Qt 5.11 | Qt Widgets | Boxes | qtbox.cpp Example File

Qt 5.11.3 Reference Documentation

# qtbox.cpp Example File

graphicsview/boxes/qtbox.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the demonstration applications of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, you may use this file under the terms of the BSD license
      ** as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
      ** met:
      **   * Redistributions of source code must retain the above copyright
      **     notice, this list of conditions and the following disclaimer.
      **   * Redistributions in binary form must reproduce the above copyright
      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
      **     distribution.
      **   * Neither the name of The Qt Company Ltd nor the names of its
      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
      **
      **
      ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #include "qtbox.h"

      const qreal ROTATE_SPEED_X = 30.0 / 1000.0;
      const qreal ROTATE_SPEED_Y = 20.0 / 1000.0;
      const qreal ROTATE_SPEED_Z = 40.0 / 1000.0;
      const int MAX_ITEM_SIZE = 512;
      const int MIN_ITEM_SIZE = 16;

      //============================================================================//
      //                                  ItemBase                                  //
      //============================================================================//

      ItemBase::ItemBase(int size, int x, int y) : m_size(size), m_isResizing(false)
      {
          setFlag(QGraphicsItem::ItemIsMovable, true);
          setFlag(QGraphicsItem::ItemIsSelectable, true);
          setFlag(QGraphicsItem::ItemIsFocusable, true);
          setAcceptHoverEvents(true);
          setPos(x, y);
          m_startTime = QTime::currentTime();
      }

      ItemBase::~ItemBase()
      {
      }

      QRectF ItemBase::boundingRect() const
      {
          return QRectF(-m_size / 2, -m_size / 2, m_size, m_size);
      }

      void ItemBase::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *)
      {
          if (option->state & QStyle::State_Selected) {
              painter->setRenderHint(QPainter::Antialiasing, true);
              if (option->state & QStyle::State_HasFocus)
                  painter->setPen(Qt::yellow);
              else
                  painter->setPen(Qt::white);
              painter->drawRect(boundingRect());

              painter->drawLine(m_size / 2 - 9, m_size / 2, m_size / 2, m_size / 2 - 9);
              painter->drawLine(m_size / 2 - 6, m_size / 2, m_size / 2, m_size / 2 - 6);
              painter->drawLine(m_size / 2 - 3, m_size / 2, m_size / 2, m_size / 2 - 3);

              painter->setRenderHint(QPainter::Antialiasing, false);
          }
      }

      void ItemBase::contextMenuEvent(QGraphicsSceneContextMenuEvent *event)
      {
          if (!isSelected() && scene()) {
              scene()->clearSelection();
              setSelected(true);
          }

          QMenu menu;
          QAction *delAction = menu.addAction("Delete");
          QAction *newAction = menu.addAction("New");
          QAction *growAction = menu.addAction("Grow");
          QAction *shrinkAction = menu.addAction("Shrink");

          QAction *selectedAction = menu.exec(event->screenPos());

          if (selectedAction == delAction)
              deleteSelectedItems(scene());
          else if (selectedAction == newAction)
              duplicateSelectedItems(scene());
          else if (selectedAction == growAction)
              growSelectedItems(scene());
          else if (selectedAction == shrinkAction)
              shrinkSelectedItems(scene());
      }

      void ItemBase::duplicateSelectedItems(QGraphicsScene *scene)
      {
          if (!scene)
              return;

          QList<QGraphicsItem *> selected;
          selected = scene->selectedItems();

          foreach (QGraphicsItem *item, selected) {
              ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
              if (itemBase)
                  scene->addItem(itemBase->createNew(itemBase->m_size, itemBase->pos().x() + itemBase->m_size, itemBase->pos().y()));
          }
      }

      void ItemBase::deleteSelectedItems(QGraphicsScene *scene)
      {
          if (!scene)
              return;

          QList<QGraphicsItem *> selected;
          selected = scene->selectedItems();

          foreach (QGraphicsItem *item, selected) {
              ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
              if (itemBase)
                  delete itemBase;
          }
      }

      void ItemBase::growSelectedItems(QGraphicsScene *scene)
      {
          if (!scene)
              return;

