Qt Reference Documentation

# cameraexample.cpp Example File

demos/mobile/qcamera/cameraexample.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** This file is part of the demonstration applications of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** 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 Nokia Corporation and its Subsidiary(-ies) 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 "cameraexample.h"
     #include "messagehandling.h"
     #include "contactsdlg.h"
     #include "button.h"
     #include "businesscardhandling.h"
     #include <QDebug>

     /*****************************************************************************
     * MyVideoSurface
     */
     MyVideoSurface::MyVideoSurface(QWidget* widget, VideoIF* target, QObject* parent)
         : QAbstractVideoSurface(parent)
     {
         m_targetWidget = widget;
         m_target = target;
         m_imageFormat = QImage::Format_Invalid;
     }

     MyVideoSurface::~MyVideoSurface()
     {
     }

     bool MyVideoSurface::start(const QVideoSurfaceFormat &format)
     {
         m_videoFormat = format;
         const QImage::Format imageFormat = QVideoFrame::imageFormatFromPixelFormat(format.pixelFormat());
         const QSize size = format.frameSize();

         if (imageFormat != QImage::Format_Invalid && !size.isEmpty()) {
             m_imageFormat = imageFormat;
             QAbstractVideoSurface::start(format);
             return true;
         } else {
             return false;
         }
     }

     bool MyVideoSurface::present(const QVideoFrame &frame)
     {
         m_frame = frame;
         if (surfaceFormat().pixelFormat() != m_frame.pixelFormat() ||
                 surfaceFormat().frameSize() != m_frame.size()) {
             stop();
             return false;
         } else {
             m_target->updateVideo();
             return true;
         }
     }

     void MyVideoSurface::paint(QPainter *painter)
      {
          if (m_frame.map(QAbstractVideoBuffer::ReadOnly)) {
              QImage image(
                      m_frame.bits(),
                      m_frame.width(),
                      m_frame.height(),
                      m_frame.bytesPerLine(),
                      m_imageFormat);

              QRect r = m_targetWidget->rect();
              QPoint centerPic((qAbs(r.size().width() - image.size().width())) / 2, (qAbs(
                  r.size().height() - image.size().height())) / 2);

              if (!image.isNull()) {
                 painter->drawImage(centerPic,image);
              }

              m_frame.unmap();
          }
      }

     QList<QVideoFrame::PixelFormat> MyVideoSurface::supportedPixelFormats(
                 QAbstractVideoBuffer::HandleType handleType) const
     {
         if (handleType == QAbstractVideoBuffer::NoHandle) {
             return QList<QVideoFrame::PixelFormat>()
                     << QVideoFrame::Format_RGB32
                     << QVideoFrame::Format_ARGB32
                     << QVideoFrame::Format_ARGB32_Premultiplied
                     << QVideoFrame::Format_RGB565
                     << QVideoFrame::Format_RGB555;
         } else {
             return QList<QVideoFrame::PixelFormat>();
         }
     }

     /*****************************************************************************
     * CameraExample
     */
     CameraExample::CameraExample(QWidget *parent) :
         QMainWindow(parent)
     {
         setWindowTitle("QCameraExample");

         // Opitimizations for screen update and drawing qwidget
         setAutoFillBackground(false);

         // Prevent to screensaver to activate
         m_systemScreenSaver = new QSystemScreenSaver(this);
         m_systemScreenSaver->setScreenSaverInhibit();

         m_myVideoSurface = 0;
         pictureCaptured = false;
         showViewFinder = false;
         m_focusing = false;

         // MMS handling
         m_message = new Message(this);
         QObject::connect(m_message, SIGNAL(messageStateChanged(int)), this, SLOT(messageStateChanged(int)));
         QObject::connect(m_message, SIGNAL(messageReceived(QString,QString,QPixmap)), this, SLOT(messageReceived(QString,QString,QPixmap)));

         // Business card handling (Contact's avatar picture)
         m_businessCardHandling = new BusinessCardHandling(this);

