/* * Copyright (c) 2000, 2007, 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 sun.awt;import java.awt.ScrollPane;import java.awt.Insets;import java.awt.Adjustable;import java.awt.event.MouseWheelEvent;import sun.util.logging.PlatformLogger;/* * ScrollPaneWheelScroller is a helper class for implmenenting mouse wheel * scrolling on a java.awt.ScrollPane. It contains only static methods. * No objects of this class may be instantiated, thus it is declared abstract. */public abstract class ScrollPaneWheelScroller { private static final PlatformLogger log = PlatformLogger.getLogger("sun.awt.ScrollPaneWheelScroller"); private ScrollPaneWheelScroller() {} /* * Called from ScrollPane.processMouseWheelEvent() */ public static void handleWheelScrolling(ScrollPane sp, MouseWheelEvent e) { if (log.isLoggable(PlatformLogger.FINER)) { log.finer("x = " + e.getX() + ", y = " + e.getY() + ", src is " + e.getSource()); } int increment = 0; if (sp != null && e.getScrollAmount() != 0) { Adjustable adj = getAdjustableToScroll(sp); if (adj != null) { increment = getIncrementFromAdjustable(adj, e); if (log.isLoggable(PlatformLogger.FINER)) { log.finer("increment from adjustable(" + adj.getClass() + ") : " + increment); } scrollAdjustable(adj, increment); } } } /* * Given a ScrollPane, determine which Scrollbar should be scrolled by the * mouse wheel, if any. */ public static Adjustable getAdjustableToScroll(ScrollPane sp) { int policy = sp.getScrollbarDisplayPolicy(); // if policy is display always or never, use vert if (policy == ScrollPane.SCROLLBARS_ALWAYS || policy == ScrollPane.SCROLLBARS_NEVER) { if (log.isLoggable(PlatformLogger.FINER)) { log.finer("using vertical scrolling due to scrollbar policy"); } return sp.getVAdjustable(); } else { Insets ins = sp.getInsets(); int vertScrollWidth = sp.getVScrollbarWidth(); if (log.isLoggable(PlatformLogger.FINER)) { log.finer("insets: l = " + ins.left + ", r = " + ins.right + ", t = " + ins.top + ", b = " + ins.bottom); log.finer("vertScrollWidth = " + vertScrollWidth); } // Check if scrollbar is showing by examining insets of the // ScrollPane if (ins.right >= vertScrollWidth) { if (log.isLoggable(PlatformLogger.FINER)) { log.finer("using vertical scrolling because scrollbar is present"); } return sp.getVAdjustable(); } else { int horizScrollHeight = sp.getHScrollbarHeight(); if (ins.bottom >= horizScrollHeight) { if (log.isLoggable(PlatformLogger.FINER)) { log.finer("using horiz scrolling because scrollbar is present"); } return sp.getHAdjustable(); } else { if (log.isLoggable(PlatformLogger.FINER)) { log.finer("using NO scrollbar becsause neither is present"); } return null; } } } } /* * Given the info in a MouseWheelEvent and an Adjustable to scroll, return * the amount by which the Adjustable should be adjusted. This value may * be positive or negative. */ public static int getIncrementFromAdjustable(Adjustable adj, MouseWheelEvent e) { if (log.isLoggable(PlatformLogger.FINE)) { if (adj == null) { log.fine("Assertion (adj != null) failed"); } } int increment = 0; if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) { increment = e.getUnitsToScroll() * adj.getUnitIncrement(); } else if (e.getScrollType() == MouseWheelEvent.WHEEL_BLOCK_SCROLL) { increment = adj.getBlockIncrement() * e.getWheelRotation(); } return increment; } /* * Scroll the given Adjustable by the given amount. Checks the Adjustable's * bounds and sets the new value to the Adjustable. */ public static void scrollAdjustable(Adjustable adj, int amount) { if (log.isLoggable(PlatformLogger.FINE)) { if (adj == null) { log.fine("Assertion (adj != null) failed"); } if (amount == 0) { log.fine("Assertion (amount != 0) failed"); } } int current = adj.getValue(); int upperLimit = adj.getMaximum() - adj.getVisibleAmount(); if (log.isLoggable(PlatformLogger.FINER)) { log.finer("doScrolling by " + amount); } if (amount > 0 && current < upperLimit) { // still some room to scroll // down if (current + amount < upperLimit) { adj.setValue(current + amount); return; } else { adj.setValue(upperLimit); return; } } else if (amount < 0 && current > adj.getMinimum()) { // still some room // to scroll up if (current + amount > adj.getMinimum()) { adj.setValue(current + amount); return; } else { adj.setValue(adj.getMinimum()); return; } } }}
/*
* Copyright (c) 2000, 2007, 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 sun.awt;
import java.awt.ScrollPane;
import java.awt.Insets;
import java.awt.Adjustable;
import java.awt.event.MouseWheelEvent;
import sun.util.logging.PlatformLogger;
/*
* ScrollPaneWheelScroller is a helper class for implmenenting mouse wheel
* scrolling on a java.awt.ScrollPane. It contains only static methods.
