Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.wicket.extensions.wizard; import java.util.Iterator; import org.apache.wicket.util.io.IClusterable; /** * This interface defines the model for wizards. This model knows about the wizard's steps and the * transitions between them, and it holds a reference to the currently active step. It might * function as a generic state holder for the wizard too, though you might find it more convenient * to use the wizard component itself for that, or even an external model. * * <p> * {@link IWizardModelListener wizard model listeners} can be registered to be notified of important * events (changing the active step) using the {@link #addListener(IWizardModelListener) add * listener} method. * </p> * * <p> * Typically, you would use {@link WizardModel the default implementation of this interface}, but if * you need to do more sophisticated stuff, like branching etc, you can consider creating your own * implementation. In that case, it is recommended you start by extending from * {@link AbstractWizardModel}. * </p> * * <p> * <a href="https://wizard-framework.dev.java.net/">Swing Wizard Framework</a> served as a valuable * source of inspiration. * </p> * * @see AbstractWizardModel * @see WizardModel * * @author Eelco Hillenius */ public interface IWizardModel extends IClusterable { /** * Adds a wizard model listener. * * @param listener * The wizard model listener to add */ void addListener(IWizardModelListener listener); /** * Removes a wizard model listener. * * @param listener * The listener to remove */ void removeListener(IWizardModelListener listener); /** * Resets the model, setting it to the first step. Implementors should notify * {@link IWizardModelListener listeners} through calling * {@link IWizardModelListener#onActiveStepChanged(IWizardStep)}. */ void reset(); /** * Returns an iterator over all the steps in the model. The iteration order is not guaranteed to * the be the order of visit. This is an optional operation; dynamic models can just return * null, and should call init the first time a step is encountered right before rendering it. * * @return an iterator over all the steps of the model or null if the wizard model is not static */ Iterator<IWizardStep> stepIterator(); /** * Gets whether the specified step is the last step in the wizard. * * @param step * the step to check * @return True if its the final step in the wizard, false< otherwise. */ boolean isLastStep(IWizardStep step); /** * Gets the current active step the wizard should display. * * @return the active step. */ IWizardStep getActiveStep(); /** * Gets whether the cancel button should be displayed. * * @return True if the cancel button should be displayed * * @see #cancel() */ boolean isCancelVisible(); /** * Cancels further processing. Implementations may clean up and reset the model. Implementations * should notify the registered {@link IWizardModelListener#onCancel() model listeners}. */ void cancel(); /** * Gets whether the previous button should be enabled. * * @return True if the previous button should be enabled, false otherwise. * * @see #previous() */ boolean isPreviousAvailable(); /** * Takes the model to the previous step.This method must only be called if * {@link #isPreviousAvailable} returns <tt>true</tt>. Implementors should notify * {@link IWizardModelListener listeners} through calling * {@link IWizardModelListener#onActiveStepChanged(IWizardStep)}. * * @see #isPreviousAvailable() */ void previous(); /** * Gets whether the next button should be enabled. * * @return True if the next button should be enabled, false otherwise. * * @see #next() */ boolean isNextAvailable(); /** * Increments the model to the next step. This method must only be called if * {@link #isNextAvailable} returns <tt>true</tt>. Implementors should notify * {@link IWizardModelListener listeners} through calling * {@link IWizardModelListener#onActiveStepChanged(IWizardStep)}. * * @see #isNextAvailable() */ void next(); /** * Gets whether the last button should be displayed. This method should only return true if the * {@link #isLastAvailable} will return true at any point. Returning false will prevent the last * button from appearing on the wizard at all. * * @return True if the last button should be displayed, False otherwise. * @see #isLastAvailable() * @see #last() */ boolean isLastVisible(); /** * Checks if the last button should be enabled. * * @return <tt>true</tt> if the last button should be enabled, <tt>false</tt> otherwise. * * @see #isLastVisible() * @see #last() */ boolean isLastAvailable(); /** * Takes the model to the last step in the wizard. This method must only be called if * {@link #isLastAvailable} returns <tt>true</tt>. Implementors should notify * {@link IWizardModelListener listeners} through calling * {@link IWizardModelListener#onActiveStepChanged(IWizardStep)}. * * @see #isLastVisible() * @see #isLastAvailable() */ void last(); /** * Gets whether the finish button should be enabled. * <p> * By default the finish button is available for the last step only. * * @return True if the finish button should be enabled, false otherwise. * * @see #isLastStep(IWizardStep) * @see #finish() */ default boolean isFinishAvailable() { return isLastStep(getActiveStep()); } /** * Instructs the wizard to finish succesfully. Typically, implementations check whether this * option is available at all. Implementations may clean up and reset the model. Implementations * should notify the registered {@link IWizardModelListener#onFinish() model listeners}. */ void finish(); }