Java tutorial
/* ****************************************************************************** * Copyright (c) 2006-2012 XMind Ltd. and others. * * This file is a part of XMind 3. XMind releases 3 and * above are dual-licensed under the Eclipse Public License (EPL), * which is available at http://www.eclipse.org/legal/epl-v10.html * and the GNU Lesser General Public License (LGPL), * which is available at http://www.gnu.org/licenses/lgpl.html * See http://www.xmind.net/license.html for details. * * Contributors: * XMind Ltd. - initial API and implementation *******************************************************************************/ package org.xmind.ui.dialogs; import java.util.ArrayList; import java.util.List; import org.eclipse.core.runtime.ListenerList; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.StyleRange; import org.eclipse.swt.events.MouseEvent; import org.eclipse.swt.events.MouseListener; import org.eclipse.swt.events.MouseTrackListener; import org.eclipse.swt.events.PaintEvent; import org.eclipse.swt.events.PaintListener; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.graphics.TextLayout; import org.eclipse.swt.graphics.TextStyle; import org.eclipse.swt.widgets.Canvas; import org.eclipse.swt.widgets.Composite; import org.eclipse.ui.forms.events.HyperlinkEvent; import org.eclipse.ui.forms.events.IHyperlinkListener; import org.xmind.ui.resources.FontUtils; import org.xmind.ui.util.EncodingUtils; public class StyledLink extends Canvas { private static final int LINE_SPACING = 1; private static final int PARAGRAPH_SPACING = 7; private static class StyledParagraph { TextLayout text; int top; } private String text = ""; //$NON-NLS-1$ private boolean styled; private StyledParagraph[] paragraphs = null; private int cachedWidth = -621735; private Point cachedSize = null; private boolean hovered = false; private Font boldFont = null; private Font italicFont = null; private Font boldItalicFont = null; private ListenerList listeners = new ListenerList(); public StyledLink(Composite parent, int style) { super(parent, style | SWT.DOUBLE_BUFFERED); this.styled = (style & SWT.SIMPLE) == 0; super.setFont(FontUtils.getFont(JFaceResources.DEFAULT_FONT)); super.setCursor(parent.getDisplay().getSystemCursor(SWT.CURSOR_HAND)); addPaintListener(new PaintListener() { public void paintControl(PaintEvent e) { drawParagraphs(e.gc); } }); addMouseListener(new MouseListener() { boolean pressed = false; public void mouseUp(MouseEvent e) { Rectangle r = getBounds(); if (pressed && e.x >= 0 && e.x < r.width && e.y >= 0 && e.y < r.height) { fireLinkActivated(createLinkEvent(e)); } pressed = false; } public void mouseDown(MouseEvent e) { pressed = true; } public void mouseDoubleClick(MouseEvent e) { pressed = false; } }); addMouseTrackListener(new MouseTrackListener() { public void mouseHover(MouseEvent e) { setHovered(true); } public void mouseExit(MouseEvent e) { setHovered(false); } public void mouseEnter(MouseEvent e) { setHovered(true); } }); } private void fireLinkActivated(HyperlinkEvent event) { for (Object listener : listeners.getListeners()) { ((IHyperlinkListener) listener).linkActivated(event); } } private HyperlinkEvent createLinkEvent(MouseEvent e) { HyperlinkEvent event = new HyperlinkEvent(this, null, getText(), e.stateMask); event.display = e.display; event.time = e.time; return event; } public void addHyperlinkListener(IHyperlinkListener listener) { listeners.add(listener); } public void removeHyperlinkListener(IHyperlinkListener listener) { listeners.remove(listener); } @Override public void setFont(Font font) { checkWidget(); releaseLines(); super.setFont(font); } @Override public void setBackground(Color