package org.argeo.cms.e4;
   
   import java.util.List;
   
   import org.argeo.cms.CmsException;
   import org.eclipse.e4.ui.model.application.MApplication;
   import org.eclipse.e4.ui.model.application.commands.MCommand;
   import org.eclipse.e4.ui.model.application.ui.basic.MPart;
   import org.eclipse.e4.ui.model.application.ui.menu.MDirectMenuItem;
  import org.eclipse.e4.ui.model.application.ui.menu.MHandledMenuItem;
  import org.eclipse.e4.ui.workbench.modeling.EModelService;
  import org.eclipse.e4.ui.workbench.modeling.EPartService;
  import org.eclipse.e4.ui.workbench.modeling.EPartService.PartState;
  import org.osgi.framework.Bundle;
  import org.osgi.framework.FrameworkUtil;
  
  /** Static utilities simplifying recurring Eclipse 4 patterns. */
  public class CmsE4Utils {
  	/** Open an editor based on its id. */
  	public static void openEditor(EPartService partService, String editorId, String key, String state) {
  		for (MPart part : partService.getParts()) {
  			String id = part.getPersistedState().get(key);
  			if (id != null && state.equals(id)) {
  				partService.showPart(part, PartState.ACTIVATE);
  				return;
  			}
  		}
  
  		// new part
  		MPart part = partService.createPart(editorId);
  		if (part == null)
  			throw new CmsException("No editor found with id " + editorId);
  		part.getPersistedState().put(key, state);
  		partService.showPart(part, PartState.ACTIVATE);
  	}
  
  	/** Dynamically creates an handled menu item from a command ID. */
  	public static MHandledMenuItem createHandledMenuItem(EModelService modelService, MApplication app,
  			String commandId) {
  		MCommand command = findCommand(modelService, app, commandId);
  		if (command == null)
  			return null;
  		MHandledMenuItem handledItem = modelService.createModelElement(MHandledMenuItem.class);
  		handledItem.setCommand(command);
  		return handledItem;
  
  	}
  
  	/**
  	 * Finds a command by ID.
  	 * 
  	 * @return the {@link MCommand} or <code>null</code> if not found.
  	 */
  	public static MCommand findCommand(EModelService modelService, MApplication app, String commandId) {
  		List<MCommand> cmds = modelService.findElements(app, null, MCommand.class, null);
  		for (MCommand cmd : cmds) {
  			if (cmd.getElementId().equals(commandId)) {
  				return cmd;
  			}
  		}
  		return null;
  	}
  
  	/** Dynamically creates a direct menu item from a class. */
  	public static MDirectMenuItem createDirectMenuItem(EModelService modelService, Class<?> clss, String label) {
  		MDirectMenuItem dynamicItem = modelService.createModelElement(MDirectMenuItem.class);
  		dynamicItem.setLabel(label);
  		Bundle bundle = FrameworkUtil.getBundle(clss);
  		dynamicItem.setContributionURI("bundleclass://" + bundle.getSymbolicName() + "/" + clss.getName());
  		return dynamicItem;
  	}
  
  	/** Singleton. */
  	private CmsE4Utils() {
  	}
  
  }