Added support for downloading DEM tiles

.appveyor.yml

@@ -1,4 +1,4 @@
-version: 9.5.{build}
+version: 9.6.{build}
 
 configuration:
   - Release

gpxsee.pro

@@ -3,7 +3,7 @@ unix:!macx {
 } else {
     TARGET = GPXSee
 }
-VERSION = 9.5
+VERSION = 9.6
 
 QT += core \
     gui \
@@ -18,10 +18,12 @@ greaterThan(QT_MAJOR_VERSION, 5) {QT += openglwidgets}
 CONFIG += object_parallel_to_source
 INCLUDEPATH += ./src
 HEADERS += src/common/config.h \
+    src/GUI/authenticationwidget.h \
     src/GUI/axislabelitem.h \
     src/GUI/dirselectwidget.h \
     src/GUI/flowlayout.h \
     src/GUI/graphicsscene.h \
+    src/GUI/infolabel.h \
     src/GUI/mapaction.h \
     src/GUI/mapitem.h \
     src/GUI/marginswidget.h \
@@ -194,6 +196,7 @@ HEADERS += src/common/config.h \
     src/data/locparser.h \
     src/data/slfparser.h \
     src/data/dem.h \
+    src/data/demloader.h \
     src/common/polygon.h \
     src/data/area.h \
     src/map/obliquestereographic.h \
@@ -231,9 +234,11 @@ HEADERS += src/common/config.h \
     src/map/worldfilemap.h
 
 SOURCES += src/main.cpp \
+    src/GUI/authenticationwidget.cpp \
     src/GUI/axislabelitem.cpp \
     src/GUI/dirselectwidget.cpp \
     src/GUI/flowlayout.cpp \
+    src/GUI/infolabel.cpp \
     src/GUI/mapitem.cpp \
     src/GUI/marginswidget.cpp \
     src/GUI/markerinfoitem.cpp \
@@ -377,6 +382,7 @@ SOURCES += src/main.cpp \
     src/data/locparser.cpp \
     src/data/slfparser.cpp \
     src/data/dem.cpp \
+    src/data/demloader.cpp \
     src/map/obliquestereographic.cpp \
     src/GUI/coordinatesitem.cpp \
     src/map/rmap.cpp \

gpxsee.qrc

@@ -43,6 +43,8 @@
 		<file alias="view-filter@2x.png">icons/GUI/view-filter@2x.png</file>
 		<file alias="applications-internet_32.png">icons/GUI/applications-internet_32.png</file>
 		<file alias="applications-internet_32@2x.png">icons/GUI/applications-internet_32@2x.png</file>
+		<file alias="view-grid.png">icons/GUI/view-grid.png</file>
+		<file alias="view-grid@2x.png">icons/GUI/view-grid@2x.png</file>
 	</qresource>
 	
 	<!-- POI icons for default IMG map style -->

pkg/gpxsee.nsi

@@ -9,7 +9,7 @@ Unicode true
 ; The name of the installer
 Name "GPXSee"
 ; Program version
-!define VERSION "9.5"
+!define VERSION "9.6"
 
 ; The file to write
 OutFile "GPXSee-${VERSION}.exe"

pkg/gpxsee64.nsi

@@ -9,7 +9,7 @@ Unicode true
 ; The name of the installer
 Name "GPXSee"
 ; Program version
-!define VERSION "9.5"
+!define VERSION "9.6"
 
 ; The file to write
 OutFile "GPXSee-${VERSION}_x64.exe"

src/GUI/authenticationwidget.cpp

@@ -0,0 +1,14 @@
+#include <QFormLayout>
+#include "authenticationwidget.h"
+
+AuthenticationWidget::AuthenticationWidget(QWidget *parent) : QWidget(parent)
+{
+	_username = new QLineEdit();
+	_password = new QLineEdit();
+
+	QFormLayout *layout = new QFormLayout();
+	layout->addRow(tr("Username:"), _username);
+	layout->addRow(tr("Password:"), _password);
+
+	setLayout(layout);
+}

src/GUI/authenticationwidget.h

@@ -0,0 +1,24 @@
+#ifndef AUTHENTICATIONWIDGET_H
+#define AUTHENTICATIONWIDGET_H
+
+#include <QWidget>
+#include <QLineEdit>
+
+class AuthenticationWidget : public QWidget
+{
+	Q_OBJECT
+
+public:
+	AuthenticationWidget(QWidget *parent = 0);
+
+	QString username() const {return _username->text();}
+	QString password() const {return _password->text();}
+
+	void setUsername(const QString &username) {_username->setText(username);}
+	void setPassword(const QString &password) {_password->setText(password);}
+
+private:
+	QLineEdit *_username, *_password;
+};
+
+#endif // AUTHENTICATIONWIDGET_H

src/GUI/gui.cpp

@@ -29,6 +29,7 @@
 #include "common/downloader.h"
 #include "data/data.h"
 #include "data/poi.h"
+#include "data/demloader.h"
 #include "map/maplist.h"
 #include "map/emptymap.h"
 #include "map/crs.h"
@@ -62,6 +63,8 @@ GUI::GUI()
 	TreeNode<POIAction*> poiActions;
 