color) { checkWidget(); releaseLines(); super.setBackground(color); } @Override public void setForeground(Color color) { checkWidget(); releaseLines(); super.setForeground(color); } @Override public void setEnabled(boolean enabled) { checkWidget(); releaseLines(); super.setEnabled(enabled); } private void releaseLines() { StyledParagraph[] ls = paragraphs; paragraphs = null; if (ls != null) { for (int i = 0; i < ls.length; i++) { ls[i].text.dispose(); } } } private void ensureParagraphs(int wHint) { if (paragraphs != null) return; if (styled) { paragraphs = parseStyledText(text, wHint); } else { paragraphs = parseSimpleText(text, wHint); } cachedSize = new Point(0, 0); if (paragraphs.length == 0) { if (wHint >= 0) cachedSize.x = wHint; } else { for (StyledParagraph p : paragraphs) { Rectangle pBounds = p.text.getBounds(); cachedSize.x = Math.max(cachedSize.x, pBounds.width); cachedSize.y = p.top + pBounds.height; } } } private StyledParagraph[] parseStyledText(String text, int wHint) { List<StyledParagraph> paragraphs = new ArrayList<StyledParagraph>(text.length() / 2); int contentStart = text.indexOf("<form>"); //$NON-NLS-1$ if (contentStart >= 0) { contentStart += 6; int contentEnd = text.indexOf("</form>", contentStart); //$NON-NLS-1$ if (contentEnd < 0) contentEnd = text.length(); String content = text.substring(contentStart, contentEnd); int pStart = 0, pEnd = 0; int top = 0; String pText; StringBuilder pBuffer; List<StyleRange> styles; boolean bold = false, italic = false; while (pStart < content.length()) { if ("<p>".equals(content.substring(pStart, pStart + 3))) { //$NON-NLS-1$ pStart += 3; } pEnd = content.indexOf("</p>", pStart); //$NON-NLS-1$ if (pEnd >= 0) { pText = content.substring(pStart, pEnd); pEnd += 4; } else { pEnd = content.indexOf("<p>", pStart); //$NON-NLS-1$ if (pEnd >= 0) { pText = content.substring(pStart, pEnd); pEnd += 3; } else { pEnd = content.length(); pText = content.substring(pStart, pEnd); } } pStart = pEnd; pBuffer = new StringBuilder(pText.length()); styles = new ArrayList<StyleRange>(pText.length()); int start = 0; int end = 0; while (start < pText.length()) { if ("<b>".equals(pText.substring(start, start + 3))) { //$NON-NLS-1$ bold = true; start += 3; } else if ("<i>".equals(pText.substring(start, start + 3))) { //$NON-NLS-1$ italic = true; start += 3; } else if ("</b>".equals(pText.substring(start, start + 4))) { //$NON-NLS-1$ bold = false; start += 4; } else if ("</i>".equals(pText.substring(start, start + 4))) { //$NON-NLS-1$ italic = false; start += 4; } else if (pText.charAt(start) == '<') { end = pText.indexOf('>', start + 1); if (end < 0) { end = pText.length(); } else { end += 1; } start = end; } else { end = pText.indexOf('<', start); if (end < 0) end = pText.length(); int styleStart = pBuffer.length(); pBuffer.append(unescape(pText.substring(start, end))); int styleEnd = pBuffer.length(); styles.add(newStyleRange(bold, italic, styleStart, styleEnd)); start = end; } } if (pBuffer.length() == 0) { top += PARAGRAPH_SPACING; } else { StyledParagraph paragraph = new StyledParagraph(); paragraph.text = new TextLayout(getDisplay()); paragraph.text.setFont(getFont()); paragraph.text.setAlignment(SWT.LEFT); paragraph.text.setSpacing(LINE_SPACING); paragraph.text.setText(pBuffer.toString()); for (StyleRange style : styles) { paragraph.text.setStyle(style, style.start, style.start + style.length); } paragraph.text.setWidth(wHint); paragraph.top = top; paragraphs.add(paragraph); top += paragraph.text.getBounds().height + PARAGRAPH_SPACING; } } } return paragraphs.toArray(new StyledParagraph[paragraphs.size()]); } private StyledParagraph[] parseSimpleText(String text, int wHint) { List<StyledParagraph> paragraphs = new