       1 /*
       2  * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.
       3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       4  *
       5  * This code is free software; you can redistribute it and/or modify it
       6  * under the terms of the GNU General Public License version 2 only, as
       7  * published by the Free Software Foundation.  Oracle designates this
       8  * particular file as subject to the "Classpath" exception as provided
       9  * by Oracle in the LICENSE file that accompanied this code.
      10  *
      11  * This code is distributed in the hope that it will be useful, but WITHOUT
      12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
      13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      14  * version 2 for more details (a copy is included in the LICENSE file that
      15  * accompanied this code).
      16  *
      17  * You should have received a copy of the GNU General Public License version
      18  * 2 along with this work; if not, write to the Free Software Foundation,
      19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
      20  *
      21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
      22  * or visit www.oracle.com if you need additional information or have any
      23  * questions.
      24  */
      25 package javax.swing.text.html;
      26
      27 import javax.swing.*;
      28 import javax.swing.event.*;
      29 import java.util.BitSet;
      30 import java.io.Serializable;
      31
      32
      33 /**
      34  * This class extends DefaultListModel, and also implements
      35  * the ListSelectionModel interface, allowing for it to store state
      36  * relevant to a SELECT form element which is implemented as a List.
      37  * If SELECT has a size attribute whose value is greater than 1,
      38  * or if allows multiple selection then a JList is used to
      39  * represent it and the OptionListModel is used as its model.
      40  * It also stores the initial state of the JList, to ensure an
      41  * accurate reset, if the user requests a reset of the form.
      42  *
      43  * @author Sunita Mani
      44  */
      45 @SuppressWarnings("serial") // Superclass is not serializable across versions
      46 class OptionListModel extends DefaultListModel<Option> implements ListSelectionModel, Serializable {
      47
      48
      49     private static final int MIN = -1;
      50     private static final int MAX = Integer.MAX_VALUE;
      51     private int selectionMode = SINGLE_SELECTION;
      52     private int minIndex = MAX;
      53     private int maxIndex = MIN;
      54     private int anchorIndex = -1;
      55     private int leadIndex = -1;
      56     private int firstChangedIndex = MAX;
      57     private int lastChangedIndex = MIN;
      58     private boolean isAdjusting = false;
      59     private BitSet value = new BitSet(32);
      60     private BitSet initialValue = new BitSet(32);
      61     protected EventListenerList listenerList = new EventListenerList();
      62
      63     protected boolean leadAnchorNotificationEnabled = true;
      64
      65     public int getMinSelectionIndex() { return isSelectionEmpty() ? -1 : minIndex; }
      66
      67     public int getMaxSelectionIndex() { return maxIndex; }
      68
      69     public boolean getValueIsAdjusting() { return isAdjusting; }
      70
      71     public int getSelectionMode() { return selectionMode; }
      72
      73     public void setSelectionMode(int selectionMode) {
      74         switch (selectionMode) {
      75         case SINGLE_SELECTION:
      76         case SINGLE_INTERVAL_SELECTION:
      77         case MULTIPLE_INTERVAL_SELECTION:
      78             this.selectionMode = selectionMode;
      79             break;
      80         default:
      81             throw new IllegalArgumentException("invalid selectionMode");
      82         }
      83     }
      84
      85     public boolean isSelectedIndex(int index) {
      86         return ((index < minIndex) || (index > maxIndex)) ? false : value.get(index);
      87     }
      88
      89     public boolean isSelectionEmpty() {
      90         return (minIndex > maxIndex);
      91     }
      92
      93     public void addListSelectionListener(ListSelectionListener l) {
      94         listenerList.add(ListSelectionListener.class, l);
      95     }
      96
      97     public void removeListSelectionListener(ListSelectionListener l) {
      98         listenerList.remove(ListSelectionListener.class, l);
      99     }
     100
     101     /**
     102      * Returns an array of all the <code>ListSelectionListener</code>s added
     103      * to this OptionListModel with addListSelectionListener().
