/* DefaultListSelectionModel.java --
Copyright (C) 2002, 2004 Free Software Foundation, Inc.
This file is part of GNU Classpath.
GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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GNU Classpath is distributed in the hope that it will be useful, but
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02111-1307 USA.
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package javax.swing;
import java.io.Serializable;
import java.util.BitSet;
import java.util.EventListener;
import javax.swing.event.EventListenerList;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
/**
* <p>This class provides a default implementation of {@link
* ListSelectioModel}, which is used by {@link javax.swing.JList} and
* similar classes to manage the selection status of a number of data
* elements. </p>
*
* <p>The class is organized <em>abstractly</em> as a set of intervals of
* integers. Each interval indicates an inclusive range of indices in a
* list -- held by some other object and unknown to this class -- which is
* considered "selected". There are various accessors for querying and
* modifying the set of intervals, with simplified forms accepting a single
* index, representing an interval with only one element. </p>
*/
public class DefaultListSelectionModel implements Cloneable,
ListSelectionModel,
Serializable
{
private static final long serialVersionUID = -5718799865110415860L;
/** The list of ListSelectionListeners subscribed to this selection model. */
protected EventListenerList listenerList = new EventListenerList();
/**
* The current list selection mode. Must be one of the numeric constants
* <code>SINGLE_SELECTION</code>, <code>SINGLE_INTERVAL_SELECTION</code>
* or <code>MULTIPLE_INTERVAL_SELECTION</code> from {@link
* ListSelectionModel}. The default value is
* <code>MULTIPLE_INTERVAL_SELECTION</code>.
*/
int selectionMode = MULTIPLE_INTERVAL_SELECTION;
/**
* The index of the "lead" of the most recent selection. The lead is the
* second argument in any call to {@link #setSelectionInterval}, {@link
* #addSelectionInterval} or {@link #removeSelectionInterval}. Generally
* the lead refers to the most recent position a user dragged their mouse
* over.
*/
int leadSelectionIndex = -1;
/**
* The index of the "anchor" of the most recent selection. The anchor is
* the first argument in any call to {@link #setSelectionInterval},
* {@link #addSelectionInterval} or {@link
* #removeSelectionInterval}. Generally the anchor refers to the first
* recent position a user clicks when they begin to drag their mouse over
* a list.
*
* @see #getAnchorSelectionIndex
* @see #setAnchorSelectionIndex
*/
int anchorSelectionIndex = -1;
/**
* controls the range of indices provided in any {@link
* ListSelectionEvent} fired by the selectionModel. Let
* <code>[A,L]</code> be the range of indices between {@link
* anchorSelectionIndex} and {@link leadSelectionIndex} inclusive, and
* let <code>[i0,i1]</code> be the range of indices changed in a given
* call which generates a {@link ListSelectionEvent}. Then when this
* property is <code>true</code>, the {@link ListSelectionEvent} contains
* the range <code>[A,L] union [i0,i1]</code>; when <code>false</code> it
* will contain only <code>[i0,i1]</code>. The default is
* <code>true</code>.
*
* @see #isLeadAnchorNotificationEnabled
* @see #setLeadAnchorNotificationEnabled
*/
boolean leadAnchorNotificationEnabled = true;
/**
* Whether the selection is currently "adjusting". Any {@link
* ListSelectionEvent} events constructed in response to changes in this
* list selection model will have their {@link
* ListSelectionEvent#isAdjusting} field set to this value.
*
* @see #getValueIsAdjusting
* @see #setValueIsAdjusting
*/
boolean valueIsAdjusting = false;
/**
* The current set of "intervals", represented simply by a {@link
* java.util.BitSet}. A set bit indicates a selected index, whereas a
* cleared bit indicates a non-selected index.
*/
BitSet sel = new BitSet();
/**
* Gets the value of the {@link #selectionMode} property.
*
* @return The current value of the property
*/
public int getSelectionMode()
{
return selectionMode;
}
/**
* Sets the value of the {@link #selectionMode} property.
*
* @param a The new value of the property
*/
public void setSelectionMode(int a)
{
selectionMode = a;
}
/**
* Gets the value of the {@link #anchorSelectionIndex} property.
*
* @return The current property value
*
* @see #setAnchorSelectionIndex
*/
public int getAnchorSelectionIndex()
{
return anchorSelectionIndex;
}
/**
* Sets the value of the {@link #anchorSelectionIndex} property.
*
* @param anchorIndex The new property value
*
* @see #getAnchorSelectionIndex
*/
public void setAnchorSelectionIndex(int anchorIndex)
{
anchorSelectionIndex = anchorIndex;
}
/**
* Gets the value of the {@link #leadSelectionIndex} property.