 	_poi = new POI(this);
+	_dem = new DEMLoader(ProgramPaths::demDir(true), this);
+	connect(_dem, &DEMLoader::finished, this, &GUI::demLoaded);
 
 	createMapView();
 	createGraphTabs();
@@ -402,6 +405,12 @@ void GUI::createActions(TreeNode<MapAction*> &mapActions,
 	_showMarkerCoordinatesAction->setCheckable(true);
 	_showMarkerCoordinatesAction->setActionGroup(markerInfoGroup);
 
+	// DEM actions
+	_downloadDEMAction = new QAction(tr("Download DEM data"), this);
+	_downloadDEMAction->setMenuRole(QAction::NoRole);
+	_downloadDEMAction->setEnabled(false);
+	connect(_downloadDEMAction, &QAction::triggered, this, &GUI::downloadDEM);
+
 	// Graph actions
 	_showGraphsAction = new QAction(QIcon(SHOW_GRAPHS_ICON), tr("Show graphs"),
 	  this);
@@ -585,18 +594,6 @@ void GUI::createMenus(const TreeNode<MapAction*> &mapActions,
 	graphMenu->addSeparator();
 	graphMenu->addAction(_showGraphsAction);
 
-	_poiMenu = menuBar()->addMenu(tr("&POI"));
-	createPOINodeMenu(poiActions, _poiMenu);
-	_poisEnd = _poiMenu->addSeparator();
-	_poiMenu->addAction(_openPOIAction);
-	_poiMenu->addAction(_selectAllPOIAction);
-	_poiMenu->addAction(_unselectAllPOIAction);
-	_poiMenu->addSeparator();
-	_poiMenu->addAction(_showPOILabelsAction);
-	_poiMenu->addAction(_overlapPOIAction);
-	_poiMenu->addSeparator();
-	_poiMenu->addAction(_showPOIAction);
-
 	QMenu *dataMenu = menuBar()->addMenu(tr("&Data"));
 	dataMenu->addAction(_showWaypointLabelsAction);
 	dataMenu->addAction(_showRouteWaypointsAction);
@@ -612,6 +609,22 @@ void GUI::createMenus(const TreeNode<MapAction*> &mapActions,
 	dataMenu->addAction(_showAreasAction);
 	dataMenu->addAction(_showWaypointsAction);
 
+	_poiMenu = menuBar()->addMenu(tr("&POI"));
+	createPOINodeMenu(poiActions, _poiMenu);
+	_poisEnd = _poiMenu->addSeparator();
+	_poiMenu->addAction(_openPOIAction);
+	_poiMenu->addAction(_selectAllPOIAction);
+	_poiMenu->addAction(_unselectAllPOIAction);
+	_poiMenu->addSeparator();
+	_poiMenu->addAction(_showPOILabelsAction);
+	_poiMenu->addAction(_overlapPOIAction);
+	_poiMenu->addSeparator();
+	_poiMenu->addAction(_showPOIAction);
+
+	QMenu *demMenu = menuBar()->addMenu(tr("DEM"));
+	demMenu->addSeparator();
+	demMenu->addAction(_downloadDEMAction);
+
 	QMenu *settingsMenu = menuBar()->addMenu(tr("&Settings"));
 	QMenu *timeMenu = settingsMenu->addMenu(tr("Time"));
 	timeMenu->addAction(_totalTimeAction);
@@ -1052,6 +1065,16 @@ void GUI::openOptions()
 	if (options.poiRadius != _options.poiRadius)
 		_poi->setRadius(options.poiRadius);
 
+	if (options.demURL != _options.demURL)
+		_dem->setUrl(options.demURL);
+	if (options.demAuthorization != _options.demAuthorization
+	  || options.demUsername != _options.demUsername
+	  || options.demPassword != _options.demPassword)
+		_dem->setAuthorization(options.demAuthorization
+		  ? Authorization(options.demUsername, options.demPassword)
+		  : Authorization());
+	_downloadDEMAction->setEnabled(!options.demURL.isEmpty());
+
 	if (options.pixmapCache != _options.pixmapCache)
 		QPixmapCache::setCacheLimit(options.pixmapCache * 1024);
 
@@ -1688,6 +1711,26 @@ void GUI::clearMapCache()
 		_mapView->clearMapCache();
 }
 