ArrayList<StyledLink.StyledParagraph>(text.length() / 2); int start = 0; int end = 0; int top = 0; StyledParagraph paragraph; while (start < text.length()) { if (text.charAt(start) == '\r') { if (start + 1 < text.length() && text.charAt(start + 1) == '\n') { start += 2; } else { start += 1; } top += PARAGRAPH_SPACING; } else if (text.charAt(start) == '\n') { start += 1; top += PARAGRAPH_SPACING; } else { end = Math.min(text.indexOf('\n', start), text.indexOf('\r', start)); if (end < 0) end = text.length(); if (end > start) { paragraph = new StyledParagraph(); paragraph.text = new TextLayout(getDisplay()); paragraph.text.setFont(getFont()); paragraph.text.setAlignment(SWT.LEFT); paragraph.text.setSpacing(LINE_SPACING); paragraph.text.setText(text.substring(start, end)); paragraph.text.setStyle(newStyle(false, false), 0, end - start); paragraph.text.setWidth(wHint); paragraph.top = top; paragraphs.add(paragraph); top += paragraph.text.getBounds().height; } start = end; } } return paragraphs.toArray(new StyledParagraph[paragraphs.size()]); } private String unescape(String text) { return EncodingUtils.unescape(text); } private StyleRange newStyleRange(boolean bold, boolean italic, int start, int end) { StyleRange style = new StyleRange(); applyStyle(style, bold, italic); style.start = start; style.length = end - start; return style; } private TextStyle newStyle(boolean bold, boolean italic) { TextStyle style = new TextStyle(); applyStyle(style, bold, italic); return style; } private void applyStyle(TextStyle style, boolean bold, boolean italic) { style.background = getBackground(); style.foreground = getForeground(); style.underline = isEnabled() && hovered; style.underlineColor = getForeground(); style.underlineStyle = SWT.UNDERLINE_LINK; style.strikeout = false; style.strikeoutColor = null; if (bold && italic) { style.font = getBoldItalicFont(); } else if (bold) { style.font = getBoldFont(); } else if (italic) { style.font = getItalicFont(); } else { style.font = getFont(); } } private Font getBoldFont() { if (boldFont == null) { boldFont = new Font(getDisplay(), FontUtils.bold(getFont().getFontData(), true)); } return boldFont; } private Font getItalicFont() { if (italicFont == null) { italicFont = new Font(getDisplay(), FontUtils.italic(getFont().getFontData(), true)); } return italicFont; } private Font getBoldItalicFont() { if (boldItalicFont == null) { boldItalicFont = new Font(getDisplay(), FontUtils.bold(FontUtils.italic(getFont().getFontData(), true), true)); } return boldItalicFont; } private void drawParagraphs(GC gc) { ensureParagraphs(cachedWidth); gc.setAntialias(SWT.ON); gc.setTextAntialias(SWT.ON); for (StyledParagraph p : paragraphs) { p.text.draw(gc, 0, p.top); } } private void setHovered(boolean hovered) { hovered = hovered && isEnabled(); if (hovered == this.hovered) return; this.hovered = hovered; releaseLines(); redraw(); } @Override public Point computeSize(int wHint, int hHint, boolean changed) { checkWidget(); if (changed || cachedWidth != wHint || paragraphs == null || cachedSize == null) { releaseLines(); ensureParagraphs(wHint); cachedWidth = wHint; } return new Point(cachedSize.x, cachedSize.y); } @Override public void dispose() { releaseLines(); if (boldFont != null) { boldFont.dispose(); boldFont = null; } if (italicFont != null) { italicFont.dispose(); italicFont = null; } if (boldItalicFont != null) { boldItalicFont.dispose(); boldItalicFont = null; } super.dispose(); } public void setText(String text) { checkWidget(); if (text == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); if (text.equals(this.text)) return; this.text = text; releaseLines(); redraw(); } public String getText() { return text; } }