001: /*
002: * Copyright 1995-2006 Sun Microsystems, Inc. All Rights Reserved.
003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004: *
005: * This code is free software; you can redistribute it and/or modify it
006: * under the terms of the GNU General Public License version 2 only, as
007: * published by the Free Software Foundation. Sun designates this
008: * particular file as subject to the "Classpath" exception as provided
009: * by Sun in the LICENSE file that accompanied this code.
010: *
011: * This code is distributed in the hope that it will be useful, but WITHOUT
012: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014: * version 2 for more details (a copy is included in the LICENSE file that
015: * accompanied this code).
016: *
017: * You should have received a copy of the GNU General Public License version
018: * 2 along with this work; if not, write to the Free Software Foundation,
019: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020: *
021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022: * CA 95054 USA or visit www.sun.com if you need additional information or
023: * have any questions.
024: */
025: package java.awt;
026:
027: import java.awt.peer.FileDialogPeer;
028: import java.io.FilenameFilter;
029: import java.io.IOException;
030: import java.io.ObjectInputStream;
031:
032: /**
033: * The <code>FileDialog</code> class displays a dialog window
034: * from which the user can select a file.
035: * <p>
036: * Since it is a modal dialog, when the application calls
037: * its <code>show</code> method to display the dialog,
038: * it blocks the rest of the application until the user has
039: * chosen a file.
040: *
041: * @see Window#show
042: *
043: * @version 1.62, 05/05/07
044: * @author Sami Shaio
045: * @author Arthur van Hoff
046: * @since JDK1.0
047: */
048: public class FileDialog extends Dialog {
049:
050: /**
051: * This constant value indicates that the purpose of the file
052: * dialog window is to locate a file from which to read.
053: */
054: public static final int LOAD = 0;
055:
056: /**
057: * This constant value indicates that the purpose of the file
058: * dialog window is to locate a file to which to write.
059: */
060: public static final int SAVE = 1;
061:
062: /*
063: * There are two <code>FileDialog</code> modes: <code>LOAD</code> and
064: * <code>SAVE</code>.
065: * This integer will represent one or the other.
066: * If the mode is not specified it will default to <code>LOAD</code>.
067: *
068: * @serial
069: * @see getMode()
070: * @see setMode()
071: * @see java.awt.FileDialog#LOAD
072: * @see java.awt.FileDialog#SAVE
073: */
074: int mode;
075:
076: /*
077: * The string specifying the directory to display
078: * in the file dialog. This variable may be <code>null</code>.
079: *
080: * @serial
081: * @see getDirectory()
082: * @see setDirectory()
083: */
084: String dir;
085:
086: /*
087: * The string specifying the initial value of the
088: * filename text field in the file dialog.
089: * This variable may be <code>null</code>.
090: *
091: * @serial
092: * @see getFile()
093: * @see setFile()
094: */
095: String file;
096:
097: /*
098: * The filter used as the file dialog's filename filter.
099: * The file dialog will only be displaying files whose
100: * names are accepted by this filter.
101: * This variable may be <code>null</code>.
102: *
103: * @serial
104: * @see #getFilenameFilter()
105: * @see #setFilenameFilter()
106: * @see FileNameFilter
107: */
108: FilenameFilter filter;
109:
110: private static final String base = "filedlg";
111: private static int nameCounter = 0;
112:
113: /*
114: * JDK 1.1 serialVersionUID
115: */
116: private static final long serialVersionUID = 5035145889651310422L;
117:
118: static {
119: /* ensure that the necessary native libraries are loaded */
120: Toolkit.loadLibraries();
121: if (!GraphicsEnvironment.isHeadless()) {
122: initIDs();
123: }
124: }
125:
126: /**
127: * Initialize JNI field and method IDs for fields that may be
128: accessed from C.
129: */
130: private static native void initIDs();
131:
132: /**
133: * Creates a file dialog for loading a file. The title of the
134: * file dialog is initially empty. This is a convenience method for
135: * <code>FileDialog(parent, "", LOAD)</code>.