         // Black background
         QPalette palette = this->palette();
         palette.setColor(QPalette::Background, Qt::black);
         setPalette(palette);

         // Main widget & layout
         QWidget* mainWidget = new QWidget(this);
         mainWidget->setPalette(palette);

         QHBoxLayout* hboxl = new QHBoxLayout;
         hboxl->setSpacing(0);
         hboxl->setMargin(0);

         // UI stack
         m_stackedWidget = new QStackedWidget();
         m_stackedWidget->setPalette(palette);

         // First widget to stack
         m_videoWidget = new QWidget();
         m_videoWidget->setPalette(palette);
         m_stackedWidget->addWidget(m_videoWidget);

         // Second widget to stack
         QWidget* secondWidget = new QWidget(this);
         secondWidget->setPalette(palette);
         m_stackedWidget->addWidget(secondWidget);
         m_stackedWidget->setCurrentIndex(0);

         hboxl->addWidget(m_stackedWidget);

         // Buttons
         QSize iconSize(80, 80);
         QVBoxLayout* vboxl = new QVBoxLayout;
         vboxl->setSpacing(0);
         vboxl->setMargin(0);

         // Exit button
         m_exit = new Button(this);
         QObject::connect(m_exit, SIGNAL(pressed()), qApp, SLOT(quit()));
         QPixmap p = QPixmap(":/icons/exit.png");
         m_exit->setPixmap(p.scaled(iconSize, Qt::KeepAspectRatio, Qt::SmoothTransformation));
         vboxl->addWidget(m_exit);
         vboxl->setAlignment(m_exit, Qt::AlignHCenter | Qt::AlignTop);

         // Camera button
         m_cameraBtn = new Button(this);
         QObject::connect(m_cameraBtn, SIGNAL(pressed()), this, SLOT(searchAndLock()));
         p = QPixmap(":/icons/camera.png");
         m_cameraBtn->setPixmap(p.scaled(iconSize, Qt::KeepAspectRatio, Qt::SmoothTransformation));
         vboxl->addWidget(m_cameraBtn);
         vboxl->setAlignment(m_cameraBtn, Qt::AlignCenter);

         // Send MMS button
         m_mms = new Button(this);
         QObject::connect(m_mms, SIGNAL(pressed()), this, SLOT(openContactsDlg()));
         p = QPixmap(":/icons/mms.png");
         m_mms->setPixmap(p.scaled(iconSize, Qt::KeepAspectRatio, Qt::SmoothTransformation));
         vboxl->addWidget(m_mms);
         vboxl->setAlignment(m_mms, Qt::AlignHCenter | Qt::AlignBottom);
     #ifndef MESSAGING_ENABLED
         m_mms->disableBtn(true);
         m_mms->setEnabled(false);
     #endif

         hboxl->addLayout(vboxl);
         mainWidget->setLayout(hboxl);

         setCentralWidget(mainWidget);

         // Enable camera after 1s, so that the application is started
         // and widget is created to landscape orientation
         QTimer::singleShot(1000,this,SLOT(enableCamera()));
     }

     CameraExample::~CameraExample()
     {
     if (m_myVideoSurface)
         m_myVideoSurface->stop();
         m_camera->stop();
         delete m_stackedWidget;
         delete m_stillImageCapture;
         delete m_camera;
     }

     void CameraExample::enableCamera()
     {
         m_camera = new QCamera();
         m_camera->setCaptureMode(QCamera::CaptureStillImage);
         connect(m_camera, SIGNAL(error(QCamera::Error)), this, SLOT(error(QCamera::Error)));
         connect(m_camera, SIGNAL(lockStatusChanged(QCamera::LockStatus,QCamera::LockChangeReason)), this, SLOT(lockStatusChanged(QCamera::LockStatus,QCamera::LockChangeReason)));

