void ImageCanvasWidget::mouseReleaseEvent(QMouseEvent *event) {
anchor_down_ = false;
if (event->button() == Qt::RightButton) {
// Get image from the canvas
QImage selection = image_.copy(options_cache_->tile_selection());
emit SendImage(&selection);
options_cache_->UpdateCursorShift();
} else if (event->button() == Qt::LeftButton) {
// Set image back to the canvas
UnsaveState();
emit RequestImage();
}
}
ImageCache::ImageCache(const QString& cache_dir, size_t size) :
network_manager_(this),
cache_dir_(cache_dir),
cache_(size),
exit_(false),
tick_(0),
cache_thread_(new CacheThread(this)),
network_request_semaphore_(MAXIMUM_NETWORK_REQUESTS)
{
QNetworkDiskCache* disk_cache = new QNetworkDiskCache(this);
disk_cache->setCacheDirectory(cache_dir_);
network_manager_.setCache(disk_cache);
connect(&network_manager_, SIGNAL(finished(QNetworkReply*)), this, SLOT(ProcessReply(QNetworkReply*)));
connect(cache_thread_, SIGNAL(RequestImage(QString)), this, SLOT(ProcessRequest(QString)));
cache_thread_->start();
cache_thread_->setPriority(QThread::NormalPriority);
}
void CacheThread::run()
{
while (!p->exit_)
{
// Wait until we're told there are images we need to request.
waiting_mutex_.lock();
// Next, get all of them and sort them by priority.
p->unprocessed_mutex_.lock();
QList<ImagePtr> images = p->unprocessed_.values();
p->unprocessed_mutex_.unlock();
qSort(images.begin(), images.end(), ComparePriority);
// Go through all of them and request them. Qt's network manager will
// only handle six simultaneous requests at once, so we use a semaphore
// to limit ourselves to that many.
// Each individual image will release the semaphore when it is done loading.
// Also, only load up to a certain number at a time in this loop. If there
// are more left afterward, we'll start over. This ensures that we
// concentrate on processing the highest-priority images.
int count = 0;
while (!p->exit_ && !images.empty() && count < MAXIMUM_SEQUENTIAL_REQUESTS)
{
p->network_request_semaphore_.acquire();
ImagePtr image = images.front();
p->unprocessed_mutex_.lock();
if (!image->Loading() && !image->Failed())
{
count++;
image->SetLoading(true);
images.pop_front();
QString uri = image->Uri();
size_t hash = p->uri_to_hash_map_[uri];
if (uri.startsWith(QString("file:///")))
{
image->InitializeImage();
QString filepath = uri.replace(QString("file:///"), QString("/"));
if (!image->GetImage()->load(filepath))
{
image->ClearImage();
image->AddFailure();
}
p->unprocessed_.remove(hash);
p->uri_to_hash_map_.remove(uri);
image->SetLoading(false);
p->network_request_semaphore_.release();
}
else
{
Q_EMIT RequestImage(image->Uri());
}
}
else
{
images.pop_front();
}
p->unprocessed_mutex_.unlock();
}
if (!images.empty())
{
waiting_mutex_.unlock();
}
}
}