odk/examples/DevelopersGuide/Forms/ControlLock.java

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  34
  35 import com.sun.star.uno.*;
  36 import com.sun.star.lang.*;
  37 import com.sun.star.container.*;
  38 import com.sun.star.beans.*;
  39 import com.sun.star.form.*;
  40 import com.sun.star.sdbc.*;
  41
  42
  43 /**************************************************************************/
  44 /** A helper class for recursively locking control models which are bound
  45     to a specific field
  46 */
  47
  48 class LockControlModels extends ComponentTreeTraversal
  49 {
  50     private String  m_sDataField;
  51     private Boolean m_aLockIt;
  52     private int     m_nLevel;   // nesting level relative to the form we started with
  53
  54     /* ------------------------------------------------------------------ */
  55     public LockControlModels( String sDataField, boolean bLockIt )
  56     {
  57         m_sDataField = sDataField;
  58         m_aLockIt = Boolean.valueOf( bLockIt );
  59         m_nLevel = 0;
  60     }
  61
  62     /* ------------------------------------------------------------------ */
  63     @Override
  64     protected boolean shouldStepInto( XIndexContainer xContainer )
  65     {
  66         if ( !super.shouldStepInto( xContainer ) )
  67             return false;   // don't try to be more clever than our base class
  68
  69         XForm xForm = UnoRuntime.queryInterface( XForm.class, xContainer );
  70         if ( ( null != xForm ) && ( m_nLevel > 1 ) )
  71             // don't step into sub forms - we only handle the form we were originally
  72             // applied to
  73             return false;
  74
  75         return true;
  76     }
  77
  78     /* ------------------------------------------------------------------ */
  79     @Override
  80     public void handle( Object aFormComponent ) throws com.sun.star.uno.Exception
  81     {
  82         // entering this nesting level
  83         ++m_nLevel;
  84
  85         // check if the component has a DataField property
  86         XPropertySet xCompProps = UNO.queryPropertySet( aFormComponent );
  87         XPropertySetInfo xPSI = null;
  88         if ( null != xCompProps )
  89             xPSI = xCompProps.getPropertySetInfo();
  90
  91         if ( ( null != xPSI ) && xPSI.hasPropertyByName( "DataField" ) )
  92         {   // indeed it has ....
  93             String sDataField = (String)xCompProps.getPropertyValue( "DataField" );
  94             if ( sDataField.equals( m_sDataField ) )
  95             {   // we found a control model which is bound to what we're looking for
  96                 xCompProps.setPropertyValue( "ReadOnly", m_aLockIt );
  97             }
  98         }
  99
 100         // allow the super class to step down, if possible
 101         super.handle( aFormComponent );
 102
 103         // leaving this nesting level
 104         --m_nLevel;
 105     }
 106 }
 107
 108 /**************************************************************************/
 109 /** a class which automatically handles control locking.
 110     <p>The class has to be bound to a form. Upon every movement of the form,
 111     all controls which are bound to a (to be specified) field are locked
 112     on existing and unlocked on new records.</p>
 113 */
 114 class ControlLock implements XRowSetListener
 115 {
 116     private XPropertySet    m_xForm;
 117     private String          m_sDataField;
 118     private boolean         m_bLockingEnabled;
 119     private boolean         m_bPreviousRoundLock;
 120
 121     /* ------------------------------------------------------------------ */
 122     ControlLock( XPropertySet xForm, String sBoundDataField )
 123     {
 124         m_xForm = xForm;
 125         m_sDataField = sBoundDataField;
 126         m_bLockingEnabled = false;
 127         m_bPreviousRoundLock = false;
 128     }
 129
 130     /* ------------------------------------------------------------------ */
 131     /** updates the locks on the affected controls
 132     */
 133     private void updateLocks( )
 134     {
 135         try
 136         {
 137             // first determine if we need to lock
 138             Boolean aIsNewRecord = (Boolean)m_xForm.getPropertyValue( "IsNew" );
 139
 140             boolean bNeedLock = m_bLockingEnabled && !aIsNewRecord.booleanValue();
 141
 142             if ( m_bPreviousRoundLock != bNeedLock )
 143             {
 144                 LockControlModels aLocker = new LockControlModels( m_sDataField, bNeedLock );
 145                 aLocker.handle( m_xForm );
 146                 m_bPreviousRoundLock = bNeedLock;
 147             }
 148
 149             // please note that we choose the expensive way here: We always loop through
 150             // _all_ control models belonging to the form. This clearly slows down the
 151             // whole process.
 152             // A better solution would be to cache the affected control models. Then we
 153             // could either rely on the fact that the model hierarchy is static, or we
 154             // could add ourself as container listener to the form.
 155         }
 156         catch(com.sun.star.uno.Exception e)
 157         {
 158             System.out.println(e);
 159             e.printStackTrace();
 160         }
 161     }
 162
 163     /* ------------------------------------------------------------------ */
 164     /** enables the locking in general
 165         <p>If the control models are really locked depends on the current
 166         record of the form: on the insert row, controls are never locked.</p>
 167     */
 168     public void enableLock( boolean bLock )
 169     {
 170         // remember this new setting
 171         m_bLockingEnabled = bLock;
 172
 173         // add or remove ourself as listener to get notified of cursor moves
 174         XRowSet xRowSet = UnoRuntime.queryInterface(
 175             XRowSet.class, m_xForm );
 176         if ( m_bLockingEnabled )
 177         {
 178             xRowSet.addRowSetListener( this );
 179         }
 180         else
 181         {
 182             xRowSet.removeRowSetListener( this );
 183         }
 184
 185         // update the locks
 186         updateLocks();
 187     }
 188
 189     /* ==================================================================
 190        = UNO callbacks
 191        ================================================================== */
 192
 193     /* ------------------------------------------------------------------ */
 194     // XResetListener overridables
 195     /* ------------------------------------------------------------------ */
 196     public void cursorMoved( EventObject aEvent ) throws com.sun.star.uno.RuntimeException
 197     {
 198         updateLocks( );
 199     }
 200
 201     /* ------------------------------------------------------------------ */
 202     public void rowChanged( EventObject aEvent ) throws com.sun.star.uno.RuntimeException
 203     {
 204         // not interested in
 205     }
 206
 207     /* ------------------------------------------------------------------ */
 208     public void rowSetChanged( EventObject aEvent ) throws com.sun.star.uno.RuntimeException
 209     {
 210         // not interested in
 211     }
 212
 213     /* ------------------------------------------------------------------ */
 214     // XEventListener overridables
 215     /* ------------------------------------------------------------------ */
 216     public void disposing( EventObject aEvent )
 217     {
 218         // not interested in
 219     }
 220 }