| /* |
| * Copyright (c) 1995, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package java.awt; |
| |
| import java.awt.peer.ScrollbarPeer; |
| import java.awt.event.*; |
| import java.util.EventListener; |
| import java.io.ObjectOutputStream; |
| import java.io.ObjectInputStream; |
| import java.io.IOException; |
| import javax.accessibility.*; |
| |
| |
| /** |
| * The {@code Scrollbar} class embodies a scroll bar, a |
| * familiar user-interface object. A scroll bar provides a |
| * convenient means for allowing a user to select from a |
| * range of values. The following three vertical |
| * scroll bars could be used as slider controls to pick |
| * the red, green, and blue components of a color: |
| * <p> |
| * <img src="doc-files/Scrollbar-1.gif" alt="Image shows 3 vertical sliders, side-by-side." |
| * style="float:center; margin: 7px 10px;"> |
| * <p> |
| * Each scroll bar in this example could be created with |
| * code similar to the following: |
| * |
| * <hr><blockquote><pre> |
| * redSlider=new Scrollbar(Scrollbar.VERTICAL, 0, 1, 0, 255); |
| * add(redSlider); |
| * </pre></blockquote><hr> |
| * <p> |
| * Alternatively, a scroll bar can represent a range of values. For |
| * example, if a scroll bar is used for scrolling through text, the |
| * width of the "bubble" (also called the "thumb" or "scroll box") |
| * can be used to represent the amount of text that is visible. |
| * Here is an example of a scroll bar that represents a range: |
| * <p> |
| * <img src="doc-files/Scrollbar-2.gif" |
| * alt="Image shows horizontal slider with starting range of 0 and ending range of 300. The slider thumb is labeled 60." |
| * style="float:center; margin: 7px 10px;"> |
| * <p> |
| * The value range represented by the bubble in this example |
| * is the <em>visible amount</em>. The horizontal scroll bar |
| * in this example could be created with code like the following: |
| * |
| * <hr><blockquote><pre> |
| * ranger = new Scrollbar(Scrollbar.HORIZONTAL, 0, 60, 0, 300); |
| * add(ranger); |
| * </pre></blockquote><hr> |
| * <p> |
| * Note that the actual maximum value of the scroll bar is the |
| * {@code maximum} minus the {@code visible amount}. |
| * In the previous example, because the {@code maximum} is |
| * 300 and the {@code visible amount} is 60, the actual maximum |
| * value is 240. The range of the scrollbar track is 0 - 300. |
| * The left side of the bubble indicates the value of the |
| * scroll bar. |
| * <p> |
| * Normally, the user changes the value of the scroll bar by |
| * making a gesture with the mouse. For example, the user can |
| * drag the scroll bar's bubble up and down, or click in the |
| * scroll bar's unit increment or block increment areas. Keyboard |
| * gestures can also be mapped to the scroll bar. By convention, |
| * the <b>Page Up</b> and <b>Page Down</b> |
| * keys are equivalent to clicking in the scroll bar's block |
| * increment and block decrement areas. |
| * <p> |
| * When the user changes the value of the scroll bar, the scroll bar |
| * receives an instance of {@code AdjustmentEvent}. |
| * The scroll bar processes this event, passing it along to |
| * any registered listeners. |
| * <p> |
| * Any object that wishes to be notified of changes to the |
| * scroll bar's value should implement |
| * {@code AdjustmentListener}, an interface defined in |
| * the package {@code java.awt.event}. |
| * Listeners can be added and removed dynamically by calling |
| * the methods {@code addAdjustmentListener} and |
| * {@code removeAdjustmentListener}. |
| * <p> |
| * The {@code AdjustmentEvent} class defines five types |
| * of adjustment event, listed here: |
| * |
| * <ul> |
| * <li>{@code AdjustmentEvent.TRACK} is sent out when the |
| * user drags the scroll bar's bubble. |
| * <li>{@code AdjustmentEvent.UNIT_INCREMENT} is sent out |
| * when the user clicks in the left arrow of a horizontal scroll |
| * bar, or the top arrow of a vertical scroll bar, or makes the |
| * equivalent gesture from the keyboard. |
| * <li>{@code AdjustmentEvent.UNIT_DECREMENT} is sent out |
| * when the user clicks in the right arrow of a horizontal scroll |
| * bar, or the bottom arrow of a vertical scroll bar, or makes the |
| * equivalent gesture from the keyboard. |
| * <li>{@code AdjustmentEvent.BLOCK_INCREMENT} is sent out |
| * when the user clicks in the track, to the left of the bubble |
| * on a horizontal scroll bar, or above the bubble on a vertical |
| * scroll bar. By convention, the <b>Page Up</b> |
| * key is equivalent, if the user is using a keyboard that |
| * defines a <b>Page Up</b> key. |
| * <li>{@code AdjustmentEvent.BLOCK_DECREMENT} is sent out |
| * when the user clicks in the track, to the right of the bubble |
| * on a horizontal scroll bar, or below the bubble on a vertical |
| * scroll bar. By convention, the <b>Page Down</b> |
| * key is equivalent, if the user is using a keyboard that |
| * defines a <b>Page Down</b> key. |
| * </ul> |
| * <p> |
| * The JDK 1.0 event system is supported for backwards |
| * compatibility, but its use with newer versions of the platform is |
| * discouraged. The five types of adjustment events introduced |
| * with JDK 1.1 correspond to the five event types |
| * that are associated with scroll bars in previous platform versions. |
| * The following list gives the adjustment event type, |
| * and the corresponding JDK 1.0 event type it replaces. |
| * |
| * <ul> |
| * <li>{@code AdjustmentEvent.TRACK} replaces |
