Symantec Visual Cafe for Java 2.5/symantec-visual-cafe-2.5-database-dev-edition.iso/VCafe/prosrc.bin/List.java

Java Source | 1998-03-18 | 14.1 KB | 481 lines

/*
 * @(#List.java
 *
 * Copyright (c) 1997 Symantec Corporation. All Rights Reserved.
 *
 */


package symantec.itools.db.awt;

import java.util.*;
import java.sql.*;
import java.lang.*;
import symantec.itools.db.net.*;
import symantec.itools.db.pro.*;
import java.awt.event.*;

/**
 * A dbAWARE List component.
 * <p>
 * This component can be "bound" to a projection within a relation view
 * so that it automatically gets and sets the values in that relation.
 * <p>
 */
public class List extends java.awt.List implements ListLink, ProjectionBean
{

    /**
     * The  Binder object which this component can use to get data from
     * the server, or change data at the database server.
     */
    private ListBinder   m_ListBinder;

    private boolean m_useStream = false;

    private RelationView    m_LookUpRelationView;
    private Vector          m_JoinColumns;
    private Vector          m_JoinColumnNames;
    private ConnectionInfo  m_Conn;
    private String          m_SQL;

    private ProjectionBeanHelper m_Helper;

    /**
     * A constant value indicating how an empty string will be saved in the database.
     */
    public static final String Default = ProjectionBeanHelper.DEFAULT;
    /**
     * A constant value indicating how an empty string will be saved in the database.
     */
    public static final String Blank = ProjectionBeanHelper.BLANK;
    /**
     * A constant value indicating how an empty string will be saved in the database.
     */
    public static final String Null = ProjectionBeanHelper.NULL;

    /**
     * Constructs a new List linked to a database.
     *
     * @param lookupRV the relation view to bind with
     * @param conn the information needed to connect to the database
     */
    public List(RelationView lookupRV, ConnectionInfo conn)
    {
        this();
        m_LookUpRelationView = lookupRV;
        m_Conn = conn;
        m_Helper = new ProjectionBeanHelper(this);
        addFocusListener(m_Helper);
    }

    /**
     * Constructs a new List with no data connectivity, initially.
     *
     * @param rows defines the number of rows of items to display.
     */
    public List(int rows)
    {
        super(rows, false);
        m_JoinColumns = new Vector();
        m_JoinColumnNames = new Vector();
        m_SQL = new String();
        m_Helper = new ProjectionBeanHelper(this);
    }

    /**
     * Constructs a default List with no data connectivity, initially.
     */
    public List()
    {
        this(0);
    }

    /**
     * Called when this component has been bound to a RelationView.
     * This component notes the ListBinder object so that it
     * may notify the dbANYWHERE server of data changes made.
     * <p>
     * This is a method in the ListLink interface.
     *
     * @param lBinder used to notify the dbANYWHERE server of any data changes
     * that are to be persistant.
     *
     * @see symantec.itools.db.pro.ListLink#init
     */
    public void init (ListBinder lBinder)
    {
        m_ListBinder = lBinder;
    }

    /**
     * This method is called to update the value of this dbAWARE component.
     * It is called when the dbANYWHERE server has detected a data change made
     * within the RelationView bound to this component.
     * The ListBinder object passed into the notification is used to get the
     * new data value.
     * <p>
     * This is a method in the ListLink interface.
     *
     * @param binder used to get the current value from the dbANYWHERE server.
     *
     * @see symantec.itools.db.pro.ListLink#notifyListChange
     */
    public void notifyListChange(ListBinder lBinder)
    {
        try
        {
            RelationView curRV = lBinder.getRelationView();
            clear();
            while ( curRV.next() == true )
            {
                if (!(curRV.isNull(1)))
                {
                    super.addItem( curRV.getString(1));
                }
            }
            Enumeration e = staticItems.elements();
            while(e.hasMoreElements())
            {
                super.addItem((String)e.nextElement());
            }
        }
        catch (SQLException Ex)
        {
            m_Helper.raiseException (Ex);
        }
    }

