With a few lines of code, you can start a web server and describe the content of the user interface using the available widgets:

#include <wui-cpp/wui.h>
#include "my_robot.h"

int main() {
	// Create a wui server on port 8080
	std::string web_root_path = "../share/resources/wui-cpp";
	wui::Server wui(web_root_path, 8080);

	double robot_max_velocity = 1.;
	double robot_current_velocity = 0.;
	std::string state = "Initialization";

	// Add some widgets
	wui.add<wui::Slider>("Robot maximum velocity", robot_max_velocity, 0., 10.);        // name, variable to pilot, min & max values
	wui.add<wui::Label> ("Robot maximum velocity", robot_max_velocity, "m/s");          // name, variable to display, suffix
	wui.add<wui::Label> ("Robot current velocity", robot_current_velocity, "m/s", "~"); // name, variable to display, suffix, prefix
	wui.add<wui::Label> ("Current state", state);                                       // name, variable to display

	// Start the wui server asynchronously so that it serves requests in the background
	wui.start();

	while(isRobotOk()) {
		std::this_thread::sleep_for(std::chrono::milliseconds(10));

		robot_current_velocity = getRobotCurrentVelocity();
		state = getRobotState();

		// Update the GUI and program state.
		// For output widgets (e.g. Label): update their displayed value according to the local variables' state
		// For control widgets (e.g. Slider): update the local variables with the values set in the GUI
		wui.update();

		// Do some stuff
		setRobotMaxVelocity(robot_max_velocity);
	}
}

As you can see, WUI-CPP was designed to not bloat your code and to ask only the bare minimum from you:

• create the server
• add your widgets
• start the server
• call update() when you need to update your data

By running this code and accessing http://localhost:8080 from a web browser, you get the following interface:

Details

The Start button will load the interface description from the server, add the corresponding widgets and start a timer at the period indicated in the spinbox (here 1000ms) to update the output widgets (here the wui::Labels in the table). The Stop button will cancel the timer and no more data will be retrieved from the server.

Input widgets, such as wui::Slider, will send an update every time their value changes and the server will store this information into its internal state. When a call to update() is issued, variables associated with input widgets (here robot_max_velocity) will be updated with the server’s internal state and variables associated with output widgets (here robot_max_velocity, robot_current_velocity and state) will be read and stored internally so that the interface can access these new values.

The graphical interface is based on jQWidgets and is free to use for non-commercial applications.

Available widgets

For now, the following widgets are available:

Here is the interface created by the wui-example demo application:

What is and is not WUI-CPP

WUI-CPP is not aimed to replace Qt, wxWidgets, gtk and alike where you can create complex and good looking applications. It will never be able to compete with such solutions.

WUI-CPP is for those who want a simple solution to add graphical capabilities to their C++ applications and/or those who need a remote access to their GUI. Being web-based, the user interface can be accessed from computers, tablets and phones, with no additional cost!

The future plans for WUI-CPP

• Write the documentation
• Add more widgets
• Make real time plotting of wui::Labels possible