| /* |
| * Copyright (c) 2000, 2008, 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. |
| * |
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| * questions. |
| */ |
| |
| package java.awt.event; |
| |
| import java.awt.Component; |
| |
| /** |
| * An event which indicates that the mouse wheel was rotated in a component. |
| * <P> |
| * A wheel mouse is a mouse which has a wheel in place of the middle button. |
| * This wheel can be rotated towards or away from the user. Mouse wheels are |
| * most often used for scrolling, though other uses are possible. |
| * <P> |
| * A MouseWheelEvent object is passed to every <code>MouseWheelListener</code> |
| * object which registered to receive the "interesting" mouse events using the |
| * component's <code>addMouseWheelListener</code> method. Each such listener |
| * object gets a <code>MouseEvent</code> containing the mouse event. |
| * <P> |
| * Due to the mouse wheel's special relationship to scrolling Components, |
| * MouseWheelEvents are delivered somewhat differently than other MouseEvents. |
| * This is because while other MouseEvents usually affect a change on |
| * the Component directly under the mouse |
| * cursor (for instance, when clicking a button), MouseWheelEvents often have |
| * an effect away from the mouse cursor (moving the wheel while |
| * over a Component inside a ScrollPane should scroll one of the |
| * Scrollbars on the ScrollPane). |
| * <P> |
| * MouseWheelEvents start delivery from the Component underneath the |
| * mouse cursor. If MouseWheelEvents are not enabled on the |
| * Component, the event is delivered to the first ancestor |
| * Container with MouseWheelEvents enabled. This will usually be |
| * a ScrollPane with wheel scrolling enabled. The source |
| * Component and x,y coordinates will be relative to the event's |
| * final destination (the ScrollPane). This allows a complex |
| * GUI to be installed without modification into a ScrollPane, and |
| * for all MouseWheelEvents to be delivered to the ScrollPane for |
| * scrolling. |
| * <P> |
| * Some AWT Components are implemented using native widgets which |
| * display their own scrollbars and handle their own scrolling. |
| * The particular Components for which this is true will vary from |
| * platform to platform. When the mouse wheel is |
| * moved over one of these Components, the event is delivered straight to |
| * the native widget, and not propagated to ancestors. |
| * <P> |
| * Platforms offer customization of the amount of scrolling that |
| * should take place when the mouse wheel is moved. The two most |
| * common settings are to scroll a certain number of "units" |
| * (commonly lines of text in a text-based component) or an entire "block" |
| * (similar to page-up/page-down). The MouseWheelEvent offers |
| * methods for conforming to the underlying platform settings. These |
| * platform settings can be changed at any time by the user. MouseWheelEvents |
| * reflect the most recent settings. |
| * <P> |
| * The <code>MouseWheelEvent</code> class includes methods for |
| * getting the number of "clicks" by which the mouse wheel is rotated. |
| * The {@link #getWheelRotation} method returns the integer number |
| * of "clicks" corresponding to the number of notches by which the wheel was |
| * rotated. In addition to this method, the <code>MouseWheelEvent</code> |
| * class provides the {@link #getPreciseWheelRotation} method which returns |
| * a double number of "clicks" in case a partial rotation occurred. |
| * The {@link #getPreciseWheelRotation} method is useful if a mouse supports |
| * a high-resolution wheel, such as a freely rotating wheel with no |
| * notches. Applications can benefit by using this method to process |
| * mouse wheel events more precisely, and thus, making visual perception |
| * smoother. |
| * |
| * @author Brent Christian |
| * @see MouseWheelListener |
| * @see java.awt.ScrollPane |
| * @see java.awt.ScrollPane#setWheelScrollingEnabled(boolean) |
| * @see javax.swing.JScrollPane |
| * @see javax.swing.JScrollPane#setWheelScrollingEnabled(boolean) |
| * @since 1.4 |
| */ |
| |
| public class MouseWheelEvent extends MouseEvent { |
| |
| /** |
| * Constant representing scrolling by "units" (like scrolling with the |
| * arrow keys) |
| * |
| * @see #getScrollType |
| */ |
| public static final int WHEEL_UNIT_SCROLL = 0; |
| |
| /** |
| * Constant representing scrolling by a "block" (like scrolling |
| * with page-up, page-down keys) |
| * |
| * @see #getScrollType |
| */ |