136: *
137: * @param parent the owner of the dialog
138: * @since JDK1.1
139: */
140: public FileDialog(Frame parent) {
141: this (parent, "", LOAD);
142: }
143:
144: /**
145: * Creates a file dialog window with the specified title for loading
146: * a file. The files shown are those in the current directory.
147: * This is a convenience method for
148: * <code>FileDialog(parent, title, LOAD)</code>.
149: *
150: * @param parent the owner of the dialog
151: * @param title the title of the dialog
152: */
153: public FileDialog(Frame parent, String title) {
154: this (parent, title, LOAD);
155: }
156:
157: /**
158: * Creates a file dialog window with the specified title for loading
159: * or saving a file.
160: * <p>
161: * If the value of <code>mode</code> is <code>LOAD</code>, then the
162: * file dialog is finding a file to read, and the files shown are those
163: * in the current directory. If the value of
164: * <code>mode</code> is <code>SAVE</code>, the file dialog is finding
165: * a place to write a file.
166: *
167: * @param parent the owner of the dialog
168: * @param title the title of the dialog
169: * @param mode the mode of the dialog; either
170: * <code>FileDialog.LOAD</code> or <code>FileDialog.SAVE</code>
171: * @exception IllegalArgumentException if an illegal file
172: * dialog mode is supplied
173: * @see java.awt.FileDialog#LOAD
174: * @see java.awt.FileDialog#SAVE
175: */
176: public FileDialog(Frame parent, String title, int mode) {
177: super (parent, title, true);
178: this .setMode(mode);
179: setLayout(null);
180: }
181:
182: /**
183: * Creates a file dialog for loading a file. The title of the
184: * file dialog is initially empty. This is a convenience method for
185: * <code>FileDialog(parent, "", LOAD)</code>.
186: *
187: * @param parent the owner of the dialog
188: * @exception java.lang.IllegalArgumentException if the <code>parent</code>'s
189: * <code>GraphicsConfiguration</code>
190: * is not from a screen device;
191: * @exception java.lang.IllegalArgumentException if <code>parent</code>
192: * is <code>null</code>; this exception is always thrown when
193: * <code>GraphicsEnvironment.isHeadless</code>
194: * returns <code>true</code>
195: * @see java.awt.GraphicsEnvironment#isHeadless
196: * @since 1.5
197: */
198: public FileDialog(Dialog parent) {
199: this (parent, "", LOAD);
200: }
201:
202: /**
203: * Creates a file dialog window with the specified title for loading
204: * a file. The files shown are those in the current directory.
205: * This is a convenience method for
206: * <code>FileDialog(parent, title, LOAD)</code>.
207: *
208: * @param parent the owner of the dialog
209: * @param title the title of the dialog; a <code>null</code> value
210: * will be accepted without causing a
211: * <code>NullPointerException</code> to be thrown
212: * @exception java.lang.IllegalArgumentException if the <code>parent</code>'s
213: * <code>GraphicsConfiguration</code>
214: * is not from a screen device;
215: * @exception java.lang.IllegalArgumentException if <code>parent</code>
216: * is <code>null</code>; this exception is always thrown when
217: * <code>GraphicsEnvironment.isHeadless</code>
218: * returns <code>true</code>
219: * @see java.awt.GraphicsEnvironment#isHeadless
220: * @since 1.5
221: */
222: public FileDialog(Dialog parent, String title) {
223: this (parent, title, LOAD);
224: }
225:
226: /**
227: * Creates a file dialog window with the specified title for loading
228: * or saving a file.
229: * <p>
230: * If the value of <code>mode</code> is <code>LOAD</code>, then the
231: * file dialog is finding a file to read, and the files shown are those
232: * in the current directory. If the value of
233: * <code>mode</code> is <code>SAVE</code>, the file dialog is finding
234: * a place to write a file.