| * {@code Event.SCROLL_ABSOLUTE} |
| * <li>{@code AdjustmentEvent.UNIT_INCREMENT} replaces |
| * {@code Event.SCROLL_LINE_UP} |
| * <li>{@code AdjustmentEvent.UNIT_DECREMENT} replaces |
| * {@code Event.SCROLL_LINE_DOWN} |
| * <li>{@code AdjustmentEvent.BLOCK_INCREMENT} replaces |
| * {@code Event.SCROLL_PAGE_UP} |
| * <li>{@code AdjustmentEvent.BLOCK_DECREMENT} replaces |
| * {@code Event.SCROLL_PAGE_DOWN} |
| * </ul> |
| * <p> |
| * <b>Note</b>: We recommend using a {@code Scrollbar} |
| * for value selection only. If you want to implement |
| * a scrollable component inside a container, we recommend you use |
| * a {@link ScrollPane ScrollPane}. If you use a |
| * {@code Scrollbar} for this purpose, you are likely to |
| * encounter issues with painting, key handling, sizing and |
| * positioning. |
| * |
| * @author Sami Shaio |
| * @see java.awt.event.AdjustmentEvent |
| * @see java.awt.event.AdjustmentListener |
| * @since 1.0 |
| */ |
| public class Scrollbar extends Component implements Adjustable, Accessible { |
| |
| /** |
| * A constant that indicates a horizontal scroll bar. |
| */ |
| public static final int HORIZONTAL = 0; |
| |
| /** |
| * A constant that indicates a vertical scroll bar. |
| */ |
| public static final int VERTICAL = 1; |
| |
| /** |
| * The value of the {@code Scrollbar}. |
| * This property must be greater than or equal to {@code minimum} |
| * and less than or equal to |
| * {@code maximum - visibleAmount} |
| * |
| * @serial |
| * @see #getValue |
| * @see #setValue |
| */ |
| int value; |
| |
| /** |
| * The maximum value of the {@code Scrollbar}. |
| * This value must be greater than the {@code minimum} |
| * value.<br> |
| * |
| * @serial |
| * @see #getMaximum |
| * @see #setMaximum |
| */ |
| int maximum; |
| |
| /** |
| * The minimum value of the {@code Scrollbar}. |
| * This value must be less than the {@code maximum} |
| * value.<br> |
| * |
| * @serial |
| * @see #getMinimum |
| * @see #setMinimum |
| */ |
| int minimum; |
| |
| /** |
| * The size of the {@code Scrollbar}'s bubble. |
| * When a scroll bar is used to select a range of values, |
| * the visibleAmount represents the size of this range. |
| * Depending on platform, this may be visually indicated |
| * by the size of the bubble. |
| * |
| * @serial |
| * @see #getVisibleAmount |
| * @see #setVisibleAmount |
| */ |
| int visibleAmount; |
| |
| /** |
| * The {@code Scrollbar}'s orientation--being either horizontal |
| * or vertical. |
| * This value should be specified when the scrollbar is created.<BR> |
| * orientation can be either : {@code VERTICAL} or |
| * {@code HORIZONTAL} only. |
| * |
| * @serial |
| * @see #getOrientation |
| * @see #setOrientation |
| */ |
| int orientation; |
| |
| /** |
| * The amount by which the scrollbar value will change when going |
| * up or down by a line. |
| * This value must be greater than zero. |
| * |
| * @serial |
| * @see #getLineIncrement |
| * @see #setLineIncrement |
| */ |
| int lineIncrement = 1; |
| |
| /** |
| * The amount by which the scrollbar value will change when going |
| * up or down by a page. |
| * This value must be greater than zero. |
| * |
| * @serial |
| * @see #getPageIncrement |
| * @see #setPageIncrement |
| */ |
| int pageIncrement = 10; |
| |
| /** |
| * The adjusting status of the {@code Scrollbar}. |
| * True if the value is in the process of changing as a result of |
| * actions being taken by the user. |
| * |
| * @see #getValueIsAdjusting |
| * @see #setValueIsAdjusting |
| * @since 1.4 |
| */ |
| transient boolean isAdjusting; |
| |
| transient AdjustmentListener adjustmentListener; |
| |
| private static final String base = "scrollbar"; |
| private static int nameCounter = 0; |
| |
| /* |
| * JDK 1.1 serialVersionUID |
| */ |
| private static final long serialVersionUID = 8451667562882310543L; |
| |
| /** |
| * Initialize JNI field and method IDs. |
| */ |
| private static native void initIDs(); |
| |
| static { |
| /* ensure that the necessary native libraries are loaded */ |
| Toolkit.loadLibraries(); |
| if (!GraphicsEnvironment.isHeadless()) { |
| initIDs(); |
| } |
| } |
| |
| /** |
| * Constructs a new vertical scroll bar. |
| * The default properties of the scroll bar are listed in |
| * the following table: |
| * |
| * <table border=1 summary="Scrollbar default properties"> |
| * <tr> |
| * <th>Property</th> |
| * <th>Description</th> |
| * <th>Default Value</th> |
| * </tr> |
| * <tr> |
| * <td>orientation</td> |
| * <td>indicates whether the scroll bar is vertical |
| * <br>or horizontal</td> |
| * <td>{@code Scrollbar.VERTICAL}</td> |
| * </tr> |
| * <tr> |
| * <td>value</td> |
| * <td>value which controls the location |
| * <br>of the scroll bar's bubble</td> |
| * <td>0</td> |
| * </tr> |
| * <tr> |
| * <td>visible amount</td> |
| * <td>visible amount of the scroll bar's range, |
| * <br>typically represented by the size of the |
| * <br>scroll bar's bubble</td> |
| * <td>10</td> |
| * </tr> |
| * <tr> |
| * <td>minimum</td> |
| * <td>minimum value of the scroll bar</td> |
| * <td>0</td> |
| * </tr> |
| * <tr> |
| * <td>maximum</td> |
| * <td>maximum value of the scroll bar</td> |
| * <td>100</td> |
| * </tr> |
| * <tr> |
| * <td>unit increment</td> |
| * <td>amount the value changes when the |
| * <br>Line Up or Line Down key is pressed, |
| * <br>or when the end arrows of the scrollbar |
| * <br>are clicked </td> |
| * <td>1</td> |
| * </tr> |
| * <tr> |
| * <td>block increment</td> |
| * <td>amount the value changes when the |
