ImageHandler.h

Go to the documentation of this file.

/*
 * The information in this file is
 * Copyright(c) 2007 Ball Aerospace & Technologies Corporation
 * and is subject to the terms and conditions of the
 * GNU Lesser General Public License Version 2.1
 * The license text is available from   
 * http://www.gnu.org/licenses/lgpl.html
 */

#ifndef IMAGEHANDLER_H
#define IMAGEHANDLER_H

#include "MuHttpServer.h"

class QBuffer;
class QString;
class SessionItem;

/**
 * Publish view and layer images via HTTP
 */
class ImageHandler : public MuHttpServer
{
   Q_OBJECT

public:
   /**
    * Construct a new ImageHandler.
    *
    * @param pParent
    *        Qt parent object
    */
   ImageHandler(QObject *pParent = NULL);

   /**
    * Construct a new ImageHandler.
    *
    * @param port
    *        TCP port where the server should listen. If this is 0, a server will
    *        not be started. This is used to add the ImageHandler to an existing
    *        server using MuHttpServer::registerPath().
    * @param pParent
    *        Qt parent object
    */
   ImageHandler(int port, QObject *pParent = NULL);

   /**
    * Destructor
    */
   ~ImageHandler();

   /**
    * Retrieve an image for a SessionItem and place the result in a buffer.
    *
    * @param pItem
    *        The SessionItem whose image is to be retrieved. Currently, this must be a:
    *            SpatialDataView or a Layer
    * @param buffer
    *        A sufficiently large buffer which will hold the resultant image.
    * @param format
    *        The format of the image data. This is anything which corresponds to
    *        a loaded Qt image format plugin. Common examples are: JPEG, PNG, TIFF, or BMP
    * @param band
    *        If pItem is a RasterLayer, change to this active band before grabbing the image.
    *        If pItem is not a RasterLayer or band is negative, this is ignored.
    * @param pBbox
    *        If this is not NULL, the bounding box as returned by SpatialDataView::getLayerImage() will be returned in this out param.
    * @return True if the image was successfully generated, false otherwise.
    */
   static bool getSessionItemImage(SessionItem *pItem, QBuffer &buffer, const QString &format, int band, int* pBbox = NULL);

protected:
   /**
    * @copydoc MuHttpServer::getRequest()
    *
    * This method serves view and layer images. The request URL should be
    * the SessionItem ID of the view or layer. The file extension represents
    * the format of the image generated. Any image format supported by the current
    * build of Qt is supported. This requires at least PNG support. If no extension
    * is specified, PNG is assumed.
    */
   MuHttpServer::Response getRequest(const QString &uri, const QString &contentType, const QString &body,
      const FormValueMap &form);

private:
   ImageHandler(const ImageHandler& rhs);
   ImageHandler& operator=(const ImageHandler& rhs);
};

#endif