---
category: swing
folder: KineticScrolling
title: JScrollPaneでキネティックスクロール
tags: [JScrollPane, Animation, MouseListener, JViewport]
author: aterai
pubdate: 2010-08-16T13:34:26+09:00
description: JScrollPaneにキネティックスクロール(慣性スクロール)風の動作をするマウスリスナーを設定します。
image: https://lh4.googleusercontent.com/_9Z4BYR88imo/TQTO32D08pI/AAAAAAAAAdE/TpuoGrYo-Q0/s800/KineticScrolling.png
hreflang:
href: https://java-swing-tips.blogspot.com/2010/08/kinetic-scrolling-jscrollpane.html
lang: en
---
* 概要 [#summary]
`JScrollPane`にキネティックスクロール(慣性スクロール)風の動作をするマウスリスナーを設定します。
#download(https://lh4.googleusercontent.com/_9Z4BYR88imo/TQTO32D08pI/AAAAAAAAAdE/TpuoGrYo-Q0/s800/KineticScrolling.png)
* サンプルコード [#sourcecode]
#code(link){{
class KineticScrollingListener2 extends MouseAdapter implements HierarchyListener {
private static final int SPEED = 4;
private static final int DELAY = 10;
private static final double D = 0.8;
private final JComponent label;
private final Point startPt = new Point();
private final Point delta = new Point();
private final Cursor dc;
private final Cursor hc = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
private final Timer inside = new Timer(DELAY, new ActionListener() {
@Override public void actionPerformed(ActionEvent e) {
JViewport vport = (JViewport) SwingUtilities.getUnwrappedParent(label);
Point vp = vport.getViewPosition();
// System.out.format("s: %s, %s%n", delta, vp);
vp.translate(-delta.x, -delta.y);
vport.setViewPosition(vp);
if (Math.abs(delta.x) > 0 || Math.abs(delta.y) > 0) {
delta.setLocation((int) (delta.x * D), (int) (delta.y * D));
// Outside
if (vp.x < 0 || vp.x + vport.getWidth() - label.getWidth() > 0) {
delta.x = (int) (delta.x * D);
}
if (vp.y < 0 || vp.y + vport.getHeight() - label.getHeight() > 0) {
delta.y = (int) (delta.y * D);
}
} else {
inside.stop();
if (!isInside(vport, label)) {
outside.start();
}
}
}
});
private final Timer outside = new Timer(DELAY, new ActionListener() {
@Override public void actionPerformed(ActionEvent e) {
JViewport vport = (JViewport) SwingUtilities.getUnwrappedParent(label);
Point vp = vport.getViewPosition();
// System.out.format("r: %s%n", vp);
if (vp.x < 0) {
vp.x = (int) (vp.x * D);
}
if (vp.y < 0) {
vp.y = (int) (vp.y * D);
}
if (vp.x + vport.getWidth() - label.getWidth() > 0) {
vp.x = (int) (vp.x - (vp.x + vport.getWidth() - label.getWidth()) * (1d - D));
}
if (vp.y + vport.getHeight() > label.getHeight()) {
vp.y = (int) (vp.y - (vp.y + vport.getHeight() - label.getHeight()) * (1d - D));
}
vport.setViewPosition(vp);
if (isInside(vport, label)) {
outside.stop();
}
}
});
protected static final int SPEED = 4;
protected static final int DELAY = 10;
protected static final double D = .8;
protected final JComponent label;
protected final Point startPt = new Point();
protected final Point delta = new Point();
protected final Cursor dc;
protected final Cursor hc = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
protected final Timer inside = new Timer(DELAY, null);
protected final Timer outside = new Timer(DELAY, null);
private static boolean isInside(JViewport vport, JComponent comp) {
Point vp = vport.getViewPosition();
return vp.x >= 0 && vp.x + vport.getWidth() - comp.getWidth() <= 0
&& vp.y >= 0 && vp.y + vport.getHeight() - comp.getHeight() <= 0;
protected static boolean isInside(JViewport viewport, JComponent comp) {
Point vp = viewport.getViewPosition();
return vp.x >= 0 && vp.x + viewport.getWidth() - comp.getWidth() <= 0
&& vp.y >= 0 && vp.y + viewport.getHeight() - comp.getHeight() <= 0;
}