| * <br>Page Up or Page Down key is pressed, |
| * <br>or when the scrollbar track is clicked |
| * <br>on either side of the bubble </td> |
| * <td>10</td> |
| * </tr> |
| * </table> |
| * |
| * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| * returns true. |
| * @see java.awt.GraphicsEnvironment#isHeadless |
| */ |
| public Scrollbar() throws HeadlessException { |
| this(VERTICAL, 0, 10, 0, 100); |
| } |
| |
| /** |
| * Constructs a new scroll bar with the specified orientation. |
| * <p> |
| * The {@code orientation} argument must take one of the two |
| * values {@code Scrollbar.HORIZONTAL}, |
| * or {@code Scrollbar.VERTICAL}, |
| * indicating a horizontal or vertical scroll bar, respectively. |
| * |
| * @param orientation indicates the orientation of the scroll bar |
| * @exception IllegalArgumentException when an illegal value for |
| * the {@code orientation} argument is supplied |
| * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| * returns true. |
| * @see java.awt.GraphicsEnvironment#isHeadless |
| */ |
| public Scrollbar(int orientation) throws HeadlessException { |
| this(orientation, 0, 10, 0, 100); |
| } |
| |
| /** |
| * Constructs a new scroll bar with the specified orientation, |
| * initial value, visible amount, and minimum and maximum values. |
| * <p> |
| * The {@code orientation} argument must take one of the two |
| * values {@code Scrollbar.HORIZONTAL}, |
| * or {@code Scrollbar.VERTICAL}, |
| * indicating a horizontal or vertical scroll bar, respectively. |
| * <p> |
| * The parameters supplied to this constructor are subject to the |
| * constraints described in {@link #setValues(int, int, int, int)}. |
| * |
| * @param orientation indicates the orientation of the scroll bar. |
| * @param value the initial value of the scroll bar |
| * @param visible the visible amount of the scroll bar, typically |
| * represented by the size of the bubble |
| * @param minimum the minimum value of the scroll bar |
| * @param maximum the maximum value of the scroll bar |
| * @exception IllegalArgumentException when an illegal value for |
| * the {@code orientation} argument is supplied |
| * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| * returns true. |
| * @see #setValues |
| * @see java.awt.GraphicsEnvironment#isHeadless |
| */ |
| public Scrollbar(int orientation, int value, int visible, int minimum, |
| int maximum) throws HeadlessException { |
| GraphicsEnvironment.checkHeadless(); |
| switch (orientation) { |
| case HORIZONTAL: |
| case VERTICAL: |
| this.orientation = orientation; |
| break; |
| default: |
| throw new IllegalArgumentException("illegal scrollbar orientation"); |
| } |
| setValues(value, visible, minimum, maximum); |
| } |
| |
| /** |
| * Constructs a name for this component. Called by {@code getName} |
| * when the name is {@code null}. |
| */ |
| String constructComponentName() { |
| synchronized (Scrollbar.class) { |
| return base + nameCounter++; |
| } |
| } |
| |
| /** |
| * Creates the {@code Scrollbar}'s peer. The peer allows you to modify |
| * the appearance of the {@code Scrollbar} without changing any of its |
| * functionality. |
| */ |
| public void addNotify() { |
| synchronized (getTreeLock()) { |
| if (peer == null) |
| peer = getComponentFactory().createScrollbar(this); |
| super.addNotify(); |
| } |
| } |
| |
| /** |
| * Returns the orientation of this scroll bar. |
| * |
| * @return the orientation of this scroll bar, either |
| * {@code Scrollbar.HORIZONTAL} or |
| * {@code Scrollbar.VERTICAL} |
| * @see java.awt.Scrollbar#setOrientation |
| */ |
| public int getOrientation() { |
| return orientation; |
| } |
| |
| /** |
| * Sets the orientation for this scroll bar. |
| * |
| * @param orientation the orientation of this scroll bar, either |
| * {@code Scrollbar.HORIZONTAL} or |
| * {@code Scrollbar.VERTICAL} |
| * @see java.awt.Scrollbar#getOrientation |
| * @exception IllegalArgumentException if the value supplied |
| * for {@code orientation} is not a |
| * legal value |
| * @since 1.1 |
| */ |
| public void setOrientation(int orientation) { |
| synchronized (getTreeLock()) { |
| if (orientation == this.orientation) { |
| return; |
| } |
| switch (orientation) { |
| case HORIZONTAL: |
| case VERTICAL: |
| this.orientation = orientation; |
| break; |
| default: |
| throw new IllegalArgumentException("illegal scrollbar orientation"); |
| } |
| /* Create a new peer with the specified orientation. */ |
| if (peer != null) { |
| removeNotify(); |
| addNotify(); |
| invalidate(); |
| } |
| } |
| if (accessibleContext != null) { |
| accessibleContext.firePropertyChange( |
| AccessibleContext.ACCESSIBLE_STATE_PROPERTY, |
| ((orientation == VERTICAL) |
| ? AccessibleState.HORIZONTAL : AccessibleState.VERTICAL), |
| ((orientation == VERTICAL) |
| ? AccessibleState.VERTICAL : AccessibleState.HORIZONTAL)); |
| } |
| } |
| |
| /** |
| * Gets the current value of this scroll bar. |
| * |
| * @return the current value of this scroll bar |
| * @see java.awt.Scrollbar#getMinimum |
| * @see java.awt.Scrollbar#getMaximum |
| */ |
| public int getValue() { |
| return value; |
| } |
| |
| /** |
| * Sets the value of this scroll bar to the specified value. |
| * <p> |
| * If the value supplied is less than the current {@code minimum} |
| * or greater than the current {@code maximum - visibleAmount}, |
| * then either {@code minimum} or {@code maximum - visibleAmount} |
| * is substituted, as appropriate. |
| * <p> |