    /**
     * Adds a column to the list of columns that this component will be bound
     * to. Use this method before calling bindList().
     *
     * @param columnName the name of the column to join
     * @exception SQLException
     * if a SQL database access error occurred
     * @see #bindList
     */
    public void join(String columnName) throws SQLException
    {
        if (!java.beans.Beans.isDesignTime()) {
            int colID = m_LookUpRelationView.findProjByName(columnName);
            if (m_JoinColumns == null)
            {
                m_JoinColumns = new Vector();
            }
            m_JoinColumns.addElement(new Integer(colID));
        }
        if (m_JoinColumnNames == null)
        {
            m_JoinColumnNames = new Vector();
        }
        m_JoinColumnNames.addElement(new String(columnName));
    }

    /**
     * Sets the sql string to use while generating the list for this component
     * to bind to. Use this method before calling bindList().
     *
     * @param sql the sql string
     * @exception SQLException
     * if a SQL database access error occurred
     *
     * @see #bindList
     * @see #getSelectClause
     */
    public void setSQL(String sql) throws SQLException
    {
        m_SQL = sql;
    }

    /**
     * Binds this component to a list of columns within a RelationView.
     * The RelationView and connection information to use is specified at
     * construction time. The columns to use are specified using the join()
     * method.
     *
     * @see #join
     * @exception SQLException
     * if a SQL database access error occurred
     */
    public void bindList() throws SQLException
    {
        m_LookUpRelationView.bindList(m_Conn, m_SQL, this, m_JoinColumns);
        m_Helper.notifyDataChange();
    }


    /**
     * Adds the specified item to the end of the list.
     * @param item the item to be added
     */
    public synchronized void addItem(String item) {
        super.addItem(item, -1);
        staticItems.addElement(item);
    }

    private Vector staticItems = new Vector();

    /**
     * Binds this component to a given projection within the specified
     * relation view.
     *
     * @param relView the relation view to bind with
     * @param projection the projection in relView to bind with
     */
    public void setBinding(RelationView relView, String projection)
    {
        m_Helper.setBinding(relView, projection);
    }

    /**
     * Returns the projection in the RelationView that this component is bound with.
     * @see #setBinding
     * @see #setProjection
     */
    public String getProjection() {
        return m_Helper.getProjection();
    }

    /**
     * Binds this component to the given projection within the RelationView
     * the component is currently bound with.
     * @see #setBinding
     * @see #getProjection
     * @see #getRelationView
     */
    public void setProjection(String projection) {
        m_Helper.setProjection(projection);
    }

    /**
     * Gets the RelationView that this component is bound with.
     * @return the RelationView currently bound with
     * @see #setRelationView
     * @see #setBinding
     * @see #getProjection
     */
    public RelationView getRelationView() {
        return m_Helper.getRelationView();
    }

    /**
     * Sets the RelationView that this component is bound with.
     * @param value the RelationView to bind with
     * @see #getRelationView
     * @see #setBinding
     * @see #setProjection
     */
    public void setRelationView(RelationView value) {
        m_Helper.setRelationView(value);
    }

    /**
     * Specifies how an empty string will be set when updating data on
     * the dbANYWHERE server.
     *
     * @param blank one of "DEFAULT", "NULL", or "BLANK"
     *
     * @see symantec.itools.db.pro.ProjBinder#setValueFromString(java.lang.String, int, int)
     */
    public void setTreatBlankAs(String value) {
        m_Helper.setTreatBlankAsString(value);
    }

    /**
     * Indicates when the component commits its changes.
     * @see #setDynamicUpdate
     */
    public boolean getDynamicUpdate() {
        return m_Helper.getDynamicUpdate();
    }

    /**
     * Sets when the component commits its changes.
     * @param value the new dynamic update mode value
     * @see #getDynamicUpdate
     */
    public void setDynamicUpdate(boolean value) {
        m_Helper.setDynamicUpdate(value);
        if (value) {
            removeFocusListener(m_Helper);
            addItemListener(m_Helper);
        }
        else {
            removeItemListener(m_Helper);
            addFocusListener(m_Helper);
        }
    }

    /**
     * Sets whether the data value of this component may be modified.
     * @param value <code>true</code> if the value may not be modified,
     * <code>false</code>if the value may be modified
     */
    public void setReadOnly(boolean value) {
    }