         // Own video output drawing that shows camera view finder pictures
         QMediaService* ms = m_camera->service();
         QVideoRendererControl* vrc = ms->requestControl<QVideoRendererControl*>();
         m_myVideoSurface = new MyVideoSurface(this,this,this);
         vrc->setSurface(m_myVideoSurface);
         // Image capturer
         m_stillImageCapture = new QCameraImageCapture(m_camera);
         connect(m_stillImageCapture, SIGNAL(imageCaptured(int,QImage)), this, SLOT(imageCaptured(int,QImage)));

         // Start camera
         if (m_camera->state() == QCamera::ActiveState) {
             m_camera->stop();
         }
         m_videoWidget->show();
         m_camera->start();
         showViewFinder = true;
     }

     void CameraExample::mousePressEvent(QMouseEvent *event)
     {
         QMainWindow::mousePressEvent(event);

         if (pictureCaptured) {
             // Starting view finder
             pictureCaptured = false;
             m_stackedWidget->setCurrentIndex(0);
             if (m_myVideoSurface) {
                 showViewFinder = true;
             }
         }
     }

     void CameraExample::searchAndLock()
     {
         m_focusing = false;
         m_focusMessage.clear();

         if (pictureCaptured) {
             // Starting view finder again
             pictureCaptured = false;
             m_stackedWidget->setCurrentIndex(0);
             if (m_myVideoSurface) {
                 showViewFinder = true;
             }
         }
         else {
             // Search and lock picture (=focus)
             if (m_camera->supportedLocks() & QCamera::LockFocus) {
                 m_focusing = true;
                 m_focusMessage = "Focusing...";
                 m_camera->searchAndLock(QCamera::LockFocus);
             } else {
             // No focus functionality, take picture right away
                 captureImage();
             }
         }
     }

     void CameraExample::lockStatusChanged(QCamera::LockStatus status, QCamera::LockChangeReason reason)
     {
         if (status == QCamera::Locked) {
             if (reason == QCamera::LockAcquired) {
                 // Focus locked
                 m_focusMessage.clear();
                 m_focusing = false;
                 // Capture new image
                 captureImage();
                 // Unlock camera
                 m_camera->unlock();
             } else {
                 if (m_focusing)
                     m_focusMessage = "No focus, try again";
             }
         } else if (status == QCamera::Unlocked && m_focusing) {
             m_focusMessage = "No focus, try again";
         }
     }

     void CameraExample::captureImage()
     {
         if (pictureCaptured) {
             // Starting view finder again
             pictureCaptured = false;
             m_stackedWidget->setCurrentIndex(0);
             showViewFinder = true;
         }
         else {
             // Capturing image
             showViewFinder = false;
             // Get picture location where to store captured images
             QString path(QDesktopServices::storageLocation(QDesktopServices::PicturesLocation));
             QDir dir(path);

             // Get next filename
             QStringList files = dir.entryList(QStringList() << "camera_*.jpg");
             int lastImage = 0;
             foreach ( QString fileName, files ) {
                     int imgNumber = fileName.mid(7, fileName.size() - 11).toInt();
                     lastImage = qMax(lastImage, imgNumber);
                 }
             // Capture image
             if (m_stillImageCapture->isReadyForCapture()) {
                 m_imageName = QString("camera_%1.jpg").arg(lastImage+1);
                 m_stillImageCapture->capture(m_imageName);
             }
         }
     }

     void CameraExample::imageCaptured(int id, const QImage &preview)
     {
         showViewFinder = false;
         m_focusing = false;

         // Image captured, show it to the user
         m_stackedWidget->setCurrentIndex(1);

         // Get picture location
         QString path(QDesktopServices::storageLocation(QDesktopServices::PicturesLocation));
         m_imageName.prepend(path + "/");

         m_capturedImage = preview;