| * Normally, a program should change a scroll bar's |
| * value only by calling {@code setValues}. |
| * The {@code setValues} method simultaneously |
| * and synchronously sets the minimum, maximum, visible amount, |
| * and value properties of a scroll bar, so that they are |
| * mutually consistent. |
| * <p> |
| * Calling this method does not fire an |
| * {@code AdjustmentEvent}. |
| * |
| * @param newValue the new value of the scroll bar |
| * @see java.awt.Scrollbar#setValues |
| * @see java.awt.Scrollbar#getValue |
| * @see java.awt.Scrollbar#getMinimum |
| * @see java.awt.Scrollbar#getMaximum |
| */ |
| public void setValue(int newValue) { |
| // Use setValues so that a consistent policy relating |
| // minimum, maximum, visible amount, and value is enforced. |
| setValues(newValue, visibleAmount, minimum, maximum); |
| } |
| |
| /** |
| * Gets the minimum value of this scroll bar. |
| * |
| * @return the minimum value of this scroll bar |
| * @see java.awt.Scrollbar#getValue |
| * @see java.awt.Scrollbar#getMaximum |
| */ |
| public int getMinimum() { |
| return minimum; |
| } |
| |
| /** |
| * Sets the minimum value of this scroll bar. |
| * <p> |
| * When {@code setMinimum} is called, the minimum value |
| * is changed, and other values (including the maximum, the |
| * visible amount, and the current scroll bar value) |
| * are changed to be consistent with the new minimum. |
| * <p> |
| * Normally, a program should change a scroll bar's minimum |
| * value only by calling {@code setValues}. |
| * The {@code setValues} method simultaneously |
| * and synchronously sets the minimum, maximum, visible amount, |
| * and value properties of a scroll bar, so that they are |
| * mutually consistent. |
| * <p> |
| * Note that setting the minimum value to {@code Integer.MAX_VALUE} |
| * will result in the new minimum value being set to |
| * {@code Integer.MAX_VALUE - 1}. |
| * |
| * @param newMinimum the new minimum value for this scroll bar |
| * @see java.awt.Scrollbar#setValues |
| * @see java.awt.Scrollbar#setMaximum |
| * @since 1.1 |
| */ |
| public void setMinimum(int newMinimum) { |
| // No checks are necessary in this method since minimum is |
| // the first variable checked in the setValues function. |
| |
| // Use setValues so that a consistent policy relating |
| // minimum, maximum, visible amount, and value is enforced. |
| setValues(value, visibleAmount, newMinimum, maximum); |
| } |
| |
| /** |
| * Gets the maximum value of this scroll bar. |
| * |
| * @return the maximum value of this scroll bar |
| * @see java.awt.Scrollbar#getValue |
| * @see java.awt.Scrollbar#getMinimum |
| */ |
| public int getMaximum() { |
| return maximum; |
| } |
| |
| /** |
| * Sets the maximum value of this scroll bar. |
| * <p> |
| * When {@code setMaximum} is called, the maximum value |
| * is changed, and other values (including the minimum, the |
| * visible amount, and the current scroll bar value) |
| * are changed to be consistent with the new maximum. |
| * <p> |
| * Normally, a program should change a scroll bar's maximum |
| * value only by calling {@code setValues}. |
| * The {@code setValues} method simultaneously |
| * and synchronously sets the minimum, maximum, visible amount, |
| * and value properties of a scroll bar, so that they are |
| * mutually consistent. |
| * <p> |
| * Note that setting the maximum value to {@code Integer.MIN_VALUE} |
| * will result in the new maximum value being set to |
| * {@code Integer.MIN_VALUE + 1}. |
| * |
| * @param newMaximum the new maximum value |
| * for this scroll bar |
| * @see java.awt.Scrollbar#setValues |
| * @see java.awt.Scrollbar#setMinimum |
| * @since 1.1 |
| */ |
| public void setMaximum(int newMaximum) { |
| // minimum is checked first in setValues, so we need to |
| // enforce minimum and maximum checks here. |
| if (newMaximum == Integer.MIN_VALUE) { |
| newMaximum = Integer.MIN_VALUE + 1; |
| } |
| |
| if (minimum >= newMaximum) { |
| minimum = newMaximum - 1; |
| } |
| |
| // Use setValues so that a consistent policy relating |
| // minimum, maximum, visible amount, and value is enforced. |
| setValues(value, visibleAmount, minimum, newMaximum); |
| } |
| |
| /** |
| * Gets the visible amount of this scroll bar. |
| * <p> |
| * When a scroll bar is used to select a range of values, |
| * the visible amount is used to represent the range of values |
| * that are currently visible. The size of the scroll bar's |
| * bubble (also called a thumb or scroll box), usually gives a |
| * visual representation of the relationship of the visible |
| * amount to the range of the scroll bar. |
| * Note that depending on platform, the value of the visible amount property |
| * may not be visually indicated by the size of the bubble. |
| * <p> |
| * The scroll bar's bubble may not be displayed when it is not |
| * moveable (e.g. when it takes up the entire length of the |
| * scroll bar's track, or when the scroll bar is disabled). |
| * Whether the bubble is displayed or not will not affect |
| * the value returned by {@code getVisibleAmount}. |
| * |
| * @return the visible amount of this scroll bar |
| * @see java.awt.Scrollbar#setVisibleAmount |
| * @since 1.1 |
| */ |
| public int getVisibleAmount() { |
| return getVisible(); |
| } |
| |
| /** |
| * Returns the visible amount of this scroll bar. |
| * |
| * @return the visible amount of this scroll bar |
| * @deprecated As of JDK version 1.1, |
| * replaced by {@code getVisibleAmount()}. |
| */ |
| @Deprecated |
