001 /* PrintServiceLookup.java --
002 Copyright (C) 2004, 2006 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.print;
040
041 import gnu.classpath.ServiceFactory;
042 import gnu.javax.print.CupsPrintServiceLookup;
043
044 import java.util.ArrayList;
045 import java.util.Arrays;
046 import java.util.HashSet;
047 import java.util.Iterator;
048
049 import javax.print.attribute.AttributeSet;
050
051
052 /**
053 * <code>PrintServiceLookup</code> implementations provide a way to lookup
054 * print services based on different constraints.
055 * <p>
056 * Implementations are located and loaded automatically through the SPI JAR
057 * file specification. Therefore implementation classes must provide a default
058 * constructor for instantiation. Furthermore, applications are able to
059 * register further instances directly at runtime.
060 * </p><p>
061 * If an SecurityManager is installed implementors should call
062 * <code>checkPrintJobAccess()</code> to disable access for untrusted code.
063 * This check is to be made in every lookup service implementation for
064 * flexibility. Print services registered by applications through
065 * <code>registerService(PrintService)</code> are suppressed in the
066 * lookup results if a security manager is installed and disallows access.
067 * </p>
068 *
069 * @author Michael Koch (konqueror@gmx.de)
070 * @author Wolfgang Baer (WBaer@gmx.de)
071 */
072 public abstract class PrintServiceLookup
073 {
074
075 private static final CupsPrintServiceLookup systemProvider;
076 private static final HashSet printServices;
077 private static final HashSet printServiceLookups;
078
079 static
080 {
081 systemProvider = new CupsPrintServiceLookup();
082
083 printServices = new HashSet();
084 printServiceLookups = new HashSet();
085
086 // check for service providers
087 Iterator it = ServiceFactory.lookupProviders(PrintServiceLookup.class);
088
089 while (it.hasNext())
090 printServiceLookups.add(it.next());
091 }
092
093 /**
094 * Constructs a <code>PrintServiceLookup</code> object.
095 */
096 public PrintServiceLookup()
097 {
098 // nothing to do here
099 }
100
101 /**
102 * Explicitly registers the provided print service lookup implementation.
103 * <p>
104 * The registration will silently fail (returning <code>false</code>) if
105 * the lookup service is already registered or the registration somehow
106 * else fails.
107 * </p>
108 *
109 * @param sp the print service lookup implementation to register.
110 * @return <code>true</code> if registered, <code>false</code> otherwise.
111 */
112 public static boolean registerServiceProvider(PrintServiceLookup sp)
113 {
114 return printServiceLookups.add(sp);
115 }
116
117 /**
118 * Explicitly registers the provided print service instance.
119 * <p>
120 * The registration will silently fail (returning <code>false</code>) if
121 * the print service instance is already registered or the registration
122 * somehow else fails.
123 * </p>
124 * @param service the single print service to register.
125 * @return <code>true</code> if registered, <code>false</code> otherwise.
126 */
127 public static boolean registerService(PrintService service)
128 {
129 if (service instanceof StreamPrintService)
130 return false;
131
132 // security
133 try
134 {
135 SecurityManager sm = System.getSecurityManager();
136 if (sm != null)
137 sm.checkPrintJobAccess();
138
139 return printServices.add(service);
140 }
141 catch (SecurityException se)
142 {
143 return false;
144 }
145 }
146
147 /**
148 * Searches print services capable of printing in the given document flavor
149 * which supports the specified printing attributes.
150 *
151 * @param flavor the document flavor to support. If <code>null</code> this
152 * constraint is ignored during lookup.
153 * @param attributes the printing attributes to support. If
154 * <code>null</code> this constraint is ignored during lookup.
155 * @return The resulting available print services, or an array of length 0
156 * if none is found.
157 */
158 public static final PrintService[] lookupPrintServices(DocFlavor flavor,
159 AttributeSet attributes)
160 {
161 ArrayList result = new ArrayList();
162
163 PrintService[] services =
164 systemProvider.getPrintServices(flavor, attributes);
165 result.addAll(Arrays.asList(services));
166
167 for (Iterator it = printServiceLookups.iterator(); it.hasNext(); )
168 {
169 PrintServiceLookup lookup = (PrintServiceLookup) it.next();
170 services = lookup.getPrintServices(flavor, attributes);
171 result.addAll(Arrays.asList(services));
172 }
173
174 for (Iterator it = printServices.iterator(); it.hasNext(); )
175 {
176 PrintService service = (PrintService) it.next();
177 if (systemProvider.checkPrintService(flavor, attributes, service))
178 result.add(service);
179 }
180
181 return (PrintService[]) result.toArray(new PrintService[result.size()]);
182 }
183
184 /**
185 * Searches print services capable of multi document printing in all of the
186 * given document flavors and supporting the specified printing attributes.