| public static final int WHEEL_BLOCK_SCROLL = 1; |
| |
| /** |
| * Indicates what sort of scrolling should take place in response to this |
| * event, based on platform settings. Legal values are: |
| * <ul> |
| * <li> WHEEL_UNIT_SCROLL |
| * <li> WHEEL_BLOCK_SCROLL |
| * </ul> |
| * |
| * @see #getScrollType |
| */ |
| int scrollType; |
| |
| /** |
| * Only valid for scrollType WHEEL_UNIT_SCROLL. |
| * Indicates number of units that should be scrolled per |
| * click of mouse wheel rotation, based on platform settings. |
| * |
| * @see #getScrollAmount |
| * @see #getScrollType |
| */ |
| int scrollAmount; |
| |
| /** |
| * Indicates how far the mouse wheel was rotated. |
| * |
| * @see #getWheelRotation |
| */ |
| int wheelRotation; |
| |
| /** |
| * Indicates how far the mouse wheel was rotated. |
| * |
| * @see #getPreciseWheelRotation |
| */ |
| double preciseWheelRotation; |
| |
| /* |
| * serialVersionUID |
| */ |
| |
| private static final long serialVersionUID = 6459879390515399677L; |
| |
| /** |
| * Constructs a <code>MouseWheelEvent</code> object with the |
| * specified source component, type, modifiers, coordinates, |
| * scroll type, scroll amount, and wheel rotation. |
| * <p>Absolute coordinates xAbs and yAbs are set to source's location on screen plus |
| * relative coordinates x and y. xAbs and yAbs are set to zero if the source is not showing. |
| * <p>Note that passing in an invalid <code>id</code> results in |
| * unspecified behavior. This method throws an |
| * <code>IllegalArgumentException</code> if <code>source</code> |
| * is <code>null</code>. |
| * |
| * @param source the <code>Component</code> that originated |
| * the event |
| * @param id the integer that identifies the event |
| * @param when a long that gives the time the event occurred |
| * @param modifiers the modifier keys down during event |
| * (shift, ctrl, alt, meta) |
| * @param x the horizontal x coordinate for the mouse location |
| * @param y the vertical y coordinate for the mouse location |
| * @param clickCount the number of mouse clicks associated with event |
| * @param popupTrigger a boolean, true if this event is a trigger for a |
| * popup-menu |
| * @param scrollType the type of scrolling which should take place in |
| * response to this event; valid values are |
| * <code>WHEEL_UNIT_SCROLL</code> and |
| * <code>WHEEL_BLOCK_SCROLL</code> |
| * @param scrollAmount for scrollType <code>WHEEL_UNIT_SCROLL</code>, |
| * the number of units to be scrolled |
| * @param wheelRotation the integer number of "clicks" by which the mouse |
| * wheel was rotated |
| * |
| * @throws IllegalArgumentException if <code>source</code> is null |
| * @see MouseEvent#MouseEvent(java.awt.Component, int, long, int, int, int, int, boolean) |
| * @see MouseEvent#MouseEvent(java.awt.Component, int, long, int, int, int, int, int, int, boolean, int) |
| */ |
| public MouseWheelEvent (Component source, int id, long when, int modifiers, |
| int x, int y, int clickCount, boolean popupTrigger, |
| int scrollType, int scrollAmount, int wheelRotation) { |
| |
| this(source, id, when, modifiers, x, y, 0, 0, clickCount, |
| popupTrigger, scrollType, scrollAmount, wheelRotation); |
| } |
| |
| /** |
| * Constructs a <code>MouseWheelEvent</code> object with the |
| * specified source component, type, modifiers, coordinates, |
| * absolute coordinates, scroll type, scroll amount, and wheel rotation. |
| * <p>Note that passing in an invalid <code>id</code> results in |
| * unspecified behavior. This method throws an |
| * <code>IllegalArgumentException</code> if <code>source</code> |
| * is <code>null</code>.<p> |
| * Even if inconsistent values for relative and absolute coordinates are |
| * passed to the constructor, the MouseWheelEvent instance is still |
| * created and no exception is thrown. |
| * |
| * @param source the <code>Component</code> that originated |
| * the event |
| * @param id the integer that identifies the event |
| * @param when a long that gives the time the event occurred |
| * @param modifiers the modifier keys down during event |
| * (shift, ctrl, alt, meta) |
| * @param x the horizontal x coordinate for the mouse location |
| * @param y the vertical y coordinate for the mouse location |
| * @param xAbs the absolute horizontal x coordinate for the mouse location |
| * @param yAbs the absolute vertical y coordinate for the mouse location |
| * @param clickCount the number of mouse clicks associated with event |
| * @param popupTrigger a boolean, true if this event is a trigger for a |
