git.defcon.no Git - qopencamwidget/blob - view.cpp

   1 /*
   2  QOpenCamWidget demo application main window (view.c)
   3  This file is part of a demonstration application, illustrating
   4  how to use the QOpenCamWidget, a Qt 4 widget that displays
   5  video input from a webcam, along with a snapshot button.
   6
   7  Copyright (C) 2009 Jon Langseth
   8
   9  This program is free software; you can redistribute it and/or
  10  modify it under the terms of the GNU General Public License
  11  as published by the Free Software Foundation in its version 2
  12  of the License.
  13
  14  This program is distributed in the hope that it will be useful,
  15  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  GNU General Public License for more details.
  18
  19  You should have received a copy of the GNU General Public License
  20  along with this program; if not, write to the Free Software
  21  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  22  */
  23
  24 #include "view.h"
  25 #include "qopencamwidget.h"
  26
  27 // The View class is a QMainWindow, used to display our QOpenCamWidget
  28 // The constructor of the View takes care of setting up the Widget,
  29 // and handles the result of a user clicking (or activating) the
  30 // "Take snapshot" button.
  31
  32 View::View( QWidget *parent)
  33         : QMainWindow(parent)
  34 {
  35
  36         QWidget *cw = new QWidget();
  37         QVBoxLayout *layout = new QVBoxLayout();
  38
  39         // This button will be used to trigger a snapshot later on..
  40         QPushButton *trigger = new QPushButton(this);
  41         trigger->setText("Take picture");
  42
  43         // Create the widget, setting the Main window (this) as its parent.
  44         QOpenCamWidget *cwcam = new QOpenCamWidget(this, new QSize(320, 240), new QSize(960,720));
  45         // bool QOpenCamWidget::grabCapture(int source) tries to get a
  46         // video capture handle from OpenCV, using the source number
  47         // as the device to open. Here I use -1 as the number, meaning
  48         // "give me any supported and available video devica you can find".
  49         if ( cwcam->grabCapture(-1) )
  50         {
  51                 // grabCapture() returns true on success. This means that
  52                 // we have a capture device available, and can start streaming
  53                 // video from the device to display on the widget.
  54
  55                 // Video output does not start until QOpenCamWidget::startCapture()
  56                 // is explicitly called.
  57                 cwcam->startCapture();
  58         }
  59
  60         // The QOpenCamWidget does not provide a video stream for further
  61         // processing, but it does provide a snapshot of the stream if
  62         // the SLOT void QOpenCamWidget::startSnap(void) is triggered.
  63         // In this demo app, the slot is connected to the widgets
  64         // internal "Take snapshot" trigger button, but the SLOT is
  65         // public, and may easily be triggered from "outside".
  66         //
  67         // When startSnap() is triggered, it will use a SIGNAL to return
  68         // its image, if the aquisition was successful. The image
  69         // will be available through QOpenCamWidget::imageReady(Qimage);
  70         // In this sample, I hook that signal up to a slot on this QMainWindow,
  71         // that saves the image, and exits the application.
  72         connect( cwcam, SIGNAL(imageReady(QImage)), this, SLOT(saveImage(QImage)));
  73
  74         // To trigger the startSnap(), we hook our previously created
  75         // pushbutton to that SLOT.
  76         connect( trigger, SIGNAL(clicked()), cwcam, SLOT(startSnap()));
  77
  78         // Add it all up, and we are ready to run.
  79         layout->addWidget(cwcam);
  80         layout->addWidget(trigger);
  81         cw->setLayout(layout);
  82         this->setCentralWidget(cw);
  83 }
  84
  85 View::~View(void)
  86 {
  87 }
  88
  89 void View::saveImage(QImage image)
  90 {
  91         // This is the SLOT that recieves QOpenCamWidget::imageReady(QImage) SIGNAL.
  92         // To keep the example as simple as possible, I do as little as possible..
  93         qDebug() << "Recieved an image of size "
  94                 << image.width() << "x" << image.height();
  95         image.save("snapshot.png");
  96
  97         QApplication::exit();
  98 }