+void GUI::downloadDEM()
+{
+	_demRect = _mapView->boundingRect();
+
+	if (_dem->loadTiles(_demRect))
+		_downloadDEMAction->setEnabled(false);
+	else
+		demLoaded();
+}
+
+void GUI::demLoaded()
+{
+	if (!_dem->checkTiles(_demRect))
+		QMessageBox::warning(this, APP_NAME,
+		  tr("Could not download all required DEM files."));
+
+	reloadFiles();
+	_downloadDEMAction->setEnabled(!_options.demURL.isEmpty());
+}
+
 void GUI::updateStatusBarInfo()
 {
 	if (_files.count() == 0)
@@ -2236,6 +2279,14 @@ void GUI::writeSettings()
 		settings.setValue(USE_SEGMENTS_SETTING, _options.useSegments);
 	if (_options.poiRadius != POI_RADIUS_DEFAULT)
 		settings.setValue(POI_RADIUS_SETTING, _options.poiRadius);
+	if (_options.demURL != DEM_URL_DEFAULT)
+		settings.setValue(DEM_URL_SETTING, _options.demURL);
+	if (_options.demAuthorization != DEM_AUTH_DEFAULT)
+		settings.setValue(DEM_AUTH_SETTING, _options.demAuthorization);
+	if (_options.demUsername != DEM_USERNAME_DEFAULT)
+		settings.setValue(DEM_USERNAME_SETTING, _options.demUsername);
+	if (_options.demPassword != DEM_PASSWORD_DEFAULT)
+		settings.setValue(DEM_PASSWORD_SETTING, _options.demPassword);
 	if (_options.useOpenGL != USE_OPENGL_DEFAULT)
 		settings.setValue(USE_OPENGL_SETTING, _options.useOpenGL);
 	if (_options.enableHTTP2 != ENABLE_HTTP2_DEFAULT)
@@ -2547,6 +2598,13 @@ void GUI::readSettings()
 	  PAUSE_INTERVAL_DEFAULT).toInt();
 	_options.poiRadius = settings.value(POI_RADIUS_SETTING, POI_RADIUS_DEFAULT)
 	  .toInt();
+	_options.demURL = settings.value(DEM_URL_SETTING, DEM_URL_DEFAULT).toString();
+	_options.demAuthorization = settings.value(DEM_AUTH_SETTING,
+	  DEM_AUTH_DEFAULT).toBool();
+	_options.demUsername = settings.value(DEM_USERNAME_SETTING,
+	  DEM_USERNAME_DEFAULT).toString();
+	_options.demPassword = settings.value(DEM_PASSWORD_SETTING,
+	  DEM_PASSWORD_DEFAULT).toString();
 	_options.useOpenGL = settings.value(USE_OPENGL_SETTING, USE_OPENGL_DEFAULT)
 	  .toBool();
 	_options.enableHTTP2 = settings.value(ENABLE_HTTP2_SETTING,
@@ -2641,6 +2699,13 @@ void GUI::readSettings()
 
 	_poi->setRadius(_options.poiRadius);
 
+	_dem->setUrl(_options.demURL);
+	if (_options.demAuthorization)
+		_dem->setAuthorization(Authorization(_options.demUsername,
+		  _options.demPassword));
+	if (!_options.demURL.isEmpty())
+		_downloadDEMAction->setEnabled(true);
+
 	QPixmapCache::setCacheLimit(_options.pixmapCache * 1024);
 
 	settings.endGroup();

src/GUI/gui.h

@@ -7,6 +7,7 @@
 #include <QDate>
 #include <QPrinter>
 #include "common/treenode.h"
+#include "common/rectc.h"
 #include "data/graph.h"
 #include "units.h"
 #include "timetype.h"
@@ -32,6 +33,7 @@ class QScreen;
 class MapAction;
 class POIAction;
 class Data;
+class DEMLoader;
 
 class GUI : public QMainWindow
 {
@@ -71,6 +73,7 @@ private slots:
 	void prevMap();
 	void openOptions();
 	void clearMapCache();
+	void downloadDEM();
 
 	void mapChanged(QAction *action);
 	void graphChanged(int);
@@ -102,6 +105,8 @@ private slots:
 	void mapLoadedDir();
 	void mapInitialized();
 
+	void demLoaded();
+
 private:
 	typedef QPair<QDateTime, QDateTime> DateTimeRange;
 
@@ -224,6 +229,7 @@ private:
 	QAction *_showTicksAction;
 	QAction *_showCoordinatesAction;
 	QAction *_openOptionsAction;
+	QAction *_downloadDEMAction;
 	QAction *_mapsEnd;
 	QAction *_poisEnd;
 
@@ -239,6 +245,7 @@ private:
 
 	POI *_poi;
 	Map *_map;
+	DEMLoader *_dem;
 
 	FileBrowser *_browser;
 	QList<QString> _files;
@@ -260,6 +267,8 @@ private:
 	QString _dataDir, _mapDir, _poiDir;
 
 	Units _units;
+
+	RectC _demRect;
 };
 
