25,6 +28,8 @@ void MainWindow::paintEvent(QPaintEvent*) {
     for (auto ball : balls) {
         ball->draw(painter);
     }
+
+    platform->draw(painter);
 }
 
 void MainWindow::onDeleteBall(Ball* ball) {

src/mainwindow.h

@@ -2,6 +2,7 @@
 #define MAINWINDOW_H
 
 #include "ball.h"
+#include "platform.h"
 #include <QMainWindow>
 
 QT_BEGIN_NAMESPACE
@@ -26,5 +27,6 @@ class MainWindow : public QMainWindow {
   private:
     Ui::MainWindow* ui;
     QList<std::shared_ptr<Ball>> balls;
+    std::shared_ptr<Platform> platform;
 };
 #endif // MAINWINDOW_H

src/platform.cpp

@@ -0,0 +1,26 @@
+#include "platform.h"
+#include <QDebug>
+
+#define TICK_SPEED 15
+#define PLATFORM_WIDTH 100
+#define PLATFORM_HEIGHT 20
+#define PLATFORM_MARGIN_BOTTOM 80
+#define SPEED 5.0
+
+Platform::Platform(QWidget* parent) : m_parent{parent} {
+    QRect rct = parent->rect();
+
+    m_x = rand() % (rct.width() - PLATFORM_WIDTH);
+    m_y = rct.height() - (PLATFORM_HEIGHT + PLATFORM_MARGIN_BOTTOM);
+
+    start(TICK_SPEED);
+}
+
+void Platform::draw(QPainter& painter) {
+    QRect rct(m_x, m_y, PLATFORM_WIDTH, PLATFORM_HEIGHT);
+    painter.drawRect(rct);
+}
+
+void Platform::timerEvent(QTimerEvent*) {
+    m_parent->update();
+}

src/platform.h

@@ -0,0 +1,25 @@
+#ifndef PLATFORM_H
+#define PLATFORM_H
+
+#include <QPainter>
+#include <QTimer>
+#include <QWidget>
+
+class Platform : public QTimer {
+    Q_OBJECT
+
+  public:
+    Platform(QWidget* parent);
+
+    void draw(QPainter& painter);
+
+  protected:
+    virtual void timerEvent(QTimerEvent*) override;
+
+  private:
+    QWidget* m_parent;
+    double m_x;
+    double m_y;
+};
+
+#endif // PLATFORM_H