187 *
188 * @param flavors the document flavors to support. If <code>null</code> this
189 * constraint is ignored during lookup.
190 * @param attributes the printing attributes to support. If
191 * <code>null</code> this constraint is ignored during lookup.
192 * @return The resulting available multi document print services, or an
193 * array of length 0 if none is found.
194 */
195 public static final MultiDocPrintService[] lookupMultiDocPrintServices(
196 DocFlavor[] flavors, AttributeSet attributes)
197 {
198 ArrayList result = new ArrayList();
199
200 MultiDocPrintService[] services =
201 systemProvider.getMultiDocPrintServices(flavors, attributes);
202 result.addAll(Arrays.asList(services));
203
204 for (Iterator it = printServiceLookups.iterator(); it.hasNext(); )
205 {
206 PrintServiceLookup lookup = (PrintServiceLookup) it.next();
207 services = lookup.getMultiDocPrintServices(flavors, attributes);
208 result.addAll(Arrays.asList(services));
209 }
210
211 for (Iterator it = printServices.iterator(); it.hasNext(); )
212 {
213 PrintService service = (PrintService) it.next();
214 if (systemProvider.checkMultiDocPrintService(flavors, attributes, service))
215 result.add(service);
216 }
217
218 return (MultiDocPrintService[]) result.toArray(
219 new MultiDocPrintService[result.size()]);
220 }
221
222
223 /**
224 * Searches the default print service in the current environment.
225 * <p>
226 * If multiple lookup services are registered and each has a default
227 * print service the result is not specified. Usually the default
228 * print service of the native platform lookup service is returned.
229 * </p><p>
230 * The GNU classpath implementation will return the CUPS default
231 * printing service as the default print service, if available.
232 * </p><p>
233 * The default print service may be overriden by users through
234 * the property <code>javax.print.defaultPrinter</code>. A service
235 * specified must be found to be returned as the default.
236 * </p>
237 *
238 * @return The default print service, or <code>null</code> if none found.
239 */
240 public static final PrintService lookupDefaultPrintService()
241 {
242 // TODO Find out what the property controls and use it
243 // String defaultPrinter = System.getProperty("javax.print.defaultPrinter");
244
245 // first test for platform specified default services
246 PrintService service = systemProvider.getDefaultPrintService();
247
248 if (service != null)
249 return service;
250
251 // none available by systemDefaultProvider
252 // search in other registered ones and take first
253 for (Iterator it = printServiceLookups.iterator(); it.hasNext(); )
254 {
255 service = ((PrintServiceLookup) it.next()).getDefaultPrintService();
256 if (service != null)
257 return service;
258 }
259
260 return null;
261 }
262
263 /**
264 * Not to be called directly by applications.
265 *
266 * @return The default lookup service of the implementing lookup service or
267 * <code>null</code> if there is no default one.
268 */
269 public abstract PrintService getDefaultPrintService();
270
271 /**
272 * Not to be called directly by applications.
273 *
274 * @param flavors the document flavors which have to be supported.
275 * @param attributes the attributes which have to be supported.
276 *
277 * @return The multidoc print services of the implementing lookup service
278 * for the given parameters, or an array of length 0 if none is available.
279 */
280 public abstract MultiDocPrintService[]
281 getMultiDocPrintServices(DocFlavor[] flavors, AttributeSet attributes);
282
283 /**
284 * Not to be called directly by applications.
285 *
286 * @return All known print services of the implementing lookup service
287 * regardless of supported features, or an array of length 0 if none is
288 * available.
289 */
290 public abstract PrintService[] getPrintServices();
291
292 /**
293 * Not to be called directly by applications.
294 *
295 * @param flavor the document flavor which has to be supported.
296 * @param attributes the attributes which have to be supported.
297 *
298 * @return The print services of the implementing lookup service
299 * for the given parameters, or an array of length 0 if none is available.
300 */
301 public abstract PrintService[]
302 getPrintServices(DocFlavor flavor, AttributeSet attributes);
303 }