*
* @return The current property value
*
* @see #setLeadSelectionIndex
*/
public int getLeadSelectionIndex()
{
return leadSelectionIndex;
}
/**
* <p>Sets the value of the {@link #anchorSelectionIndex} property. As a
* side effect, alters the selection status of two ranges of indices. Let
* <code>OL</code> be the old lead selection index, <code>NL</code> be
* the new lead selection index, and <code>A</code> be the anchor
* selection index. Then if <code>A</code> is a valid selection index,
* one of two things happens depending on the seleciton status of
* <code>A</code>:</p>
*
* <ul>
*
* <li><code>isSelectedIndex(A) == true</code>: set <code>[A,OL]</code>
* to <em>deselected</em>, then set <code>[A,NL]</code> to
* <em>selected</em>.</li>
*
* <li><code>isSelectedIndex(A) == false</code>: set <code>[A,OL]</code>
* to <em>selected</em>, then set <code>[A,NL]</code> to
* <em>deselected</em>.</li>
*
* </ul>
*
* <p>This method generates at most a single {@link ListSelectionEvent}
* despite changing multiple ranges. The range of values provided to the
* {@link ListSelectionEvent} includes only the minimum range of values
* which changed selection status between the beginning and end of the
* method.</p>
*
* @param anchorIndex The new property value
*
* @see #getAnchorSelectionIndex
*/
public void setLeadSelectionIndex(int leadIndex)
{
int oldLeadIndex = leadSelectionIndex;
leadSelectionIndex = leadIndex;
if (anchorSelectionIndex == -1)
return;
int R1 = Math.min(anchorSelectionIndex, oldLeadIndex);
int R2 = Math.max(anchorSelectionIndex, oldLeadIndex);
int S1 = Math.min(anchorSelectionIndex, leadIndex);
int S2 = Math.max(anchorSelectionIndex, leadIndex);
int lo = Math.min(R1, S1);
int hi = Math.max(R2, S2);
BitSet oldRange = sel.get(lo, hi+1);
if (isSelectedIndex(anchorSelectionIndex))
{
sel.clear(R1, R2+1);
sel.set(S1, S2+1);
}
else
{
sel.set(R1, R2+1);
sel.clear(S1, S2+1);
}
BitSet newRange = sel.get(lo, hi+1);
newRange.xor(oldRange);
int beg = sel.nextSetBit(0), end = -1;
for(int i=beg; i >= 0; i=sel.nextSetBit(i+1))
{
end = i;
}
fireValueChanged(beg, end, valueIsAdjusting);
}
/**
* Gets the value of the {@link #leadAnchorNotificationEnabled} property.
*
* @return The current property value
*
* @see #setLeadAnchorNotificationEnabled
*/
public boolean isLeadAnchorNotificationEnabled()
{
return leadAnchorNotificationEnabled;
}
/**
* Sets the value of the {@link #leadAnchorNotificationEnabled} property.
*
* @param flag The new property value
*
* @see #getLeadAnchorNotificationEnabled
*/
public void setLeadAnchorNotificationEnabled(boolean l)
{
leadAnchorNotificationEnabled = l;
}
/**
* Gets the value of the {@link #valueIsAdjusting} property.
*
* @return The current property value
*
* @see #setValueIsAdjusting
*/
public boolean getValueIsAdjusting()
{
return valueIsAdjusting;
}
/**
* Sets the value of the {@link #valueIsAdjusting} property.
*
* @param v The new property value
*
* @see #getValueIsAdjusting
*/
public void setValueIsAdjusting(boolean v)
{
valueIsAdjusting = v;
}
/**
* Determines whether the selection is empty.
*
* @return <code>true</code> if the selection is empty, otherwise
* <code>false</code>
*/
public boolean isSelectionEmpty()
{
return sel.isEmpty();
}
/**
* Gets the smallest index which is currently a member of a selection
* interval.
*
* @return The least integer <code>i</code> such that <code>i >=
* 0</code> and <code>i</code> is a member of a selected interval, or
* <code>-1</code> if there are no selected intervals
*
* @see #getMaxSelectionIndex
*/
public int getMinSelectionIndex()
{
if (isSelectionEmpty())
return -1;
return sel.nextSetBit(0);
}
/**
* Gets the largest index which is currently a member of a selection
* interval.
*
* @return The greatest integer <code>i</code> such that <code>i >=
* 0</code> and <code>i</code> is a member of a selected interval, or
* <code>-1</code> if there are no selected intervals
*
* @see #getMinSelectionIndex
*/
public int getMaxSelectionIndex()
{
if (isSelectionEmpty())
return -1;
int mx = -1;
for(int i=sel.nextSetBit(0); i >= 0; i=sel.nextSetBit(i+1))
{
mx = i;
}
return mx;
}
/**
* Determines whether a particular index is a member of a selection
* interval.
*
* @param a The index to search for
*
* @return <code>true</code> if the index is a member of a selection interval,
* otherwise <code>false</code>
*/
public boolean isSelectedIndex(int a)
{
return sel.get(a);
}
/**
* If the {@link #selectionMode} property is equal to
* <code>SINGLE_SELECTION</code> or
* <code>SINGLE_INTERVAL_SELECTION</code>, equivalent to calling
* <code>setSelectionInterval(index1, index2)</code>; otherwise adds the
* range <code>[index0, index1]</code> to the selection interval set.
