---
category: swing
folder: TranslucentToolTips
title: JToolTipを半透明にする
tags: [JToolTip, JList, Calendar]
author: aterai
pubdate: 2019-06-03T15:15:47+09:00
description: JToolTipを半透明に設定し、その形状や表示位置も変更します。
image: https://drive.google.com/uc?id=1yfrneVdDempFHGb54FMzcxO4DIlyzJd-Ew
hreflang:
href: https://java-swing-tips.blogspot.com/2019/06/make-jtooltip-translucent-and-change.html
lang: en
---
* Summary [#summary]
`JToolTip`を半透明に設定し、その形状や表示位置も変更します。
#download(https://drive.google.com/uc?id=1yfrneVdDempFHGb54FMzcxO4DIlyzJd-Ew)
* Source Code Examples [#sourcecode]
#code(link){{
class BalloonToolTip extends JToolTip {
private static final int TRI_HEIGHT = 4;
private HierarchyListener listener;
@Override public void updateUI() {
removeHierarchyListener(listener);
super.updateUI();
listener = e -> {
Component c = e.getComponent();
if ((e.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) != 0
&& c.isShowing()) {
Optional.ofNullable(SwingUtilities.getRoot(c))
.filter(JWindow.class::isInstance).map(JWindow.class::cast)
.ifPresent(w -> w.setBackground(new Color(0x0, true)));
}
};
addHierarchyListener(listener);
setOpaque(false);
setForeground(Color.WHITE);
setBackground(new Color(0xC8_00_00_00, true));
setBorder(BorderFactory.createEmptyBorder(5, 5, 5 + TRI_HEIGHT, 5));
}
@Override public Dimension getPreferredSize() {
Dimension d = super.getPreferredSize();
d.height = 32;
return d;
}
@Override protected void paintComponent(Graphics g) {
Shape s = makeBalloonShape();
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(getBackground());
g2.fill(s);
g2.dispose();
super.paintComponent(g);
}
private Shape makeBalloonShape() {
int w = getWidth() - 1;
int h = getHeight() - TRI_HEIGHT - 1;
int r = 10;
int cx = getWidth() / 2;
Polygon triangle = new Polygon();
triangle.addPoint(cx - TRI_HEIGHT, h);
triangle.addPoint(cx, h + TRI_HEIGHT);
triangle.addPoint(cx + TRI_HEIGHT, h);
Area area = new Area(new RoundRectangle2D.Float(0, 0, w, h, r, r));
area.add(new Area(triangle));
return area;
}
}
}}
* Description [#explanation]
* Description [#description]
- 半透明化と形状の変更
-- `JToolTip`自体は`setOpaque(false)`で透明化し、別途`JToolTip#paintComponent(...)`をオーバーライドして吹き出し図形を半透明色で描画
-- `JToolTip`が対象コンポーネントの親`JFrame`外に表示される場合は`JToolTip`の親`JWindow`を`setBackground(new Color(0x0, true)))`で完全透明化
- 表示位置の変更
-- `JList#getToolTipLocation(...)`をオーバーライドして、マウスカーソルの下側ではなく対象セルの真上に`JToolTip`が表示されるよう位置を調整
#code{{
@Override public String getToolTipText(MouseEvent e) {
Point p = e.getPoint();
int idx = locationToIndex(p);
Rectangle rect = getCellBounds(idx, idx);
if (idx < 0 || !rect.contains(p.x, p.y)) {
return null;
}
Contribution value = getModel().getElementAt(idx);
String act = value.activity == 0
? "No"
: Objects.toString(value.activity);
return "<html>" + act
+ " contribution <span style='color:#C8C8C8'> on "
+ value.date.toString();
}
@Override public Point getToolTipLocation(MouseEvent e) {
Point p = e.getPoint();
int i = locationToIndex(p);
Rectangle rect = getCellBounds(i, i);
String toolTipText = getToolTipText(e);
if (Objects.nonNull(toolTipText)) {
JToolTip tip = createToolTip();
tip.setTipText(toolTipText);
Dimension d = tip.getPreferredSize();
int gap = 2;
return new Point((int) (rect.getCenterX() - d.getWidth() / 2d),
rect.y - d.height - gap);
}
return null;
}
@Override public JToolTip createToolTip() {
if (tip == null) {
tip = new BalloonToolTip();
tip.setComponent(this);
}
return tip;
}
}}
* Reference [#reference]
- [[JListでウィークカレンダーを作成してヒートマップを表示する>Swing/CalendarHeatmapList]]
- [[JListのセル上にToolTipを表示する>Swing/ToolTipOnCellBounds]]
- [[JToolTipの形状を吹き出し風に変更する>Swing/BalloonToolTip]]
* Comment [#comment]
#comment
#comment