 #endif // GUI_H

src/GUI/icons.h

@@ -26,5 +26,6 @@
 #define PRINT_EXPORT_ICON ":/document-print_32.png"
 #define DATA_ICON         ":/view-filter.png"
 #define MAPS_ICON         ":/applications-internet_32.png"
+#define DEM_ICON          ":/view-grid.png"
 
 #endif /* ICONS_H */

src/GUI/infolabel.cpp

@@ -0,0 +1,10 @@
+#include "infolabel.h"
+
+InfoLabel::InfoLabel(const QString &text, QWidget *parent)
+  : QLabel(text, parent)
+{
+	QFont f(font());
+	f.setPointSize(f.pointSize() - 1);
+	setWordWrap(true);
+	setFont(f);
+}

src/GUI/infolabel.h

@@ -0,0 +1,12 @@
+#ifndef INFOLABEL_H
+#define INFOLABEL_H
+
+#include <QLabel>
+
+class InfoLabel : public QLabel
+{
+public:
+	InfoLabel(const QString &text, QWidget *parent = 0);
+};
+
+#endif // INFOLABEL_H

src/GUI/mapview.h

@@ -88,6 +88,8 @@ public:
 	void clearMapCache();
 	void fitContentToSize();
 
+	RectC boundingRect() const {return _tr | _rr | _wr | _ar;}
+
 public slots:
 	void showMap(bool show);
 	void showPOI(bool show);

src/GUI/optionsdialog.cpp

@@ -14,12 +14,14 @@
 #include <QSysInfo>
 #include <QButtonGroup>
 #include "icons.h"
+#include "infolabel.h"
 #include "colorbox.h"
 #include "stylecombobox.h"
 #include "oddspinbox.h"
 #include "percentslider.h"
 #include "projectioncombobox.h"
 #include "dirselectwidget.h"
+#include "authenticationwidget.h"
 #include "optionsdialog.h"
 
 
@@ -53,17 +55,11 @@ QWidget *OptionsDialog::createMapPage()
 	_inputProjection->setCurrentIndex(_inputProjection->findData(
 	  _options.inputProjection));
 
-	QLabel *inInfo = new QLabel(tr("Select the proper projection of maps"
+	InfoLabel *inInfo = new InfoLabel(tr("Select the proper projection of maps"
 	  " without a projection definition (JNX, KMZ and world file maps)."));
-	QLabel *outInfo = new QLabel(tr("Select the desired projection of vector"
+	InfoLabel *outInfo = new InfoLabel(tr("Select the desired projection of"
-	  " maps (IMG and Mapsforge maps). The projection must be valid for"
+	  " vector maps (IMG and Mapsforge maps). The projection must be valid for"
 	  " the whole map area."));
-	QFont f = inInfo->font();
-	f.setPointSize(f.pointSize() - 1);
-	inInfo->setWordWrap(true);
-	outInfo->setWordWrap(true);
-	inInfo->setFont(f);
-	outInfo->setFont(f);
 
 	_hidpi = new QRadioButton(tr("High-resolution"));
 	_lodpi = new QRadioButton(tr("Standard"));
@@ -71,14 +67,10 @@ QWidget *OptionsDialog::createMapPage()
 		_hidpi->setChecked(true);
 	else
 		_lodpi->setChecked(true);
-	QLabel *lhi = new QLabel(tr("Non-HiDPI maps are loaded as HiDPI maps. "
+	InfoLabel *lhi = new InfoLabel(tr("Non-HiDPI maps are loaded as HiDPI maps. "
 	  "The map is sharp but map objects are small/hard to read."));
-	QLabel *llo = new QLabel(tr("Non-HiDPI maps are loaded such as they are. "
+	InfoLabel *llo = new InfoLabel(tr("Non-HiDPI maps are loaded such as they are. "
 	  "Map objects have the expected size but the map is blurry."));
-	lhi->setWordWrap(true);
-	llo->setWordWrap(true);
-	lhi->setFont(f);
-	llo->setFont(f);
 
 	QVBoxLayout *inLayout = new QVBoxLayout();
 	inLayout->addWidget(_inputProjection);
@@ -576,6 +568,42 @@ QWidget *OptionsDialog::createPOIPage()
 	return poiPage;
 }
 
