Running C++ applications with TotalCross

Introduction
We hope you learn how to use TotalCross Runtime and Process implementations. See more about:
Java 7 Runtime class​
Java 8 Process class​
These implementations work only for Linux platforms
Requirements
Can compile C ++ applications and finish Get Started:
Running C++ applications with TotalCross
/documentation/guides/running-c++-applications-with-totalcross
Guide
Use external codes with Totalcross:
Step 1: create a blank project based in HelloWorld of VS Code plugin (we named it RunningCpp)
Step 2:  create an I/O sample in C++, in our case we did:
#include <iostream>
#include <string>
​
int main()
{
    std::string input;
    std::getline(std::cin, input);
    std::cout << "\nI received: " + input + "\n";
    return 0;
}
It's a simple application to get an I/O input and shortly thereafter return it as output.
Step 3: compile (something like this):
Step 4: inside initUI method at RunningCpp class, create a label to show the results:
// Label to show the results
Label label;
label = new Label();
label.setBackForeColors(Color.WHITE,  Color.BLACK);
Step 5: create a child process:
// Process initialization
Process process = null;
Step 6: output to the target program:
// Output to program
byte[] output = "Take the output!!!\n".getBytes();              // convert string to
                                                                // byte array 
try {
    process = Runtime.getRuntime().exec("./io");                // execute your
                                                                // application (sh like)
    process.getOutputStream().write(output, 0, output.length);  // write output into 
                                                                // output strem
    process.waitFor();                                          // blocking method 
                                                                // (wait io finish)
} catch (IOException ioe) {
    ioe.printStackTrace();
} catch (InterruptedException ie) {
    ie.printStackTrace();
};
Step 7: read the C++ program output as input to TotalCross application
// Input from program
String input;
try {
    // Read line by line the buffered stream
    LineReader lineReader = new LineReader(Stream.asStream(process.getInputStream()));
    while ((input = lineReader.readLine()) != null) {
        label.setText(input);
    }
} catch (IOException ioe) {
    ioe.printStackTrace();
};
​
// Add label to window
add(label, CENTER, CENTER);
Step 8: run TotalCross: Package with VS Code plugin or run mvn package in your terminal.
Step 9: copy C++ binary to target folder (something like):
Step 10: run your program!!!
See more
See our article about how to run RS232 protocol. See the full code:
package com.totalcross;
​
import java.io.IOException; 
import java.lang.Process;
​
import totalcross.ui.Label; 
import totalcross.ui.MainWindow; 
import totalcross.ui.gfx.Color; 
​
import totalcross.io.LineReader; 
import totalcross.io.Stream; 
​
import totalcross.sys.Settings;
​
public class RunningCPP extends MainWindow {
    public RunningCPP() {
        setUIStyle(Settings.MATERIAL_UI);
    }
    
    @Override
    public void initUI() {
        // Label to show the results
        Label label;
        label = new Label();
        label.setBackForeColors(Color.WHITE,  Color.BLACK);
    
        // Process initialization
        Process process = null;
    
        // Output to program
        byte[] output = "Take the output!!!\n".getBytes();              // convert string to
                                                                        // byte array 
        try {
            process = Runtime.getRuntime().exec("./io");                // execute your
                                                                        // application (sh like)
            process.getOutputStream().write(output, 0, output.length);  // write output into 
                                                                        // output strem
            process.waitFor();                                          // blocking method 
                                                                        // (wait io finish)
        } catch (IOException ioe) {
            ioe.printStackTrace();
        } catch (InterruptedException ie) {
            ie.printStackTrace();
        };
    
        // Input from program
        String input;
        try {
            LineReader lineReader = new LineReader(Stream.asStream(process.getInputStream()));
            while ((input = lineReader.readLine()) != null) {
                label.setText(input);
            }
        } catch (IOException ioe) {
            ioe.printStackTrace();
        };
    
        // Add label to window
        add(label, CENTER, CENTER);
    }
}
References
Java 7 Runtime class​
Java 8 Process class​
Understanding TotalCross for Linux ARM
Web Services
Last updated 5 months ago