Don't call UI functions from helper code

This may seem much more complicated but actually is much cleaner. Add each
thread we start to the list of future results and add a new UI function
that updates the UI once all of the threads have finished.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/divepicturewidget.cpp

@@ -4,6 +4,7 @@
 #include "divelist.h"
 #include <QtConcurrentMap>
 #include <QtConcurrentRun>
+#include <QFuture>
 #include <QDir>
 #include <QCryptographicHash>
 #include <mainwindow.h>
@@ -53,6 +54,14 @@ SPixmap scaleImages(picturepointer picture)
 	return ret;
 }
 
+void DivePictureModel::updateDivePicturesWhenDone(QList<QFuture<void> > futures)
+{
+	Q_FOREACH (QFuture<void> f, futures) {
+		f.waitForFinished();
+	}
+	updateDivePictures();
+}
+
 void DivePictureModel::updateDivePictures()
 {
 	if (numberOfPictures != 0) {

qt-ui/divepicturewidget.h

@@ -4,6 +4,7 @@
 #include <QAbstractTableModel>
 #include <QListView>
 #include <QThread>
+#include <QFuture>
 
 typedef QPair<QString, QByteArray> SHashedFilename;
 
@@ -25,6 +26,7 @@ public:
 	virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
 	virtual int rowCount(const QModelIndex &parent = QModelIndex()) const;
 	void updateDivePictures();
+	void updateDivePicturesWhenDone(QList<QFuture<void> >);
 	void removePicture(const QString& fileUrl);
 
 private:

qt-ui/mainwindow.cpp

@@ -327,14 +327,15 @@ void MainWindow::on_actionHash_images_triggered()
 	dialog.setLabelText(QFileDialog::Accept, tr("Scan"));
 	dialog.setLabelText(QFileDialog::Reject, tr("Cancel"));
 	QStringList dirnames;
+	QList<QFuture<void> > futures;
 	if (dialog.exec())
 		dirnames = dialog.selectedFiles();
 	if (dirnames.isEmpty())
 		return;
 	foreach (QString dir, dirnames) {
-		QtConcurrent::run(learnImages, QDir(dir), 10, false);
+		futures << QtConcurrent::run(learnImages, QDir(dir), 10, false);
 	}
-
+	DivePictureModel::instance()->updateDivePicturesWhenDone(futures);
 }
 
 ProfileWidget2 *MainWindow::graphics() const

qthelper.cpp

@@ -870,6 +870,4 @@ void learnImages(const QDir dir, int max_recursions, bool recursed)
 	}
 
 	QtConcurrent::blockingMap(files, hashFile);
-	if (!recursed)
-		DivePictureModel::instance()->updateDivePictures();
 }