FORGE-1774: Default --help for Forge commands

HelpUICommandTransformer.java

/**
 * Copyright 2014 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Eclipse Public License version 1.0, available at
 * http://www.eclipse.org/legal/epl-v10.html
 */

package org.jboss.forge.addon.shell.ui.transformer;

import javax.inject.Inject;

import org.jboss.forge.addon.ui.command.UICommand;
import org.jboss.forge.addon.ui.command.UICommandTransformer;
import org.jboss.forge.addon.ui.context.UIContext;
import org.jboss.forge.addon.ui.input.InputComponentFactory;

/**
 * Adds the "help" attribute on commands when executed in Shell
 * 
 * @author <a href="ggastald@redhat.com">George Gastaldi</a>
 */
public class HelpUICommandTransformer implements UICommandTransformer
{

   @Inject
   private InputComponentFactory inputComponentFactory;

   @Override
   public UICommand transform(UIContext context, UICommand original)
   {
      // Show in shell only
      if (!context.getProvider().isGUI())
      {
         return new HelpWizard(original, inputComponentFactory);
      }
      else
      {
         return original;
      }
   }
}

HelpWizard.java

/**
 * Copyright 2014 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Eclipse Public License version 1.0, available at
 * http://www.eclipse.org/legal/epl-v10.html
 */

package org.jboss.forge.addon.shell.ui.transformer;

import javax.enterprise.inject.Vetoed;

import org.jboss.forge.addon.ui.command.UICommand;
import org.jboss.forge.addon.ui.context.UIBuilder;
import org.jboss.forge.addon.ui.context.UIContext;
import org.jboss.forge.addon.ui.context.UIExecutionContext;
import org.jboss.forge.addon.ui.context.UINavigationContext;
import org.jboss.forge.addon.ui.context.UIValidationContext;
import org.jboss.forge.addon.ui.input.InputComponent;
import org.jboss.forge.addon.ui.input.InputComponentFactory;
import org.jboss.forge.addon.ui.input.UIInput;
import org.jboss.forge.addon.ui.metadata.UICommandMetadata;
import org.jboss.forge.addon.ui.result.NavigationResult;
import org.jboss.forge.addon.ui.result.Result;
import org.jboss.forge.addon.ui.wizard.UIWizard;

/**
 * A command that adds the "help" option to an existing {@link UICommand} object
 * 
 * @author <a href="ggastald@redhat.com">George Gastaldi</a>
 */
@Vetoed
public class HelpWizard implements UIWizard
{
   private static final String HELP_INPUT_NAME = "help";
   private final UICommand command;
   private final InputComponentFactory inputComponentFactory;
   private UIInput<Boolean> helpOption;
   private boolean containsHelpOption;

   public HelpWizard(UICommand command, InputComponentFactory inputComponentFactory)
   {
      this.command = command;
      this.inputComponentFactory = inputComponentFactory;
   }

   @Override
   public UICommandMetadata getMetadata(UIContext context)
   {
      return command.getMetadata(context);
   }

   @Override
   public boolean isEnabled(UIContext context)
   {
      return command.isEnabled(context);
   }

   @Override
   public void initializeUI(final UIBuilder builder) throws Exception
   {
      UIBuilder wrapperBuilder = new UIBuilder()
      {
         @Override
         public UIContext getUIContext()
         {
            return builder.getUIContext();
         }

         @Override
         public UIBuilder add(InputComponent<?, ?> input)
         {
            builder.add(input);
            if (input.getName().equals(HELP_INPUT_NAME))
            {
               HelpWizard.this.containsHelpOption = true;
            }
            return this;
         }
      };
      command.initializeUI(wrapperBuilder);
      if (!containsHelpOption)
      {
         helpOption = inputComponentFactory.createInput(HELP_INPUT_NAME, 'h', Boolean.class);
         builder.add(helpOption);
      }

   }

   @Override
   public void validate(UIValidationContext context)
   {
      if (!isHelpOptionSet())
      {
         command.validate(context);
      }
   }

   @Override
   public Result execute(UIExecutionContext context) throws Exception
   {
      if (isHelpOptionSet())
      {
         // TODO: Execute man
         return null;
      }
      else
      {
         return command.execute(context);
      }
   }

   private boolean isHelpOptionSet()
   {
      return (helpOption != null && helpOption.getValue());
   }

   @Override
   public NavigationResult next(UINavigationContext context) throws Exception
   {
      if (isHelpOptionSet())
      {
         return null;
      }
      else
      {
         if (command instanceof UIWizard)
         {
            return ((UIWizard) command).next(context);
         }
         else
         {
            return null;
         }
      }
   }

}