          QList<QGraphicsItem *> selected;
          selected = scene->selectedItems();

          foreach (QGraphicsItem *item, selected) {
              ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
              if (itemBase) {
                  itemBase->prepareGeometryChange();
                  itemBase->m_size *= 2;
                  if (itemBase->m_size > MAX_ITEM_SIZE)
                      itemBase->m_size = MAX_ITEM_SIZE;
              }
          }
      }

      void ItemBase::shrinkSelectedItems(QGraphicsScene *scene)
      {
          if (!scene)
              return;

          QList<QGraphicsItem *> selected;
          selected = scene->selectedItems();

          foreach (QGraphicsItem *item, selected) {
              ItemBase *itemBase = qgraphicsitem_cast<ItemBase *>(item);
              if (itemBase) {
                  itemBase->prepareGeometryChange();
                  itemBase->m_size /= 2;
                  if (itemBase->m_size < MIN_ITEM_SIZE)
                      itemBase->m_size = MIN_ITEM_SIZE;
              }
          }
      }

      void ItemBase::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
      {
          if (m_isResizing) {
              int dx = int(2.0 * event->pos().x());
              int dy = int(2.0 * event->pos().y());
              prepareGeometryChange();
              m_size = (dx > dy ? dx : dy);
              if (m_size < MIN_ITEM_SIZE)
                  m_size = MIN_ITEM_SIZE;
              else if (m_size > MAX_ITEM_SIZE)
                  m_size = MAX_ITEM_SIZE;
          } else {
              QGraphicsItem::mouseMoveEvent(event);
          }
      }

      void ItemBase::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
      {
          if (m_isResizing || (isInResizeArea(event->pos()) && isSelected()))
              setCursor(Qt::SizeFDiagCursor);
          else
              setCursor(Qt::ArrowCursor);
          QGraphicsItem::hoverMoveEvent(event);
      }

      void ItemBase::mousePressEvent(QGraphicsSceneMouseEvent *event)
      {
          static qreal z = 0.0;
          setZValue(z += 1.0);
          if (event->button() == Qt::LeftButton && isInResizeArea(event->pos())) {
              m_isResizing = true;
          } else {
              QGraphicsItem::mousePressEvent(event);
          }
      }

      void ItemBase::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
      {
          if (event->button() == Qt::LeftButton && m_isResizing) {
              m_isResizing = false;
          } else {
              QGraphicsItem::mouseReleaseEvent(event);
          }
      }

      void ItemBase::keyPressEvent(QKeyEvent *event)
      {
          switch (event->key()) {
          case Qt::Key_Delete:
              deleteSelectedItems(scene());
              break;
          case Qt::Key_Insert:
              duplicateSelectedItems(scene());
              break;
          case Qt::Key_Plus:
              growSelectedItems(scene());
              break;
          case Qt::Key_Minus:
              shrinkSelectedItems(scene());
              break;
          default:
              QGraphicsItem::keyPressEvent(event);
              break;
          }
      }

      void ItemBase::wheelEvent(QGraphicsSceneWheelEvent *event)
      {
          prepareGeometryChange();
          m_size = int(m_size * qExp(-event->delta() / 600.0));
          if (m_size > MAX_ITEM_SIZE)
              m_size = MAX_ITEM_SIZE;
          else if (m_size < MIN_ITEM_SIZE)
              m_size = MIN_ITEM_SIZE;
      }

      int ItemBase::type() const
      {
          return Type;
      }

      bool ItemBase::isInResizeArea(const QPointF &pos)
      {
          return (-pos.y() < pos.x() - m_size + 9);
      }

      //============================================================================//
      //                                    QtBox                                   //
      //============================================================================//