    /**
     * Gets the RelationView this component is bound with.
     * @return the RelationView
     */
    public RelationView getLookUpRelationView() {
        return m_LookUpRelationView;
    }

    /**
     * Sets the RelationView this component is bound with.
     * @param value the RelationView
     */
    public void setLookUpRelationView(RelationView value) {
    }

    /**
     * Gets the ConnectionInfo this component uses to connect with the database.
     * @return the information needed to connect to the database
     * @see #setConnectionInfo
     */
    public ConnectionInfo getConnectionInfo() {
        return m_Conn;
    }

    /**
     * Sets the ConnectionInfo this component uses to connect with the database.
     * @param conn the information needed to connect to the database
     * @see #getConnectionInfo
     */
    public void setConnectionInfo(ConnectionInfo conn) {
        m_Conn = conn;
    }


    /**
     * Gets the sql string to use while generating the list for this component
     * to bind to.
     * @return the sql statment
     * @see #setSQL
     */
    public String getSelectClause() {
        return m_SQL;
    }

    /**
     * Sets the value of this component to the given value.
     * @param value the new component value
     * @see #getData
     */
    public void setData(Object value) {
        String text = (String)value;
        boolean bitemFound = false;
        for (int index = 0; index < countItems(); index++)
        {
            if (text.equals(getItem(index)))
            {
                select(index);
                makeVisible(index);
                bitemFound = true;
                break;
            }
            if (!bitemFound)
            {
                if (getSelectedIndex() != -1)
                {
                    deselect(getSelectedIndex());
                }
            }
        }
    }

    /**
     * Gets the value of this component.
     * @return the current component value
     * @see #setData
     */
    public Object getData() {
        String text = null;
        String[] selectedItems = getSelectedItems();
        if (selectedItems.length == 1)
        {
            text = selectedItems[0];
        }
        return text;
    }

    /**
     * Gets whether this component saves its value as a text String.
     * @return <code>true</code> if the value is saved as text,
     * <code>false</code> otherwise
     */
    public boolean isTextBased() {
        return true;
    }

    /**
     * Gets the list of columns that this component will be bound to.
     * @return the list of columns
     * @see #join
     */
    public String[] getJoinColumns() {
        String[] joinColumns = new String[m_JoinColumnNames.size()];
        for (int index = 0; index < m_JoinColumnNames.size(); index++) {
            joinColumns[index] = new String((String)m_JoinColumnNames.elementAt(index));
        }
        return joinColumns;
    }

    /**
     * Sets the list of columns that this component will be bound to.
     * Use this method before calling bindList().
     * @param value the names of the columns to join
     * @see #join
     * @see #getJoinColumns
     * @see #bindList
     */
    public void setJoinColumns(String[] value) {
    }

    /**
     * Gets the number of digits to the right of the decimal point for
     * this component's value.
     * @return the number of digits to the right of the decimal point
     */
    public int getScale() {
        return ProjBinder.DEFAULTSCALE;
    }

    /**
     * Registers the standard event listener(s) for this component.
     */
    public void registerListeners() {
        addItemListener(m_Helper);
    }

     /**
     * Sets the value of the Empty Means Null property.
     * This determines how an empty string will be saved when updating data on
     * the database server.
     * A value of <code>true</code>indicates an empty string will be saved as a
     * SQL NULL value. Otherwise it will be saved as a blank value.
     * @param propertyValue <code>true</code> for NULL, <code>false</code> for BLANK
     * @see #getEmptyMeansNull
     */
    public void setEmptyMeansNull(boolean propertyValue)
    {
        m_Helper.setEmptyMeansNull(propertyValue);
    }

     /**
     * Gets the value of the Empty Means Null property.
     * This determines how an empty string will be saved when updating data on
     * the database server.
     * A value of <code>true</code>indicates an empty string will be saved as a
     * SQL NULL value. Otherwise it will be saved as a blank value.
     * @return <code>true</code> for NULL, <code>false</code> for BLANK
     * @see #setEmptyMeansNull
     */
    public boolean getEmptyMeansNull()
    {
        return m_Helper.getEmptyMeansNull();
    }
}