     104      *
     105      * @return all of the <code>ListSelectionListener</code>s added or an empty
     106      *         array if no listeners have been added
     107      * @since 1.4
     108      */
     109     public ListSelectionListener[] getListSelectionListeners() {
     110         return listenerList.getListeners(ListSelectionListener.class);
     111     }
     112
     113     /**
     114      * Notify listeners that we are beginning or ending a
     115      * series of value changes
     116      */
     117     protected void fireValueChanged(boolean isAdjusting) {
     118         fireValueChanged(getMinSelectionIndex(), getMaxSelectionIndex(), isAdjusting);
     119     }
     120
     121
     122     /**
     123      * Notify ListSelectionListeners that the value of the selection,
     124      * in the closed interval firstIndex,lastIndex, has changed.
     125      */
     126     protected void fireValueChanged(int firstIndex, int lastIndex) {
     127         fireValueChanged(firstIndex, lastIndex, getValueIsAdjusting());
     128     }
     129
     130     /**
     131      * @param firstIndex The first index in the interval.
     132      * @param lastIndex The last index in the interval.
     133      * @param isAdjusting True if this is the final change in a series of them.
     134      * @see EventListenerList
     135      */
     136     protected void fireValueChanged(int firstIndex, int lastIndex, boolean isAdjusting)
     137     {
     138         Object[] listeners = listenerList.getListenerList();
     139         ListSelectionEvent e = null;
     140
     141         for (int i = listeners.length - 2; i >= 0; i -= 2) {
     142             if (listeners[i] == ListSelectionListener.class) {
     143                 if (e == null) {
     144                     e = new ListSelectionEvent(this, firstIndex, lastIndex, isAdjusting);
     145                 }
     146                 ((ListSelectionListener)listeners[i+1]).valueChanged(e);
     147             }
     148         }
     149     }
     150
     151     private void fireValueChanged() {
     152         if (lastChangedIndex == MIN) {
     153             return;
     154         }
     155         /* Change the values before sending the event to the
     156          * listeners in case the event causes a listener to make
     157          * another change to the selection.
     158          */
     159         int oldFirstChangedIndex = firstChangedIndex;
     160         int oldLastChangedIndex = lastChangedIndex;
     161         firstChangedIndex = MAX;
     162         lastChangedIndex = MIN;
     163         fireValueChanged(oldFirstChangedIndex, oldLastChangedIndex);
     164     }
     165
     166
     167     // Update first and last change indices
     168     private void markAsDirty(int r) {
     169         firstChangedIndex = Math.min(firstChangedIndex, r);
     170         lastChangedIndex =  Math.max(lastChangedIndex, r);
     171     }
     172
     173     // Set the state at this index and update all relevant state.
     174     private void set(int r) {
     175         if (value.get(r)) {
     176             return;
     177         }
     178         value.set(r);
     179         Option option = get(r);
     180         option.setSelection(true);
     181         markAsDirty(r);
     182
     183         // Update minimum and maximum indices
     184         minIndex = Math.min(minIndex, r);
     185         maxIndex = Math.max(maxIndex, r);
     186     }
     187
     188     // Clear the state at this index and update all relevant state.
     189     private void clear(int r) {
     190         if (!value.get(r)) {
     191             return;
     192         }
     193         value.clear(r);
     194         Option option = get(r);
     195         option.setSelection(false);
     196         markAsDirty(r);
     197
     198         // Update minimum and maximum indices
     199         /*
     200            If (r > minIndex) the minimum has not changed.
     201            The case (r < minIndex) is not possible because r'th value was set.
     202            We only need to check for the case when lowest entry has been cleared,
     203            and in this case we need to search for the first value set above it.
     204         */
     205         if (r == minIndex) {
     206             for(minIndex = minIndex + 1; minIndex <= maxIndex; minIndex++) {
     207                 if (value.get(minIndex)) {
     208                     break;
     209                 }
     210             }
     211         }
     212         /*
     213            If (r < maxIndex) the maximum has not changed.
     214            The case (r > maxIndex) is not possible because r'th value was set.
     215            We only need to check for the case when highest entry has been cleared,
     216            and in this case we need to search for the first value set below it.
     217         */
     218         if (r == maxIndex) {
     219             for(maxIndex = maxIndex - 1; minIndex <= maxIndex; maxIndex--) {
     220                 if (value.get(maxIndex)) {
     221                     break;
     222                 }
     223             }
     224         }
     225         /* Performance note: This method is called from inside a loop in
     226            changeSelection() but we will only iterate in the loops
     227            above on the basis of one iteration per deselected cell - in total.
