| /* |
| * Copyright (c) 2000, 2006, 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.event.AdjustmentEvent; |
| import java.awt.event.AdjustmentListener; |
| import java.awt.peer.ScrollPanePeer; |
| import java.io.Serializable; |
| |
| |
| /** |
| * This class represents the state of a horizontal or vertical |
| * scrollbar of a <code>ScrollPane</code>. Objects of this class are |
| * returned by <code>ScrollPane</code> methods. |
| * |
| * @since 1.4 |
| */ |
| public class ScrollPaneAdjustable implements Adjustable, Serializable { |
| |
| /** |
| * The <code>ScrollPane</code> this object is a scrollbar of. |
| * @serial |
| */ |
| private ScrollPane sp; |
| |
| /** |
| * Orientation of this scrollbar. |
| * |
| * @serial |
| * @see #getOrientation |
| * @see java.awt.Adjustable#HORIZONTAL |
| * @see java.awt.Adjustable#VERTICAL |
| */ |
| private int orientation; |
| |
| /** |
| * The value of this scrollbar. |
| * <code>value</code> should be greater than <code>minimum</code> |
| * and less than <code>maximum</code> |
| * |
| * @serial |
| * @see #getValue |
| * @see #setValue |
| */ |
| private int value; |
| |
| /** |
| * The minimum value of this scrollbar. |
| * This value can only be set by the <code>ScrollPane</code>. |
| * <p> |
| * <strong>ATTN:</strong> In current implementation |
| * <code>minimum</code> is always <code>0</code>. This field can |
| * only be altered via <code>setSpan</code> method and |
| * <code>ScrollPane</code> always calls that method with |
| * <code>0</code> for the minimum. <code>getMinimum</code> method |
| * always returns <code>0</code> without checking this field. |
| * |
| * @serial |
| * @see #getMinimum |
| * @see #setSpan(int, int, int) |
| */ |
| private int minimum; |
| |
| /** |
| * The maximum value of this scrollbar. |
| * This value can only be set by the <code>ScrollPane</code>. |
| * |
| * @serial |
| * @see #getMaximum |
| * @see #setSpan(int, int, int) |
| */ |
| private int maximum; |
| |
| /** |
| * The size of the visible portion of this scrollbar. |
| * This value can only be set by the <code>ScrollPane</code>. |
| * |
| * @serial |
| * @see #getVisibleAmount |
| * @see #setSpan(int, int, int) |
| */ |
| private int visibleAmount; |
| |
| /** |
| * The adjusting status of the <code>Scrollbar</code>. |
| * 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 |
| */ |
| private transient boolean isAdjusting; |
| |
| /** |
| * The amount by which the scrollbar value will change when going |
| * up or down by a line. |
| * This value should be a non negative integer. |
| * |
| * @serial |
| * @see #getUnitIncrement |
| * @see #setUnitIncrement |
| */ |
| private int unitIncrement = 1; |
| |
| /** |
| * The amount by which the scrollbar value will change when going |
| * up or down by a page. |
| * This value should be a non negative integer. |
| * |
| * @serial |
| * @see #getBlockIncrement |
| * @see #setBlockIncrement |
| */ |
| private int blockIncrement = 1; |
| |
| private AdjustmentListener adjustmentListener; |
| |
| /** |
| * Error message for <code>AWTError</code> reported when one of |
| * the public but unsupported methods is called. |
| */ |
| private static final String SCROLLPANE_ONLY = |
| "Can be set by scrollpane only"; |
| |
| |
| /** |
| * Initialize JNI field and method ids. |
| */ |
| private static native void initIDs(); |
| |
| static { |
| Toolkit.loadLibraries(); |
| if (!GraphicsEnvironment.isHeadless()) { |
| initIDs(); |
| } |
| } |
| |
| /** |
| * JDK 1.1 serialVersionUID. |
| */ |
| private static final long serialVersionUID = -3359745691033257079L; |
| |
| |
| /** |
| * Constructs a new object to represent specified scrollabar |
| * of the specified <code>ScrollPane</code>. |
| * Only ScrollPane creates instances of this class. |
