git.maemo.org Git - situare/blob - src/map/mapfetcher.cpp

   1 /*
   2    Situare - A location system for Facebook
   3    Copyright (C) 2010  Ixonos Plc. Authors:
   4
   5        Jussi Laitinen - jussi.laitinen@ixonos.com
   6
   7    Situare is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU General Public License
   9    version 2 as published by the Free Software Foundation.
  10
  11    Situare is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with Situare; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
  19    USA.
  20 */
  21
  22 #include <QNetworkAccessManager>
  23 #include <QNetworkRequest>
  24 #include <QNetworkReply>
  25 #include <QUrl>
  26 #include <QDebug>
  27 #include <QPixmap>
  28 #include <QNetworkDiskCache>
  29 #include <QDesktopServices>
  30
  31 #include "mapfetcher.h"
  32
  33 static int MAX_PARALLEL_DOWNLOADS = 2;
  34 static int DOWNLOAD_QUEUE_SIZE = 50;
  35
  36 MapFetcher::MapFetcher(QNetworkAccessManager *manager, QObject *parent)
  37     : QObject(parent), m_manager(manager)
  38 {
  39     QNetworkDiskCache *diskCache = new QNetworkDiskCache(this);
  40     diskCache->setCacheDirectory(QDesktopServices::storageLocation(
  41             QDesktopServices::CacheLocation));
  42     m_manager->setCache(diskCache);
  43
  44     connect(m_manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(
  45             downloadFinished(QNetworkReply*)));
  46 }
  47
  48 void MapFetcher::fetchMapImage(const QUrl &url)
  49 {
  50     //qDebug() << __PRETTY_FUNCTION__;
  51
  52     if (url.isEmpty() || !url.isValid())
  53         return;
  54
  55     if (loadImageFromCache(url))
  56         return;
  57
  58     if (m_downloadQueue.size() >= DOWNLOAD_QUEUE_SIZE)
  59         m_downloadQueue.dequeue();
  60
  61     m_downloadQueue.enqueue(url);
  62
  63     if (m_currentDownloads.size() < MAX_PARALLEL_DOWNLOADS)
  64         startNextDownload();
  65 }
  66
  67 bool MapFetcher::loadImageFromCache(const QUrl &url)
  68 {
  69     //qDebug() << __PRETTY_FUNCTION__;
  70
  71     bool imageFound = false;
  72
  73     if (m_manager->cache()) {
  74         QIODevice *cacheImage = m_manager->cache()->data(url);
  75
  76         if (cacheImage) {
  77             QImage image;
  78
  79             if (image.load(cacheImage, 0)) {
  80                 imageFound = true;
  81                 emit mapImageReceived(url, QPixmap::fromImage(image));
  82             }
  83
  84             delete cacheImage;
  85         }
  86     }
  87
  88     return imageFound;
  89 }
  90
  91 void MapFetcher::startNextDownload()
  92 {
  93     //qDebug() << __PRETTY_FUNCTION__;
  94
  95     if (m_downloadQueue.isEmpty())
  96         return;
  97
  98     QUrl url = m_downloadQueue.dequeue();
  99
 100     QNetworkRequest request(url);
 101     request.setRawHeader("User-Agent", "Map Test");
 102     QNetworkReply *reply = m_manager->get(request);
 103
 104     m_currentDownloads.append(reply);
 105 }
 106
 107 void MapFetcher::downloadFinished(QNetworkReply *reply)
 108 {
 109     //qDebug() << __PRETTY_FUNCTION__;
 110
 111     if (reply->error() == QNetworkReply::NoError) {
 112         QImage image;
 113         QUrl url = reply->url();
 114
 115         if (!image.load(reply, 0)) {
 116             qDebug() << "Could not load image";
 117             image = QImage();
 118         }
 119
 120         emit mapImageReceived(url, QPixmap::fromImage(image));
 121     }
 122     else {
 123         emit error(reply->errorString());
 124     }
 125
 126     m_currentDownloads.removeAll(reply);
 127     reply->deleteLater();
 128     startNextDownload();
 129 }
 130
 131 MapFetcher::~MapFetcher()
 132 {
 133
 134 }