Package org.eclipse.e4.core.commands

Interface ECommandService

All Known Implementing Classes:
CommandServiceImpl
public interface ECommandService
This service allows access to the command subsystem. A command is an abstract notion of a user action like "copy" and "paste". A handler is an object that executes the actual code when the command is activated.

Many handlers may be associated with a command (e.g. "copy") because each handler typically only handles the command when in a specific context. An example of different contexts is the use of the "copy" command in a text editor versus in a table. In each case the command is the same, but the code to handle the case in that context is very different.

You should not implement this service, an implementation is provided by Eclipse.

It is usually not needed to use this service in your programs because command creation is done by Eclipse using the application model. However, in some cases it may be needed to programmatically create commands, or activate a handler using the EHandlerService

Example usage: 

 
 @inject  ECommandService cs;
 @inject  EHandlerService hs;

 Command command = cs.getCommand(commandId);
 if (command.isDefined()) {
        Map<String, Object> parameters = new HashMap<String, Object>();
        parameters.put("parm1", "hello, world");
        ParameterizedCommand parmCmd = cs.createCommand(commandId, parameters);
        if (hs.canExecute(parmCmd)) {
                hs.executeHandler(parmCmd);
        }
        else {logger.error("Cannot execute command");}
 }
 else {logger.error("Command is not defined");}
Since:
1.0
See Also:
Restriction:
This interface is not intended to be implemented by clients.
Restriction:
This interface is not intended to be extended by clients.

  • Method Details

    • createCommand

      ParameterizedCommand createCommand(String id, Map<String,?> parameters)
      Allows to create an instance of an existing command based on the id parameter
      Parameters:
      id - - Command to create
      parameters - - Map of the parameters of the command or null
      Returns:
      ParameterizedCommand - created command or null

    • createCommand

      ParameterizedCommand createCommand(String id)
      Allows to create an instance of an existing command based on the id parameter which does not require parameters Delegates to createCommand(String,Map) passing in null as Map parameter
      Parameters:
      id - - Command to create
      Returns:
      ParameterizedCommand - created command or null

    • defineCategory

      Category defineCategory(String id, String name, String description)
      Parameters:
      id - - Category to define
      name - - The name of this category; must not be null
      description - - The description for this category; may be null
      Returns:
      the defined category
      Restriction:

    • defineCommand

      Command defineCommand(String id, String name, String description, Category category, IParameter[] parameters)
      Parameters:
      id - - Command to define
      name - - The name of this command; must not be null
      description - - The description for this command; may be null
      category - - The category for this command; must not be null
      parameters - - The parameters understood by this command. This value may be either null or empty if the command does not accept parameters
      Returns:
      the defined command
      Restriction:

    • defineCommand

      Command defineCommand(String id, String name, String description, Category category, IParameter[] parameters, String helpContextId)
      Parameters:
      id - - Command to define
      name - - The name of this command; must not be null
      description - - The description for this command; may be null
      category - - The category for this command; must not be null
      parameters - - The parameters understood by this command. This value may be either null or empty if the command does not accept parameters
      helpContextId - - The identifier of the help context to associate with this command; may be null if this command does not have any help associated with it
      Returns:
      the defined command
      Restriction:

    • getCategory

      Category getCategory(String categoryId)
      Get category for id.
      Parameters:
      categoryId - - The category id
      Returns:
      the category for id

    • getCommand

      Command getCommand(String commandId)
      Get command for id.
      Parameters:
      commandId - - The command id
      Returns:
      the command for id