| * @param sp <code>ScrollPane</code> |
| * @param l <code>AdjustmentListener</code> to add upon creation. |
| * @param orientation specifies which scrollbar this object represents, |
| * can be either <code>Adjustable.HORIZONTAL</code> |
| * or <code>Adjustable.VERTICAL</code>. |
| */ |
| ScrollPaneAdjustable(ScrollPane sp, AdjustmentListener l, int orientation) { |
| this.sp = sp; |
| this.orientation = orientation; |
| addAdjustmentListener(l); |
| } |
| |
| /** |
| * This is called by the scrollpane itself to update the |
| * <code>minimum</code>, <code>maximum</code> and |
| * <code>visible</code> values. The scrollpane is the only one |
| * that should be changing these since it is the source of these |
| * values. |
| */ |
| void setSpan(int min, int max, int visible) { |
| // adjust the values to be reasonable |
| minimum = min; |
| maximum = Math.max(max, minimum + 1); |
| visibleAmount = Math.min(visible, maximum - minimum); |
| visibleAmount = Math.max(visibleAmount, 1); |
| blockIncrement = Math.max((int)(visible * .90), 1); |
| setValue(value); |
| } |
| |
| /** |
| * Returns the orientation of this scrollbar. |
| * @return the orientation of this scrollbar, either |
| * <code>Adjustable.HORIZONTAL</code> or |
| * <code>Adjustable.VERTICAL</code> |
| */ |
| public int getOrientation() { |
| return orientation; |
| } |
| |
| /** |
| * This method should <strong>NOT</strong> be called by user code. |
| * This method is public for this class to properly implement |
| * <code>Adjustable</code> interface. |
| * |
| * @throws <code>AWTError</code> Always throws an error when called. |
| */ |
| public void setMinimum(int min) { |
| throw new AWTError(SCROLLPANE_ONLY); |
| } |
| |
| public int getMinimum() { |
| // XXX: This relies on setSpan always being called with 0 for |
| // the minimum (which is currently true). |
| return 0; |
| } |
| |
| /** |
| * This method should <strong>NOT</strong> be called by user code. |
| * This method is public for this class to properly implement |
| * <code>Adjustable</code> interface. |
| * |
| * @throws <code>AWTError</code> Always throws an error when called. |
| */ |
| public void setMaximum(int max) { |
| throw new AWTError(SCROLLPANE_ONLY); |
| } |
| |
| public int getMaximum() { |
| return maximum; |
| } |
| |
| public synchronized void setUnitIncrement(int u) { |
| if (u != unitIncrement) { |
| unitIncrement = u; |
| if (sp.peer != null) { |
| ScrollPanePeer peer = (ScrollPanePeer) sp.peer; |
| peer.setUnitIncrement(this, u); |
| } |
| } |
| } |
| |
| public int getUnitIncrement() { |
| return unitIncrement; |
| } |
| |
| public synchronized void setBlockIncrement(int b) { |
| blockIncrement = b; |
| } |
| |
| public int getBlockIncrement() { |
| return blockIncrement; |
| } |
| |
| /** |
| * This method should <strong>NOT</strong> be called by user code. |
| * This method is public for this class to properly implement |
| * <code>Adjustable</code> interface. |
| * |
| * @throws <code>AWTError</code> Always throws an error when called. |
| */ |
| public void setVisibleAmount(int v) { |
| throw new AWTError(SCROLLPANE_ONLY); |
| } |
| |
| public int getVisibleAmount() { |
| return visibleAmount; |
| } |
| |
| |
| /** |
| * Sets the <code>valueIsAdjusting</code> property. |
| * |
| * @param b new adjustment-in-progress status |
| * @see #getValueIsAdjusting |
| * @since 1.4 |
| */ |
| public void setValueIsAdjusting(boolean b) { |
| if (isAdjusting != b) { |
| isAdjusting = b; |
| AdjustmentEvent e = |
| new AdjustmentEvent(this, |
| AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, |
| AdjustmentEvent.TRACK, value, b); |
| adjustmentListener.adjustmentValueChanged(e); |
| } |
| } |
| |
| /** |
| * 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</code> property |