     228            Ie. the next time this method is called the work of the previous
     229            deselection will not be repeated.
     230
     231            We also don't need to worry about the case when the min and max
     232            values are in their unassigned states. This cannot happen because
     233            this method's initial check ensures that the selection was not empty
     234            and therefore that the minIndex and maxIndex had 'real' values.
     235
     236            If we have cleared the whole selection, set the minIndex and maxIndex
     237            to their cannonical values so that the next set command always works
     238            just by using Math.min and Math.max.
     239         */
     240         if (isSelectionEmpty()) {
     241             minIndex = MAX;
     242             maxIndex = MIN;
     243         }
     244     }
     245
     246     /**
     247      * Sets the value of the leadAnchorNotificationEnabled flag.
     248      * @see             #isLeadAnchorNotificationEnabled()
     249      */
     250     public void setLeadAnchorNotificationEnabled(boolean flag) {
     251         leadAnchorNotificationEnabled = flag;
     252     }
     253
     254     /**
     255      * Returns the value of the leadAnchorNotificationEnabled flag.
     256      * When leadAnchorNotificationEnabled is true the model
     257      * generates notification events with bounds that cover all the changes to
     258      * the selection plus the changes to the lead and anchor indices.
     259      * Setting the flag to false causes a norrowing of the event's bounds to
     260      * include only the elements that have been selected or deselected since
     261      * the last change. Either way, the model continues to maintain the lead
     262      * and anchor variables internally. The default is true.
     263      * @return          the value of the leadAnchorNotificationEnabled flag
     264      * @see             #setLeadAnchorNotificationEnabled(boolean)
     265      */
     266     public boolean isLeadAnchorNotificationEnabled() {
     267         return leadAnchorNotificationEnabled;
     268     }
     269
     270     private void updateLeadAnchorIndices(int anchorIndex, int leadIndex) {
     271         if (leadAnchorNotificationEnabled) {
     272             if (this.anchorIndex != anchorIndex) {
     273                 if (this.anchorIndex != -1) { // The unassigned state.
     274                     markAsDirty(this.anchorIndex);
     275                 }
     276                 markAsDirty(anchorIndex);
     277             }
     278
     279             if (this.leadIndex != leadIndex) {
     280                 if (this.leadIndex != -1) { // The unassigned state.
     281                     markAsDirty(this.leadIndex);
     282                 }
     283                 markAsDirty(leadIndex);
     284             }
     285         }
     286         this.anchorIndex = anchorIndex;
     287         this.leadIndex = leadIndex;
     288     }
     289
     290     private boolean contains(int a, int b, int i) {
     291         return (i >= a) && (i <= b);
     292     }
     293
     294     private void changeSelection(int clearMin, int clearMax,
     295                                  int setMin, int setMax, boolean clearFirst) {
     296         for(int i = Math.min(setMin, clearMin); i <= Math.max(setMax, clearMax); i++) {
     297
     298             boolean shouldClear = contains(clearMin, clearMax, i);
     299             boolean shouldSet = contains(setMin, setMax, i);
     300
     301             if (shouldSet && shouldClear) {
     302                 if (clearFirst) {
     303                     shouldClear = false;
     304                 }
     305                 else {
     306                     shouldSet = false;
     307                 }
     308             }
     309
     310             if (shouldSet) {
     311                 set(i);
     312             }
     313             if (shouldClear) {
     314                 clear(i);
     315             }
     316         }
     317         fireValueChanged();
     318     }
     319
     320    /*   Change the selection with the effect of first clearing the values
     321     *   in the inclusive range [clearMin, clearMax] then setting the values
     322     *   in the inclusive range [setMin, setMax]. Do this in one pass so
     323     *   that no values are cleared if they would later be set.