         // Set suitable size to the image
         QSize s = m_videoWidget->size();
         s = s - QSize(20, 20);
         m_capturedImage = m_capturedImage.scaled(s, Qt::KeepAspectRatio, Qt::SmoothTransformation);

         pictureCaptured = true;
         update();
     }

     void CameraExample::error(QCamera::Error e)
     {
         switch (e) {
         case QCamera::NoError:
         {
             break;
         }
         case QCamera::CameraError:
         {
             QMessageBox::warning(this, "QCameraExample", "General Camera error");
             break;
         }
         case QCamera::InvalidRequestError:
         {
             QMessageBox::warning(this, "QCameraExample", "Camera invalid request error");
             break;
         }
         case QCamera::ServiceMissingError:
         {
             QMessageBox::warning(this, "QCameraExample", "Camera service missing error");
             break;
         }
         case QCamera::NotSupportedFeatureError :
         {
             QMessageBox::warning(this, "QCameraExample", "Camera not supported error");
             break;
         }
         };
     }

     void CameraExample::openContactsDlg()
     {
         // Open dialog for showing contacts
         if (!m_contactsDialog) {

             if (m_capturedImage.isNull()) {
                 QMessageBox::information(this, "QCameraExample", "Take picture first");
                 return;
             }

             // Show dialog
             m_contactsDialog = new ContactsDialog(this);
             QObject::connect(m_contactsDialog, SIGNAL(contactSelected(QString)),
             this, SLOT(contactSelected(QString)));
             m_contactsDialog->exec();
             QObject::disconnect(m_contactsDialog, SIGNAL(contactSelected(QString)),
             this, SLOT(contactSelected(QString)));

             delete m_contactsDialog;
             m_contactsDialog = 0;
         }
     }

     void CameraExample::contactSelected(QString phoneNumber)
     {
         m_phoneNumber = phoneNumber;
         QTimer::singleShot(1000,this,SLOT(sendMMS()));
     }

     void CameraExample::sendMMS()
     {
     #ifdef MESSAGING_ENABLED
         m_message->sendMMS(m_imageName, m_phoneNumber);
     #endif
     }

     void CameraExample::messageStateChanged(int /*error*/)
     {
     }

     void CameraExample::updateVideo()
     {
         if (showViewFinder) {
             repaint();
         }
     }

     void CameraExample::paintEvent(QPaintEvent *event)
     {
         //QMainWindow::paintEvent(event);

         QPainter painter(this);
         QRect r = this->rect();

         QFont font = painter.font();
         font.setPixelSize(20);
         painter.setFont(font);
         painter.setPen(Qt::white);

         if (showViewFinder && m_myVideoSurface && m_myVideoSurface->isActive()) {
             // Show view finder
             m_myVideoSurface->paint(&painter);

             // Paint focus message
             if (!m_focusMessage.isEmpty())
                 painter.drawText(r, Qt::AlignCenter, m_focusMessage);

         } else {
             // Draw black
             painter.fillRect(event->rect(), palette().background());
             // Show captured image
             if (pictureCaptured) {
                 // Paint captured image
                 QPoint centerPic((qAbs(r.size().width() - m_capturedImage.size().width())) / 2, (qAbs(
                     r.size().height() - m_capturedImage.size().height())) / 2);

                 painter.drawImage(centerPic, m_capturedImage);

                 // Paint filename
                 painter.drawText(r, Qt::AlignBottom | Qt::AlignCenter, m_imageName);
             }
         }

     }

     void CameraExample::messageReceived(QString phoneNumber, QString filename, QPixmap pixmap)
     {
     #ifdef MESSAGING_ENABLED
         // MMS message received
         // Check that is came from some of our contact
         QContact contact;
         if (m_businessCardHandling->findContact(phoneNumber, contact)) {
             // Ask from user to store it as sender avatar picture into contacts
             if (QMessageBox::question(
                 this,
                 "QCameraExample",
                 QString(
                     "MMS picture message received from %1. Do you want to store it as sender avatar picture?").arg(
                     contact.displayLabel()), QMessageBox::Yes | QMessageBox::No) == QMessageBox::Yes) {

                 m_businessCardHandling->storeAvatarToContact(phoneNumber, filename, pixmap);
             }
         }
     #endif
     }