| public int getVisible() { |
| return visibleAmount; |
| } |
| |
| /** |
| * Sets the visible amount of this scroll bar. |
| * <p> |
| * When a scroll bar is used to select a range of values, |
| * the visible amount is used to represent the range of values |
| * that are currently visible. The size of the scroll bar's |
| * bubble (also called a thumb or scroll box), usually gives a |
| * visual representation of the relationship of the visible |
| * amount to the range of the scroll bar. |
| * Note that depending on platform, the value of the visible amount property |
| * may not be visually indicated by the size of the bubble. |
| * <p> |
| * The scroll bar's bubble may not be displayed when it is not |
| * moveable (e.g. when it takes up the entire length of the |
| * scroll bar's track, or when the scroll bar is disabled). |
| * Whether the bubble is displayed or not will not affect |
| * the value returned by {@code getVisibleAmount}. |
| * <p> |
| * If the visible amount supplied is less than {@code one} |
| * or greater than the current {@code maximum - minimum}, |
| * then either {@code one} or {@code maximum - minimum} |
| * is substituted, as appropriate. |
| * <p> |
| * Normally, a program should change a scroll bar's |
| * value only by calling {@code setValues}. |
| * The {@code setValues} method simultaneously |
| * and synchronously sets the minimum, maximum, visible amount, |
| * and value properties of a scroll bar, so that they are |
| * mutually consistent. |
| * |
| * @param newAmount the new visible amount |
| * @see java.awt.Scrollbar#getVisibleAmount |
| * @see java.awt.Scrollbar#setValues |
| * @since 1.1 |
| */ |
| public void setVisibleAmount(int newAmount) { |
| // Use setValues so that a consistent policy relating |
| // minimum, maximum, visible amount, and value is enforced. |
| setValues(value, newAmount, minimum, maximum); |
| } |
| |
| /** |
| * Sets the unit increment for this scroll bar. |
| * <p> |
| * The unit increment is the value that is added or subtracted |
| * when the user activates the unit increment area of the |
| * scroll bar, generally through a mouse or keyboard gesture |
| * that the scroll bar receives as an adjustment event. |
| * The unit increment must be greater than zero. |
| * Attempts to set the unit increment to a value lower than 1 |
| * will result in a value of 1 being set. |
| * <p> |
| * In some operating systems, this property |
| * can be ignored by the underlying controls. |
| * |
| * @param v the amount by which to increment or decrement |
| * the scroll bar's value |
| * @see java.awt.Scrollbar#getUnitIncrement |
| * @since 1.1 |
| */ |
| public void setUnitIncrement(int v) { |
| setLineIncrement(v); |
| } |
| |
| /** |
| * Sets the unit increment for this scroll bar. |
| * |
| * @param v the increment value |
| * |
| * @deprecated As of JDK version 1.1, |
| * replaced by {@code setUnitIncrement(int)}. |
| */ |
| @Deprecated |
| public synchronized void setLineIncrement(int v) { |
| int tmp = (v < 1) ? 1 : v; |
| |
| if (lineIncrement == tmp) { |
| return; |
| } |
| lineIncrement = tmp; |
| |
| ScrollbarPeer peer = (ScrollbarPeer)this.peer; |
| if (peer != null) { |
| peer.setLineIncrement(lineIncrement); |
| } |
| } |
| |
| /** |
| * Gets the unit increment for this scrollbar. |
| * <p> |
| * The unit increment is the value that is added or subtracted |
| * when the user activates the unit increment area of the |
| * scroll bar, generally through a mouse or keyboard gesture |
| * that the scroll bar receives as an adjustment event. |
| * The unit increment must be greater than zero. |
| * <p> |
| * In some operating systems, this property |
| * can be ignored by the underlying controls. |
| * |
| * @return the unit increment of this scroll bar |
| * @see java.awt.Scrollbar#setUnitIncrement |
| * @since 1.1 |
| */ |
| public int getUnitIncrement() { |
| return getLineIncrement(); |
| } |
| |
| /** |
| * Returns the unit increment for this scrollbar. |
| * |
| * @return the unit increment for this scrollbar |
| * @deprecated As of JDK version 1.1, |
| * replaced by {@code getUnitIncrement()}. |
| */ |
| @Deprecated |
| public int getLineIncrement() { |
| return lineIncrement; |
| } |
| |
| /** |
| * Sets the block increment for this scroll bar. |
| * <p> |
| * The block increment is the value that is added or subtracted |
| * when the user activates the block increment area of the |
| * scroll bar, generally through a mouse or keyboard gesture |
| * that the scroll bar receives as an adjustment event. |
| * The block increment must be greater than zero. |
| * Attempts to set the block increment to a value lower than 1 |
| * will result in a value of 1 being set. |
| * |
| * @param v the amount by which to increment or decrement |
| * the scroll bar's value |
| * @see java.awt.Scrollbar#getBlockIncrement |
| * @since 1.1 |
| */ |
| public void setBlockIncrement(int v) { |
| setPageIncrement(v); |
| } |
| |
| /** |
| * Sets the block increment for this scroll bar. |
| * |
| * @param v the block increment |
| * @deprecated As of JDK version 1.1, |
| * replaced by {@code setBlockIncrement()}. |
| */ |
| @Deprecated |
| public synchronized void setPageIncrement(int v) { |
| int tmp = (v < 1) ? 1 : v; |
| |
| if (pageIncrement == tmp) { |
| return; |
| } |
| pageIncrement = tmp; |
| |
| ScrollbarPeer peer = (ScrollbarPeer)this.peer; |
| if (peer != null) { |
| peer.setPageIncrement(pageIncrement); |
| } |
| } |
| |
| /** |