235: *
236: * @param parent the owner of the dialog
237: * @param title the title of the dialog; a <code>null</code> value
238: * will be accepted without causing a
239: * <code>NullPointerException</code> to be thrown
240: * @param mode the mode of the dialog; either
241: * <code>FileDialog.LOAD</code> or <code>FileDialog.SAVE</code>
242: * @exception java.lang.IllegalArgumentException if an illegal
243: * file dialog mode is supplied;
244: * @exception java.lang.IllegalArgumentException if the <code>parent</code>'s
245: * <code>GraphicsConfiguration</code>
246: * is not from a screen device;
247: * @exception java.lang.IllegalArgumentException if <code>parent</code>
248: * is <code>null</code>; this exception is always thrown when
249: * <code>GraphicsEnvironment.isHeadless</code>
250: * returns <code>true</code>
251: * @see java.awt.GraphicsEnvironment#isHeadless
252: * @see java.awt.FileDialog#LOAD
253: * @see java.awt.FileDialog#SAVE
254: * @since 1.5
255: */
256: public FileDialog(Dialog parent, String title, int mode) {
257: super (parent, title, true);
258: this .setMode(mode);
259: setLayout(null);
260: }
261:
262: /**
263: * Constructs a name for this component. Called by <code>getName()</code>
264: * when the name is <code>null</code>.
265: */
266: String constructComponentName() {
267: synchronized (FileDialog.class) {
268: return base + nameCounter++;
269: }
270: }
271:
272: /**
273: * Creates the file dialog's peer. The peer allows us to change the look
274: * of the file dialog without changing its functionality.
275: */
276: public void addNotify() {
277: synchronized (getTreeLock()) {
278: if (parent != null && parent.getPeer() == null) {
279: parent.addNotify();
280: }
281: if (peer == null)
282: peer = getToolkit().createFileDialog(this );
283: super .addNotify();
284: }
285: }
286:
287: /**
288: * Indicates whether this file dialog box is for loading from a file
289: * or for saving to a file.
290: *
291: * @return the mode of this file dialog window, either
292: * <code>FileDialog.LOAD</code> or
293: * <code>FileDialog.SAVE</code>
294: * @see java.awt.FileDialog#LOAD
295: * @see java.awt.FileDialog#SAVE
296: * @see java.awt.FileDialog#setMode
297: */
298: public int getMode() {
299: return mode;
300: }
301:
302: /**
303: * Sets the mode of the file dialog. If <code>mode</code> is not
304: * a legal value, an exception will be thrown and <code>mode</code>
305: * will not be set.
306: *
307: * @param mode the mode for this file dialog, either
308: * <code>FileDialog.LOAD</code> or
309: * <code>FileDialog.SAVE</code>
310: * @see java.awt.FileDialog#LOAD
311: * @see java.awt.FileDialog#SAVE
312: * @see java.awt.FileDialog#getMode
313: * @exception IllegalArgumentException if an illegal file
314: * dialog mode is supplied
315: * @since JDK1.1
316: */
317: public void setMode(int mode) {
318: switch (mode) {
319: case LOAD:
320: case SAVE:
321: this .mode = mode;
322: break;
323: default:
324: throw new IllegalArgumentException(
325: "illegal file dialog mode");
326: }
327: }
328:
329: /**
330: * Gets the directory of this file dialog.
331: *
332: * @return the (potentially <code>null</code> or invalid)
333: * directory of this <code>FileDialog</code>
334: * @see java.awt.FileDialog#setDirectory
335: */
336: public String getDirectory() {
337: return dir;
338: }
339:
340: /**
341: * Sets the directory of this file dialog window to be the
342: * specified directory. Specifying a <code>null</code> or an
343: * invalid directory implies an implementation-defined default.
344: * This default will not be realized, however, until the user
345: * has selected a file. Until this point, <code>getDirectory()</code>
346: * will return the value passed into this method.
