DirectoryDialog


1   /*******************************************************************************
2    * Copyright (c) 2000, 2006 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   *******************************************************************************/
11  package org.eclipse.swt.widgets;
12  
13  
14  import org.eclipse.swt.internal.*;
15  import org.eclipse.swt.internal.win32.*;
16  import org.eclipse.swt.*;
17  
18  /**
19   * Instances of this class allow the user to navigate
20   * the file system and select a directory.
21   * <dl>
22   * <dt><b>Styles:</b></dt>
23   * <dd>(none)</dd>
24   * <dt><b>Events:</b></dt>
25   * <dd>(none)</dd>
26   * </dl>
27   * <p>
28   * IMPORTANT: This class is intended to be subclassed <em>only</em>
29   * within the SWT implementation.
30   * </p>
31   */
32  
33  public class DirectoryDialog extends Dialog {
34      String   message = "", filterPath = "";  //$NON-NLS-1$//$NON-NLS-2$
35      String   directoryPath;
36      
37  /**
38   * Constructs a new instance of this class given only its parent.
39   *
40   * @param parent a shell which will be the parent of the new instance
41   *
42   * @exception IllegalArgumentException <ul>
43   *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
44   * </ul>
45   * @exception SWTException <ul>
46   *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
47   *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
48   * </ul>
49   */
50  public DirectoryDialog (Shell parent) {
51      this (parent, SWT.PRIMARY_MODAL);
52  }
53  
54  /**
55   * Constructs a new instance of this class given its parent
56   * and a style value describing its behavior and appearance.
57   * <p>
58   * The style value is either one of the style constants defined in
59   * class <code>SWT</code> which is applicable to instances of this
60   * class, or must be built by <em>bitwise OR</em>'ing together 
61   * (that is, using the <code>int</code> "|" operator) two or more
62   * of those <code>SWT</code> style constants. The class description
63   * lists the style constants that are applicable to the class.
64   * Style bits are also inherited from superclasses.
65   * </p>
66   *
67   * @param parent a shell which will be the parent of the new instance
68   * @param style the style of dialog to construct
69   *
70   * @exception IllegalArgumentException <ul>
71   *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
72   * </ul>
73   * @exception SWTException <ul>
74   *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
75   *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
76   * </ul>
77   */
78  public DirectoryDialog (Shell parent, int style) {
79      super (parent, style);
80      checkSubclass ();
81  }
82  
83  int BrowseCallbackProc (int hwnd, int uMsg, int lParam, int lpData) {
84      switch (uMsg) {
85          case OS.BFFM_INITIALIZED:
86              if (filterPath != null && filterPath.length () != 0) {
87                  /* Use the character encoding for the default locale */
88                  TCHAR buffer = new TCHAR (0, filterPath.replace ('/', '\\'), true);
89                  OS.SendMessage (hwnd, OS.BFFM_SETSELECTION, 1, buffer);
90              }
91              if (title != null && title.length () != 0) {
92                  /* Use the character encoding for the default locale */
93                  TCHAR buffer = new TCHAR (0, title, true);
94                  OS.SetWindowText (hwnd, buffer);
95              }
96              break;
97          case OS.BFFM_VALIDATEFAILEDA:
98          case OS.BFFM_VALIDATEFAILEDW:
99              /* Use the character encoding for the default locale */
100             int length = OS.IsUnicode ? OS.wcslen (lParam) : OS.strlen (lParam);
101             TCHAR buffer = new TCHAR (0, length);
102             int byteCount = buffer.length () * TCHAR.sizeof;
103             OS.MoveMemory (buffer, lParam, byteCount);
104             directoryPath = buffer.toString (0, length);
105             break;
106     }
107     return 0;
108 }
109 
110 /**
111  * Returns the path which the dialog will use to filter
112  * the directories it shows.
113  *
114  * @return the filter path
115  * 
116  * @see #setFilterPath
117  */
118 public String   getFilterPath () {
119     return filterPath;
120 }
121 
122 /**
123  * Returns the dialog's message, which is a description of
124  * the purpose for which it was opened. This message will be
125  * visible on the dialog while it is open.
126  *
127  * @return the message
128  */
129 public String   getMessage () {
130     return message;
131 }
132 
133 /**
134  * Makes the dialog visible and brings it to the front
135  * of the display.