+QWidget *OptionsDialog::createDEMPage()
+{
+	_demURL = new QLineEdit();
+	_demURL->setText(_options.demURL);
+	_demAuth = new AuthenticationWidget();
+	_demAuth->setUsername(_options.demUsername);
+	_demAuth->setPassword(_options.demPassword);
+	_demAuth->setEnabled(_options.demAuthorization);
+
+	QCheckBox *useAuth = new QCheckBox(tr("Use HTTP authentication"));
+	useAuth->setChecked(_demAuth->isEnabled());
+	connect(useAuth, &QRadioButton::toggled, _demAuth,
+	  &AuthenticationWidget::setEnabled);
+
+	InfoLabel *info = new InfoLabel(tr("Use $lat and $lon for NYY/SYY and EXXX/WXXX in the URL."));
+
+	QFormLayout *urlLayout = new QFormLayout();
+	urlLayout->addRow(tr("URL:"), _demURL);
+	urlLayout->addRow(info);
+
+	QVBoxLayout *sourceLayout = new QVBoxLayout();
+	sourceLayout->addLayout(urlLayout);
+	sourceLayout->addSpacing(10);
+	sourceLayout->addWidget(useAuth);
+	sourceLayout->addWidget(_demAuth);
+	sourceLayout->addStretch();
+
+	QWidget *sourceTab = new QWidget();
+	sourceTab->setLayout(sourceLayout);
+
+	QTabWidget *demPage = new QTabWidget();
+	demPage->addTab(sourceTab, tr("Source"));
+
+	return demPage;
+}
+
 QWidget *OptionsDialog::createExportPage()
 {
 	_wysiwyg = new QRadioButton(tr("WYSIWYG"));
@@ -584,17 +612,11 @@ QWidget *OptionsDialog::createExportPage()
 		_hires->setChecked(true);
 	else
 		_wysiwyg->setChecked(true);
-	QLabel *lw = new QLabel(tr("The printed area is approximately the display"
+	InfoLabel *lw = new InfoLabel(tr("The printed area is approximately the "
-	  " area. The map zoom level does not change."));
+	  "display area. The map zoom level does not change."));
-	QLabel *lh = new QLabel(tr("The zoom level will be changed so that"
+	InfoLabel *lh = new InfoLabel(tr("The zoom level will be changed so that"
 	  " the whole content (tracks/waypoints) fits to the printed area and"
 	  " the map resolution is as close as possible to the print resolution."));
-	QFont f = lw->font();
-	f.setPointSize(f.pointSize() - 1);
-	lw->setWordWrap(true);
-	lh->setWordWrap(true);
-	lw->setFont(f);
-	lh->setFont(f);
 
 	QVBoxLayout *modeTabLayout = new QVBoxLayout();
 	modeTabLayout->addWidget(_wysiwyg);
@@ -691,12 +713,8 @@ QWidget *OptionsDialog::createSystemPage()
 	_poiPath = new DirSelectWidget();
 	_poiPath->setDir(_options.poiPath);
 
-	QLabel *info = new QLabel(tr("Select the initial paths of the file open"
+	InfoLabel *info = new InfoLabel(tr("Select the initial paths of the file"
-	  " dialogues. Leave the field empty for the system default."));
+	  " open dialogues. Leave the field empty for the system default."));
-	QFont f = info->font();
-	f.setPointSize(f.pointSize() - 1);
-	info->setFont(f);
-	info->setWordWrap(true);
 
 	QFormLayout *pathsFormLayout = new QFormLayout();
 	pathsFormLayout->addRow(tr("Data:"), _dataPath);
@@ -705,8 +723,8 @@ QWidget *OptionsDialog::createSystemPage()
 
 	QWidget *pathsTab = new QWidget();
 	QVBoxLayout *pathsTabLayout = new QVBoxLayout();
-	pathsTabLayout->addWidget(info);
 	pathsTabLayout->addLayout(pathsFormLayout);
+	pathsTabLayout->addWidget(info);
 	pathsTabLayout->addStretch();
 	pathsTab->setLayout(pathsTabLayout);
 
@@ -725,6 +743,7 @@ OptionsDialog::OptionsDialog(Options &options, Units units, QWidget *parent)
 	pages->addWidget(createMapPage());
 	pages->addWidget(createDataPage());
 	pages->addWidget(createPOIPage());
+	pages->addWidget(createDEMPage());
 	pages->addWidget(createExportPage());
 	pages->addWidget(createSystemPage());
 
@@ -735,6 +754,7 @@ OptionsDialog::OptionsDialog(Options &options, Units units, QWidget *parent)
 	new QListWidgetItem(QIcon(MAPS_ICON), tr("Maps"), menu);
 	new QListWidgetItem(QIcon(DATA_ICON), tr("Data"), menu);
 	new QListWidgetItem(QIcon(POI_ICON), tr("POI"), menu);
+	new QListWidgetItem(QIcon(DEM_ICON), tr("DEM"), menu);
 	new QListWidgetItem(QIcon(PRINT_EXPORT_ICON), tr("Print & Export"),
 	  menu);
 	new QListWidgetItem(QIcon(SYSTEM_ICON), tr("System"), menu);
@@ -831,6 +851,11 @@ void OptionsDialog::accept()
 	if (qAbs(poiRadius - _options.poiRadius) > 0.01)
 		_options.poiRadius = poiRadius;
 
+	_options.demURL = _demURL->text();
+	_options.demAuthorization = _demAuth->isEnabled();
+	_options.demUsername = _demAuth->username();
+	_options.demPassword = _demAuth->password();
+
 	_options.useOpenGL = _useOpenGL->isChecked();
 	_options.enableHTTP2 = _enableHTTP2->isChecked();
 	_options.pixmapCache = _pixmapCache->value();

src/GUI/optionsdialog.h

@@ -6,18 +6,19 @@
 #include "units.h"
 #include "timezoneinfo.h"
 