      QtBox::QtBox(int size, int x, int y) : ItemBase(size, x, y), m_texture(0)
      {
          for (int i = 0; i < 8; ++i) {
              m_vertices[i].setX(i & 1 ? 0.5f : -0.5f);
              m_vertices[i].setY(i & 2 ? 0.5f : -0.5f);
              m_vertices[i].setZ(i & 4 ? 0.5f : -0.5f);
          }
          for (int i = 0; i < 4; ++i) {
              m_texCoords[i].setX(i & 1 ? 1.0f : 0.0f);
              m_texCoords[i].setY(i & 2 ? 1.0f : 0.0f);
          }
          m_normals[0] = QVector3D(-1.0f, 0.0f, 0.0f);
          m_normals[1] = QVector3D(1.0f, 0.0f, 0.0f);
          m_normals[2] = QVector3D(0.0f, -1.0f, 0.0f);
          m_normals[3] = QVector3D(0.0f, 1.0f, 0.0f);
          m_normals[4] = QVector3D(0.0f, 0.0f, -1.0f);
          m_normals[5] = QVector3D(0.0f, 0.0f, 1.0f);
      }

      QtBox::~QtBox()
      {
          if (m_texture)
              delete m_texture;
      }

      ItemBase *QtBox::createNew(int size, int x, int y)
      {
          return new QtBox(size, x, y);
      }

      void QtBox::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
      {
          QRectF rect = boundingRect().translated(pos());
          float width = float(painter->device()->width());
          float height = float(painter->device()->height());

          float left = 2.0f * float(rect.left()) / width - 1.0f;
          float right = 2.0f * float(rect.right()) / width - 1.0f;
          float top = 1.0f - 2.0f * float(rect.top()) / height;
          float bottom = 1.0f - 2.0f * float(rect.bottom()) / height;
          float moveToRectMatrix[] = {
              0.5f * (right - left), 0.0f, 0.0f, 0.0f,
              0.0f, 0.5f * (bottom - top), 0.0f, 0.0f,
              0.0f, 0.0f, 1.0f, 0.0f,
              0.5f * (right + left), 0.5f * (bottom + top), 0.0f, 1.0f
          };

          painter->beginNativePainting();

          glMatrixMode(GL_PROJECTION);
          glPushMatrix();
          glLoadMatrixf(moveToRectMatrix);
          qgluPerspective(60.0, 1.0, 0.01, 10.0);

          glMatrixMode(GL_MODELVIEW);
          glPushMatrix();
          glLoadIdentity();

          //glEnable(GL_DEPTH_TEST);
          glEnable(GL_CULL_FACE);
          glEnable(GL_LIGHTING);
          glEnable(GL_COLOR_MATERIAL);
          glEnable(GL_NORMALIZE);

          if(m_texture == 0)
              m_texture = new GLTexture2D(":/res/boxes/qt-logo.jpg", 64, 64);
          m_texture->bind();
          glEnable(GL_TEXTURE_2D);

          glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
          float lightColour[] = {1.0f, 1.0f, 1.0f, 1.0f};
          float lightDir[] = {0.0f, 0.0f, 1.0f, 0.0f};
          glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColour);
          glLightfv(GL_LIGHT0, GL_POSITION, lightDir);
          glEnable(GL_LIGHT0);

          glTranslatef(0.0f, 0.0f, -1.5f);
          glRotatef(ROTATE_SPEED_X * m_startTime.msecsTo(QTime::currentTime()), 1.0f, 0.0f, 0.0f);
          glRotatef(ROTATE_SPEED_Y * m_startTime.msecsTo(QTime::currentTime()), 0.0f, 1.0f, 0.0f);
          glRotatef(ROTATE_SPEED_Z * m_startTime.msecsTo(QTime::currentTime()), 0.0f, 0.0f, 1.0f);
          int dt = m_startTime.msecsTo(QTime::currentTime());
          if (dt < 500)
              glScalef(dt / 500.0f, dt / 500.0f, dt / 500.0f);

          for (int dir = 0; dir < 3; ++dir) {
              glColor4f(1.0f, 1.0f, 1.0f, 1.0);

              glBegin(GL_TRIANGLE_STRIP);
              glNormal3fv(reinterpret_cast<float *>(&m_normals[2 * dir + 0]));
              for (int i = 0; i < 2; ++i) {
                  for (int j = 0; j < 2; ++j) {
                      glTexCoord2fv(reinterpret_cast<float *>(&m_texCoords[(j << 1) | i]));
                      glVertex3fv(reinterpret_cast<float *>(&m_vertices[(i << ((dir + 2) % 3)) | (j << ((dir + 1) % 3))]));
                  }
              }
              glEnd();

              glBegin(GL_TRIANGLE_STRIP);
              glNormal3fv(reinterpret_cast<float *>(&m_normals[2 * dir + 1]));
              for (int i = 0; i < 2; ++i) {
                  for (int j = 0; j < 2; ++j) {
                      glTexCoord2fv(reinterpret_cast<float *>(&m_texCoords[(j << 1) | i]));
                      glVertex3fv(reinterpret_cast<float *>(&m_vertices[(1 << dir) | (i << ((dir + 1) % 3)) | (j << ((dir + 2) % 3))]));
                  }
              }
              glEnd();
          }
          m_texture->unbind();

