- Qt 5.5
- Qt Widgets
- Sub-Attaq
- states.cpp Example File
- Qt 5.5.1 Reference Documentation

# states.cpp Example File

animation/sub-attaq/states.cpp

    /****************************************************************************
    **
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    ** This file is part of the QtCore module of the Qt Toolkit.
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    ** $QT_BEGIN_LICENSE:LGPL21$
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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);
    }