347: * <p>
348: * Specifying "" as the directory is exactly equivalent to
349: * specifying <code>null</code> as the directory.
350: *
351: * @param dir the specified directory
352: * @see java.awt.FileDialog#getDirectory
353: */
354: public void setDirectory(String dir) {
355: this .dir = (dir != null && dir.equals("")) ? null : dir;
356: FileDialogPeer peer = (FileDialogPeer) this .peer;
357: if (peer != null) {
358: peer.setDirectory(this .dir);
359: }
360: }
361:
362: /**
363: * Gets the selected file of this file dialog. If the user
364: * selected <code>CANCEL</code>, the returned file is <code>null</code>.
365: *
366: * @return the currently selected file of this file dialog window,
367: * or <code>null</code> if none is selected
368: * @see java.awt.FileDialog#setFile
369: */
370: public String getFile() {
371: return file;
372: }
373:
374: /**
375: * Sets the selected file for this file dialog window to be the
376: * specified file. This file becomes the default file if it is set
377: * before the file dialog window is first shown.
378: * <p>
379: * Specifying "" as the file is exactly equivalent to specifying
380: * <code>null</code>
381: * as the file.
382: *
383: * @param file the file being set
384: * @see java.awt.FileDialog#getFile
385: */
386: public void setFile(String file) {
387: this .file = (file != null && file.equals("")) ? null : file;
388: FileDialogPeer peer = (FileDialogPeer) this .peer;
389: if (peer != null) {
390: peer.setFile(this .file);
391: }
392: }
393:
394: /**
395: * Determines this file dialog's filename filter. A filename filter
396: * allows the user to specify which files appear in the file dialog
397: * window. Filename filters do not function in Sun's reference
398: * implementation for Microsoft Windows.
399: *
400: * @return this file dialog's filename filter
401: * @see java.io.FilenameFilter
402: * @see java.awt.FileDialog#setFilenameFilter
403: */
404: public FilenameFilter getFilenameFilter() {
405: return filter;
406: }
407:
408: /**
409: * Sets the filename filter for this file dialog window to the
410: * specified filter.
411: * Filename filters do not function in Sun's reference
412: * implementation for Microsoft Windows.
413: *
414: * @param filter the specified filter
415: * @see java.io.FilenameFilter
416: * @see java.awt.FileDialog#getFilenameFilter
417: */
418: public synchronized void setFilenameFilter(FilenameFilter filter) {
419: this .filter = filter;
420: FileDialogPeer peer = (FileDialogPeer) this .peer;
421: if (peer != null) {
422: peer.setFilenameFilter(filter);
423: }
424: }
425:
426: /**
427: * Reads the <code>ObjectInputStream</code> and performs
428: * a backwards compatibility check by converting
429: * either a <code>dir</code> or a <code>file</code>
430: * equal to an empty string to <code>null</code>.
431: *
432: * @param s the <code>ObjectInputStream</code> to read
433: */
434: private void readObject(ObjectInputStream s)
435: throws ClassNotFoundException, IOException {
436: s.defaultReadObject();
437:
438: // 1.1 Compatibility: "" is not converted to null in 1.1
439: if (dir != null && dir.equals("")) {
440: dir = null;
441: }
442: if (file != null && file.equals("")) {
443: file = null;
444: }
445: }
446:
447: /**
448: * Returns a string representing the state of this <code>FileDialog</code>
449: * window. This method is intended to be used only for debugging purposes,
450: * and the content and format of the returned string may vary between
451: * implementations. The returned string may be empty but may not be
452: * <code>null</code>.
453: *
454: * @return the parameter string of this file dialog window
455: */
456: protected String paramString() {
457: String str = super .paramString();
458: str += ",dir= " + dir;
459: str += ",file= " + file;
460: return str + ((mode == LOAD) ? ",load" : ",save");
461: }
462:
463: boolean postsOldMouseEvents() {
464: return false;
465: }
466: }
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