| * @see #setValueIsAdjusting |
| */ |
| public boolean getValueIsAdjusting() { |
| return isAdjusting; |
| } |
| |
| /** |
| * Sets the value of this scrollbar to the specified value. |
| * <p> |
| * If the value supplied is less than the current minimum or |
| * greater than the current maximum, then one of those values is |
| * substituted, as appropriate. |
| * |
| * @param v the new value of the scrollbar |
| */ |
| public void setValue(int v) { |
| setTypedValue(v, AdjustmentEvent.TRACK); |
| } |
| |
| /** |
| * Sets the value of this scrollbar to the specified value. |
| * <p> |
| * If the value supplied is less than the current minimum or |
| * greater than the current maximum, then one of those values is |
| * substituted, as appropriate. Also, creates and dispatches |
| * the AdjustementEvent with specified type and value. |
| * |
| * @param v the new value of the scrollbar |
| * @param type the type of the scrolling operation occured |
| */ |
| private void setTypedValue(int v, int type) { |
| v = Math.max(v, minimum); |
| v = Math.min(v, maximum - visibleAmount); |
| |
| if (v != value) { |
| value = v; |
| // Synchronously notify the listeners so that they are |
| // guaranteed to be up-to-date with the Adjustable before |
| // it is mutated again. |
| AdjustmentEvent e = |
| new AdjustmentEvent(this, |
| AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, |
| type, value, isAdjusting); |
| adjustmentListener.adjustmentValueChanged(e); |
| } |
| } |
| |
| public int getValue() { |
| return value; |
| } |
| |
| /** |
| * Adds the specified adjustment listener to receive adjustment |
| * events from this <code>ScrollPaneAdjustable</code>. |
| * If <code>l</code> is <code>null</code>, 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.AdjustmentListener |
| * @see java.awt.event.AdjustmentEvent |
| */ |
| public synchronized void addAdjustmentListener(AdjustmentListener l) { |
| if (l == null) { |
| return; |
| } |
| adjustmentListener = AWTEventMulticaster.add(adjustmentListener, l); |
| } |
| |
| /** |
| * Removes the specified adjustment listener so that it no longer |
| * receives adjustment events from this <code>ScrollPaneAdjustable</code>. |
| * If <code>l</code> is <code>null</code>, 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.AdjustmentListener |
| * @see java.awt.event.AdjustmentEvent |
| * @since JDK1.1 |
| */ |
| 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 <code>ScrollPaneAdjustable</code>. |
| * |
| * @return all of this <code>ScrollPaneAdjustable</code>'s |
| * <code>AdjustmentListener</code>s |
| * or an empty array if no adjustment |
| * listeners are currently registered |
| * |
| * @see #addAdjustmentListener |
| * @see #removeAdjustmentListener |
| * @see java.awt.event.AdjustmentListener |
| * @see java.awt.event.AdjustmentEvent |
| * @since 1.4 |
| */ |
| public synchronized AdjustmentListener[] getAdjustmentListeners() { |
| return (AdjustmentListener[])(AWTEventMulticaster.getListeners( |
| adjustmentListener, |
| AdjustmentListener.class)); |
| } |
| |
| /** |
| * Returns a string representation of this scrollbar and its values. |
| * @return a string representation of this scrollbar. |
| */ |
| public String toString() { |
| return getClass().getName() + "[" + paramString() + "]"; |
| } |
| |
| /** |
| * Returns a string representing the state of this 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</code>. |
| * |
| * @return the parameter string of this scrollbar. |
| */ |
| public String paramString() { |
| return ((orientation == Adjustable.VERTICAL ? "vertical," |
| :"horizontal,") |
| + "[0.."+maximum+"]" |
| + ",val=" + value |
| + ",vis=" + visibleAmount |
| + ",unit=" + unitIncrement |
| + ",block=" + blockIncrement |
| + ",isAdjusting=" + isAdjusting); |
| } |
| } |
