00001 /* 00002 QOpenCamWidget demo application main window (view.c) 00003 This file is part of a demonstration application, illustrating 00004 how to use the QOpenCamWidget, a Qt 4 widget that displays 00005 video input from a webcam, along with a snapshot button. 00006 00007 Copyright (C) 2009 Jon Langseth 00008 00009 This program is free software; you can redistribute it and/or 00010 modify it under the terms of the GNU General Public License 00011 as published by the Free Software Foundation in its version 2 00012 of the License. 00013 00014 This program is distributed in the hope that it will be useful, 00015 but WITHOUT ANY WARRANTY; without even the implied warranty of 00016 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00017 GNU General Public License for more details. 00018 00019 You should have received a copy of the GNU General Public License 00020 along with this program; if not, write to the Free Software 00021 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 00022 */ 00023 00024 #include "view.h" 00025 #include "qopencamwidget.h" 00026 00027 // The View class is a QMainWindow, used to display our QOpenCamWidget 00028 // The constructor of the View takes care of setting up the Widget, 00029 // and handles the result of a user clicking (or activating) the widget's 00030 // "Take snapshot" button. 00031 00032 View::View( QWidget *parent) 00033 : QMainWindow(parent) 00034 { 00035 00036 // Create the widget, setting the Main window (this) as its parent. 00037 QOpenCamWidget *cw = new QOpenCamWidget(this); 00038 00039 // bool QOpenCamWidget::grabCapture(int source) tries to get a 00040 // video capture handle from OpenCV, using the source number 00041 // as the device to open. Here I use -1 as the number, meaning 00042 // "give me any supported and available video devica you can find". 00043 if ( cw->grabCapture(-1) ) 00044 { 00045 // grabCapture() returns true on success. This means that 00046 // we have a capture device available, and can start streaming 00047 // video from the device to display on the widget. 00048 00049 // TODO: Document this feature.. 00050 cw->setSnapshotVisible(true); 00051 00052 // Video output does not start until QOpenCamWidget::startCapture() 00053 // is explicitly called. 00054 cw->startCapture(); 00055 } 00056 00057 // The QOpenCamWidget does not provide a video stream for further 00058 // processing, but it does provide a snapshot of the stream if 00059 // the SLOT void QOpenCamWidget::startSnap(void) is triggered. 00060 // In this demo app, the slot is connected to the widgets 00061 // internal "Take snapshot" trigger button, but the SLOT is 00062 // public, and may easily be triggered from "outside". 00063 // 00064 // When startSnap() is triggered, it will use a SIGNAL to return 00065 // its image, if the aquisition was successful. The image 00066 // will be available through QOpenCamWidget::imageReady(Qimage); 00067 // In this sample, I hook that signal up to a slot on this QMainWindow, 00068 // that saves the image, and exits the application. 00069 connect( cw, SIGNAL(imageReady(QImage)), this, SLOT(saveImage(QImage))); 00070 00071 this->setCentralWidget(cw); 00072 } 00073 00074 View::~View(void) 00075 { 00076 } 00077 00078 void View::saveImage(QImage image) 00079 { 00080 // This is the SLOT that recieves QOpenCamWidget::imageReady(QImage) SIGNAL. 00081 // To keep the example as simple as possible, I do as little as possible.. 00082 qDebug() << "Recieved an image of size " 00083 << image.width() << "x" << image.height(); 00084 image.save("snapshot.png"); 00085 00086 QApplication::exit(); 00087 }