org.eclipse.ui.texteditor.MessageRegion.java Source code

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Here is the source code for org.eclipse.ui.texteditor.MessageRegion.java

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/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.texteditor;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;

import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.IMessageProvider;
import org.eclipse.jface.resource.JFaceColors;
import org.eclipse.jface.resource.JFaceResources;

/**
 * The MessageRegion is the optional area to
 * show messages in the page.
 * <p>
 * XXX: Copied from org.eclipse.jface.preference.PreferencePage.MessageRegion
 *       see https://bugs.eclipse.org/bugs/show_bug.cgi?id=84061
 * </p>
 *
 * @since 3.1
 */
class MessageRegion {

    private Text messageText;

    private Label messageImageLabel;

    private Composite messageComposite;

    private String lastMessageText = "";//$NON-NLS-1$

    private int lastMessageType;

    /**
     * Create a new instance of the receiver.
     */
    public MessageRegion() {
        //No initial behavior
    }

    /**
     * Create the contents for the receiver.
     *
     * @param parent the Composite that the children will be created in
     */
    public void createContents(Composite parent) {
        messageComposite = new Composite(parent, SWT.NONE);
        GridLayout messageLayout = new GridLayout();
        messageLayout.numColumns = 2;
        messageLayout.marginWidth = 0;
        messageLayout.marginHeight = 0;
        messageLayout.makeColumnsEqualWidth = false;
        messageComposite.setLayout(messageLayout);
        messageImageLabel = new Label(messageComposite, SWT.NONE);

        GridData imageData = new GridData(GridData.VERTICAL_ALIGN_CENTER);
        Image sizingImage = JFaceResources.getImage(Dialog.DLG_IMG_MESSAGE_ERROR);
        Rectangle imageBounds;
        if (sizingImage == null)
            imageBounds = new Rectangle(0, 0, IDialogConstants.VERTICAL_MARGIN * 2,
                    IDialogConstants.VERTICAL_MARGIN * 2);
        else
            imageBounds = sizingImage.getBounds();
        imageData.heightHint = imageBounds.height + IDialogConstants.VERTICAL_SPACING;
        imageData.widthHint = imageBounds.width + IDialogConstants.HORIZONTAL_SPACING;
        messageImageLabel.setLayoutData(imageData);

        messageText = new Text(messageComposite, SWT.NONE);
        messageText.setEditable(false);
        messageText.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND));

        GridData textData = new GridData(
                GridData.GRAB_HORIZONTAL | GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_CENTER);
        messageText.setLayoutData(textData);
        hideRegion();

    }

    /**
     * Set the layoutData for the messageArea. In most cases this will be a copy of the layoutData
     * used in setTitleLayoutData.
     *
     * @param layoutData the layoutData for the message area composite.
     */
    public void setMessageLayoutData(Object layoutData) {
        messageComposite.setLayoutData(layoutData);
    }

    /**
     * Show the new message in the message text and update the image. Base the background color on
     * whether or not there are errors.
     *
     * @param newMessage The new value for the message
     * @param newType One of the IMessageProvider constants. If newType is IMessageProvider.NONE
     *            show the title.
     * @see IMessageProvider
     */
    public void updateText(String newMessage, int newType) {
        Image newImage = null;
        boolean showingError = false;
        switch (newType) {
        case IMessageProvider.NONE:
            hideRegion();
            return;
        case IMessageProvider.INFORMATION:
            newImage = JFaceResources.getImage(Dialog.DLG_IMG_MESSAGE_INFO);
            break;
        case IMessageProvider.WARNING:
            newImage = JFaceResources.getImage(Dialog.DLG_IMG_MESSAGE_WARNING);
            break;
        case IMessageProvider.ERROR:
            newImage = JFaceResources.getImage(Dialog.DLG_IMG_MESSAGE_ERROR);
            showingError = true;
            break;
        }

        if (newMessage == null) {//No message so clear the area
            hideRegion();
            return;
        }
        showRegion();
        // Any more updates required
        if (newMessage.equals(messageText.getText()) && newImage == messageImageLabel.getImage())
            return;
        messageImageLabel.setImage(newImage);
        messageText.setText(newMessage);
        if (showingError)
            setMessageColors(JFaceColors.getErrorBackground(messageComposite.getDisplay()));
        else {
            lastMessageText = newMessage;
            setMessageColors(JFaceColors.getBannerBackground(messageComposite.getDisplay()));
        }

    }

    /**
     * Show and enable the widgets in the message region
     */
    private void showRegion() {
        messageComposite.setVisible(true);
    }

    /**
     * Hide the message region and clear out the caches.
     */
    private void hideRegion() {
        messageComposite.setVisible(false);
        lastMessageText = null;
        lastMessageType = IMessageProvider.NONE;
    }

    /**
     * Set the colors of the message area.
     *
     * @param color the color to be use in the message area.
     */
    private void setMessageColors(Color color) {
        messageText.setBackground(color);
        messageComposite.setBackground(color);
        messageImageLabel.setBackground(color);
    }

    /**
     * Clear the error message. Restore the previously displayed message if
     * there is one, if not restore the title label.
     *
     */
    public void clearErrorMessage() {
        updateText(lastMessageText, lastMessageType);
    }
}