odk/examples/DevelopersGuide/Forms/GridFieldValidator.java

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  34
  35 /**************************************************************************/
  36 import com.sun.star.uno.*;
  37 import com.sun.star.beans.*;
  38 import com.sun.star.form.*;
  39 import com.sun.star.lang.*;
  40 import com.sun.star.sdb.*;
  41 import com.sun.star.task.*;
  42
  43 /**************************************************************************/
  44 /** helper class for validating a grid field before it is updated
  45
  46     <p>Actually, the mechanism for validating the field is not restricted to
  47     grid control fields. Instead, it can be used for any bound controls.</p>
  48 */
  49 class GridFieldValidator implements XUpdateListener
  50 {
  51     private XComponentContext   m_xCtx;
  52     private XPropertySet        m_xWatchedColumn;
  53
  54     private boolean         m_bWatching;
  55
  56     /* ------------------------------------------------------------------ */
  57     public GridFieldValidator( XComponentContext xCtx, XPropertySet xWatchedGridColumn )
  58     {
  59         // remember
  60         m_xCtx = xCtx;
  61         m_xWatchedColumn = xWatchedGridColumn;
  62         DocumentHelper.getDocumentForComponent(xWatchedGridColumn,
  63                                                              xCtx);
  64
  65         m_bWatching = false;
  66     }
  67
  68     /* ------------------------------------------------------------------ */
  69     public void enableColumnWatch( boolean bEnable )
  70     {
  71         if ( bEnable == m_bWatching )
  72             return;
  73
  74         XUpdateBroadcaster xUpdate = UnoRuntime.queryInterface(
  75             XUpdateBroadcaster.class, m_xWatchedColumn );
  76
  77         if ( bEnable )
  78             xUpdate.addUpdateListener( this );
  79         else
  80             xUpdate.removeUpdateListener( this );
  81
  82         m_bWatching = bEnable;
  83     }
  84
  85     /* ------------------------------------------------------------------ */
  86     /** shows a message that we can't do several things due to an implementation error
  87     */
  88     private void showInvalidValueMessage( )
  89     {
  90         try
  91         {
  92             // build the message we want to show
  93             String sMessage = "The column \"";
  94             sMessage += FLTools.getLabel( m_xWatchedColumn );
  95             sMessage += "\" is not allowed to contain empty strings.";
  96
  97             SQLContext aError = new SQLContext(
  98                 "Invalid Value Entered",
  99                 null,
 100                 "S1000",
 101                 0,
 102                 new Any( new Type(), null ),
 103                 sMessage
 104             );
 105
 106             // instantiate an interaction handler who can handle SQLExceptions
 107             XInteractionHandler xHandler = UnoRuntime.queryInterface(
 108                 XInteractionHandler.class,
 109                 m_xCtx.getServiceManager().createInstanceWithContext(
 110                     "com.sun.star.task.InteractionHandler", m_xCtx ) );
 111
 112             // create a new request and execute it
 113             InteractionRequest aRequest = new InteractionRequest( aError );
 114             xHandler.handle( aRequest );
 115         }
 116         catch( com.sun.star.uno.Exception e )
 117         {
 118             System.out.println(e);
 119             e.printStackTrace();
 120         }
 121     }
 122
 123     /* ------------------------------------------------------------------ */
 124     // XUpdateListener overridables
 125     /* ------------------------------------------------------------------ */
 126     public boolean approveUpdate( EventObject aEvent ) throws com.sun.star.uno.RuntimeException
 127     {
 128         boolean bApproved = true;
 129         try
 130         {
 131             // the control model which fired the event
 132             XPropertySet xSourceProps = UNO.queryPropertySet( aEvent.Source );
 133
 134             String sNewText = (String)xSourceProps.getPropertyValue( "Text" );
 135             if ( 0 == sNewText.length() )
 136             {
 137                 // say that the value is invalid
 138                 showInvalidValueMessage( );
 139                 bApproved = false;
 140
 141                 // reset the control value
 142                 // for this, we take the current value from the row set field the control
 143                 // is bound to, and forward it to the control model
 144                 XColumn xBoundColumn = UNO.queryColumn( xSourceProps.getPropertyValue( "BoundField" ) );
 145                 if ( null != xBoundColumn )
 146                 {
 147                     xSourceProps.setPropertyValue( "Text", xBoundColumn.getString() );
 148                 }
 149             }
 150         }
 151         catch( com.sun.star.uno.Exception e )
 152         {
 153             System.out.println(e);
 154             e.printStackTrace();
 155         }
 156         return bApproved;
 157     }
 158
 159     /* ------------------------------------------------------------------ */
 160     public void updated( EventObject aEvent ) throws com.sun.star.uno.RuntimeException
 161     {
 162     }
 163
 164     /* ------------------------------------------------------------------ */
 165     // XEventListener overridables
 166     /* ------------------------------------------------------------------ */
 167     public void disposing( EventObject aEvent )
 168     {
 169         // not interested in
 170     }
 171 }