com.google.cloud.tools.eclipse.preferences.areas.FieldEditorWrapper.java Source code

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Here is the source code for com.google.cloud.tools.eclipse.preferences.areas.FieldEditorWrapper.java

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/*
 * Copyright 2016 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.cloud.tools.eclipse.preferences.areas;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.dialogs.DialogPage;
import org.eclipse.jface.dialogs.IMessageProvider;
import org.eclipse.jface.preference.FieldEditor;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

/**
 * Wrap an existing {@link FieldEditor}.
 *
 * @param <FET> the type of wrapped {@linkplain FieldEditor}
 */
public abstract class FieldEditorWrapper<FET extends FieldEditor> extends PreferenceArea {
    private static final String PLUGIN_ID = "com.google.cloud.tools.eclipse.preferences";

    /**
     * A dummy page that exists for its #setMessage() and #setErrorMessage().
     */
    private static class MessageGatheringDialogPage extends DialogPage {
        @Override
        public void createControl(Composite parent) {
            // should never ever be called
        }
    }

    private FET fieldEditor;
    private MessageGatheringDialogPage messages = new MessageGatheringDialogPage();

    protected FieldEditorWrapper() {
    }

    @Override
    public Control createContents(Composite parent) {
        Composite container = new Composite(parent, SWT.NONE);
        parent.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
        fieldEditor = createFieldEditor(container);
        fieldEditor.setPage(messages);
        fieldEditor.setPropertyChangeListener(new IPropertyChangeListener() {
            @Override
            public void propertyChange(PropertyChangeEvent event) {
                if (FieldEditor.IS_VALID.equals(event.getProperty())) {
                    fireValueChanged(IS_VALID, event.getOldValue(), event.getNewValue());
                } else if (FieldEditor.VALUE.equals(event.getProperty())) {
                    fireValueChanged(VALUE, event.getOldValue(), event.getNewValue());
                }
            }
        });
        fieldEditor.setPreferenceStore(getPreferenceStore());
        fieldEditor.load();
        fieldEditor.fillIntoGrid(container, fieldEditor.getNumberOfControls());
        return container;
    }

    protected abstract FET createFieldEditor(Composite container);

    @Override
    public void dispose() {
        if (fieldEditor != null) {
            fieldEditor.dispose();
        }
    }

    @Override
    public IStatus getStatus() {
        // DialogPage has an unfortunately complex set of message possibilities
        String message = messages.getErrorMessage();
        if (message != null) {
            return new Status(IStatus.ERROR, PLUGIN_ID, message);
        }
        int messageType = messages.getMessageType();
        switch (messageType) {
        case IMessageProvider.INFORMATION:
            return new Status(IStatus.INFO, PLUGIN_ID, messages.getMessage());
        case IMessageProvider.WARNING:
            return new Status(IStatus.WARNING, PLUGIN_ID, messages.getMessage());
        case IMessageProvider.ERROR:
            return new Status(IStatus.ERROR, PLUGIN_ID, messages.getMessage());
        default:
            return Status.OK_STATUS;
        }
    }

    @Override
    public void performApply() {
        fieldEditor.store();
    }

    @Override
    public void load() {
        fieldEditor.load();
    }

    @Override
    public void loadDefault() {
        fieldEditor.loadDefault();
    }
}