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 widget's
  30 // "Take snapshot" button.
  31
  32 View::View( QWidget *parent)
  33         : QMainWindow(parent)
  34 {
  35
  36         // Create the widget, setting the Main window (this) as its parent.
  37         QOpenCamWidget *cw = new QOpenCamWidget(this);
  38
  39         // bool QOpenCamWidget::grabCapture(int source) tries to get a
  40         // video capture handle from OpenCV, using the source number
  41         // as the device to open. Here I use -1 as the number, meaning
  42         // "give me any supported and available video devica you can find".
  43         if ( cw->grabCapture(-1) )
  44         {
  45                 // grabCapture() returns true on success. This means that
  46                 // we have a capture device available, and can start streaming
  47                 // video from the device to display on the widget.
  48
  49                 // TODO: Document this feature..
  50                 cw->setSnapshotVisible(true);
  51
  52                 // Video output does not start until QOpenCamWidget::startCapture()
  53                 // is explicitly called.
  54                 cw->startCapture();
  55         }
  56
  57         // The QOpenCamWidget does not provide a video stream for further
  58         // processing, but it does provide a snapshot of the stream if
  59         // the SLOT void QOpenCamWidget::startSnap(void) is triggered.
  60         // In this demo app, the slot is connected to the widgets
  61         // internal "Take snapshot" trigger button, but the SLOT is
  62         // public, and may easily be triggered from "outside".
  63         //
  64         // When startSnap() is triggered, it will use a SIGNAL to return
  65         // its image, if the aquisition was successful. The image
  66         // will be available through QOpenCamWidget::imageReady(Qimage);
  67         // In this sample, I hook that signal up to a slot on this QMainWindow,
  68         // that saves the image, and exits the application.
  69         connect( cw, SIGNAL(imageReady(QImage)), this, SLOT(saveImage(QImage)));
  70
  71         this->setCentralWidget(cw);
  72 }
  73
  74 View::~View(void)
  75 {
  76 }
  77
  78 void View::saveImage(QImage image)
  79 {
  80         // This is the SLOT that recieves QOpenCamWidget::imageReady(QImage) SIGNAL.
  81         // To keep the example as simple as possible, I do as little as possible..
  82         qDebug() << "Recieved an image of size "
  83                 << image.width() << "x" << image.height();
  84         image.save("snapshot.png");
  85
  86         QApplication::exit();
  87 }