* No objects of this class may be instantiated, thus it is declared abstract.
*/
public abstract class ScrollPaneWheelScroller {
private static final PlatformLogger log = PlatformLogger.getLogger("sun.awt.ScrollPaneWheelScroller");
private ScrollPaneWheelScroller() {}
/*
* Called from ScrollPane.processMouseWheelEvent()
*/
public static void handleWheelScrolling(ScrollPane sp, MouseWheelEvent e) {
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("x = " + e.getX() + ", y = " + e.getY() + ", src is " + e.getSource());
}
int increment = 0;
if (sp != null && e.getScrollAmount() != 0) {
Adjustable adj = getAdjustableToScroll(sp);
if (adj != null) {
increment = getIncrementFromAdjustable(adj, e);
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("increment from adjustable(" + adj.getClass() + ") : " + increment);
}
scrollAdjustable(adj, increment);
}
}
}
/*
* Given a ScrollPane, determine which Scrollbar should be scrolled by the
* mouse wheel, if any.
*/
public static Adjustable getAdjustableToScroll(ScrollPane sp) {
int policy = sp.getScrollbarDisplayPolicy();
// if policy is display always or never, use vert
if (policy == ScrollPane.SCROLLBARS_ALWAYS ||
policy == ScrollPane.SCROLLBARS_NEVER) {
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("using vertical scrolling due to scrollbar policy");
}
return sp.getVAdjustable();
}
else {
Insets ins = sp.getInsets();
int vertScrollWidth = sp.getVScrollbarWidth();
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("insets: l = " + ins.left + ", r = " + ins.right +
", t = " + ins.top + ", b = " + ins.bottom);
log.finer("vertScrollWidth = " + vertScrollWidth);
}
// Check if scrollbar is showing by examining insets of the
// ScrollPane
if (ins.right >= vertScrollWidth) {
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("using vertical scrolling because scrollbar is present");
}
return sp.getVAdjustable();
}
else {
int horizScrollHeight = sp.getHScrollbarHeight();
if (ins.bottom >= horizScrollHeight) {
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("using horiz scrolling because scrollbar is present");
}
return sp.getHAdjustable();
}
else {
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("using NO scrollbar becsause neither is present");
}
return null;
}
}
}
}
/*
* Given the info in a MouseWheelEvent and an Adjustable to scroll, return
* the amount by which the Adjustable should be adjusted. This value may
* be positive or negative.
*/
public static int getIncrementFromAdjustable(Adjustable adj,
MouseWheelEvent e) {
if (log.isLoggable(PlatformLogger.FINE)) {
if (adj == null) {
log.fine("Assertion (adj != null) failed");
}
}
int increment = 0;
if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) {
increment = e.getUnitsToScroll() * adj.getUnitIncrement();
}
else if (e.getScrollType() == MouseWheelEvent.WHEEL_BLOCK_SCROLL) {
increment = adj.getBlockIncrement() * e.getWheelRotation();
}
return increment;
}
/*
* Scroll the given Adjustable by the given amount. Checks the Adjustable's
* bounds and sets the new value to the Adjustable.
*/
public static void scrollAdjustable(Adjustable adj, int amount) {
if (log.isLoggable(PlatformLogger.FINE)) {
if (adj == null) {
log.fine("Assertion (adj != null) failed");
}
if (amount == 0) {
log.fine("Assertion (amount != 0) failed");
}
}
int current = adj.getValue();
int upperLimit = adj.getMaximum() - adj.getVisibleAmount();
if (log.isLoggable(PlatformLogger.FINER)) {
log.finer("doScrolling by " + amount);
}
if (amount > 0 && current < upperLimit) { // still some room to scroll
// down
if (current + amount < upperLimit) {
adj.setValue(current + amount);
return;
}
else {
adj.setValue(upperLimit);
return;
}
}
else if (amount < 0 && current > adj.getMinimum()) { // still some room
// to scroll up
if (current + amount > adj.getMinimum()) {
adj.setValue(current + amount);
return;
}
else {
adj.setValue(adj.getMinimum());
return;
}
}
}
}