OcdFileImport: Import embedded images

Layout raster image objects can also be stored as embedded images
directly in the .ocd file.
This commit allows to save the embedded image locally in order to be
added as a template to the map.

src/fileformats/ocd_file_import.cpp

@@ -52,6 +52,10 @@
 #include <QTextCodec>
 #include <QTextDecoder>
 #include <QVariant>
+#include <QMessageBox>
+#include <QFile>
+#include <QFileInfo>
+#include <QFileDevice>
 
 #include "settings.h"
 #include "core/georeferencing.h"
@@ -83,6 +87,7 @@
 #include "templates/template_placeholder.h"
 #include "util/encoding.h"
 #include "util/util.h"
+#include "gui/file_dialog.h"
 
 
 namespace OpenOrienteering {
@@ -1116,6 +1121,7 @@ void OcdFileImport::importLayoutObjects(const QString& param_string)
 	double x_value = 0.0;
 	double y_value = 0.0;
 	int dimming = 0;
+	QByteArray embedded_image;
 
 	while (parameters.readNext())
 	{
@@ -1173,6 +1179,9 @@ void OcdFileImport::importLayoutObjects(const QString& param_string)
 		case 'd':
 			dimming = param_value.toInt();
 			break;
+		case 'F':
+			embedded_image = QByteArray::fromBase64(param_value.toUtf8());
+			break;
 		default:
 			; // nothing
 		}
@@ -1184,7 +1193,42 @@ void OcdFileImport::importLayoutObjects(const QString& param_string)
 	}
 	else if (type == 1)
 	{
-		addWarning(tr("Layout image object (%1) imported as template.").arg(path_or_description));
+		if (!embedded_image.isEmpty())
+		{
+			QMessageBox msgBox(QMessageBox::Question, tr("Import embedded image"), 
+							   tr("The map contains an embedded image (%1) which cannot be imported directly.\nDo you want to save the image locally and import it as template?").arg(path_or_description),
+							   QMessageBox::Yes | QMessageBox::No, nullptr);
+			if (msgBox.exec() != QMessageBox::Yes)
+				return;
+
+			auto const filename = path_or_description.replace(QLatin1Char('\\'), QLatin1Char('/'));
+			const QFileInfo proposed_imagefile(QFileInfo(QDir::cleanPath(path)).dir(), QFileInfo(QDir::cleanPath(filename)).fileName());
+			QString imagefilename = FileDialog::getSaveFileName(
+									nullptr,
+									tr("Save embedded image"),
+									proposed_imagefile.filePath(),
+									tr("All files (*.*)"),
+									nullptr);
+			if (imagefilename.isEmpty())
+				return;
+
+			QFile file(imagefilename);
+			if (file.open(QIODevice::WriteOnly))
+			{
+				file.write(embedded_image);
+				file.close();
+			}
+			if (file.error() != QFileDevice::NoError)
+			{
+				addWarning(tr("Error when trying to save embedded image (%1) locally.").arg(imagefilename));
+				return;
+			}
+			path_or_description = imagefilename;
+		}
+		else
+		{
+			addWarning(tr("Layout image object (%1) imported as template.").arg(path_or_description));
+		}
 
 		auto const filename = path_or_description.replace(QLatin1Char('\\'), QLatin1Char('/'));
 		auto const clean_path = QDir::cleanPath(filename);