| * popup-menu |
| * @param scrollType the type of scrolling which should take place in |
| * response to this event; valid values are |
| * <code>WHEEL_UNIT_SCROLL</code> and |
| * <code>WHEEL_BLOCK_SCROLL</code> |
| * @param scrollAmount for scrollType <code>WHEEL_UNIT_SCROLL</code>, |
| * the number of units to be scrolled |
| * @param wheelRotation the integer number of "clicks" by which the mouse |
| * wheel was rotated |
| * |
| * @throws IllegalArgumentException if <code>source</code> is null |
| * @see MouseEvent#MouseEvent(java.awt.Component, int, long, int, int, int, int, boolean) |
| * @see MouseEvent#MouseEvent(java.awt.Component, int, long, int, int, int, int, int, int, boolean, int) |
| * @since 1.6 |
| */ |
| public MouseWheelEvent (Component source, int id, long when, int modifiers, |
| int x, int y, int xAbs, int yAbs, int clickCount, boolean popupTrigger, |
| int scrollType, int scrollAmount, int wheelRotation) { |
| |
| this(source, id, when, modifiers, x, y, xAbs, yAbs, clickCount, popupTrigger, |
| scrollType, scrollAmount, wheelRotation, wheelRotation); |
| |
| } |
| |
| |
| /** |
| * Constructs a <code>MouseWheelEvent</code> object with the specified |
| * source component, type, modifiers, coordinates, absolute coordinates, |
| * scroll type, scroll amount, and wheel rotation. |
| * <p>Note that passing in an invalid <code>id</code> parameter results |
| * in unspecified behavior. This method throws an |
| * <code>IllegalArgumentException</code> if <code>source</code> equals |
| * <code>null</code>. |
| * <p>Even if inconsistent values for relative and absolute coordinates |
| * are passed to the constructor, a <code>MouseWheelEvent</code> instance |
| * is still created and no exception is thrown. |
| * |
| * @param source the <code>Component</code> that originated the event |
| * @param id the integer value that identifies the event |
| * @param when a long value that gives the time when the event occurred |
| * @param modifiers the modifier keys down during event |
| * (shift, ctrl, alt, meta) |
| * @param x the horizontal <code>x</code> coordinate for the |
| * mouse location |
| * @param y the vertical <code>y</code> coordinate for the |
| * mouse location |
| * @param xAbs the absolute horizontal <code>x</code> coordinate for |
| * the mouse location |
| * @param yAbs the absolute vertical <code>y</code> coordinate for |
| * the mouse location |
| * @param clickCount the number of mouse clicks associated with the event |
| * @param popupTrigger a boolean value, <code>true</code> if this event is a trigger |
| * for a popup-menu |
| * @param scrollType the type of scrolling which should take place in |
| * response to this event; valid values are |
| * <code>WHEEL_UNIT_SCROLL</code> and |
| * <code>WHEEL_BLOCK_SCROLL</code> |
| * @param scrollAmount for scrollType <code>WHEEL_UNIT_SCROLL</code>, |
| * the number of units to be scrolled |
| * @param wheelRotation the integer number of "clicks" by which the mouse wheel |
| * was rotated |
| * @param preciseWheelRotation the double number of "clicks" by which the mouse wheel |
| * was rotated |
| * |
| * @throws IllegalArgumentException if <code>source</code> is null |
| * @see MouseEvent#MouseEvent(java.awt.Component, int, long, int, int, int, int, boolean) |
| * @see MouseEvent#MouseEvent(java.awt.Component, int, long, int, int, int, int, int, int, boolean, int) |
| * @since 1.7 |
| */ |
| public MouseWheelEvent (Component source, int id, long when, int modifiers, |
| int x, int y, int xAbs, int yAbs, int clickCount, boolean popupTrigger, |
| int scrollType, int scrollAmount, int wheelRotation, double preciseWheelRotation) { |
| |
| super(source, id, when, modifiers, x, y, xAbs, yAbs, clickCount, |
| popupTrigger, MouseEvent.NOBUTTON); |
| |
| this.scrollType = scrollType; |
| this.scrollAmount = scrollAmount; |
| this.wheelRotation = wheelRotation; |
| this.preciseWheelRotation = preciseWheelRotation; |
| |
| } |
| |
| /** |
| * Returns the type of scrolling that should take place in response to this |
| * event. This is determined by the native platform. Legal values are: |
| * <ul> |
| * <li> MouseWheelEvent.WHEEL_UNIT_SCROLL |
| * <li> MouseWheelEvent.WHEEL_BLOCK_SCROLL |
| * </ul> |
| * |
| * @return either MouseWheelEvent.WHEEL_UNIT_SCROLL or |
| * MouseWheelEvent.WHEEL_BLOCK_SCROLL, depending on the configuration of |
| * the native platform. |
| * @see java.awt.Adjustable#getUnitIncrement |
| * @see java.awt.Adjustable#getBlockIncrement |
| * @see javax.swing.Scrollable#getScrollableUnitIncrement |