     324     */
     325     private void changeSelection(int clearMin, int clearMax, int setMin, int setMax) {
     326         changeSelection(clearMin, clearMax, setMin, setMax, true);
     327     }
     328
     329     public void clearSelection() {
     330         removeSelectionInterval(minIndex, maxIndex);
     331     }
     332
     333     public void setSelectionInterval(int index0, int index1) {
     334         if (index0 == -1 || index1 == -1) {
     335             return;
     336         }
     337
     338         if (getSelectionMode() == SINGLE_SELECTION) {
     339             index0 = index1;
     340         }
     341
     342         updateLeadAnchorIndices(index0, index1);
     343
     344         int clearMin = minIndex;
     345         int clearMax = maxIndex;
     346         int setMin = Math.min(index0, index1);
     347         int setMax = Math.max(index0, index1);
     348         changeSelection(clearMin, clearMax, setMin, setMax);
     349     }
     350
     351     public void addSelectionInterval(int index0, int index1)
     352     {
     353         if (index0 == -1 || index1 == -1) {
     354             return;
     355         }
     356
     357         if (getSelectionMode() != MULTIPLE_INTERVAL_SELECTION) {
     358             setSelectionInterval(index0, index1);
     359             return;
     360         }
     361
     362         updateLeadAnchorIndices(index0, index1);
     363
     364         int clearMin = MAX;
     365         int clearMax = MIN;
     366         int setMin = Math.min(index0, index1);
     367         int setMax = Math.max(index0, index1);
     368         changeSelection(clearMin, clearMax, setMin, setMax);
     369     }
     370
     371
     372     public void removeSelectionInterval(int index0, int index1)
     373     {
     374         if (index0 == -1 || index1 == -1) {
     375             return;
     376         }
     377
     378         updateLeadAnchorIndices(index0, index1);
     379
     380         int clearMin = Math.min(index0, index1);
     381         int clearMax = Math.max(index0, index1);
     382         int setMin = MAX;
     383         int setMax = MIN;
     384         changeSelection(clearMin, clearMax, setMin, setMax);
     385     }
     386
     387     private void setState(int index, boolean state) {
     388         if (state) {
     389             set(index);
     390         }
     391         else {
     392             clear(index);
     393         }
     394     }
     395
     396     /**
     397      * Insert length indices beginning before/after index. If the value
     398      * at index is itself selected, set all of the newly inserted
     399      * items, otherwise leave them unselected. This method is typically
     400      * called to sync the selection model with a corresponding change
     401      * in the data model.
     402      */
     403     public void insertIndexInterval(int index, int length, boolean before)
     404     {
     405         /* The first new index will appear at insMinIndex and the last
     406          * one will appear at insMaxIndex
     407          */
     408         int insMinIndex = (before) ? index : index + 1;
     409         int insMaxIndex = (insMinIndex + length) - 1;
     410
     411         /* Right shift the entire bitset by length, beginning with
     412          * index-1 if before is true, index+1 if it's false (i.e. with
     413          * insMinIndex).
     414          */
     415         for(int i = maxIndex; i >= insMinIndex; i--) {
     416             setState(i + length, value.get(i));
     417         }
     418
     419         /* Initialize the newly inserted indices.
     420          */
     421         boolean setInsertedValues = value.get(index);
     422         for(int i = insMinIndex; i <= insMaxIndex; i++) {
     423             setState(i, setInsertedValues);
     424         }
     425     }
     426
     427
     428     /**
     429      * Remove the indices in the interval index0,index1 (inclusive) from
     430      * the selection model.  This is typically called to sync the selection
     431      * model width a corresponding change in the data model.  Note
     432      * that (as always) index0 can be greater than index1.
     433      */
     434     public void removeIndexInterval(int index0, int index1)
     435     {
     436         int rmMinIndex = Math.min(index0, index1);
     437         int rmMaxIndex = Math.max(index0, index1);
     438         int gapLength = (rmMaxIndex - rmMinIndex) + 1;
     439
     440         /* Shift the entire bitset to the left to close the index0, index1
     441          * gap.
     442          */
     443         for(int i = rmMinIndex; i <= maxIndex; i++) {
     444             setState(i, value.get(i + gapLength));
     445         }
     446     }
     447
     448
     449     public void setValueIsAdjusting(boolean isAdjusting) {
     450         if (isAdjusting != this.isAdjusting) {
     451             this.isAdjusting = isAdjusting;
     452             this.fireValueChanged(isAdjusting);
     453         }
     454     }
     455
     456
     457     public String toString() {
     458         String s =  ((getValueIsAdjusting()) ? "~" : "=") + value.toString();
     459         return getClass().getName() + " " + Integer.toString(hashCode()) + " " + s;
     460     }
     461
     462     /**
     463      * Returns a clone of the receiver with the same selection.
