padnavigator.cpp Example File

graphicsview/padnavigator/padnavigator.cpp
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#include "flippablepad.h"
#include "padnavigator.h"
#include "splashitem.h"

#ifndef QT_NO_OPENGL
#include <QtOpenGL>
#else
#include <QtWidgets>
#endif

PadNavigator::PadNavigator(const QSize &size, QWidget *parent)
    : QGraphicsView(parent)
{
    // Splash item
    SplashItem *splash = new SplashItem;
    splash->setZValue(1);

    // Pad item
    FlippablePad *pad = new FlippablePad(size);
    QGraphicsRotation *flipRotation = new QGraphicsRotation(pad);
    QGraphicsRotation *xRotation = new QGraphicsRotation(pad);
    QGraphicsRotation *yRotation = new QGraphicsRotation(pad);
    flipRotation->setAxis(Qt::YAxis);
    xRotation->setAxis(Qt::YAxis);
    yRotation->setAxis(Qt::XAxis);
    pad->setTransformations(QList<QGraphicsTransform *>()
                            << flipRotation
                            << xRotation << yRotation);

    // Back (proxy widget) item
    QGraphicsProxyWidget *backItem = new QGraphicsProxyWidget(pad);
    QWidget *widget = new QWidget;
    form.setupUi(widget);
    form.hostName->setFocus();
    backItem->setWidget(widget);
    backItem->setVisible(false);
    backItem->setFocus();
    backItem->setCacheMode(QGraphicsItem::ItemCoordinateCache);
    const QRectF r = backItem->rect();
    backItem->setTransform(QTransform()
                           .rotate(180, Qt::YAxis)
                           .translate(-r.width()/2, -r.height()/2));

    // Selection item
    RoundRectItem *selectionItem = new RoundRectItem(QRectF(-60, -60, 120, 120), Qt::gray, pad);
    selectionItem->setZValue(0.5);

    // Splash animations
    QPropertyAnimation *smoothSplashMove = new QPropertyAnimation(splash, "y");
    QPropertyAnimation *smoothSplashOpacity = new QPropertyAnimation(splash, "opacity");
    smoothSplashMove->setEasingCurve(QEasingCurve::InQuad);
    smoothSplashMove->setDuration(250);
    smoothSplashOpacity->setDuration(250);

    // Selection animation
    QPropertyAnimation *smoothXSelection = new QPropertyAnimation(selectionItem, "x");
    QPropertyAnimation *smoothYSelection = new QPropertyAnimation(selectionItem, "y");
    QPropertyAnimation *smoothXRotation = new QPropertyAnimation(xRotation, "angle");
    QPropertyAnimation *smoothYRotation = new QPropertyAnimation(yRotation, "angle");
    smoothXSelection->setDuration(125);
    smoothYSelection->setDuration(125);
    smoothXRotation->setDuration(125);
    smoothYRotation->setDuration(125);
    smoothXSelection->setEasingCurve(QEasingCurve::InOutQuad);
    smoothYSelection->setEasingCurve(QEasingCurve::InOutQuad);
    smoothXRotation->setEasingCurve(QEasingCurve::InOutQuad);
    smoothYRotation->setEasingCurve(QEasingCurve::InOutQuad);