-class ColorBox;
-class StyleComboBox;
-class OddSpinBox;
 class QSpinBox;
 class QDoubleSpinBox;
 class QComboBox;
 class QCheckBox;
 class QRadioButton;
+class QLineEdit;
+class ColorBox;
+class StyleComboBox;
+class OddSpinBox;
 class PercentSlider;
 class ProjectionComboBox;
 class DirSelectWidget;
-
+class AuthenticationWidget;
 
 struct Options {
 	// Appearance
@@ -61,6 +62,11 @@ struct Options {
 	bool useSegments;
 	// POI
 	int poiRadius;
+	// DEM
+	QString demURL;
+	QString demUsername;
+	QString demPassword;
+	bool demAuthorization;
 	// System
 	bool useOpenGL;
 	bool enableHTTP2;
@@ -100,6 +106,7 @@ private:
 	QWidget *createPOIPage();
 	QWidget *createSystemPage();
 	QWidget *createExportPage();
+	QWidget *createDEMPage();
 
 	Options &_options;
 
@@ -153,6 +160,9 @@ private:
 	QCheckBox *_useSegments;
 	// POI
 	QDoubleSpinBox *_poiRadius;
+	// DEM
+	QLineEdit *_demURL;
+	AuthenticationWidget *_demAuth;
 	// System
 	QSpinBox *_pixmapCache;
 	QSpinBox *_connectionTimeout;

src/GUI/settings.h

@@ -173,6 +173,14 @@
 #define USE_SEGMENTS_DEFAULT              true
 #define POI_RADIUS_SETTING                "poiRadius"
 #define POI_RADIUS_DEFAULT                (int)(IMPERIAL_UNITS() ? MIINM : KMINM)
+#define DEM_URL_SETTING                   "demURL"
+#define DEM_URL_DEFAULT                   ""
+#define DEM_AUTH_SETTING                  "demAuthentication"
+#define DEM_AUTH_DEFAULT                  false
+#define DEM_USERNAME_SETTING              "demUsername"
+#define DEM_USERNAME_DEFAULT              ""
+#define DEM_PASSWORD_SETTING              "demPassword"
+#define DEM_PASSWORD_DEFAULT              ""
 #define USE_OPENGL_SETTING                "useOpenGL"
 #define USE_OPENGL_DEFAULT                false
 #define ENABLE_HTTP2_SETTING              "enableHTTP2"

src/common/downloader.cpp

@@ -77,7 +77,7 @@ QNetworkAccessManager *Downloader::_manager = 0;
 int Downloader::_timeout = 30;
 bool Downloader::_http2 = true;
 
-bool Downloader::doDownload(const Download &dl, const QByteArray &authorization)
+bool Downloader::doDownload(const Download &dl, const Authorization &auth)
 {
 	const QUrl &url = dl.url();
 
@@ -98,8 +98,8 @@ bool Downloader::doDownload(const Download &dl, const QByteArray &authorization)
 	  QNetworkRequest::NoLessSafeRedirectPolicy);
 	request.setAttribute(ATTR_HTTP2_ALLOWED, QVariant(_http2));
 	request.setRawHeader("User-Agent", USER_AGENT);
-	if (!authorization.isNull())
+	if (!auth.isNull())
-		request.setRawHeader("Authorization", authorization);
+		request.setRawHeader("Authorization", auth.header());
 
 	QFile *file = new QFile(tmpName(dl.file()));
 	if (!file->open(QIODevice::WriteOnly)) {
@@ -182,7 +182,7 @@ bool Downloader::get(const QList<Download> &list,
 	bool finishEmitted = false;
 
 	for (int i = 0; i < list.count(); i++)
-		finishEmitted |= doDownload(list.at(i), authorization.header());
+		finishEmitted |= doDownload(list.at(i), authorization);
 
 	return finishEmitted;
 }

src/common/downloader.h

@@ -29,6 +29,7 @@ public:
 	Authorization() {}
 	Authorization(const QString &username, const QString &password);
 
+	bool isNull() const {return _header.isNull();}
 	const QByteArray &header() const {return _header;}
 
 private:
@@ -79,7 +80,7 @@ private:
 	class ReplyTimeout;
 
 	void insertError(const QUrl &url, QNetworkReply::NetworkError error);
-	bool doDownload(const Download &dl, const QByteArray &authorization);
+	bool doDownload(const Download &dl, const Authorization &auth);
 	void downloadFinished(QNetworkReply *reply);
 	void readData(QNetworkReply *reply);
 

src/data/dem.cpp

@@ -16,7 +16,7 @@
 #include <QDir>
 #include <QFile>
 #include <private/qzipreader_p.h>
-#include "common/coordinates.h"
+#include "common/rectc.h"
 #include "dem.h"
 