          //glDisable(GL_DEPTH_TEST);
          glDisable(GL_CULL_FACE);
          glDisable(GL_LIGHTING);
          glDisable(GL_COLOR_MATERIAL);
          glDisable(GL_TEXTURE_2D);
          glDisable(GL_LIGHT0);
          glDisable(GL_NORMALIZE);

          glPopMatrix();

          glMatrixMode(GL_PROJECTION);
          glPopMatrix();

          painter->endNativePainting();

          ItemBase::paint(painter, option, widget);
      }

      //============================================================================//
      //                                 CircleItem                                 //
      //============================================================================//

      CircleItem::CircleItem(int size, int x, int y) : ItemBase(size, x, y)
      {
           m_color = QColor::fromHsv(QRandomGenerator::global()->bounded(360), 255, 255);
      }

      void CircleItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
      {
          int dt = m_startTime.msecsTo(QTime::currentTime());

          qreal r0 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 3800) % 4000)));
          qreal r1 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 0) % 4000)));
          qreal r2 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 1800) % 4000)));
          qreal r3 = 0.5 * m_size * (1.0 - qExp(-0.001 * ((dt + 2000) % 4000)));

          if (r0 > r1)
              r0 = 0.0;
          if (r2 > r3)
              r2 = 0.0;

          QPainterPath path;
          path.moveTo(r1, 0.0);
          path.arcTo(-r1, -r1, 2 * r1, 2 * r1, 0.0, 360.0);
          path.lineTo(r0, 0.0);
          path.arcTo(-r0, -r0, 2 * r0, 2 * r0, 0.0, -360.0);
          path.closeSubpath();
          path.moveTo(r3, 0.0);
          path.arcTo(-r3, -r3, 2 * r3, 2 * r3, 0.0, 360.0);
          path.lineTo(r0, 0.0);
          path.arcTo(-r2, -r2, 2 * r2, 2 * r2, 0.0, -360.0);
          path.closeSubpath();
          painter->setRenderHint(QPainter::Antialiasing, true);
          painter->setBrush(QBrush(m_color));
          painter->setPen(Qt::NoPen);
          painter->drawPath(path);
          painter->setBrush(Qt::NoBrush);
          painter->setPen(Qt::SolidLine);
          painter->setRenderHint(QPainter::Antialiasing, false);

          ItemBase::paint(painter, option, widget);
      }

      ItemBase *CircleItem::createNew(int size, int x, int y)
      {
          return new CircleItem(size, x, y);
      }

      //============================================================================//
      //                                 SquareItem                                 //
      //============================================================================//

      SquareItem::SquareItem(int size, int x, int y) : ItemBase(size, x, y)
      {
          m_image = QPixmap(":/res/boxes/square.jpg");
      }

      void SquareItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
      {
          int dt = m_startTime.msecsTo(QTime::currentTime());
          QTransform oldTransform = painter->worldTransform();
          int dtMod = dt % 2000;
          qreal amp = 0.002 * (dtMod < 1000 ? dtMod : 2000 - dtMod) - 1.0;

          qreal scale = 0.6 + 0.2 * amp * amp;
          painter->setWorldTransform(QTransform().rotate(15.0 * amp).scale(scale, scale), true);

          painter->drawPixmap(-m_size / 2, -m_size / 2, m_size, m_size, m_image);

          painter->setWorldTransform(oldTransform, false);
          ItemBase::paint(painter, option, widget);
      }

      ItemBase *SquareItem::createNew(int size, int x, int y)
      {
          return new SquareItem(size, x, y);
      }