add an example to embed a server in a Qt GUI app

examples/CMakeLists.txt

@@ -40,10 +40,14 @@ target_link_libraries(form_urlencoded_client ${EXAMPLE_LIBS})
 add_executable(form_server form_server.cc)
 target_link_libraries(form_server ${EXAMPLE_LIBS})
 
-add_subdirectory(book_server)
-add_subdirectory(book_client)
-
 if(WIN32)
     add_executable(url_unicode url_unicode.cc encoding.cc encoding.h)
     target_link_libraries(url_unicode ${EXAMPLE_LIBS})
 endif()
+
+add_subdirectory(book_server)
+add_subdirectory(book_client)
+
+if(WEBCC_ENABLE_QT_EXAMPLES)
+    add_subdirectory(qt_app_server)
+endif()

examples/qt_app_server/CMakeLists.txt

@@ -0,0 +1,11 @@
+project(qt_app_server)
+
+find_package(Qt5 CONFIG REQUIRED Core Gui Widgets)
+
+set(CMAKE_AUTOMOC ON)
+
+file(GLOB SRCS *.cpp *.h)
+
+add_executable(qt_app_server ${SRCS})
+
+target_link_libraries(qt_app_server Qt5::Core Qt5::Gui Qt5::Widgets ${EXAMPLE_LIBS})

examples/qt_app_server/main.cpp

@@ -0,0 +1,56 @@
+#include <thread>
+
+#include <QApplication>
+
+#include "examples/qt_app_server/main_window.h"
+
+#include "webcc/logger.h"
+#include "webcc/response_builder.h"
+#include "webcc/server.h"
+#include "webcc/view.h"
+
+class ApiView : public webcc::View {
+public:
+  explicit ApiView(Context* context) : context_(context) {
+  }
+
+  webcc::ResponsePtr Handle(webcc::RequestPtr request) override {
+    if (request->method() == "GET") {
+      emit context_->SomeApiSignal("A GET request has been handled");
+      return webcc::ResponseBuilder{}.OK().Body("Hello, World!")();
+    }
+
+    return {};
+  }
+
+private:
+  Context* context_;
+};
+
+int main(int argc, char** argv) {
+  QApplication app{ argc, argv };
+
+  WEBCC_LOG_INIT("", webcc::LOG_CONSOLE);
+
+  Context context;
+
+  // Create a server and bind view.
+  webcc::Server server{ boost::asio::ip::tcp::v4(), 8000 };
+  server.Route("/", std::make_shared<ApiView>(&context));
+
+  // Run the server in a thread to avoid blocking the GUI.
+  std::thread server_thread{ [&server]() { server.Run(); } };
+
+  // Now show our Qt main window and execute the application loop.
+  MainWindow main_window{ &context };
+  main_window.resize(400, 300);
+  main_window.showNormal();
+
+  int code = app.exec();
+
+  // Stop the server and wait for it to finish.
+  server.Stop();
+  server_thread.join();
+
+  return code;
+}

examples/qt_app_server/main_window.cpp

@@ -0,0 +1,21 @@
+#include "examples/qt_app_server/main_window.h"
+
+#include <QDebug>
+
+MainWindow::MainWindow(Context* context, QWidget* parent)
+    : QMainWindow(parent) {
+  setWindowTitle("Qt App Server");
+
+#if 1
+  connect(context, &Context::SomeApiSignal, this, &MainWindow::OnSomeApiSignal);
+#else
+  // NOTE: Seems not necessary to use QueuedConnection (because we are using
+  // std::thread instead of QThread?).
+  connect(context, &Context::SomeApiSignal, this, &MainWindow::OnSomeApiSignal,
+          Qt::QueuedConnection);
+#endif
+}
+
+void MainWindow::OnSomeApiSignal(const QString& text) {
+  qDebug() << text;
+}

examples/qt_app_server/main_window.h

@@ -0,0 +1,34 @@
+#ifndef MAIN_WINDOW_H_
+#define MAIN_WINDOW_H_
+
+#include <QMainWindow>
+
+// Some global QObject with public signals for ApiView to inform the handling
+// of client requests.
+// "Context" is a bad name, you should change it.
+class Context : public QObject {
+  Q_OBJECT
+
+public:
+  explicit Context(QObject* parent = nullptr) : QObject(parent) {
+  }
+
+  // Public signals emitted from ApiView:
+signals:
+  void SomeApiSignal(const QString& text);
+  // Add other signals here...
+};
+
+class MainWindow : public QMainWindow {
+  Q_OBJECT
+
+public:
+  explicit MainWindow(Context* context, QWidget* parent = nullptr);
+
+private:
+  // You should encapsulate the required information as the signal parameters.
+  // I use QString just for demostrating how to transfer data from ApiView.
+  void OnSomeApiSignal(const QString& text);
+};
+
+#endif  // MAIN_WINDOW_H_