 
@@ -66,19 +66,26 @@ static qreal height(const Coordinates &c, const QByteArray *data)
 }
 
 
-QString DEM::_dir;
+QString DEM::Tile::latStr() const
-QCache<DEM::Key, QByteArray> DEM::_data;
-
-QString DEM::baseName(const Key &key)
 {
-	const char ns = (key.lat() >= 0) ? 'N' : 'S';
+	const char ns = (_lat >= 0) ? 'N' : 'S';
-	const char ew = (key.lon() >= 0) ? 'E' : 'W';
+	return QString("%1%2").arg(ns).arg(qAbs(_lat), 2, 10, QChar('0'));
-
-	return QString("%1%2%3%4.hgt").arg(ns)
-	  .arg(qAbs(key.lat()), 2, 10, QChar('0')).arg(ew)
-	  .arg(qAbs(key.lon()), 3, 10, QChar('0'));
 }
 
+QString DEM::Tile::lonStr() const
+{
+	const char ew = (_lon >= 0) ? 'E' : 'W';
+	return QString("%1%2").arg(ew).arg(qAbs(_lon), 3, 10, QChar('0'));
+}
+
+QString DEM::Tile::baseName() const
+{
+	return QString("%1%2.hgt").arg(latStr(), lonStr());
+}
+
+QString DEM::_dir;
+QCache<DEM::Tile, QByteArray> DEM::_data;
+
 QString DEM::fileName(const QString &baseName)
 {
 	return QDir(_dir).absoluteFilePath(baseName);
@@ -87,6 +94,7 @@ QString DEM::fileName(const QString &baseName)
 void DEM::setDir(const QString &path)
 {
 	_dir = path;
+	_data.clear();
 }
 
 qreal DEM::elevation(const Coordinates &c)
@@ -94,11 +102,11 @@ qreal DEM::elevation(const Coordinates &c)
 	if (_dir.isEmpty())
 		return NAN;
 
-	Key k(qFloor(c.lon()), qFloor(c.lat()));
+	Tile tile(qFloor(c.lon()), qFloor(c.lat()));
 
-	QByteArray *ba = _data[k];
+	QByteArray *ba = _data[tile];
 	if (!ba) {
-		QString bn(baseName(k));
+		QString bn(tile.baseName());
 		QString fn(fileName(bn));
 		QString zn(fn + ".zip");
 
@@ -106,22 +114,30 @@ qreal DEM::elevation(const Coordinates &c)
 			QZipReader zip(zn, QIODevice::ReadOnly);
 			ba = new QByteArray(zip.fileData(bn));
 			qreal ele = height(c, ba);
-			_data.insert(k, ba);
+			_data.insert(tile, ba);
 			return ele;
 		} else {
 			QFile file(fn);
 			if (!file.open(QIODevice::ReadOnly)) {
 				qWarning("%s: %s", qPrintable(file.fileName()),
 				  qPrintable(file.errorString()));
-				_data.insert(k, new QByteArray());
+				_data.insert(tile, new QByteArray());
 				return NAN;
 			} else {
 				ba = new QByteArray(file.readAll());
 				qreal ele = height(c, ba);
-				_data.insert(k, ba);
+				_data.insert(tile, ba);
 				return ele;
 			}
 		}
 	} else
 		return height(c, ba);
 }
+
+#ifndef QT_NO_DEBUG
+QDebug operator<<(QDebug dbg, const DEM::Tile &tile)
+{
+	dbg.nospace() << "Tile(" << tile.baseName() << ")";
+	return dbg.space();
+}
+#endif // QT_NO_DEBUG

src/data/dem.h

@@ -8,18 +8,23 @@
 
 class QString;
 class Coordinates;
+class RectC;
 
 class DEM
 {
-private:
-	class Key {
 public:
-		Key(int lon, int lat) : _lon(lon), _lat(lat) {}
+	class Tile {
+	public:
+		Tile(int lon, int lat) : _lon(lon), _lat(lat) {}
 
 		int lon() const {return _lon;}
 		int lat() const {return _lat;}
 
-		bool operator==(const Key &other) const
+		QString lonStr() const;
+		QString latStr() const;
+		QString baseName() const;
+
+		bool operator==(const Tile &other) const
 		{
 			return (_lon == other._lon && _lat == other._lat);
 		}
@@ -28,22 +33,23 @@ private:
 		int _lon, _lat;
 	};
 
-	static QString baseName(const Key &key);
-	static QString fileName(const QString &baseName);
-
-	static QString _dir;
-	static QCache<Key, QByteArray> _data;
-
-public:
 	static void setDir(const QString &path);
 	static qreal elevation(const Coordinates &c);
 
-	friend HASH_T qHash(const Key &key);
+private:
+	static QString fileName(const QString &baseName);
+
+	static QString _dir;
+	static QCache<Tile, QByteArray> _data;
 };
 
