2

Picocli offers the ability to add a nice header in the @Command annotation, for example:

@Command(name = "git-star", header = {
    "@|green       _ _      _             |@", 
    "@|green  __ _(_) |_ __| |_ __ _ _ _  |@",
    "@|green / _` | |  _(_-<  _/ _` | '_| |@",
    "@|green \\__, |_|\\__/__/\\__\\__,_|_|   |@",
    "@|green |___/                        |@"},
    description = "Shows GitHub stars for a project",
    mixinStandardHelpOptions = true, version = "git-star 0.1")

How do I always show that header/banner when the program is running, without duplicating this banner in two places?

(See also https://github.com/remkop/picocli/issues/517)

Remko Popma
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2 Answers2

3

There are two aspects to this:

  • How to get the banner text from the application?
  • How to render the ANSI colors and styles?

You can get the banner from the usage help message, either with new CommandLine(new App()).getCommandSpec().usageHelpMessage().header() or by injecting a @Spec annotated CommandSpec field in your application.

To render the ANSI styles, use CommandLine.Help.Ansi.AUTO.string(line) for each banner line.

Putting it all together:

@Command(name = "git-star", header = {
        "@|green       _ _      _             |@", 
        "@|green  __ _(_) |_ __| |_ __ _ _ _  |@",
        "@|green / _` | |  _(_-<  _/ _` | '_| |@",
        "@|green \\__, |_|\\__/__/\\__\\__,_|_|   |@",
        "@|green |___/                        |@"},
        description = "Shows GitHub stars for a project",
        mixinStandardHelpOptions = true, version = "git-star 0.1")
class GitStar implements Runnable {

  @Option(names = "-c")
  int count;

  @Spec CommandSpec spec;

  // prints banner every time the command is invoked
  public void run() {

    String[] banner = spec.usageHelpMessage().header();

    // or: String[] banner = new CommandLine(new GitStar())
    //        .getCommandSpec().usageHelpMessage().header();

    for (String line : banner) {
      System.out.println(CommandLine.Help.Ansi.AUTO.string(line));
    }

    // business logic here...
  }

  public static void main(String[] args) {
    CommandLine.run(new GitStar(), args);
  }
}
Remko Popma
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0

For me in Picocli 4.5.2, works like that:

public void run() {
    CommandLine cmd = new CommandLine(new App());
    cmd.usage(System.out, Ansi.ON);

    // business logic here...
}
caiosduarte
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  • That works too, and prints the full usage help message. If that’s what suitable for the application that’s fine of course. The original question came from a situation where the application wanted to print just the banner (without the description for the options), followed by some other output. – Remko Popma Jan 10 '21 at 06:42