java.awt.event.MouseWheelEvent Maven / Gradle / Ivy
/*
NOTICE
(c) 2005-2007 Sun Microsystems, Inc. All Rights Reserved.
Neither this file nor any files generated from it describe a complete
specification, and they may only be used as described below. For
example, no permission is given for you to incorporate this file, in
whole or in part, in an implementation of a Java specification.
Sun Microsystems Inc. owns the copyright in this file and it is provided
to you for informative, as opposed to normative, use. The file and any
files generated from it may be used to generate other informative
documentation, such as a unified set of documents of API signatures for
a platform that includes technologies expressed as Java APIs. The file
may also be used to produce "compilation stubs," which allow
applications to be compiled and validated for such platforms.
Any work generated from this file, such as unified javadocs or compiled
stub files, must be accompanied by this notice in its entirety.
This work corresponds to the API signatures of JSR 217: Personal Basis
Profile 1.1. In the event of a discrepency between this work and the
JSR 217 specification, which is available at
http://www.jcp.org/en/jsr/detail?id=217, the latter takes precedence.
*/
package java.awt.event;
import java.awt.Component;
// import sun.awt.DebugHelper;
// PBP/PP 6214663
/**
* An event which indicates that the mouse wheel was rotated in a component.
*
* 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.
*
* A MouseWheelEvent object is passed to every MouseWheelListener
* object which registered to receive the "interesting" mouse events using the
* component's addMouseWheelListener method. Each such listener
* object gets a MouseEvent containing the mouse event.
*
* 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.
*
* 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. The source
* Component and x,y coordinates will be relative to the event's
* final destination.
*
* 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.
*
* 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.
*
*
*
* Note: The generation of mouse wheel events is not guaranteed.
* Applications should not be written to rely on the receipt of such events
* for proper operation. Nonetheless, applications may still
* create MouseWheelEvent objects and post them to the system event queue.
*
* @author Brent Christian
* @version 1.7 01/23/03
* @see MouseWheelListener
*
*
* @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:
*
* - WHEEL_UNIT_SCROLL
*
- WHEEL_BLOCK_SCROLL
*
*
* @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;
/**
* Constructs a MouseWheelEvent object with the
* specified source component, type, modifiers, coordinates,
* scroll type, scroll amount, and wheel rotation.
* Note that passing in an invalid id results in
* unspecified behavior.
*
* @param source the Component 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
* WHEEL_UNIT_SCROLL and
* WHEEL_BLOCK_SCROLL
* @param scrollAmount for scrollType WHEEL_UNIT_SCROLL,
* the number of units to be scrolled
* @param wheelRotation the amount that the mouse wheel was rotated (the
* number of "clicks")
*
* @see MouseEvent#MouseEvent(java.awt.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(null, 0, 0, 0, 0, 0, 0, false, 0);
}
/**
* Returns the type of scrolling that should take place in response to this
* event. This is determined by the native platform. Legal values are:
*
* - MouseWheelEvent.WHEEL_UNIT_SCROLL
*
- MouseWheelEvent.WHEEL_BLOCK_SCROLL
*
*
*
* @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
*
*/
public int getScrollType() { return 0; }
/**
* Returns the number of units that should be scrolled in response to this
* event. Only valid if getScrollType returns
* MouseWheelEvent.WHEEL_UNIT_SCROLL
*
* @return number of units to scroll, or an undefined value if
* getScrollType returns
* MouseWheelEvent.WHEEL_BLOCK_SCROLL
* @see #getScrollType
*/
public int getScrollAmount() { return 0; }
/**
* Returns the number of "clicks" the mouse wheel was rotated.
*
* @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
*/
public int getWheelRotation() { return 0; }
// PBP/PP
// [6187235]
// PBP/PP 6214663
/**
* This is a convenience method to aid in the implementation of
* the common-case MouseWheelListener.
* .
*
* This method returns the number of units to scroll when scroll type is
* MouseWheelEvent.WHEEL_UNIT_SCROLL, and should only be called if
* getScrollType returns MouseWheelEvent.WHEEL_UNIT_SCROLL.
*
* 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 unit increment, as this will vary among
* scrolling components.
*
* @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
*
*
*/
public int getUnitsToScroll() { return 0; }
/**
* 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() { return null; }
}