-inline HASH_T qHash(const DEM::Key &key)
+inline HASH_T qHash(const DEM::Tile &tile)
 {
-	return (qHash(key.lon()) ^ qHash(key.lat()));
+	return (qHash(tile.lon()) ^ qHash(tile.lat()));
 }
 
+#ifndef QT_NO_DEBUG
+QDebug operator<<(QDebug dbg, const DEM::Tile &tile);
+#endif // QT_NO_DEBUG
+
 #endif // DEM_H

src/data/demloader.cpp

@@ -0,0 +1,102 @@
+#include <QtMath>
+#include <QDir>
+#include <QFileInfo>
+#include "common/rectc.h"
+#include "demloader.h"
+
+
+#define DOWNLOAD_LIMIT 32
+
+static QList<DEM::Tile> tiles(const RectC &rect)
+{
+	QList<DEM::Tile> list;
+
+	if (!rect.isValid())
+		return list;
+
+	for (int i = qFloor(rect.top()); i >= qFloor(rect.bottom()); i--)
+		for (int j = qFloor(rect.left()); j <= qFloor(rect.right()); j++)
+			list.append(DEM::Tile(j, i));
+
+	return list;
+}
+
+static bool isZip(const QUrl &url)
+{
+	QFileInfo fi(url.fileName());
+	return (fi.suffix().toLower() == "zip");
+}
+
+
+DEMLoader::DEMLoader(const QString &dir, QObject *parent)
+  : QObject(parent), _dir(dir)
+{
+	_downloader = new Downloader(this);
+	connect(_downloader, &Downloader::finished, this, &DEMLoader::finished);
+}
+
+bool DEMLoader::loadTiles(const RectC &rect)
+{
+	QList<DEM::Tile> tl(tiles(rect));
+	QList<Download> dl;
+
+	/* Create the user DEM dir only when a download is requested as it will
+	   override the global DEM dir. */
+	if (!QDir().mkpath(_dir)) {
+		qWarning("%s: %s", qPrintable(_dir), "Error creating DEM directory");
+		return false;
+	}
+	/* This also clears the DEM data cache which is necessary to use the data
+	   from the downloaded DEM tiles. */
+	DEM::setDir(_dir);
+
+	for (int i = 0; i < tl.size(); i++) {
+		const DEM::Tile &t = tl.at(i);
+		QString fn(tileFile(t));
+		QString zn(fn + ".zip");
+
+		if (!(QFileInfo(zn).exists() || QFileInfo(fn).exists())) {
+			QUrl url(tileUrl(t));
+			dl.append(Download(url, isZip(url) ? zn : fn));
+		}
+	}
+
+	if (dl.size() > DOWNLOAD_LIMIT) {
+		qWarning("DEM download limit exceeded. Limit/requested: %u/%u.",
+		  DOWNLOAD_LIMIT, dl.size());
+		return false;
+	}
+
+	return _downloader->get(dl, _authorization);
+}
+
+bool DEMLoader::checkTiles(const RectC &rect) const
+{
+	QList<DEM::Tile> tl(tiles(rect));
+
+	for (int i = 0; i < tl.size(); i++) {
+		const DEM::Tile &t = tl.at(i);
+		QString fn(tileFile(t));
+		QString zn(fn + ".zip");
+
+		if (!(QFileInfo(zn).exists() || QFileInfo(fn).exists()))
+			return false;
+	}
+
+	return true;
+}
+
+QUrl DEMLoader::tileUrl(const DEM::Tile &tile) const
+{
+	QString url(_url);
+
+	url.replace("$lon", tile.lonStr());
+	url.replace("$lat", tile.latStr());
+
+	return QUrl(url);
+}
+
+QString DEMLoader::tileFile(const DEM::Tile &tile) const
+{
+	return _dir + QLatin1Char('/') + tile.baseName();
+}

src/data/demloader.h

@@ -0,0 +1,37 @@
+#ifndef DEMLOADER_H
+#define DEMLOADER_H
+
+#include <QObject>
+#include "common/downloader.h"
+#include "dem.h"
+
+class RectC;
+
+class DEMLoader : public QObject
+{
+	Q_OBJECT
+
+public:
+	DEMLoader(const QString &dir, QObject *parent = 0);
+
+	void setUrl(const QString &url) {_url = url;}
+	void setAuthorization(const Authorization &authorization)
+	  {_authorization = authorization;}
+
+	bool loadTiles(const RectC &rect);
+	bool checkTiles(const RectC &rect) const;
+
+signals:
+	void finished();
+
+private:
+	QUrl tileUrl(const DEM::Tile &tile) const;
+	QString tileFile(const DEM::Tile &tile) const;
+
+	Downloader *_downloader;
+	QString _url;
+	QString _dir;
+	Authorization _authorization;
+};
+
+#endif // DEMLOADER_H