states.cpp Example File

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  //Own
  #include "states.h"
  #include "graphicsscene.h"
  #include "boat.h"
  #include "submarine.h"
  #include "torpedo.h"
  #include "animationmanager.h"
  #include "progressitem.h"
  #include "textinformationitem.h"

  //Qt
  #include <QtWidgets/QMessageBox>
  #include <QtWidgets/QGraphicsView>
  #include <QtCore/QStateMachine>
  #include <QtWidgets/QKeyEventTransition>
  #include <QtCore/QFinalState>

  PlayState::PlayState(GraphicsScene *scene, QState *parent)
      : QState(parent),
      scene(scene),
      machine(0),
      currentLevel(0),
      score(0)
  {
  }

  PlayState::~PlayState()
  {
      delete machine;
  }

  void PlayState::onEntry(QEvent *)
  {
      //We are now playing?
      if (machine) {
          machine->stop();
          //we hide the information
          scene->textInformationItem->hide();
          scene->clearScene();
          currentLevel = 0;
          score = 0;
          delete machine;
      }

      machine = new QStateMachine;

      //This state is when player is playing
      LevelState *levelState = new LevelState(scene, this, machine);

      //This state is when the player is actually playing but the game is not paused
      QState *playingState = new QState(levelState);
      levelState->setInitialState(playingState);

      //This state is when the game is paused
      PauseState *pauseState = new PauseState(scene, levelState);

      //We have one view, it receive the key press event
      QKeyEventTransition *pressPplay = new QKeyEventTransition(scene->views().at(0), QEvent::KeyPress, Qt::Key_P);
      pressPplay->setTargetState(pauseState);
      QKeyEventTransition *pressPpause = new QKeyEventTransition(scene->views().at(0), QEvent::KeyPress, Qt::Key_P);
      pressPpause->setTargetState(playingState);

      //Pause "P" is triggered, the player pause the game
      playingState->addTransition(pressPplay);

      //To get back playing when the game has been paused
      pauseState->addTransition(pressPpause);

      //This state is when player have lost
      LostState *lostState = new LostState(scene, this, machine);

      //This state is when player have won
      WinState *winState = new WinState(scene, this, machine);

      //The boat has been destroyed then the game is finished
      levelState->addTransition(scene->boat, SIGNAL(boatExecutionFinished()),lostState);

      //This transition check if we won or not
      WinTransition *winTransition = new WinTransition(scene, this, winState);

      //The boat has been destroyed then the game is finished
      levelState->addTransition(winTransition);

      //This state is an animation when the score changed
      UpdateScoreState *scoreState = new UpdateScoreState(levelState);

      //This transition update the score when a submarine die
      UpdateScoreTransition *scoreTransition = new UpdateScoreTransition(scene, this, levelState);
      scoreTransition->setTargetState(scoreState);

      //The boat has been destroyed then the game is finished
      playingState->addTransition(scoreTransition);

      //We go back to play state
      scoreState->addTransition(playingState);

      //We start playing!!!
      machine->setInitialState(levelState);

      //Final state
      QFinalState *final = new QFinalState(machine);

      //This transition is triggered when the player press space after completing a level
      CustomSpaceTransition *spaceTransition = new CustomSpaceTransition(scene->views().at(0), this, QEvent::KeyPress, Qt::Key_Space);
      spaceTransition->setTargetState(levelState);
      winState->addTransition(spaceTransition);

      //We lost we should reach the final state
      lostState->addTransition(lostState, SIGNAL(finished()), final);

      machine->start();
  }

  LevelState::LevelState(GraphicsScene *scene, PlayState *game, QState *parent) : QState(parent), scene(scene), game(game)
  {
  }
  void LevelState::onEntry(QEvent *)
  {
      initializeLevel();
  }

  void LevelState::initializeLevel()
  {
      //we re-init the boat
      scene->boat->setPos(scene->width()/2, scene->sealLevel() - scene->boat->size().height());
      scene->boat->setCurrentSpeed(0);
      scene->boat->setCurrentDirection(Boat::None);
      scene->boat->setBombsLaunched(0);
      scene->boat->show();
      scene->setFocusItem(scene->boat, Qt::OtherFocusReason);
      scene->boat->run();

      scene->progressItem->setScore(game->score);
      scene->progressItem->setLevel(game->currentLevel + 1);

