com.github.apetrelli.gwtintegration.editor.client.ParseableValueEditor.java Source code

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Here is the source code for com.github.apetrelli.gwtintegration.editor.client.ParseableValueEditor.java

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/*
 * Copyright 2010 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.github.apetrelli.gwtintegration.editor.client;

import java.text.ParseException;

import com.google.gwt.editor.client.EditorDelegate;
import com.google.gwt.editor.client.HasEditorDelegate;
import com.google.gwt.editor.client.adapters.TakesValueEditor;
import com.google.gwt.user.client.TakesValue;
import com.google.gwt.user.client.ui.IsWidget;
import com.google.gwt.user.client.ui.ValueBoxBase;

/**
 * Adapts the {@link ValueBoxBase} interface to the Editor framework. This
 * adapter uses {@link ValueBoxBase#getValueOrThrow()} to report parse errors to
 * the Editor framework.
 *
 * @param <T>
 *            the type of value to be edited
 */
public class ParseableValueEditor<W extends IsWidget & TakesParseableValue<T>, T> extends TakesValueEditor<T>
        implements HasEditorDelegate<T> {

    /**
     * Returns a new TakesValueEditor that adapts a {@link ValueBoxBase}
     * instance.
     *
     * @param valueBox
     *            a {@link ValueBoxBase} instance to adapt
     * @return a ParseableValueEditor instance of the same type as the adapted
     *         {@link ValueBoxBase} instance
     */
    public static <W extends IsWidget & TakesParseableValue<T>, T> ParseableValueEditor<W, T> of(W valueBox) {
        return new ParseableValueEditor<W, T>(valueBox);
    }

    private EditorDelegate<T> delegate;
    private final W peer;
    private T value;

    /**
     * Constructs a new ParseableValueEditor that adapts a {@link ValueBoxBase} peer
     * instance.
     *
     * @param peer
     *            a {@link ValueBoxBase} instance of type T
     */
    protected ParseableValueEditor(W peer) {
        super((TakesValue<T>) peer);
        this.peer = peer;
    }

    /**
     * Returns the {@link EditorDelegate} for this instance.
     *
     * @return an {@link EditorDelegate}, or {@code null}
     * @see #setDelegate(EditorDelegate)
     */
    public EditorDelegate<T> getDelegate() {
        return delegate;
    }

    /**
     * Calls {@link ValueBoxBase#getValueOrThrow()}. If a {@link ParseException}
     * is thrown, it will be available through
     * {@link com.google.gwt.editor.client.EditorError#getUserData()
     * EditorError.getUserData()}.
     *
     * @return a value of type T
     * @see #setValue(Object)
     */
    @Override
    public T getValue() {
        try {
            value = peer.getValueOrThrow();
        } catch (ParseException e) {
            // TODO i18n
            getDelegate().recordError("Bad value (" + peer.getUnparsedText() + ")", peer.getUnparsedText(), e);
        }
        return value;
    }

    /**
     * Sets the {@link EditorDelegate} for this instance. This method is only
     * called by the driver.
     *
     * @param delegate
     *            an {@link EditorDelegate}, or {@code null}
     * @see #getDelegate()
     */
    public void setDelegate(EditorDelegate<T> delegate) {
        this.delegate = delegate;
    }

    @Override
    public void setValue(T value) {
        peer.setValue(this.value = value);
    }
}