public KineticScrollingListener2(JComponent comp) {
protected KineticScrollingListener2(JComponent comp) {
super();
this.label = comp;
this.dc = comp.getCursor();
inside.addActionListener(e -> dragInside());
outside.addActionListener(e -> dragOutside());
}
private void dragInside() {
JViewport viewport = (JViewport) SwingUtilities.getUnwrappedParent(label);
Point vp = viewport.getViewPosition();
// System.out.format("s: %s, %s%n", delta, vp);
vp.translate(-delta.x, -delta.y);
viewport.setViewPosition(vp);
if (Math.abs(delta.x) > 0 || Math.abs(delta.y) > 0) {
delta.setLocation((int) (delta.x * D), (int) (delta.y * D));
// Outside
if (vp.x < 0 || vp.x + viewport.getWidth() - label.getWidth() > 0) {
delta.x = (int) (delta.x * D);
}
if (vp.y < 0 || vp.y + viewport.getHeight() - label.getHeight() > 0) {
delta.y = (int) (delta.y * D);
}
} else {
inside.stop();
if (!isInside(viewport, label)) {
outside.start();
}
}
}
private void dragOutside() {
JViewport viewport = (JViewport) SwingUtilities.getUnwrappedParent(label);
Point vp = viewport.getViewPosition();
// System.out.format("r: %s%n", vp);
if (vp.x < 0) {
vp.x = (int) (vp.x * D);
}
if (vp.y < 0) {
vp.y = (int) (vp.y * D);
}
if (vp.x + viewport.getWidth() - label.getWidth() > 0) {
vp.x = (int) (vp.x - (vp.x + viewport.getWidth() - label.getWidth()) * (1d - D));
}
if (vp.y + viewport.getHeight() > label.getHeight()) {
vp.y = (int) (vp.y - (vp.y + viewport.getHeight() - label.getHeight()) * (1d - D));
}
viewport.setViewPosition(vp);
if (isInside(viewport, label)) {
outside.stop();
}
}
@Override public void mousePressed(MouseEvent e) {
e.getComponent().setCursor(hc);
startPt.setLocation(e.getPoint());
inside.stop();
outside.stop();
}
@Override public void mouseDragged(MouseEvent e) {
Point pt = e.getPoint();
JViewport vport = (JViewport) SwingUtilities.getUnwrappedParent(label);
Point vp = vport.getViewPosition();
JViewport viewport = (JViewport) SwingUtilities.getUnwrappedParent(label);
Point vp = viewport.getViewPosition();
vp.translate(startPt.x - pt.x, startPt.y - pt.y);
vport.setViewPosition(vp);
viewport.setViewPosition(vp);
delta.setLocation(SPEED * (pt.x - startPt.x), SPEED * (pt.y - startPt.y));
startPt.setLocation(pt);
}
@Override public void mouseReleased(MouseEvent e) {
e.getComponent().setCursor(dc);
JViewport vport = (JViewport) SwingUtilities.getUnwrappedParent(label);
if (isInside(vport, label)) {
JViewport viewport = (JViewport) SwingUtilities.getUnwrappedParent(label);
if (isInside(viewport, label)) {
inside.start();
} else {
outside.start();
}
}
@Override public void hierarchyChanged(HierarchyEvent e) {
Component c = e.getComponent();
if ((e.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0
&& !c.isDisplayable()) {
inside.stop();
outside.stop();
}
}
}
}}
* 解説 [#explanation]
- `scrollRectToVisible`
-- マウスがリリースされたらタイマーを起動し、`JComponent#scrollRectToVisible(Rectangle)`メソッドでスクロール
- `setViewPosition`
-- マウスがリリースされたらタイマーを起動し、`JViewport#setViewPosition(Point)`メソッドでスクロール
-- `View`として設定されている`JLabel`の外で移動が止まった(またはマウスがリリースされた)場合は、別のタイマーで`JLabel`の縁まで戻る
* 参考リンク [#reference]
- [[JScrollPaneのViewportをマウスで掴んでスクロール>Swing/HandScroll]]
- [[JScrollPaneのオートスクロール>Swing/AutoScroll]]
* コメント [#comment]
#comment
- 慣性(モーメンタム)スクロール、フリックスクロール(フリック+慣性スクロール？)、・・・でもやっぱり猫の掌スクロールを最初に思い出してしまう。 -- &user(aterai); &new{2010-08-16 (月) 13:41:47};
- `JDK 1.7.0`では、`JViewport#setViewPosition(Point)`を使って右下外部に移動できなくなっているので、[[JScrollPaneのViewportをマウスで掴んでスクロール>Swing/HandScroll]]と同じ対応をしてソースを更新。 -- &user(aterai); &new{2011-10-03 (月) 18:08:23};
#comment