Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2015 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.forms; import java.util.ArrayList; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.ui.forms.events.HyperlinkEvent; import org.eclipse.ui.forms.events.IHyperlinkListener; import org.eclipse.ui.forms.widgets.Hyperlink; /** * Manages a group of hyperlinks. It tracks activation, updates normal and * active colors and updates underline state depending on the underline * preference. Hyperlink labels are added to the group after creation and are * automatically removed from the group when they are disposed. * * @since 3.0 */ public final class HyperlinkGroup extends HyperlinkSettings { private ArrayList<Hyperlink> links = new ArrayList<>(); private Hyperlink lastActivated; private Hyperlink lastEntered; private GroupListener listener; private boolean isActiveBackgroundSet; private boolean isActiveForegroundSet; private boolean isBackgroundSet; private boolean isForegroundSet; private class GroupListener implements Listener, IHyperlinkListener { private Color previousBackground; private Color previousForeground; @Override public void handleEvent(Event e) { switch (e.type) { case SWT.MouseEnter: onMouseEnter(e); break; case SWT.MouseExit: onMouseExit(e); break; case SWT.MouseDown: onMouseDown(e); break; case SWT.Dispose: unhook((Hyperlink) e.widget); break; } } private void onMouseEnter(Event e) { Hyperlink link = (Hyperlink) e.widget; previousBackground = link.getBackground(); previousForeground = link.getForeground(); if (isActiveBackgroundSet) link.setBackground(getActiveBackground()); if (isActiveForegroundSet) link.setForeground(getActiveForeground()); if (getHyperlinkUnderlineMode() == UNDERLINE_HOVER) link.setUnderlined(true); link.setCursor(getHyperlinkCursor()); } private void onMouseExit(Event e) { Hyperlink link = (Hyperlink) e.widget; if (isActiveBackgroundSet) link.setBackground(previousBackground); if (isActiveForegroundSet) link.setForeground(previousForeground); if (getHyperlinkUnderlineMode() == UNDERLINE_HOVER) link.setUnderlined(false); } @Override public void linkActivated(HyperlinkEvent e) { } @Override public void linkEntered(HyperlinkEvent e) { Hyperlink link = (Hyperlink) e.widget; if (lastEntered != null) { linkExited(lastEntered); } lastEntered = link; } @Override public void linkExited(HyperlinkEvent e) { linkExited((Hyperlink) e.widget); } private void linkExited(Hyperlink link) { link.setCursor(null); if (lastEntered == link) lastEntered = null; } } /** * Creates a hyperlink group. */ public HyperlinkGroup(Display display) { super(display); listener = new GroupListener(); } /** * Returns the link that has been active the last, or <code>null</code> * if no link has been active yet or the last active link has been * disposed. * * @return the last active link or <code>null</code> */ public Hyperlink getLastActivated() { return lastActivated; } /** * Adds a hyperlink to the group to be jointly managed. Hyperlink will be * managed until it is disposed. Settings like colors, cursors and modes * will affect all managed hyperlinks. * * @param link */ public void add(Hyperlink link) { if (isBackgroundSet) link.setBackground(getBackground()); if (isForegroundSet) link.setForeground(getForeground()); if (getHyperlinkUnderlineMode() == UNDERLINE_ALWAYS) link.setUnderlined(true); hook(link); } /** * Sets the new active hyperlink background for all the links. * * @param newActiveBackground * the new active background */ @Override public void setActiveBackground(Color newActiveBackground) { super.setActiveBackground(newActiveBackground); isActiveBackgroundSet = true; } /** * Sets the new active hyperlink foreground for all the links. * * @param newActiveForeground * the new active foreground */ @Override public void setActiveForeground(Color newActiveForeground) { super.setActiveForeground(newActiveForeground); isActiveForegroundSet = true; } /** * Sets the group background and also sets the background of all the * currently managed links. * * @param bg * the new background */ @Override public void setBackground(Color bg) { super.setBackground(bg); isBackgroundSet = true; if (links != null) { for (int i = 0; i < links.size(); i++) { Hyperlink label = links.get(i); label.setBackground(bg); } } } /** * Sets the group foreground and also sets the background of all the * currently managed links. * * @param fg * the new foreground */ @Override public void setForeground(Color fg) { super.setForeground(fg); isForegroundSet = true; if (links != null) { for (int i = 0; i < links.size(); i++) { Hyperlink label = links.get(i); label.setForeground(fg); } } } /** * Sets the hyperlink underline mode. * * @param mode * the new hyperlink underline mode * @see HyperlinkSettings */ @Override public void setHyperlinkUnderlineMode(int mode) { super.setHyperlinkUnderlineMode(mode); if (links != null) { for (int i = 0; i < links.size(); i++) { Hyperlink label = links.get(i); label.setUnderlined(mode == UNDERLINE_ALWAYS); } } } private void hook(Hyperlink link) { link.addListener(SWT.MouseDown, listener); link.addHyperlinkListener(listener); link.addListener(SWT.Dispose, listener); link.addListener(SWT.MouseEnter, listener); link.addListener(SWT.MouseExit, listener); links.add(link); } private void unhook(Hyperlink link) { link.removeListener(SWT.MouseDown, listener); link.removeHyperlinkListener(listener); link.removeListener(SWT.MouseEnter, listener); link.removeListener(SWT.MouseExit, listener); if (lastActivated == link) lastActivated = null; if (lastEntered == link) lastEntered = null; links.remove(link); } private void onMouseDown(Event e) { if (e.button == 1) return; lastActivated = (Hyperlink) e.widget; } }