      GraphicsScene::LevelDescription currentLevelDescription = scene->levelsData.value(game->currentLevel);

      for (int i = 0; i < currentLevelDescription.submarines.size(); ++i ) {

          QPair<int,int> subContent = currentLevelDescription.submarines.at(i);
          GraphicsScene::SubmarineDescription submarineDesc = scene->submarinesData.at(subContent.first);

          for (int j = 0; j < subContent.second; ++j ) {
              SubMarine *sub = new SubMarine(submarineDesc.type, submarineDesc.name, submarineDesc.points);
              scene->addItem(sub);
              int random = (qrand() % 15 + 1);
              qreal x = random == 13 || random == 5 ? 0 : scene->width() - sub->size().width();
              qreal y = scene->height() -(qrand() % 150 + 1) - sub->size().height();
              sub->setPos(x,y);
              sub->setCurrentDirection(x == 0 ? SubMarine::Right : SubMarine::Left);
              sub->setCurrentSpeed(qrand() % 3 + 1);
          }
      }
  }

  /** Pause State */
  PauseState::PauseState(GraphicsScene *scene, QState *parent) : QState(parent),scene(scene)
  {
  }
  void PauseState::onEntry(QEvent *)
  {
      AnimationManager::self()->pauseAll();
      scene->boat->setEnabled(false);
  }
  void PauseState::onExit(QEvent *)
  {
      AnimationManager::self()->resumeAll();
      scene->boat->setEnabled(true);
      scene->boat->setFocus();
  }

  /** Lost State */
  LostState::LostState(GraphicsScene *scene, PlayState *game, QState *parent) : QState(parent), scene(scene), game(game)
  {
  }

  void LostState::onEntry(QEvent *)
  {
      //The message to display
      QString message = QString("You lose on level %1. Your score is %2.").arg(game->currentLevel+1).arg(game->score);

      //We set the level back to 0
      game->currentLevel = 0;

      //We set the score back to 0
      game->score = 0;

      //We clear the scene
      scene->clearScene();

      //We inform the player
      scene->textInformationItem->setMessage(message);
      scene->textInformationItem->show();
  }

  void LostState::onExit(QEvent *)
  {
      //we hide the information
      scene->textInformationItem->hide();
  }

  /** Win State */
  WinState::WinState(GraphicsScene *scene, PlayState *game, QState *parent) : QState(parent), scene(scene), game(game)
  {
  }

  void WinState::onEntry(QEvent *)
  {
      //We clear the scene
      scene->clearScene();

      QString message;
      if (scene->levelsData.size() - 1 != game->currentLevel) {
          message = QString("You win the level %1. Your score is %2.\nPress Space to continue.").arg(game->currentLevel+1).arg(game->score);
          //We increment the level number
          game->currentLevel++;
      } else {
          message = QString("You finish the game on level %1. Your score is %2.").arg(game->currentLevel+1).arg(game->score);
          //We set the level back to 0
          game->currentLevel = 0;
          //We set the score back to 0
          game->score = 0;
      }

      //We inform the player
      scene->textInformationItem->setMessage(message);
      scene->textInformationItem->show();
  }

  void WinState::onExit(QEvent *)
  {
      //we hide the information
      scene->textInformationItem->hide();
  }

  /** UpdateScore State */
  UpdateScoreState::UpdateScoreState(QState *parent) : QState(parent)
  {
  }

  /** Win transition */
  UpdateScoreTransition::UpdateScoreTransition(GraphicsScene *scene, PlayState *game, QAbstractState *target)
      : QSignalTransition(scene,SIGNAL(subMarineDestroyed(int))),
      game(game), scene(scene)
  {
      setTargetState(target);
  }

  bool UpdateScoreTransition::eventTest(QEvent *event)
  {
      if (!QSignalTransition::eventTest(event))
          return false;
      QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(event);
      game->score += se->arguments().at(0).toInt();
      scene->progressItem->setScore(game->score);
      return true;
  }

  /** Win transition */
  WinTransition::WinTransition(GraphicsScene *scene, PlayState *game, QAbstractState *target)
      : QSignalTransition(scene,SIGNAL(allSubMarineDestroyed(int))),
      game(game), scene(scene)
  {
      setTargetState(target);
  }

  bool WinTransition::eventTest(QEvent *event)
  {
      if (!QSignalTransition::eventTest(event))
          return false;
      QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(event);
      game->score += se->arguments().at(0).toInt();
      scene->progressItem->setScore(game->score);
      return true;
  }

  /** Space transition */
  CustomSpaceTransition::CustomSpaceTransition(QWidget *widget, PlayState *game, QEvent::Type type, int key)
      :   QKeyEventTransition(widget, type, key),
          game(game)
  {
  }

  bool CustomSpaceTransition::eventTest(QEvent *event)
  {
      if (!QKeyEventTransition::eventTest(event))
          return false;
      return (game->currentLevel != 0);
  }