    // Flip animation setup
    QPropertyAnimation *smoothFlipRotation = new QPropertyAnimation(flipRotation, "angle");
    QPropertyAnimation *smoothFlipScale = new QPropertyAnimation(pad, "scale");
    QPropertyAnimation *smoothFlipXRotation = new QPropertyAnimation(xRotation, "angle");
    QPropertyAnimation *smoothFlipYRotation = new QPropertyAnimation(yRotation, "angle");
    QParallelAnimationGroup *flipAnimation = new QParallelAnimationGroup(this);
    smoothFlipScale->setDuration(500);
    smoothFlipRotation->setDuration(500);
    smoothFlipXRotation->setDuration(500);
    smoothFlipYRotation->setDuration(500);
    smoothFlipScale->setEasingCurve(QEasingCurve::InOutQuad);
    smoothFlipRotation->setEasingCurve(QEasingCurve::InOutQuad);
    smoothFlipXRotation->setEasingCurve(QEasingCurve::InOutQuad);
    smoothFlipYRotation->setEasingCurve(QEasingCurve::InOutQuad);
    smoothFlipScale->setKeyValueAt(0, qvariant_cast<qreal>(1.0));
    smoothFlipScale->setKeyValueAt(0.5, qvariant_cast<qreal>(0.7));
    smoothFlipScale->setKeyValueAt(1, qvariant_cast<qreal>(1.0));
    flipAnimation->addAnimation(smoothFlipRotation);
    flipAnimation->addAnimation(smoothFlipScale);
    flipAnimation->addAnimation(smoothFlipXRotation);
    flipAnimation->addAnimation(smoothFlipYRotation);

    // Flip animation delayed property assignment
    QSequentialAnimationGroup *setVariablesSequence = new QSequentialAnimationGroup;
    QPropertyAnimation *setFillAnimation = new QPropertyAnimation(pad, "fill");
    QPropertyAnimation *setBackItemVisibleAnimation = new QPropertyAnimation(backItem, "visible");
    QPropertyAnimation *setSelectionItemVisibleAnimation = new QPropertyAnimation(selectionItem, "visible");
    setFillAnimation->setDuration(0);
    setBackItemVisibleAnimation->setDuration(0);
    setSelectionItemVisibleAnimation->setDuration(0);
    setVariablesSequence->addPause(250);
    setVariablesSequence->addAnimation(setBackItemVisibleAnimation);
    setVariablesSequence->addAnimation(setSelectionItemVisibleAnimation);
    setVariablesSequence->addAnimation(setFillAnimation);
    flipAnimation->addAnimation(setVariablesSequence);

    // Build the state machine
    QStateMachine *stateMachine = new QStateMachine(this);
    QState *splashState = new QState(stateMachine);
    QState *frontState = new QState(stateMachine);
    QHistoryState *historyState = new QHistoryState(frontState);
    QState *backState = new QState(stateMachine);
    frontState->assignProperty(pad, "fill", false);
    frontState->assignProperty(splash, "opacity", 0.0);
    frontState->assignProperty(backItem, "visible", false);
    frontState->assignProperty(flipRotation, "angle", qvariant_cast<qreal>(0.0));
    frontState->assignProperty(selectionItem, "visible", true);
    backState->assignProperty(pad, "fill", true);
    backState->assignProperty(backItem, "visible", true);
    backState->assignProperty(xRotation, "angle", qvariant_cast<qreal>(0.0));
    backState->assignProperty(yRotation, "angle", qvariant_cast<qreal>(0.0));
    backState->assignProperty(flipRotation, "angle", qvariant_cast<qreal>(180.0));
    backState->assignProperty(selectionItem, "visible", false);
    stateMachine->addDefaultAnimation(smoothXRotation);
    stateMachine->addDefaultAnimation(smoothYRotation);
    stateMachine->addDefaultAnimation(smoothXSelection);
    stateMachine->addDefaultAnimation(smoothYSelection);
    stateMachine->setInitialState(splashState);

    // Transitions
    QEventTransition *anyKeyTransition = new QEventTransition(this, QEvent::KeyPress, splashState);
    anyKeyTransition->setTargetState(frontState);
    anyKeyTransition->addAnimation(smoothSplashMove);
    anyKeyTransition->addAnimation(smoothSplashOpacity);

