Multiselection in a T-list

Question

When I use a T-list, I can select only one item at once.So, how could I do that this T-list let me select more than one at time applying 'Shift' or 'Ctrl' whit mouse or 'key-down'/'key-up' ?

Answer 1

It is possible to use a Pluggable Java Component to do this.
Here's the code for an ehnaced version of the TList that allows MultiSelect and makes a list of the selected values available in a Custom Property called LIST_SELECTION.
You enable Multselect by calling the Custom property ENABLE_LIST_MULTISELECT witht he value 'TRUE' using SET_CUSTOM_PROPERTY().
A fully packaged version of this code will be availble off of the otn.oracle.com/products/forms pages soon, but I thought I'd put the source here for anyone who's brave:
-------- Code for EnhancedTList.java -----
// Copyright (c) 2001 Oracle Corp
package oracle.forms.demos.enhancedwidgets;
import oracle.forms.ui.*;
import oracle.forms.properties.ID;
import java.util.StringTokenizer;
* <H3><FONT COLOR="#002299">Pluggable Java Components for Oracle Forms Server 6<I>i</I></FONT></H3>
* This class is a Pluggable Java Component for Oracle Forms, that implements
* a method for setting UI properties on an instance by instance basis that would
* not normally be allowed
* Also allows multi-select TList for use in Picker controls etc.
* The class implements the following Custom properties for the programmer to
* use on a Tlist:
* <ul><li>INSTANCE_ENABLED</li>
* <li>INSTANCE_DISPLAYED</li>
* <li>ENABLE_LIST_MULTISELECT</li>
* <li>LIST_SELECTION</li>
* <li>CLEAR_LIST_SELECTION</li></ul>
* @version 1.0 24/June/2001 created<br>
* @author Duncan Mills
public class EnhancedTList extends VTList
private boolean debugOn = false;
private String debugClassName = null;
* Constructs a new instance.
public EnhancedTList()
super();
* Implimentation of setProperty in the IView interface
* @param pid property to be set
* @param value new value of the property
* @return true (if the property could be set), false otherwise
* @see IView
public boolean setProperty(ID pid, Object value)
if ( pid == EnhancedWidgets.INSTANCE_ENABLED )
PJCUtil.log(debugOn, debugClassName, "setting INSTANCE_ENABLED to " + PJCUtil.toBoolean(value,true));
this.setEnabled(PJCUtil.toBoolean(value,true));
else if ( pid == EnhancedWidgets.INSTANCE_DISPLAYED )
PJCUtil.log(debugOn, debugClassName, "setting INSTANCE_DISPLAYED to " + PJCUtil.toBoolean(value,true));
this.setVisible(PJCUtil.toBoolean(value,true));
else if (pid == EnhancedWidgets.ENABLE_LIST_MULTISELECT)
PJCUtil.log(debugOn, debugClassName, "setting ENABLE_LIST_MULTISELECT to " + PJCUtil.toBoolean(value,true));
this.setMultipleMode(PJCUtil.toBoolean(value,false));
else if (pid == EnhancedWidgets.LIST_SELECTION)
this.deselectAll();
StringTokenizer tok = new StringTokenizer(value.toString(),",");
while (tok.hasMoreElements())
try
this.select(Integer.parseInt(tok.nextToken())-1);
} catch (NumberFormatException e)
return false;
else if (pid == EnhancedWidgets.CLEAR_LIST_SELECTION)
this.deselectAll();
else if (pid == EnhancedWidgets.DEBUGMESSAGES)
debugOn = PJCUtil.toBoolean(value,false);
if (debugOn)
debugClassName = getClass().getName();
else
return super.setProperty(pid, value);
return true;
* Implimentation of getProperty in the IView interface
* @param pid property to be set
* @return the value of the property
* @see IView
public Object getProperty(ID pid)
if (pid == EnhancedWidgets.LIST_SELECTION)
if (this.getSelectedIndexes().length > 0)
StringBuffer returnList = new StringBuffer();
for (int i = 0; i < this.getSelectedIndexes().length; i++)
returnList.append((this.getSelectedIndexes() + 1) + ",");
return returnList.toString().substring(0,(returnList.length()-1));
else
return new String("");
else
return super.getProperty(pid);
-------- Code for PJCUtil.java -----------
// Copyright ( c) 2001 Oracle Corp
package oracle.forms.demos.enhancedwidgets;
* Utility class for Forms PJCs.
* <P>
* @author Duncan Mills
final class PJCUtil extends Object
* Converts a string value containing TRUE or FALSE
* as a string to the equivilent boolean
* @param value String containing the words True or false in any case or the Forms Constants PROPERTY_TRUE/PROPERTY_FALSE
* @return boolean value of the value
protected final static boolean toBoolean(Object value, boolean defaultValue)
boolean RC = defaultValue;
if (value.toString().equalsIgnoreCase("false")&#0124; &#0124;value.toString().equals("5"))
RC = false;
else if (value.toString().equalsIgnoreCase("true")&#0124; &#0124;value.toString().equals("4"))
RC = true;
return RC;
* Outputs the specified message to the Java Console
* if Debug is enabled
* @param debugOn boolean flag to indicate if debug is on
* @param debugClass Classname of the class being debugged
* @param debugMessage String to display
protected final static void log(boolean debugOn, Object debugClass, String debugMessage)
if(debugOn)
System.out.println(debugClass.getClass().getName() + ": " + debugMessage);