/*
* Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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*/
package javax.swing;
import java.awt.*;
import java.awt.event.*;
import sun.awt.
AWTAccessor;
import sun.awt.
AWTAccessor.
MouseEventAccessor;
/**
* Autoscroller is responsible for generating synthetic mouse dragged
* events. It is the responsibility of the Component (or its MouseListeners)
* that receive the events to do the actual scrolling in response to the
* mouse dragged events.
*
* @author Dave Moore
* @author Scott Violet
*/
class
Autoscroller implements
ActionListener {
/**
* Global Autoscroller.
*/
private static
Autoscroller sharedInstance = new
Autoscroller();
// As there can only ever be one autoscroller active these fields are
// static. The Timer is recreated as necessary to target the appropriate
// Autoscroller instance.
private static
MouseEvent event;
private static
Timer timer;
private static
JComponent component;
//
// The public API, all methods are cover methods for an instance method
//
/**
* Stops autoscroll events from happening on the specified component.
*/
public static void
stop(
JComponent c) {
sharedInstance.
_stop(
c);
}
/**
* Stops autoscroll events from happening on the specified component.
*/
public static boolean
isRunning(
JComponent c) {
return
sharedInstance.
_isRunning(
c);
}
/**
* Invoked when a mouse dragged event occurs, will start the autoscroller
* if necessary.
*/
public static void
processMouseDragged(
MouseEvent e) {
sharedInstance.
_processMouseDragged(
e);
}
Autoscroller() {
}
/**
* Starts the timer targeting the passed in component.
*/
private void
start(
JComponent c,
MouseEvent e) {
Point screenLocation =
c.
getLocationOnScreen();
if (
component !=
c) {
_stop(
component);
}
component =
c;
event = new
MouseEvent(
component,
e.
getID(),
e.
getWhen(),
e.
getModifiers(),
e.
getX() +
screenLocation.
x,
e.
getY() +
screenLocation.
y,
e.
getXOnScreen(),
e.
getYOnScreen(),
e.
getClickCount(),
e.
isPopupTrigger(),
MouseEvent.
NOBUTTON);
MouseEventAccessor meAccessor =
AWTAccessor.
getMouseEventAccessor();
meAccessor.
setCausedByTouchEvent(
event,
meAccessor.
isCausedByTouchEvent(
e));
if (
timer == null) {
timer = new
Timer(100, this);
}
if (!
timer.
isRunning()) {
timer.
start();
}
}
//
// Methods mirror the public static API
//
/**
* Stops scrolling for the passed in widget.
*/
private void
_stop(
JComponent c) {
if (
component ==
c) {
if (
timer != null) {
timer.
stop();
}
timer = null;
event = null;
component = null;
}
}
/**
* Returns true if autoscrolling is currently running for the specified
* widget.
*/
private boolean
_isRunning(
JComponent c) {
return (
c ==
component &&
timer != null &&
timer.
isRunning());
}
/**
* MouseListener method, invokes start/stop as necessary.
*/
private void
_processMouseDragged(
MouseEvent e) {
JComponent component = (
JComponent)
e.
getComponent();
boolean
stop = true;
if (
component.
isShowing()) {
Rectangle visibleRect =
component.
getVisibleRect();
stop =
visibleRect.
contains(
e.
getX(),
e.
getY());
}
if (
stop) {
_stop(
component);
} else {
start(
component,
e);
}
}
//
// ActionListener
//
/**
* ActionListener method. Invoked when the Timer fires. This will scroll
* if necessary.
*/
public void
actionPerformed(
ActionEvent x) {
JComponent component =
Autoscroller.
component;
if (
component == null || !
component.
isShowing() || (
event == null)) {
_stop(
component);
return;
}
Point screenLocation =
component.
getLocationOnScreen();
MouseEvent e = new
MouseEvent(
component,
event.
getID(),
event.
getWhen(),
event.
getModifiers(),
event.
getX() -
screenLocation.
x,
event.
getY() -
screenLocation.
y,
event.
getXOnScreen(),
event.
getYOnScreen(),
event.
getClickCount(),
event.
isPopupTrigger(),
MouseEvent.
NOBUTTON);
MouseEventAccessor meAccessor =
AWTAccessor.
getMouseEventAccessor();
meAccessor.
setCausedByTouchEvent(
e,
meAccessor.
isCausedByTouchEvent(
event));
component.
superProcessMouseMotionEvent(
e);
}
}