    QKeyEventTransition *enterTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                   Qt::Key_Enter, backState);
    QKeyEventTransition *returnTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                    Qt::Key_Return, backState);
    QKeyEventTransition *backEnterTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                       Qt::Key_Enter, frontState);
    QKeyEventTransition *backReturnTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                        Qt::Key_Return, frontState);
    enterTransition->setTargetState(historyState);
    returnTransition->setTargetState(historyState);
    backEnterTransition->setTargetState(backState);
    backReturnTransition->setTargetState(backState);
    enterTransition->addAnimation(flipAnimation);
    returnTransition->addAnimation(flipAnimation);
    backEnterTransition->addAnimation(flipAnimation);
    backReturnTransition->addAnimation(flipAnimation);

    // Create substates for each icon; store in temporary grid.
    int columns = size.width();
    int rows = size.height();
    QVector< QVector< QState * > > stateGrid;
    stateGrid.resize(rows);
    for (int y = 0; y < rows; ++y) {
        stateGrid[y].resize(columns);
        for (int x = 0; x < columns; ++x)
            stateGrid[y][x] = new QState(frontState);
    }
    frontState->setInitialState(stateGrid[0][0]);
    selectionItem->setPos(pad->iconAt(0, 0)->pos());

    // Enable key navigation using state transitions
    for (int y = 0; y < rows; ++y) {
        for (int x = 0; x < columns; ++x) {
            QState *state = stateGrid[y][x];
            QKeyEventTransition *rightTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                           Qt::Key_Right, state);
            QKeyEventTransition *leftTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                          Qt::Key_Left, state);
            QKeyEventTransition *downTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                          Qt::Key_Down, state);
            QKeyEventTransition *upTransition = new QKeyEventTransition(this, QEvent::KeyPress,
                                                                        Qt::Key_Up, state);
            rightTransition->setTargetState(stateGrid[y][(x + 1) % columns]);
            leftTransition->setTargetState(stateGrid[y][((x - 1) + columns) % columns]);
            downTransition->setTargetState(stateGrid[(y + 1) % rows][x]);
            upTransition->setTargetState(stateGrid[((y - 1) + rows) % rows][x]);
            RoundRectItem *icon = pad->iconAt(x, y);
            state->assignProperty(xRotation, "angle", -icon->x() / 6.0);
            state->assignProperty(yRotation, "angle", icon->y() / 6.0);
            state->assignProperty(selectionItem, "x", icon->x());
            state->assignProperty(selectionItem, "y", icon->y());
            frontState->assignProperty(icon, "visible", true);
            backState->assignProperty(icon, "visible", false);

            QPropertyAnimation *setIconVisibleAnimation = new QPropertyAnimation(icon, "visible");
            setIconVisibleAnimation->setDuration(0);
            setVariablesSequence->addAnimation(setIconVisibleAnimation);
        }
    }

    // Scene
    QGraphicsScene *scene = new QGraphicsScene(this);
    scene->setBackgroundBrush(QPixmap(":/images/blue_angle_swirl.jpg"));
    scene->setItemIndexMethod(QGraphicsScene::NoIndex);
    scene->addItem(pad);
    scene->setSceneRect(scene->itemsBoundingRect());
    setScene(scene);

    // Adjust splash item to scene contents
    const QRectF sbr = splash->boundingRect();
    splash->setPos(-sbr.width() / 2, scene->sceneRect().top() - 2);
    frontState->assignProperty(splash, "y", splash->y() - 100.0);
    scene->addItem(splash);

    // View
    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setMinimumSize(50, 50);
    setViewportUpdateMode(FullViewportUpdate);
    setCacheMode(CacheBackground);
    setRenderHints(QPainter::Antialiasing
                   | QPainter::SmoothPixmapTransform
                   | QPainter::TextAntialiasing);
#ifndef QT_NO_OPENGL
    setViewport(new QOpenGLWidget);
#endif

    stateMachine->start();
}

void PadNavigator::resizeEvent(QResizeEvent *event)
{
    QGraphicsView::resizeEvent(event);
    fitInView(scene()->sceneRect(), Qt::KeepAspectRatio);
}

© 2016 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.