/**
 * Creates a command that adds a layer to the map.
 *
 * @author jones
 * @since 0.6.0
 */
public class AddLayerCommand extends AbstractCommand implements UndoableCommand {

    private Layer layer;
    private int index=-1;
    /**
     * Construct <code>AddLayerCommand</code>.
     *
     * @param layer the layer that will be added.
     */
    public AddLayerCommand(Layer layer) {
        this.layer=layer;
    }

    /**
     * Construct <code>AddLayerCommand</code>.
     *
     * @param layer the layer that will be added.
     * @param index the zorder that the layer will be added.
     */
    public AddLayerCommand(Layer layer, int index) {
        this.layer=layer;
        this.index=index;
    }

    /**
     * Remove the layer that was added during execution.
     * @see org.locationtech.udig.project.command.UndoableCommand#rollback()
     */
    public void rollback() throws Exception {
        getMap().getLayersInternal().remove(layer);
    }

    /**
     * Adds a layer to the map.  Defensive programming is recommended but command
     * framework protects against exceptions raised in commands.
     * @see org.locationtech.udig.project.command.Command#run()
     */
    public void run() throws Exception {
        if( index<0 || index>getMap().getLayersInternal().size())
            getMap().getLayersInternal().add(layer);
        else
            getMap().getLayersInternal().add(index, layer);
    }

    /**
     * Returns a copy of the command.  A command should only be executed once.  If the same
     * command is to be used multiple times the command should be copied.  Some commands
     * contain internal state.
     *
     * @see org.locationtech.udig.project.command.Command#copy()
     */
    public Command copy() {
        return new AddLayerCommand(layer, index);
    }

    /**
     * Each command has a name that is displayed with the undo/redo buttons.
     * @see org.locationtech.udig.project.command.Command#getName()
     */
    public String getName() {
        return Policy.bind("AddLayerCommand.Name")+layer.getName(); //$NON-NLS-1$
    }

}