Java tutorial
/* ********************************************************************** ** ** Copyright notice ** ** ** ** (c) 2005-2009 RSSOwl Development Team ** ** http://www.rssowl.org/ ** ** ** ** 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.rssowl.org/legal/epl-v10.html ** ** ** ** A copy is found in the file epl-v10.html and important notices to the ** ** license from the team is found in the textfile LICENSE.txt distributed ** ** in this package. ** ** ** ** This copyright notice MUST APPEAR in all copies of the file! ** ** ** ** Contributors: ** ** RSSOwl Development Team - initial API and implementation ** ** ** ** ********************************************************************** */ package org.rssowl.ui.internal.dialogs; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.dialogs.IDialogSettings; import org.eclipse.jface.viewers.StructuredSelection; import org.eclipse.osgi.util.NLS; import org.eclipse.swt.SWT; import org.eclipse.swt.events.KeyAdapter; import org.eclipse.swt.events.KeyEvent; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Link; import org.eclipse.swt.widgets.Shell; import org.rssowl.core.Owl; import org.rssowl.core.connection.ConnectionException; import org.rssowl.core.connection.IProtocolHandler; import org.rssowl.core.interpreter.InterpreterException; import org.rssowl.core.interpreter.ParserException; import org.rssowl.core.persist.IBookMark; import org.rssowl.core.persist.IFeed; import org.rssowl.core.persist.INews; import org.rssowl.core.persist.reference.FeedLinkReference; import org.rssowl.core.util.CoreUtils; import org.rssowl.core.util.DateUtils; import org.rssowl.core.util.StringUtils; import org.rssowl.core.util.URIUtils; import org.rssowl.ui.internal.Activator; import org.rssowl.ui.internal.OwlUI; import org.rssowl.ui.internal.actions.OpenInBrowserAction; import org.rssowl.ui.internal.editors.feed.NewsBrowserLabelProvider; import org.rssowl.ui.internal.util.CBrowser; import org.rssowl.ui.internal.util.JobRunner; import org.rssowl.ui.internal.util.LayoutUtils; import org.rssowl.ui.internal.util.UIBackgroundJob; import java.io.InputStream; import java.util.Collections; import java.util.Comparator; import java.util.Date; import java.util.List; /** * The {@link PreviewFeedDialog} can be used to preview a {@link IBookMark}s * contents without adding it to the list of subscriptions. * * @author bpasero */ public class PreviewFeedDialog extends Dialog { private static final int DIALOG_WIDTH_DLUS = 600; private static final int DIALOG_HEIGHT_DLUS = 400; private static final String DIALOG_SETTINGS_KEY = "org.rssowl.ui.internal.dialogs.PreviewFeedDialog"; //$NON-NLS-1$ private static final int MAX_NEWS_SHOWN = 50; private IBookMark fBookmark; private FeedLinkReference fFeedReference; private IFeed fLoadedFeed; private CBrowser fBrowser; private boolean fFirstTimeOpen; private NewsBrowserLabelProvider fLabelProvider; private String fNewsFontFamily; private String fNormalFontCSS; private Link fStatusLabel; /** * @param parentShell * @param bookmark */ public PreviewFeedDialog(Shell parentShell, IBookMark bookmark) { this(parentShell, bookmark, null, null); } /** * @param parentShell * @param bookmark * @param feedReference */ public PreviewFeedDialog(Shell parentShell, IBookMark bookmark, FeedLinkReference feedReference) { this(parentShell, bookmark, null, feedReference); } /** * @param parentShell * @param bookmark * @param feed */ public PreviewFeedDialog(Shell parentShell, IBookMark bookmark, IFeed feed) { this(parentShell, bookmark, feed, null); } PreviewFeedDialog(Shell parentShell, IBookMark bookmark, IFeed feed, FeedLinkReference feedReference) { super(parentShell); fBookmark = bookmark; fLoadedFeed = feed; fFeedReference = feedReference; fFirstTimeOpen = (Activator.getDefault().getDialogSettings().getSection(DIALOG_SETTINGS_KEY) == null); createFonts(); } /* Init the Theme Font (from UI Thread) */ private void createFonts() { int fontHeight = 10; Font newsFont = OwlUI.getThemeFont(OwlUI.NEWS_TEXT_FONT_ID, SWT.NORMAL); FontData[] fontData = newsFont.getFontData(); if (fontData.length > 0) { fNewsFontFamily = fontData[0].getName(); fontHeight = fontData[0].getHeight(); } int normal = fontHeight; String fontUnit = "pt"; //$NON-NLS-1$ fNormalFontCSS = "font-size: " + normal + fontUnit + ";"; //$NON-NLS-1$ //$NON-NLS-2$ } /* * @see org.eclipse.jface.dialogs.TitleAreaDialog#createDialogArea(org.eclipse.swt.widgets.Composite) */ @Override protected Control createDialogArea(Composite parent) { /* Composite to hold all components */ Composite composite = new Composite(parent, SWT.NONE); composite.setLayout(LayoutUtils.createGridLayout(1, 0, 0)); composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true)); /* Browser to preview News */ fBrowser = new CBrowser(composite, SWT.NONE); fBrowser.getControl().setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true)); fBrowser.setScriptDisabled(true); fBrowser.getControl().addKeyListener(new KeyAdapter() { @Override public void keyPressed(KeyEvent e) { if (e.character == SWT.ESC) close(); } }); /* Label Provider to produce HTML per News */ fLabelProvider = new NewsBrowserLabelProvider(fBrowser); /* Load and Display the Feed */ loadFeed(); /* Separator */ new Label(parent, SWT.SEPARATOR | SWT.HORIZONTAL) .setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false)); applyDialogFont(composite); return composite; } private void loadFeed() { /* Show Info that Feed is loading */ if (fLoadedFeed == null || fLoadedFeed.getVisibleNews().isEmpty()) { if (StringUtils.isSet(fBookmark.getName())) showMessage(NLS.bind(Messages.PreviewFeedDialog_LOAD_FEED_N, fBookmark.getName()), false, true); else showMessage(Messages.PreviewFeedDialog_LOAD_FEED, false, true); } /* Load Feed in Background */ JobRunner.runUIUpdater(new UIBackgroundJob(fBrowser.getControl()) { private IFeed feed; private Exception error; @Override protected void runInBackground(IProgressMonitor monitor) { /* First Check if a Feed was already provided */ if (fLoadedFeed != null && !fLoadedFeed.getVisibleNews().isEmpty()) { feed = fLoadedFeed; return; } /* Otherwise Load Feed */ try { /* Resolve Feed if existing */ if (fFeedReference != null) feed = fFeedReference.resolve(); /* Create Temporary Feed */ if (feed == null || feed.getVisibleNews().isEmpty()) { feed = Owl.getModelFactory().createFeed(null, fBookmark.getFeedLinkReference().getLink()); /* Return if dialog closed */ if (monitor.isCanceled() || getShell().isDisposed() || fBrowser.getControl().isDisposed()) return; /* Retrieve Stream */ IProtocolHandler handler = Owl.getConnectionService().getHandler(feed.getLink()); InputStream inS = handler.openStream(feed.getLink(), monitor, null); /* Return if dialog closed */ if (monitor.isCanceled() || getShell().isDisposed() || fBrowser.getControl().isDisposed()) return; /* Interpret Feed */ Owl.getInterpreter().interpret(inS, feed, null); } } catch (ConnectionException e) { error = e; Activator.safeLogError(e.getMessage(), e); } catch (ParserException e) { error = e; Activator.safeLogError(e.getMessage(), e); } catch (InterpreterException e) { error = e; Activator.safeLogError(e.getMessage(), e); } } @Override protected void runInUI(IProgressMonitor monitor) { if (feed != null && error == null) showFeed(feed); else if (error != null) { String errorMessage = CoreUtils.toMessage(error); if (StringUtils.isSet(errorMessage)) showMessage(NLS.bind(Messages.PreviewFeedDialog_UNABLE_LOAD_FEED, errorMessage), true, false); } } }); } private void showMessage(String msg, boolean isError, boolean showProgress) { if (fBrowser.getControl().isDisposed()) return; StringBuilder html = new StringBuilder(); html.append("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">\n"); //$NON-NLS-1$ html.append("<html>\n"); //$NON-NLS-1$ html.append("<body style=\"overflow: auto; font-family: ").append(fNewsFontFamily) //$NON-NLS-1$ .append(",Verdanna,sans-serif; ").append(fNormalFontCSS).append("\">"); //$NON-NLS-1$ //$NON-NLS-2$ if (showProgress) html.append("<img src=\"" + OwlUI.getImageUri("/icons/obj16/progress.gif", "progress.gif") + "\" />"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ if (isError) html.append("<span style=\"color: darkred;\">"); //$NON-NLS-1$ else if (showProgress) html.append("<span style=\"padding-left:3px; vertical-align:top;\">"); //$NON-NLS-1$ html.append(msg); if (isError || showProgress) html.append("</span>"); //$NON-NLS-1$ html.append("</body>\n"); //$NON-NLS-1$ html.append("</html>\n"); //$NON-NLS-1$ fBrowser.getControl().setText(html.toString()); } private void showFeed(final IFeed feed) { if (feed != null && !fBrowser.getControl().isDisposed()) { List<INews> news = feed.getNewsByStates(INews.State.getVisible()); Collections.sort(news, new Comparator<INews>() { public int compare(INews news1, INews news2) { Date date1 = DateUtils.getRecentDate(news1); Date date2 = DateUtils.getRecentDate(news2); return date2.compareTo(date1); } }); int newsCount = news.size(); if (news.size() > MAX_NEWS_SHOWN) news = news.subList(0, MAX_NEWS_SHOWN); /* Render Elements */ String html = fLabelProvider.render(news.toArray(), (feed.getBase() != null) ? URIUtils.toHTTP(feed.getBase()) : URIUtils.toHTTP(feed.getLink()), true); /* Apply to Browser */ fBrowser.getControl().setText(html); /* Also Update Status */ if (StringUtils.isSet(fBookmark.getName())) { StringBuilder str = new StringBuilder(); if (feed.getHomepage() != null) { str.append(NLS.bind(Messages.PreviewFeedDialog_FOUND_N_NEWS_HOMEPAGE, newsCount, fBookmark.getName())); fStatusLabel.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { new OpenInBrowserAction(new StructuredSelection(feed.getHomepage())).run(); } }); } else str.append(NLS.bind(Messages.PreviewFeedDialog_FOUND_N_NEWS, newsCount, fBookmark.getName())); fStatusLabel.setText(str.toString()); } } } /* * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell) */ @Override protected void configureShell(Shell shell) { super.configureShell(shell); if (StringUtils.isSet(fBookmark.getName())) shell.setText(NLS.bind(Messages.PreviewFeedDialog_PREVIEW_OF, fBookmark.getName())); else shell.setText(Messages.PreviewFeedDialog_PREVIEW); } /* * @see org.eclipse.jface.window.Window#getShellStyle() */ @Override protected int getShellStyle() { int style = SWT.TITLE | SWT.BORDER | SWT.RESIZE | SWT.MIN | SWT.MAX | SWT.CLOSE | getDefaultOrientation(); return style; } /* * @see org.eclipse.jface.dialogs.TrayDialog#createButtonBar(org.eclipse.swt.widgets.Composite) */ @Override protected Control createButtonBar(Composite parent) { GridLayout layout = new GridLayout(1, false); layout.marginWidth = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN); layout.marginHeight = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN); layout.horizontalSpacing = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); layout.verticalSpacing = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING); Composite buttonBar = new Composite(parent, SWT.NONE); buttonBar.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false)); buttonBar.setLayout(layout); /* Status Label */ fStatusLabel = new Link(buttonBar, SWT.NONE); applyDialogFont(fStatusLabel); fStatusLabel.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, true)); if (StringUtils.isSet(fBookmark.getName())) fStatusLabel.setText(fBookmark.getName()); /* Close */ Button closeButton = createButton(buttonBar, IDialogConstants.CLOSE_ID, IDialogConstants.CLOSE_LABEL, false); closeButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { close(); } }); return buttonBar; } /* * @see org.eclipse.jface.dialogs.Dialog#getDialogBoundsSettings() */ @Override protected IDialogSettings getDialogBoundsSettings() { IDialogSettings settings = Activator.getDefault().getDialogSettings(); IDialogSettings section = settings.getSection(DIALOG_SETTINGS_KEY); if (section != null) return section; return settings.addNewSection(DIALOG_SETTINGS_KEY); } /* * @see org.eclipse.jface.dialogs.Dialog#getDialogBoundsStrategy() */ @Override protected int getDialogBoundsStrategy() { return Dialog.DIALOG_PERSISTLOCATION | Dialog.DIALOG_PERSISTSIZE; } /* * @see org.eclipse.jface.dialogs.Dialog#initializeBounds() */ @Override protected void initializeBounds() { super.initializeBounds(); Shell shell = getShell(); /* Minimum Size */ int minWidth = convertHorizontalDLUsToPixels(DIALOG_WIDTH_DLUS); int minHeight = convertHorizontalDLUsToPixels(DIALOG_HEIGHT_DLUS); /* Required Size */ Point requiredSize = shell.computeSize(SWT.DEFAULT, SWT.DEFAULT); /* Set Size */ shell.setSize(Math.max(minWidth, requiredSize.x), Math.max(minHeight, requiredSize.y)); /* Set Location */ if (fFirstTimeOpen) LayoutUtils.positionShell(shell); } }