(C++) 'Hello Wt' using Qt Creator under Raspian
January 25, 2018 · View on GitHub
(C++) 'Hello Wt' using Qt Creator under Raspian
Hello Wt application using Qt Creator under Raspian.
Technical facts
Operating system(s) or programming environment(s)
Qt Creator 2.5.2
- G++ 4.6.3
Libraries used:
Qt project file: CppHelloWtQtCreatorRaspbian.pro
QT += core QT -= gui LIBS += -L/usr/lib -lwt -lwthttp -lboost_signals QMAKE_CXXFLAGS += -DNDEBUG CONFIG += console CONFIG -= app_bundle TEMPLATE = app SOURCES += main.cpp
main.cpp
/* * Copyright 2008 Emweb bvba, Heverlee, Belgium. * * See the LICENSE file for terms of use. */ #include <Wt/WApplication> #include <Wt/WBreak> #include <Wt/WContainerWidget> #include <Wt/WLineEdit> #include <Wt/WPushButton> #include <Wt/WText> #include <boost/version.hpp> using namespace Wt; /* * A simple hello world application class which demonstrates how to react * to events, read input, and give feed-back. */ class HelloApplication : public WApplication { public: HelloApplication(const WEnvironment& env); private: WLineEdit *nameEdit_; WText *greeting_; void greet(); }; /* * The env argument contains information about the new session, and * the initial request. It must be passed to the WApplication * constructor so it is typically also an argument for your custom * application constructor. */ HelloApplication::HelloApplication(const WEnvironment& env) : WApplication(env) { setTitle("Hello world"); // application title root()->addWidget(new WText("Your name, please ? ")); // show some text nameEdit_ = new WLineEdit(root()); // allow text input nameEdit_->setFocus(); // give focus WPushButton *b = new WPushButton("Greet me.", root()); // create a button b->setMargin(5, Left); // add 5 pixels margin root()->addWidget(new WBreak()); // insert a line break greeting_ = new WText(root()); // empty text /* * Connect signals with slots * * - simple Wt-way */ b->clicked().connect(this, &HelloApplication::greet); /* * - using an arbitrary function object (binding values with boost::bind()) */ nameEdit_->enterPressed().connect (boost::bind(&HelloApplication::greet, this)); } void HelloApplication::greet() { /* * Update the text, using text input into the nameEdit_ field. */ greeting_->setText("Hello there, " + nameEdit_->text()); } WApplication *createApplication(const WEnvironment& env) { /* * You could read information from the environment to decide whether * the user has permission to start a new application */ return new HelloApplication(env); } int main(int argc, char **argv) { /* * Your main method may set up some shared resources, but should then * start the server application (FastCGI or httpd) that starts listening * for requests, and handles all of the application life cycles. * * The last argument to WRun specifies the function that will instantiate * new application objects. That function is executed when a new user surfs * to the Wt application, and after the library has negotiated browser * support. The function should return a newly instantiated application * object. */ return WRun(argc, argv, &createApplication); }
start.sh
qmake make rm Makefile rm main.o ./CppHelloWtQtCreatorRaspbian --docroot . --http-address 0.0.0.0 --http-port 8080
Deploying the Wt application locally
Call the start.sh script:
./start
In the end you will see something like shown below. Your web server is running now.
[2010-Nov-19 16:41:38.365920] 6360 - [notice] "Wt: initializing built-in httpd" [2010-Nov-19 16:41:38.366043] 6360 - [notice] "Reading Wt config file: /etc/wt/wt_config.xml (location = '/home/richel/qtsdk-2010.04/bin/Projects/Website/CppHelloWtQtCreatorUbuntu-build-desktop/CppHelloWtQtCreatorUbuntu')" [2010-Nov-19 16:41:38.366592] 6360 - [notice] "Started server: http://0.0.0.0:8080"
Now, start your web browser and go to the following address:
http://127.0.0.1:8080/
You will see the 'Hello Wt' dynamic website. You just deployed your Wt application locally. This is just fine for debugging. If the application is ready to be put on the web, deploy the Wt application globally.