com.google.gwt.editor.client.EditorDriver.java Source code

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Here is the source code for com.google.gwt.editor.client.EditorDriver.java

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/*
 * Copyright 2011 Google Inc.
 * 
 * Licensed 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 com.google.gwt.editor.client;

import java.util.List;

import javax.validation.ConstraintViolation;

/**
 * Defines common capabilities of editor drivers.
 * <p>
 * The {@code EditorDriver} interface cannot be used with
 * {@link com.google.gwt.core.client.GWT#create(Class) GWT.create()} directly.
 * Instead, use one of the specializations of this interface.
 * 
 * @param <T> the type of data returned from {@link #flush()}
 * @see com.google.gwt.editor.client.SimpleBeanEditorDriver
 * @see com.google.web.bindery.requestfactory.gwt.client.RequestFactoryEditorDriver
 */
public interface EditorDriver<T> {
    /**
     * Visit the Editor hierarchy controlled by the EditorDriver.
     */
    void accept(EditorVisitor visitor);

    /**
     * Update the object being edited with the current state of the Editor.
     * 
     * @return an implementation-specific value
     */
    T flush();

    /**
     * Returns any unconsumed EditorErrors from the last call to {@link #flush()}.
     * 
     * @return a List of {@link EditorError} instances
     */
    List<EditorError> getErrors();

    /**
     * Indicates if the last call to {@link #flush()} resulted in any errors.
     * 
     * @return {@code true} if errors are present
     */
    boolean hasErrors();

    /**
     * Returns {@code true} if any of the Editors in the hierarchy have been
     * modified relative to the last value passed into {@link SimpleBeanEditorDriver#edit(Object)}.
     * <p>
     * This method is not affected by {@link #flush()} to support the following
     * workflow:
     * <ol>
     * <li>{@code EditorDriver.edit()}</li>
     * <li>The user edits the on-screen values</li>
     * <li>{@code EditorDriver.flush()}</li>
     * <li>The data in the edited object is validated:
     * <ol>
     * <li>The validation fails, returning to step 2</li>
     * <li>The validation succeeds and the editing UI is dismissed</li>
     * </ol>
     * </ol>
     * The simplest implementation of a "navigate away from dirty UI warning" by
     * checking {@code isDirty()} is correct for the above workflow. If the
     * {@link #flush()} method were to clear the dirty state, it would be
     * necessary to implement an alternate flag to distinguish between a
     * newly-initialized editor entering step 2 or re-entering step 2.
     * 
     * @see EditorDelegate#setDirty(boolean)
     */
    boolean isDirty();

    /**
     * Show {@link ConstraintViolation ConstraintViolations} generated through a
     * {@link javax.validation.Validator Validator}. The violations will be
     * converted into {@link EditorError} objects whose
     * {@link EditorError#getUserData() getUserData()} method can be used to
     * access the original ConstraintViolation object.
     * 
     * @param violations an Iterable over {@link ConstraintViolation} instances
     * @return <code>true</code> if there were any unconsumed EditorErrors which
     *         can be retrieved from {@link #getErrors()}
     */
    boolean setConstraintViolations(Iterable<ConstraintViolation<?>> violations);
}