Java tutorial
/******************************************************************************* * Copyright (C) 2005, 2009 Wolfgang Schramm and Contributors * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License as published by the Free Software * Foundation version 2 of the License. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA *******************************************************************************/ package net.tourbook.ui; 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; 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; /** * The MessageRegion is the optional area to show messages in the page. * <p> * 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 } /** * 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); } /** * Create the contents for the receiver. * * @param parent * the Composite that the children will be created in */ public void createContents(final Composite parent) { messageComposite = new Composite(parent, SWT.NONE); final 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); final GridData imageData = new GridData(GridData.VERTICAL_ALIGN_CENTER); final 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)); final GridData textData = new GridData( GridData.GRAB_HORIZONTAL | GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_CENTER); messageText.setLayoutData(textData); hideRegion(); } /** * 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(final Color color) { messageText.setBackground(color); messageComposite.setBackground(color); messageImageLabel.setBackground(color); } /** * 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(final Object layoutData) { messageComposite.setLayoutData(layoutData); } /** * Show and enable the widgets in the message region */ private void showRegion() { messageComposite.setVisible(true); } /** * 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(final String newMessage, final 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())); } } }