From 23541920100b4b07a0b2b01034c6d3f1b6fccbd2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=A1clav=20Kubern=C3=A1t?= <vkubernat@elektroline.cz>
Date: Thu, 10 Aug 2023 16:06:45 +0200
Subject: [PATCH] Add a demo map viewer for QtWidgets

---
 Demos/CMakeLists.txt           |   5 +-
 Demos/meson.build              |   9 +++
 Demos/src/QtWidgetsDemoApp.cpp | 114 +++++++++++++++++++++++++++++++++
 3 files changed, 127 insertions(+), 1 deletion(-)
 create mode 100644 Demos/src/QtWidgetsDemoApp.cpp

diff --git a/Demos/CMakeLists.txt b/Demos/CMakeLists.txt
index 53bc0a3af..857b0915b 100644
--- a/Demos/CMakeLists.txt
+++ b/Demos/CMakeLists.txt
@@ -210,8 +210,11 @@ if(${OSMSCOUT_BUILD_CLIENT_QT})
 			COMMAND Qt5::windeployqt --dir "${CMAKE_BINARY_DIR}/windeployqt" "$<TARGET_FILE_DIR:RoutingParameters>/$<TARGET_FILE_NAME:RoutingParameters>"
 			)
 	endif()
+
+	#---- QtWidgetsDemoApp
+	osmscout_demo_project(NAME QtWidgetsDemoApp SOURCES src/QtWidgetsDemoApp.cpp TARGET OSMScout::ClientQt)
 else()
-	message("Skip ElevationProfileChart, NavigationSimulation and RoutingParameters demo, libosmscout-client-qt is missing.")
+	message("Skip ElevationProfileChart, NavigationSimulation and RoutingParameters QtWidgetsDemoApp demo, libosmscout-client-qt is missing.")
 endif()
 
 #---- DrawMapSVG
diff --git a/Demos/meson.build b/Demos/meson.build
index 9b1040d1b..ee6d87a6f 100644
--- a/Demos/meson.build
+++ b/Demos/meson.build
@@ -170,6 +170,15 @@ if buildClientQt
                                   override_options : ['unity=off'], # generated code for qt resources use static variables with the same name
                                   install: true,
                                   install_dir: demoInstallDir)
+
+    QtWidgetsDemoApp = executable('QtWidgetsDemoApp',
+                                  ['src/QtWidgetsDemoApp.cpp'],
+                                  cpp_args: ['-fPIC'],
+                                  include_directories: [osmscoutIncDir, osmscoutmapIncDir, osmscoutmapqtIncDir, osmscoutclientIncDir, osmscoutclientqtIncDir],
+                                  dependencies: [qtClientDep],
+                                  link_with: [osmscout, osmscoutmap, osmscoutmapqt, osmscoutclientqt],
+                                  install: true,
+                                  install_dir: demoInstallDir)
 endif
 
 Routing = executable('Routing',
diff --git a/Demos/src/QtWidgetsDemoApp.cpp b/Demos/src/QtWidgetsDemoApp.cpp
new file mode 100644
index 000000000..25d15eb47
--- /dev/null
+++ b/Demos/src/QtWidgetsDemoApp.cpp
@@ -0,0 +1,114 @@
+#include <QApplication>
+#include <QWidget>
+
+#include <osmscoutclientqt/OSMScoutQt.h>
+
+const auto MAX_ZOOM = 20;
+const auto MIN_ZOOM = 0;
+const auto MAP_DPI = 96;
+
+namespace {
+template <typename EventType>
+auto pos(EventType* event)
+{
+#if QT_VERSION < 0x051400
+    return event->pos();
+#else
+    return event->position().toPoint();
+#endif
+}
+}
+
+class MapFrame : public QWidget {
+public:
+    explicit MapFrame(const QString& maps_dir, const QString& stylesheet_file)
+    {
+        m_currentProjection.Set({0, 0}, 0.0, osmscout::Magnification{osmscout::Magnification::magWorld}, MAP_DPI, width(), height());
+
+        QFileInfo stylesheetFile(stylesheet_file);
+        if (!osmscout::OSMScoutQt::NewInstance()
+                .WithMapLookupDirectories({maps_dir})
+                .WithStyleSheetDirectory(stylesheetFile.dir().path())
+                .WithStyleSheetFile(stylesheetFile.fileName())
+                .Init()) {
+            throw std::runtime_error{"failed to init OSMScoutQt"};
+        }
+
+        m_renderer = osmscout::OSMScoutQt::GetInstance().MakeMapRenderer(osmscout::RenderingType::TiledRendering);
+        connect(m_renderer, &osmscout::MapRenderer::Redraw, this, [this] {update();});
+    }
+
+protected:
+    void paintEvent(QPaintEvent*) override
+    {
+        auto painter = QPainter(this);
+        painter.setRenderHint(QPainter::Antialiasing, true);
+        painter.setRenderHint(QPainter::TextAntialiasing, true);
+        painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
+
+        m_renderer->RenderMap(painter, osmscout::MapViewStruct{
+            m_currentProjection.GetCenter(),
+            osmscout::Bearing{},
+            m_currentProjection.GetMagnification(),
+            static_cast<size_t>(width()),
+            static_cast<size_t>(height()),
+            MAP_DPI,
+        });
+    }
+
+    void mousePressEvent(QMouseEvent* ev) override
+    {
+        m_lastMousePos = ::pos(ev);
+    }
+
+    void mouseMoveEvent(QMouseEvent* ev) override
+    {
+        auto x_delta = ::pos(ev).x() - m_lastMousePos.x();
+        auto y_delta = ::pos(ev).y() - m_lastMousePos.y();
+        m_currentProjection.Move(-x_delta, y_delta);
+        m_lastMousePos = ::pos(ev);
+        update();
+    }
+
+    void wheelEvent(QWheelEvent* ev) override
+    {
+        auto magnification = m_currentProjection.GetMagnification().GetLevel();
+        if (ev->angleDelta().y() > 0) {
+            if (magnification >= MAX_ZOOM) {
+                return;
+            }
+            magnification++;
+            auto x_delta = (width() / 2. - ::pos(ev).x()) * 0.75;
+            auto y_delta = (height() / 2. - ::pos(ev).y()) * 0.75;
+            m_currentProjection.Move(-x_delta, y_delta);
+        } else {
+            if (magnification <= MIN_ZOOM) {
+                return;
+            }
+            magnification--;
+            auto x_delta = (width() / 2. - ::pos(ev).x()) * 0.75;
+            auto y_delta = (height() / 2. - ::pos(ev).y()) * 0.75;
+            m_currentProjection.Move(x_delta, -y_delta);
+        }
+        m_currentProjection.Set(m_currentProjection.GetCenter(), osmscout::Magnification{osmscout::MagnificationLevel{magnification}}, width(), height());
+        update();
+    }
+
+private:
+    osmscout::MapRenderer* m_renderer;
+    osmscout::MercatorProjection m_currentProjection;
+    QPoint m_lastMousePos;
+};
+
+int main(int argc, char *argv[])
+{
+    if (argc != 3) {
+        std::cerr << "Usage: " << argv[0] << ": <map_database_directory> <stylesheet_file>\n";
+        return 1;
+    }
+    osmscout::OSMScoutQt::RegisterQmlTypes();
+    QApplication app(argc, argv);
+    MapFrame map(argv[1], argv[2]);
+    map.show();
+    return QApplication::exec();
+}