| * Gets the block increment of this scroll bar. |
| * <p> |
| * The block increment is the value that is added or subtracted |
| * when the user activates the block increment area of the |
| * scroll bar, generally through a mouse or keyboard gesture |
| * that the scroll bar receives as an adjustment event. |
| * The block increment must be greater than zero. |
| * |
| * @return the block increment of this scroll bar |
| * @see java.awt.Scrollbar#setBlockIncrement |
| * @since 1.1 |
| */ |
| public int getBlockIncrement() { |
| return getPageIncrement(); |
| } |
| |
| /** |
| * Returns the block increment of this scroll bar. |
| * |
| * @return the block increment of this scroll bar |
| * |
| * @deprecated As of JDK version 1.1, |
| * replaced by {@code getBlockIncrement()}. |
| */ |
| @Deprecated |
| public int getPageIncrement() { |
| return pageIncrement; |
| } |
| |
| /** |
| * Sets the values of four properties for this scroll bar: |
| * {@code value}, {@code visibleAmount}, |
| * {@code minimum}, and {@code maximum}. |
| * If the values supplied for these properties are inconsistent |
| * or incorrect, they will be changed to ensure consistency. |
| * <p> |
| * This method simultaneously and synchronously sets the values |
| * of four scroll bar properties, assuring that the values of |
| * these properties are mutually consistent. It enforces the |
| * following constraints: |
| * {@code maximum} must be greater than {@code minimum}, |
| * {@code maximum - minimum} must not be greater |
| * than {@code Integer.MAX_VALUE}, |
| * {@code visibleAmount} must be greater than zero. |
| * {@code visibleAmount} must not be greater than |
| * {@code maximum - minimum}, |
| * {@code value} must not be less than {@code minimum}, |
| * and {@code value} must not be greater than |
| * {@code maximum - visibleAmount} |
| * <p> |
| * Calling this method does not fire an |
| * {@code AdjustmentEvent}. |
| * |
| * @param value is the position in the current window |
| * @param visible is the visible amount of the scroll bar |
| * @param minimum is the minimum value of the scroll bar |
| * @param maximum is the maximum value of the scroll bar |
| * @see #setMinimum |
| * @see #setMaximum |
| * @see #setVisibleAmount |
| * @see #setValue |
| */ |
| public void setValues(int value, int visible, int minimum, int maximum) { |
| int oldValue; |
| synchronized (this) { |
| if (minimum == Integer.MAX_VALUE) { |
| minimum = Integer.MAX_VALUE - 1; |
| } |
| if (maximum <= minimum) { |
| maximum = minimum + 1; |
| } |
| |
| long maxMinusMin = (long) maximum - (long) minimum; |
| if (maxMinusMin > Integer.MAX_VALUE) { |
| maxMinusMin = Integer.MAX_VALUE; |
| maximum = minimum + (int) maxMinusMin; |
| } |
| if (visible > (int) maxMinusMin) { |
| visible = (int) maxMinusMin; |
| } |
| if (visible < 1) { |
| visible = 1; |
| } |
| |
| if (value < minimum) { |
| value = minimum; |
| } |
| if (value > maximum - visible) { |
| value = maximum - visible; |
| } |
| |
| oldValue = this.value; |
| this.value = value; |
| this.visibleAmount = visible; |
| this.minimum = minimum; |
| this.maximum = maximum; |
| ScrollbarPeer peer = (ScrollbarPeer)this.peer; |
| if (peer != null) { |
| peer.setValues(value, visibleAmount, minimum, maximum); |
| } |
| } |
| |
| if ((oldValue != value) && (accessibleContext != null)) { |
| accessibleContext.firePropertyChange( |
| AccessibleContext.ACCESSIBLE_VALUE_PROPERTY, |
| Integer.valueOf(oldValue), |
| Integer.valueOf(value)); |
| } |
| } |
| |
| /** |
| * Returns true if the value is in the process of changing as a |
| * result of actions being taken by the user. |
| * |
| * @return the value of the {@code valueIsAdjusting} property |
| * @see #setValueIsAdjusting |
| * @since 1.4 |
| */ |
| public boolean getValueIsAdjusting() { |
| return isAdjusting; |
| } |
| |
| /** |
| * Sets the {@code valueIsAdjusting} property. |
| * |
| * @param b new adjustment-in-progress status |
| * @see #getValueIsAdjusting |
| * @since 1.4 |
| */ |
| public void setValueIsAdjusting(boolean b) { |
| boolean oldValue; |
| |
| synchronized (this) { |
| oldValue = isAdjusting; |
| isAdjusting = b; |
| } |
| |
| if ((oldValue != b) && (accessibleContext != null)) { |
| accessibleContext.firePropertyChange( |
| AccessibleContext.ACCESSIBLE_STATE_PROPERTY, |
| ((oldValue) ? AccessibleState.BUSY : null), |
| ((b) ? AccessibleState.BUSY : null)); |
| } |
| } |
| |
| |
| |
| /** |
| * Adds the specified adjustment listener to receive instances of |
| * {@code AdjustmentEvent} from this scroll bar. |
| * If l is {@code null}, no exception is thrown and no |
| * action is performed. |
| * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" |
| * >AWT Threading Issues</a> for details on AWT's threading model. |
| * |
| * @param l the adjustment listener |
| * @see #removeAdjustmentListener |
| * @see #getAdjustmentListeners |
| * @see java.awt.event.AdjustmentEvent |
| * @see java.awt.event.AdjustmentListener |
| * @since 1.1 |
| */ |
| public synchronized void addAdjustmentListener(AdjustmentListener l) { |
| if (l == null) { |
| return; |
| } |
| adjustmentListener = AWTEventMulticaster.add(adjustmentListener, l); |
| newEventsOnly = true; |
| } |
| |
| /** |
| * Removes the specified adjustment listener so that it no longer |
| * receives instances of {@code AdjustmentEvent} from this scroll bar. |
| * If l is {@code null}, no exception is thrown and no action |
| * is performed. |
| * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" |