     464      * <code>listenerLists</code> are not duplicated.
     465      *
     466      * @return a clone of the receiver
     467      * @exception CloneNotSupportedException if the receiver does not
     468      *    both (a) implement the <code>Cloneable</code> interface
     469      *    and (b) define a <code>clone</code> method
     470      */
     471     public OptionListModel clone() throws CloneNotSupportedException {
     472         @SuppressWarnings("unchecked")
     473         OptionListModel clone = (OptionListModel)super.clone();
     474         clone.value = (BitSet)value.clone();
     475         clone.listenerList = new EventListenerList();
     476         return clone;
     477     }
     478
     479     public int getAnchorSelectionIndex() {
     480         return anchorIndex;
     481     }
     482
     483     public int getLeadSelectionIndex() {
     484         return leadIndex;
     485     }
     486
     487     /**
     488      * Set the anchor selection index, leaving all selection values unchanged.
     489      *
     490      * @see #getAnchorSelectionIndex
     491      * @see #setLeadSelectionIndex
     492      */
     493     public void setAnchorSelectionIndex(int anchorIndex) {
     494         this.anchorIndex = anchorIndex;
     495     }
     496
     497     /**
     498      * Set the lead selection index, ensuring that values between the
     499      * anchor and the new lead are either all selected or all deselected.
     500      * If the value at the anchor index is selected, first clear all the
     501      * values in the range [anchor, oldLeadIndex], then select all the values
     502      * values in the range [anchor, newLeadIndex], where oldLeadIndex is the old
     503      * leadIndex and newLeadIndex is the new one.
     504      * <p>
     505      * If the value at the anchor index is not selected, do the same thing in reverse,
     506      * selecting values in the old range and deselecting values in the new one.
     507      * <p>
     508      * Generate a single event for this change and notify all listeners.
     509      * For the purposes of generating minimal bounds in this event, do the
     510      * operation in a single pass; that way the first and last index inside the
     511      * ListSelectionEvent that is broadcast will refer to cells that actually
     512      * changed value because of this method. If, instead, this operation were
     513      * done in two steps the effect on the selection state would be the same
     514      * but two events would be generated and the bounds around the changed values
     515      * would be wider, including cells that had been first cleared and only
     516      * to later be set.
     517      * <p>
     518      * This method can be used in the mouseDragged() method of a UI class
     519      * to extend a selection.
     520      *
     521      * @see #getLeadSelectionIndex
     522      * @see #setAnchorSelectionIndex
     523      */
     524     public void setLeadSelectionIndex(int leadIndex) {
     525         int anchorIndex = this.anchorIndex;
     526         if (getSelectionMode() == SINGLE_SELECTION) {
     527             anchorIndex = leadIndex;
     528         }
     529
     530         int oldMin = Math.min(this.anchorIndex, this.leadIndex);
     531         int oldMax = Math.max(this.anchorIndex, this.leadIndex);
     532         int newMin = Math.min(anchorIndex, leadIndex);
     533         int newMax = Math.max(anchorIndex, leadIndex);
     534         if (value.get(this.anchorIndex)) {
     535             changeSelection(oldMin, oldMax, newMin, newMax);
     536         }
     537         else {
     538             changeSelection(newMin, newMax, oldMin, oldMax, false);
     539         }
     540         this.anchorIndex = anchorIndex;
     541         this.leadIndex = leadIndex;
     542     }
     543
     544
     545     /**
     546      * This method is responsible for storing the state
     547      * of the initial selection.  If the selectionMode
     548      * is the default, i.e allowing only for SINGLE_SELECTION,
     549      * then the very last OPTION that has the selected
     550      * attribute set wins.
     551      */
     552     public void setInitialSelection(int i) {
     553         if (initialValue.get(i)) {
     554             return;
     555         }
     556         if (selectionMode == SINGLE_SELECTION) {
     557             // reset to empty
     558             initialValue.and(new BitSet());
     559         }
     560         initialValue.set(i);
     561     }
     562
     563     /**
     564      * Fetches the BitSet that represents the initial
     565      * set of selected items in the list.
     566      */
     567     public BitSet getInitialSelection() {
     568         return initialValue;
     569     }
     570 }