| * @see javax.swing.Scrollable#getScrollableBlockIncrement |
| */ |
| public int getScrollType() { |
| return scrollType; |
| } |
| |
| /** |
| * Returns the number of units that should be scrolled per |
| * click of mouse wheel rotation. |
| * Only valid if <code>getScrollType</code> returns |
| * <code>MouseWheelEvent.WHEEL_UNIT_SCROLL</code> |
| * |
| * @return number of units to scroll, or an undefined value if |
| * <code>getScrollType</code> returns |
| * <code>MouseWheelEvent.WHEEL_BLOCK_SCROLL</code> |
| * @see #getScrollType |
| */ |
| public int getScrollAmount() { |
| return scrollAmount; |
| } |
| |
| /** |
| * Returns the number of "clicks" the mouse wheel was rotated, as an integer. |
| * A partial rotation may occur if the mouse supports a high-resolution wheel. |
| * In this case, the method returns zero until a full "click" has been accumulated. |
| * |
| * @return negative values if the mouse wheel was rotated up/away from |
| * the user, and positive values if the mouse wheel was rotated down/ |
| * towards the user |
| * @see #getPreciseWheelRotation |
| */ |
| public int getWheelRotation() { |
| return wheelRotation; |
| } |
| |
| /** |
| * Returns the number of "clicks" the mouse wheel was rotated, as a double. |
| * A partial rotation may occur if the mouse supports a high-resolution wheel. |
| * In this case, the return value will include a fractional "click". |
| * |
| * @return negative values if the mouse wheel was rotated up or away from |
| * the user, and positive values if the mouse wheel was rotated down or |
| * towards the user |
| * @see #getWheelRotation |
| * @since 1.7 |
| */ |
| public double getPreciseWheelRotation() { |
| return preciseWheelRotation; |
| } |
| |
| /** |
| * This is a convenience method to aid in the implementation of |
| * the common-case MouseWheelListener - to scroll a ScrollPane or |
| * JScrollPane by an amount which conforms to the platform settings. |
| * (Note, however, that <code>ScrollPane</code> and |
| * <code>JScrollPane</code> already have this functionality built in.) |
| * <P> |
| * This method returns the number of units to scroll when scroll type is |
| * MouseWheelEvent.WHEEL_UNIT_SCROLL, and should only be called if |
| * <code>getScrollType</code> returns MouseWheelEvent.WHEEL_UNIT_SCROLL. |
| * <P> |
| * Direction of scroll, amount of wheel movement, |
| * and platform settings for wheel scrolling are all accounted for. |
| * This method does not and cannot take into account value of the |
| * Adjustable/Scrollable unit increment, as this will vary among |
| * scrolling components. |
| * <P> |
| * A simplified example of how this method might be used in a |
| * listener: |
| * <pre> |
| * mouseWheelMoved(MouseWheelEvent event) { |
| * ScrollPane sp = getScrollPaneFromSomewhere(); |
| * Adjustable adj = sp.getVAdjustable() |
| * if (MouseWheelEvent.getScrollType() == WHEEL_UNIT_SCROLL) { |
| * int totalScrollAmount = |
| * event.getUnitsToScroll() * |
| * adj.getUnitIncrement(); |
| * adj.setValue(adj.getValue() + totalScrollAmount); |
| * } |
| * } |
| * </pre> |
| * |
| * @return the number of units to scroll based on the direction and amount |
| * of mouse wheel rotation, and on the wheel scrolling settings of the |
| * native platform |
| * @see #getScrollType |
| * @see #getScrollAmount |
| * @see MouseWheelListener |
| * @see java.awt.Adjustable |
| * @see java.awt.Adjustable#getUnitIncrement |
| * @see javax.swing.Scrollable |
| * @see javax.swing.Scrollable#getScrollableUnitIncrement |
| * @see java.awt.ScrollPane |
| * @see java.awt.ScrollPane#setWheelScrollingEnabled |
| * @see javax.swing.JScrollPane |
| * @see javax.swing.JScrollPane#setWheelScrollingEnabled |
| */ |
| public int getUnitsToScroll() { |
| return scrollAmount * wheelRotation; |
| } |
| |
| /** |
| * Returns a parameter string identifying this event. |
| * This method is useful for event-logging and for debugging. |
| * |
| * @return a string identifying the event and its attributes |
| */ |
| public String paramString() { |
| String scrollTypeStr = null; |
| |
| if (getScrollType() == WHEEL_UNIT_SCROLL) { |
| scrollTypeStr = "WHEEL_UNIT_SCROLL"; |
| } |
| else if (getScrollType() == WHEEL_BLOCK_SCROLL) { |
| scrollTypeStr = "WHEEL_BLOCK_SCROLL"; |
| } |
| else { |
| scrollTypeStr = "unknown scroll type"; |
| } |
| return super.paramString()+",scrollType="+scrollTypeStr+ |
| ",scrollAmount="+getScrollAmount()+",wheelRotation="+ |
| getWheelRotation()+",preciseWheelRotation="+getPreciseWheelRotation(); |
| } |
| } |