| * >AWT Threading Issues</a> for details on AWT's threading model. |
| * |
| * @param l the adjustment listener |
| * @see #addAdjustmentListener |
| * @see #getAdjustmentListeners |
| * @see java.awt.event.AdjustmentEvent |
| * @see java.awt.event.AdjustmentListener |
| * @since 1.1 |
| */ |
| public synchronized void removeAdjustmentListener(AdjustmentListener l) { |
| if (l == null) { |
| return; |
| } |
| adjustmentListener = AWTEventMulticaster.remove(adjustmentListener, l); |
| } |
| |
| /** |
| * Returns an array of all the adjustment listeners |
| * registered on this scrollbar. |
| * |
| * @return all of this scrollbar's {@code AdjustmentListener}s |
| * or an empty array if no adjustment |
| * listeners are currently registered |
| * @see #addAdjustmentListener |
| * @see #removeAdjustmentListener |
| * @see java.awt.event.AdjustmentEvent |
| * @see java.awt.event.AdjustmentListener |
| * @since 1.4 |
| */ |
| public synchronized AdjustmentListener[] getAdjustmentListeners() { |
| return getListeners(AdjustmentListener.class); |
| } |
| |
| /** |
| * Returns an array of all the objects currently registered |
| * as <code><em>Foo</em>Listener</code>s |
| * upon this {@code Scrollbar}. |
| * <code><em>Foo</em>Listener</code>s are registered using the |
| * <code>add<em>Foo</em>Listener</code> method. |
| * <p> |
| * You can specify the {@code listenerType} argument |
| * with a class literal, such as |
| * <code><em>Foo</em>Listener.class</code>. |
| * For example, you can query a |
| * {@code Scrollbar c} |
| * for its mouse listeners with the following code: |
| * |
| * <pre>MouseListener[] mls = (MouseListener[])(c.getListeners(MouseListener.class));</pre> |
| * |
| * If no such listeners exist, this method returns an empty array. |
| * |
| * @param listenerType the type of listeners requested; this parameter |
| * should specify an interface that descends from |
| * {@code java.util.EventListener} |
| * @return an array of all objects registered as |
| * <code><em>Foo</em>Listener</code>s on this component, |
| * or an empty array if no such listeners have been added |
| * @exception ClassCastException if {@code listenerType} |
| * doesn't specify a class or interface that implements |
| * {@code java.util.EventListener} |
| * |
| * @since 1.3 |
| */ |
| public <T extends EventListener> T[] getListeners(Class<T> listenerType) { |
| EventListener l = null; |
| if (listenerType == AdjustmentListener.class) { |
| l = adjustmentListener; |
| } else { |
| return super.getListeners(listenerType); |
| } |
| return AWTEventMulticaster.getListeners(l, listenerType); |
| } |
| |
| // REMIND: remove when filtering is done at lower level |
| boolean eventEnabled(AWTEvent e) { |
| if (e.id == AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED) { |
| if ((eventMask & AWTEvent.ADJUSTMENT_EVENT_MASK) != 0 || |
| adjustmentListener != null) { |
| return true; |
| } |
| return false; |
| } |
| return super.eventEnabled(e); |
| } |
| |
| /** |
| * Processes events on this scroll bar. If the event is an |
| * instance of {@code AdjustmentEvent}, it invokes the |
| * {@code processAdjustmentEvent} method. |
| * Otherwise, it invokes its superclass's |
| * {@code processEvent} method. |
| * <p>Note that if the event parameter is {@code null} |
| * the behavior is unspecified and may result in an |
| * exception. |
| * |
| * @param e the event |
| * @see java.awt.event.AdjustmentEvent |
| * @see java.awt.Scrollbar#processAdjustmentEvent |
| * @since 1.1 |
| */ |
| protected void processEvent(AWTEvent e) { |
| if (e instanceof AdjustmentEvent) { |
| processAdjustmentEvent((AdjustmentEvent)e); |
| return; |
| } |
| super.processEvent(e); |
| } |
| |
| /** |
| * Processes adjustment events occurring on this |
| * scrollbar by dispatching them to any registered |
| * {@code AdjustmentListener} objects. |
| * <p> |
| * This method is not called unless adjustment events are |
| * enabled for this component. Adjustment events are enabled |
| * when one of the following occurs: |
| * <ul> |
| * <li>An {@code AdjustmentListener} object is registered |
| * via {@code addAdjustmentListener}. |
| * <li>Adjustment events are enabled via {@code enableEvents}. |
| * </ul> |
| * <p>Note that if the event parameter is {@code null} |
| * the behavior is unspecified and may result in an |
| * exception. |
| * |
| * @param e the adjustment event |
| * @see java.awt.event.AdjustmentEvent |
| * @see java.awt.event.AdjustmentListener |
| * @see java.awt.Scrollbar#addAdjustmentListener |
| * @see java.awt.Component#enableEvents |
| * @since 1.1 |
| */ |
| protected void processAdjustmentEvent(AdjustmentEvent e) { |
| AdjustmentListener listener = adjustmentListener; |
| if (listener != null) { |
| listener.adjustmentValueChanged(e); |
| } |
| } |
| |
| /** |
| * Returns a string representing the state of this {@code Scrollbar}. |
| * This method is intended to be used only for debugging purposes, and the |
| * content and format of the returned string may vary between |
| * implementations. The returned string may be empty but may not be |
| * {@code null}. |
| * |
| * @return the parameter string of this scroll bar |
| */ |
| protected String paramString() { |
| return super.paramString() + |
| ",val=" + value + |
| ",vis=" + visibleAmount + |
| ",min=" + minimum + |
| ",max=" + maximum + |
| ((orientation == VERTICAL) ? ",vert" : ",horz") + |
| ",isAdjusting=" + isAdjusting; |
| } |
| |
| |
| /* Serialization support. |
| */ |
| |
