odk/examples/DevelopersGuide/Forms/GridFieldValidator.java

   1 /*************************************************************************
   2  *
   3  *  $RCSfile: GridFieldValidator.java,v $
   4  *
   5  *  $Revision: 1.4 $
   6  *
   7  *  last change: $Author: rt $ $Date: 2005-01-31 16:30:37 $
   8  *
   9  *  The Contents of this file are made available subject to the terms of
  10  *  the BSD license.
  11  *
  12  *  Copyright (c) 2003 by Sun Microsystems, Inc.
  13  *  All rights reserved.
  14  *
  15  *  Redistribution and use in source and binary forms, with or without
  16  *  modification, are permitted provided that the following conditions
  17  *  are met:
  18  *  1. Redistributions of source code must retain the above copyright
  19  *     notice, this list of conditions and the following disclaimer.
  20  *  2. Redistributions in binary form must reproduce the above copyright
  21  *     notice, this list of conditions and the following disclaimer in the
  22  *     documentation and/or other materials provided with the distribution.
  23  *  3. Neither the name of Sun Microsystems, Inc. nor the names of its
  24  *     contributors may be used to endorse or promote products derived
  25  *     from this software without specific prior written permission.
  26  *
  27  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  30  *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  31  *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  32  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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  37  *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  *
  39  *************************************************************************/
  40
  41 /**************************************************************************/
  42 import com.sun.star.uno.*;
  43 import com.sun.star.beans.*;
  44 import com.sun.star.form.*;
  45 import com.sun.star.lang.*;
  46 import com.sun.star.sdb.*;
  47 import com.sun.star.sdbc.*;
  48 import com.sun.star.sdbcx.*;
  49 import com.sun.star.container.*;
  50 import com.sun.star.awt.*;
  51 import com.sun.star.task.*;
  52
  53 /**************************************************************************/
  54 /** helper class for validating a grid field before it is updated
  55
  56     <p>Actually, the mechanism for validating the field is not restricted to
  57     grid control fields. Instead, it can be used for any bound controls.</p>
  58 */
  59 class GridFieldValidator implements XUpdateListener
  60 {
  61     private DocumentHelper              m_aDocument;
  62     private     XComponentContext       m_xCtx;
  63     private XPropertySet                m_xWatchedColumn;
  64
  65     private     boolean                 m_bWatching;
  66
  67     /* ------------------------------------------------------------------ */
  68     public GridFieldValidator( XComponentContext xCtx, XPropertySet xWatchedGridColumn )
  69     {
  70         // remember
  71         m_xCtx = xCtx;
  72         m_xWatchedColumn = xWatchedGridColumn;
  73         m_aDocument = DocumentHelper.getDocumentForComponent(xWatchedGridColumn,
  74                                                              xCtx);
  75
  76         m_bWatching = false;
  77     }
  78
  79     /* ------------------------------------------------------------------ */
  80     public void enableColumnWatch( boolean bEnable )
  81     {
  82         if ( bEnable == m_bWatching )
  83             return;
  84
  85         XUpdateBroadcaster xUpdate = (XUpdateBroadcaster)UnoRuntime.queryInterface(
  86             XUpdateBroadcaster.class, m_xWatchedColumn );
  87
  88         if ( bEnable )
  89             xUpdate.addUpdateListener( this );
  90         else
  91             xUpdate.removeUpdateListener( this );
  92
  93         m_bWatching = bEnable;
  94     }
  95
  96     /* ------------------------------------------------------------------ */
  97     /** shows a message that we can't do several things due to an implementation error
  98     */
  99     private void showInvalidValueMessage( )
 100     {
 101         try
 102         {
 103             // build the message we want to show
 104             String sMessage = "The column \"";
 105             sMessage += FLTools.getLabel( m_xWatchedColumn );
 106             sMessage += "\" is not allowed to contain empty strings.";
 107
 108             SQLContext aError = new SQLContext(
 109                 new String( "Invalid Value Entered" ),
 110                 null,
 111                 new String( "S1000" ),
 112                 0,
 113                 new Any( new Type(), null ),
 114                 sMessage
 115             );
 116
 117             // instantiate an interaction handler who can handle SQLExceptions
 118             XInteractionHandler xHandler = (XInteractionHandler)UnoRuntime.queryInterface(
 119                 XInteractionHandler.class,
 120                 m_xCtx.getServiceManager().createInstanceWithContext(
 121                     "com.sun.star.sdb.InteractionHandler", m_xCtx ) );
 122
 123             // create a new request and execute it
 124             InteractionRequest aRequest = new InteractionRequest( aError );
 125             xHandler.handle( aRequest );
 126         }
 127         catch( com.sun.star.uno.Exception e )
 128         {
 129             System.out.println(e);
 130             e.printStackTrace();
 131         }
 132     }
 133
 134     /* ------------------------------------------------------------------ */
 135     // XUpdateListener overridables
 136     /* ------------------------------------------------------------------ */
 137     public boolean approveUpdate( EventObject aEvent ) throws com.sun.star.uno.RuntimeException
 138     {
 139         boolean bApproved = true;
 140         try
 141         {
 142             // the control model which fired the event
 143             XPropertySet xSourceProps = UNO.queryPropertySet( aEvent.Source );
 144
 145             String sNewText = (String)xSourceProps.getPropertyValue( "Text" );
 146             if ( 0 == sNewText.length() )
 147             {
 148                 // say that the value is invalid
 149                 showInvalidValueMessage( );
 150                 bApproved = false;
 151
 152                 // reset the control value
 153                 // for this, we take the current value from the row set field the control
 154                 // is bound to, and forward it to the control model
 155                 XColumn xBoundColumn = UNO.queryColumn( xSourceProps.getPropertyValue( "BoundField" ) );
 156                 if ( null != xBoundColumn )
 157                 {
 158                     xSourceProps.setPropertyValue( "Text", xBoundColumn.getString() );
 159                 }
 160             }
 161         }
 162         catch( com.sun.star.uno.Exception e )
 163         {
 164             System.out.println(e);
 165             e.printStackTrace();
 166         }
 167         return bApproved;
 168     }
 169
 170     /* ------------------------------------------------------------------ */
 171     public void updated( EventObject aEvent ) throws com.sun.star.uno.RuntimeException
 172     {
 173     }
 174
 175     /* ------------------------------------------------------------------ */
 176     // XEventListener overridables
 177     /* ------------------------------------------------------------------ */
 178     public void disposing( EventObject aEvent )
 179     {
 180         // not interested in
 181     }
 182 };