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Diffstat (limited to 'libjava/classpath/java/awt/event/MouseWheelEvent.java')
| -rw-r--r-- | libjava/classpath/java/awt/event/MouseWheelEvent.java | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/libjava/classpath/java/awt/event/MouseWheelEvent.java b/libjava/classpath/java/awt/event/MouseWheelEvent.java new file mode 100644 index 000000000..1ca946582 --- /dev/null +++ b/libjava/classpath/java/awt/event/MouseWheelEvent.java @@ -0,0 +1,232 @@ +/* MouseWheelEvent.java -- a mouse wheel event + Copyright (C) 2002, 2005 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 +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +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 +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.awt.event; + +import java.awt.Adjustable; +import java.awt.Component; +import java.awt.Rectangle; +import java.awt.ScrollPane; + +import javax.swing.JScrollPane; +import javax.swing.Scrollable; + +/** + * This event is generated for a mouse wheel rotation. The wheel (the middle + * mouse button on most modern mice) can be rotated towards or away from the + * user, and is often used for scrolling. + * + * <p>Because of the special use for scrolling components, MouseWheelEvents + * often affect a different component than the one located at the point of + * the event. If the component under the mouse cursor does not accept wheel + * events, the event is passed to the first ancestor container which does. This + * is often a ScrollPane, which knows how to scroll. If an AWT component is + * built from a native widget that knows how to use mouse wheel events, that + * component will consume the event. + * + * <p>The two most common scroll types are "units" (lines at a time) or + * "blocks" (pages at a time). The initial setting is taken from the platform, + * although the user can adjust the setting at any time. + * + * @author Eric Blake (ebb9@email.byu.edu) + * @see MouseWheelListener + * @see ScrollPane + * @see ScrollPane#setWheelScrollingEnabled(boolean) + * @see JScrollPane + * @see JScrollPane#setWheelScrollingEnabled(boolean) + * @since 1.4 + * @status updated to 1.4 + */ +public class MouseWheelEvent extends MouseEvent +{ + /** + * Compatible with JDK 1.4+. + */ + private static final long serialVersionUID = 6459879390515399677L; + + /** + * Indicates scrolling by units (lines). + * + * @see #getScrollType() + */ + public static final int WHEEL_UNIT_SCROLL = 0; + + /** + * Indicates scrolling by blocks (pages). + * + * @see #getScrollType() + */ + public static final int WHEEL_BLOCK_SCROLL = 1; + + /** + * Indicates what scroll type should take place. This should be limited + * to {@link #WHEEL_UNIT_SCROLL} and {@link #WHEEL_BLOCK_SCROLL}. + * + * @serial the scroll type + */ + private final int scrollType; + + /** + * Indicates the scroll amount. This is only meaningful if scrollType is + * WHEEL_UNIT_SCROLL. + * + * @serial the number of lines to scroll + */ + private final int scrollAmount; + + /** + * Indicates how far the mouse wheel was rotated. + * + * @serial the rotation amount + */ + private final int wheelRotation; + + /** + * Initializes a new instance of <code>MouseWheelEvent</code> with the + * specified information. Note that an invalid id leads to unspecified + * results. + * + * @param source the source of the event + * @param id the event id + * @param when the timestamp of when the event occurred + * @param modifiers any modifier bits for this event + * @param x the X coordinate of the mouse point + * @param y the Y coordinate of the mouse point + * @param clickCount the number of mouse clicks for this event + * @param popupTrigger true if this event triggers a popup menu + * @param scrollType one of {@link #WHEEL_UNIT_SCROLL}, + * {@link #WHEEL_BLOCK_SCROLL} + * @param scrollAmount the number of units to scroll, ignored for block type + * @param wheelRotation the number of rotation "clicks" + * @throws IllegalArgumentException if source is null + * @see MouseEvent#MouseEvent(Component, int, long, int, int, int, int, + * boolean) + */ + public MouseWheelEvent(Component source, int id, long when, int modifiers, + int x, int y, int clickCount, boolean popupTrigger, + int scrollType, int scrollAmount, int wheelRotation) + { + super(source, id, when, modifiers, x, y, clickCount, popupTrigger); + this.scrollType = scrollType; + this.scrollAmount = scrollAmount; + this.wheelRotation = wheelRotation; + } + + /** + * This method returns the scrolling pattern this event requests. Legal + * values are {@link #WHEEL_UNIT_SCROLL} and {@link #WHEEL_BLOCK_SCROLL}. + * + * @return the scroll type + * @see Adjustable#getUnitIncrement() + * @see Adjustable#getBlockIncrement() + * @see Scrollable#getScrollableUnitIncrement(Rectangle, int, int) + * @see Scrollable#getScrollableBlockIncrement(Rectangle, int, int) + */ + public int getScrollType() + { + return scrollType; + } + + /** + * Returns the number of units to scroll in response to this event. This + * only makes sense when the scroll type is WHEEL_UNIT_SCROLL. + * + * @return the number of scroll units, if defined + * @see #getScrollType() + */ + public int getScrollAmount() + { + return scrollAmount; + } + + /** + * Gets the number of "clicks" the wheel was rotated. Negative values move + * up (away) from the user, positive values move down (towards) the user. + * + * @return the number of rotation clicks + */ + public int getWheelRotation() + { + return wheelRotation; + } + + /** + * This is a convenience method which aids in a common listener for scrolling + * a scrollpane (although this is already built into ScrollPane and + * JScrollPane). This method only makes sense when getScrollType() returns + * WHEEL_UNIT_SCROLL. + * + * <p>This accounts for direction of scroll and amount of wheel movement, as + * interpreted by the platform settings. + * + * @return the number of units to scroll + * @see #getScrollType() + * @see #getScrollAmount() + * @see MouseWheelListener + * @see Adjustable + * @see Adjustable#getUnitIncrement() + * @see Scrollable + * @see Scrollable#getScrollableUnitIncrement(Rectangle, int, int) + * @see ScrollPane + * @see ScrollPane#setWheelScrollingEnabled(boolean) + * @see JScrollPane + * @see JScrollPane#setWheelScrollingEnabled(boolean) + */ + public int getUnitsToScroll() + { + return wheelRotation * scrollAmount; + } + + /** + * Returns a string identifying this event. For mouse wheel events, this + * is <code>super.paramString() + ",scrollType=WHEEL_" + + * (getScrollType() == WHEEL_UNIT_SCROLL ? "UNIT" : "BLOCK") + * + "_SCROLL,scrollAmount=" + getScrollAmount() + ",wheelRotation=" + * + getWheelRotation()</code>. + * + * @return a string identifying this event + */ + public String paramString() + { + return super.paramString() + ",scrollType=" + + (scrollType == WHEEL_UNIT_SCROLL ? "WHEEL_UNIT_SCROLL" + : scrollType == WHEEL_BLOCK_SCROLL ? "WHEEL_BLOCK_SCROLL" + : "unknown scroll type") + + ",scrollAmount=" + scrollAmount + ",wheelRotation=" + wheelRotation; + } +} // class MouseWheelEvent |