| /** |
| * The scroll bar's serialized Data Version. |
| * |
| * @serial |
| */ |
| private int scrollbarSerializedDataVersion = 1; |
| |
| /** |
| * Writes default serializable fields to stream. Writes |
| * a list of serializable {@code AdjustmentListeners} |
| * as optional data. The non-serializable listeners are |
| * detected and no attempt is made to serialize them. |
| * |
| * @param s the {@code ObjectOutputStream} to write |
| * @serialData {@code null} terminated sequence of 0 |
| * or more pairs; the pair consists of a {@code String} |
| * and an {@code Object}; the {@code String} indicates |
| * the type of object and is one of the following: |
| * {@code adjustmentListenerK} indicating an |
| * {@code AdjustmentListener} object |
| * |
| * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener) |
| * @see java.awt.Component#adjustmentListenerK |
| * @see #readObject(ObjectInputStream) |
| */ |
| private void writeObject(ObjectOutputStream s) |
| throws IOException |
| { |
| s.defaultWriteObject(); |
| |
| AWTEventMulticaster.save(s, adjustmentListenerK, adjustmentListener); |
| s.writeObject(null); |
| } |
| |
| /** |
| * Reads the {@code ObjectInputStream} and if |
| * it isn't {@code null} adds a listener to |
| * receive adjustment events fired by the |
| * {@code Scrollbar}. |
| * Unrecognized keys or values will be ignored. |
| * |
| * @param s the {@code ObjectInputStream} to read |
| * @exception HeadlessException if |
| * {@code GraphicsEnvironment.isHeadless} returns |
| * {@code true} |
| * @see java.awt.GraphicsEnvironment#isHeadless |
| * @see #writeObject(ObjectOutputStream) |
| */ |
| private void readObject(ObjectInputStream s) |
| throws ClassNotFoundException, IOException, HeadlessException |
| { |
| GraphicsEnvironment.checkHeadless(); |
| s.defaultReadObject(); |
| |
| Object keyOrNull; |
| while(null != (keyOrNull = s.readObject())) { |
| String key = ((String)keyOrNull).intern(); |
| |
| if (adjustmentListenerK == key) |
| addAdjustmentListener((AdjustmentListener)(s.readObject())); |
| |
| else // skip value for unrecognized key |
| s.readObject(); |
| } |
| } |
| |
| |
| ///////////////// |
| // Accessibility support |
| //////////////// |
| |
| /** |
| * Gets the {@code AccessibleContext} associated with this |
| * {@code Scrollbar}. For scrollbars, the |
| * {@code AccessibleContext} takes the form of an |
| * {@code AccessibleAWTScrollBar}. A new |
| * {@code AccessibleAWTScrollBar} instance is created if necessary. |
| * |
| * @return an {@code AccessibleAWTScrollBar} that serves as the |
| * {@code AccessibleContext} of this {@code ScrollBar} |
| * @since 1.3 |
| */ |
| public AccessibleContext getAccessibleContext() { |
| if (accessibleContext == null) { |
| accessibleContext = new AccessibleAWTScrollBar(); |
| } |
| return accessibleContext; |
| } |
| |
| /** |
| * This class implements accessibility support for the |
| * {@code Scrollbar} class. It provides an implementation of |
| * the Java Accessibility API appropriate to scrollbar |
| * user-interface elements. |
| * @since 1.3 |
| */ |
| protected class AccessibleAWTScrollBar extends AccessibleAWTComponent |
| implements AccessibleValue |
| { |
| /* |
| * JDK 1.3 serialVersionUID |
| */ |
| private static final long serialVersionUID = -344337268523697807L; |
| |
| /** |
| * Get the state set of this object. |
| * |
| * @return an instance of {@code AccessibleState} |
| * containing the current state of the object |
| * @see AccessibleState |
| */ |
| public AccessibleStateSet getAccessibleStateSet() { |
| AccessibleStateSet states = super.getAccessibleStateSet(); |
| if (getValueIsAdjusting()) { |
| states.add(AccessibleState.BUSY); |
| } |
| if (getOrientation() == VERTICAL) { |
| states.add(AccessibleState.VERTICAL); |
| } else { |
| states.add(AccessibleState.HORIZONTAL); |
| } |
| return states; |
| } |
| |
| /** |
| * Get the role of this object. |
| * |
| * @return an instance of {@code AccessibleRole} |
| * describing the role of the object |
| */ |
| public AccessibleRole getAccessibleRole() { |
| return AccessibleRole.SCROLL_BAR; |
| } |
| |
| /** |
| * Get the {@code AccessibleValue} associated with this |
| * object. In the implementation of the Java Accessibility |
| * API for this class, return this object, which is |
| * responsible for implementing the |
| * {@code AccessibleValue} interface on behalf of itself. |
| * |
| * @return this object |
| */ |
| public AccessibleValue getAccessibleValue() { |
| return this; |
| } |
| |
| /** |
| * Get the accessible value of this object. |
| * |
| * @return The current value of this object. |
| */ |
| public Number getCurrentAccessibleValue() { |
| return Integer.valueOf(getValue()); |
| } |
| |
| /** |
| * Set the value of this object as a Number. |
| * |
| * @return True if the value was set. |
| */ |
| public boolean setCurrentAccessibleValue(Number n) { |
| if (n instanceof Integer) { |
| setValue(n.intValue()); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| /** |
| * Get the minimum accessible value of this object. |
| * |
| * @return The minimum value of this object. |
| */ |
| public Number getMinimumAccessibleValue() { |
| return Integer.valueOf(getMinimum()); |
| } |
| |
| /** |
| * Get the maximum accessible value of this object. |
| * |
| * @return The maximum value of this object. |
| */ |
| public Number getMaximumAccessibleValue() { |
| return Integer.valueOf(getMaximum()); |
| } |
| |
| } // AccessibleAWTScrollBar |
| |
| } |