136  *
137  * @return a string describing the absolute path of the selected directory,
138  *         or null if the dialog was cancelled or an error occurred
139  *
140  * @exception SWTException <ul>
141  *    <li>ERROR_WIDGET_DISPOSED - if the dialog has been disposed</li>
142  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the dialog</li>
143  * </ul>
144  */
145 public String   open () {
146     if (OS.IsWinCE) SWT.error (SWT.ERROR_NOT_IMPLEMENTED);
147     
148     int hHeap = OS.GetProcessHeap ();
149     
150     /* Get the owner HWND for the dialog */
151     int hwndOwner = 0;
152     if (parent != null) hwndOwner = parent.handle;
153 
154     /* Copy the message to OS memory */
155     int lpszTitle = 0;
156     if (message.length () != 0) {
157         String   string = message;
158         if (string.indexOf ('&') != -1) {
159             int length = string.length ();
160             char [] buffer = new char [length * 2];
161             int index = 0;
162             for (int i=0; i<length; i++) {
163                 char ch = string.charAt (i);
164                 if (ch == '&') buffer [index++] = '&';
165                 buffer [index++] = ch;
166             }
167             string = new String   (buffer, 0, index);
168         }
169         /* Use the character encoding for the default locale */
170         TCHAR buffer = new TCHAR (0, string, true);
171         int byteCount = buffer.length () * TCHAR.sizeof;
172         lpszTitle = OS.HeapAlloc (hHeap, OS.HEAP_ZERO_MEMORY, byteCount);
173         OS.MoveMemory (lpszTitle, buffer, byteCount);
174     }
175 
176     /* Create the BrowseCallbackProc */
177     Callback callback = new Callback (this, "BrowseCallbackProc", 4); //$NON-NLS-1$
178     int lpfn = callback.getAddress ();
179     if (lpfn == 0) SWT.error (SWT.ERROR_NO_MORE_CALLBACKS);
180     
181     /* Make the parent shell be temporary modal */
182     Shell oldModal = null;
183     Display display = parent.getDisplay ();
184     if ((style & (SWT.APPLICATION_MODAL | SWT.SYSTEM_MODAL)) != 0) {
185         oldModal = display.getModalDialogShell ();
186         display.setModalDialogShell (parent);
187     }
188     
189     directoryPath = null;
190     BROWSEINFO lpbi = new BROWSEINFO ();
191     lpbi.hwndOwner = hwndOwner;
192     lpbi.lpszTitle = lpszTitle;
193     lpbi.ulFlags = OS.BIF_NEWDIALOGSTYLE | OS.BIF_RETURNONLYFSDIRS | OS.BIF_EDITBOX | OS.BIF_VALIDATE;
194     lpbi.lpfn = lpfn;
195     /*
196     * Bug in Windows.  On some hardware configurations, SHBrowseForFolder()
197     * causes warning dialogs with the message "There is no disk in the drive
198     * Please insert a disk into \Device\Harddisk0\DR0".  This is possibly
199     * caused by SHBrowseForFolder() calling internally GetVolumeInformation().
200     * MSDN for GetVolumeInformation() says:
201     * 
202     * "If you are attempting to obtain information about a floppy drive
203     * that does not have a floppy disk or a CD-ROM drive that does not 
204     * have a compact disc, the system displays a message box asking the 
205     * user to insert a floppy disk or a compact disc, respectively. 
206     * To prevent the system from displaying this message box, call the 
207     * SetErrorMode function with SEM_FAILCRITICALERRORS."
208     * 
209     * The fix is to save and restore the error mode using SetErrorMode()
210     * with the SEM_FAILCRITICALERRORS flag around SHBrowseForFolder().
211     */
212     int oldErrorMode = OS.SetErrorMode (OS.SEM_FAILCRITICALERRORS);
213     
214     /*
215     * Bug in Windows.  When a WH_MSGFILTER hook is used to run code
216     * during the message loop for SHBrowseForFolder(), running code
217     * in the hook can cause a GP.  Specifically, SetWindowText()
218     * for static controls seemed to make the problem happen.
219     * The fix is to disable async messages while the directory
220     * dialog is open.
221     * 
222     * NOTE:  This only happens in versions of the comctl32.dll
223     * earlier than 6.0.
224     */
225     boolean oldRunMessages = display.runMessages;
226     if (OS.COMCTL32_MAJOR < 6) display.runMessages = false;
227     int lpItemIdList = OS.SHBrowseForFolder (lpbi);
228     if (OS.COMCTL32_MAJOR < 6) display.runMessages = oldRunMessages;
229     OS.SetErrorMode (oldErrorMode);
230     
231     /* Clear the temporary dialog modal parent */
232     if ((style & (SWT.APPLICATION_MODAL | SWT.SYSTEM_MODAL)) != 0) {
233         display.setModalDialogShell (oldModal);
234     }
235     
236     boolean success = lpItemIdList != 0;
237     if (success) {
238         /* Use the character encoding for the default locale */
239         TCHAR buffer = new TCHAR (0, OS.MAX_PATH);
240         if (OS.SHGetPathFromIDList (lpItemIdList, buffer)) {
241             directoryPath = buffer.toString (0, buffer.strlen ());
242             filterPath = directoryPath;
243         }
244     }
245 
246     /* Free the BrowseCallbackProc */
247     callback.dispose ();
248     
249     /* Free the OS memory */
250     if (lpszTitle != 0) OS.HeapFree (hHeap, 0, lpszTitle);
251 
252     /* Free the pointer to the ITEMIDLIST */
253     int [] ppMalloc = new int [1];
254     if (OS.SHGetMalloc (ppMalloc) == OS.S_OK) {
255         /* void Free (struct IMalloc *this, void *pv); */
256         OS.VtblCall (5, ppMalloc [0], lpItemIdList);
257     }
258     
259     /*
260     * This code is intentionally commented.  On some
261     * platforms, the owner window is repainted right
262     * away when a dialog window exits.  This behavior
263     * is currently unspecified.
264     */
265 //  if (hwndOwner != 0) OS.UpdateWindow (hwndOwner);
266     
267     /* Return the directory path */
268     if (!success) return null;
269     return directoryPath;
270 }
271 
272 /**
273  * Sets the path that the dialog will use to filter
274  * the directories it shows to the argument, which may
275  * be null. If the string is null, then the operating
276  * system's default filter path will be used.
277  * <p>
278  * Note that the path string is platform dependent.
279  * For convenience, either '/' or '\' can be used
280  * as a path separator.
281  * </p>
282  *
283  * @param string the filter path
284  */
285 public void setFilterPath (String   string) {
286     filterPath = string;
287 }
288 
289 /**
290  * Sets the dialog's message, which is a description of
291  * the purpose for which it was opened. This message will be
292  * visible on the dialog while it is open.
293  *
294  * @param string the message
295  * 
296  * @exception IllegalArgumentException <ul>
297  *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
298  * </ul>
299  */
300 public void setMessage (String   string) {
301     if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
302     message = string;
303 }
304 
305 }
306
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