*
* @param index0 The beginning of the range of indices to select
* @param index1 The end of the range of indices to select
*
* @see #setSelectionInterval
* @see #removeSelectionInterval
*/
public void addSelectionInterval(int index0, int index1)
{
if (selectionMode == SINGLE_SELECTION
|| selectionMode == SINGLE_INTERVAL_SELECTION)
sel.clear();
if (selectionMode == SINGLE_SELECTION)
index0 = index1;
int lo = Math.min(index0, index1);
int hi = Math.max(index0, index1);
sel.set(lo, hi+1);
fireValueChanged(lo, hi, valueIsAdjusting);
}
/**
* Deselects all indices in the inclusive range
* <code>[index0,index1]</code>.
*
* @param index0 The beginning of the range of indices to deselect
* @param index1 The end of the range of indices to deselect
*
* @see #addSelectionInterval
* @see #setSelectionInterval
*/
public void removeSelectionInterval(int index0,
int index1)
{
int lo = Math.min(index0, index1);
int hi = Math.max(index0, index1);
sel.clear(lo, hi+1);
fireValueChanged(lo, hi, valueIsAdjusting);
}
/**
* Removes all intervals in the selection set.
*/
public void clearSelection()
{
int sz = sel.size();
sel.clear();
fireValueChanged(0, sz, valueIsAdjusting);
}
/**
* Clears the current selection and marks a given interval as
* "selected". If the current selection mode is
* <code>SINGLE_SELECTION</code> only the index <code>index2</code> is
* selected.
*
* @param index0 The low end of the new selection
* @param index1 The high end of the new selection
*/
public void setSelectionInterval(int index0, int index1)
{
sel.clear();
if (selectionMode == SINGLE_SELECTION)
index0 = index1;
int lo = Math.min(index0, index1);
int hi = Math.max(index0, index1);
sel.set(lo, hi+1);
fireValueChanged(lo, hi, valueIsAdjusting);
}
/**
* Inserts a number of indices either before or after a particular
* position in the set of indices. Renumbers all indices after the
* inserted range. The new indices in the inserted range are not
* selected. This method is typically called to synchronize the selection
* model with an inserted range of elements in a {@link ListModel}.
*
* @param index The position to insert indices at
* @param length The number of indices to insert
* @param before Indicates whether to insert the indices before the index
* or after it
*/
public void insertIndexInterval(int index,
int length,
boolean before)
{
if (!before)
{
index++;
length--;
}
BitSet tmp = sel.get(index, sel.size());
sel.clear(index, sel.size());
int n = tmp.size();
for (int i = 0; i < n; ++i)
sel.set(index + length + i, tmp.get(i));
}
/**
* Removes a range from the set of indices. Renumbers all indices after
* the removed range. This method is typically called to synchronize the
* selection model with a deleted range of elements in a {@link
* ListModel}.
*
* @param index0 The first index to remove (inclusive)
* @param index1 The last index to remove (inclusive)
*/
public void removeIndexInterval(int index0,
int index1)
{
int lo = Math.min(index0, index1);
int hi = Math.max(index0, index1);
BitSet tmp = sel.get(hi, sel.size());
sel.clear(lo, sel.size());
int n = tmp.size();
for (int i = 0; i < n; ++i)
sel.set(lo + i, tmp.get(i));
}
/**
* Fires a {@link ListSelectionEvent} to all the listeners of type {@link
* ListSelectionListener} registered with this selection model.
*
* @param firstIndex The low index of the changed range
* @param lastIndex The high index of the changed range
* @param isAdjusting Whether this change is part of a seqence of adjustments
* made to the selection, such as during interactive scrolling
*/
protected void fireValueChanged(int firstIndex, int lastIndex,
boolean isAdjusting)
{
ListSelectionEvent evt = new ListSelectionEvent(this, firstIndex,
lastIndex, isAdjusting);
ListSelectionListener[] listeners = getListSelectionListeners();
for (int i = 0; i < listeners.length; ++i)
listeners[i].valueChanged(evt);
}
/**
* Adds a listener.
*
* @param listener The listener to add
*
* @see removeListSelectionListener
* @see getListSelectionListeners
*/
public void addListSelectionListener(ListSelectionListener listener)
{
listenerList.add(ListSelectionListener.class, listener);
}
/**
* Removes a registered listener.
*
* @param listener The listener to remove
*
* @see addListSelectionListener
* @see getListSelectionListeners
*/
public void removeListSelectionListener(ListSelectionListener listener)
{
listenerList.remove(ListSelectionListener.class, listener);
}
/**
* Returns an array of all registerers listeners.
*
* @param listenerType The type of listener to retrieve
*
* @return The array
*
* @see getListSelectionListener
* @since 1.3
*/
public EventListener[] getListeners(Class listenerType)
{
return listenerList.getListeners(listenerType);
}
/**
* Returns an array of all registerd list selection listeners.
*
* @return the array
*
* @see addListSelectionListener
* @see removeListSelectionListener
* @see getListeners
* @since 1.4
*/
public ListSelectionListener[] getListSelectionListeners()
{
return (ListSelectionListener[]) getListeners(ListSelectionListener.class);
}
}