Swing/SliderTicksPosition の変更点

---
category: swing
folder: SliderTicksPosition
title: JSliderの目盛り表示位置をトラック上部に変更する
tags: [JSlider, JLayer]
author: aterai
pubdate: 2022-07-18T09:24:25+09:00
description: 水平JSliderの目盛りをトラック上部に表示し、つまみの矢印も上向きに描画するよう変更します。
image: https://drive.google.com/uc?id=1Jm5tHOewLJQ6ExRVgFWdzBBTezrNjzZA
hreflang:
    href: https://java-swing-tips.blogspot.com/2022/12/inverse-display-position-of-jsliders.html
    lang: en
---
* 概要 [#summary]
水平`JSlider`の目盛りをトラック上部に表示し、つまみの矢印も上向きに描画するよう変更します。

#download(https://drive.google.com/uc?id=1Jm5tHOewLJQ6ExRVgFWdzBBTezrNjzZA)

* サンプルコード [#sourcecode]
#code(link){{
class VerticalFlipLayerUI extends LayerUI<JComponent> {
  @Override public void paint(Graphics g, JComponent c) {
    if (c instanceof JLayer) {
      Graphics2D g2 = (Graphics2D) g.create();
      g2.setTransform(getAffineTransform(c.getSize()));
      super.paint(g2, c);
      g2.dispose();
    } else {
      super.paint(g, c);
    }
  }

  @Override public void installUI(JComponent c) {
    super.installUI(c);
    if (c instanceof JLayer) {
      JLayer<?> l = (JLayer<?>) c;
      l.setLayerEventMask(AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK);
    }
  }

  @Override public void uninstallUI(JComponent c) {
    if (c instanceof JLayer) {
      ((JLayer<?>) c).setLayerEventMask(0);
    }
    super.uninstallUI(c);
  }

  @Override public void eventDispatched(AWTEvent e, JLayer<? extends JComponent> l) {
    if (e instanceof MouseEvent) {
      MouseEvent me = (MouseEvent) e;
      Point2D pt = me.getPoint();
      try {
        pt = getAffineTransform(l.getSize()).inverseTransform(pt, null);
      } catch (NoninvertibleTransformException ex) {
        ex.printStackTrace();
        UIManager.getLookAndFeel().provideErrorFeedback(me.getComponent());
      }
      // Horizontal: me.translatePoint((int) pt.getX() - me.getX(), 0);
      me.translatePoint(0, (int) pt.getY() - me.getY());
      me.getComponent().repaint();
    }
    super.eventDispatched(e, l);
  }

  private AffineTransform getAffineTransform(Dimension d) {
    AffineTransform at = AffineTransform.getTranslateInstance(0d, d.height);
    at.scale(1d, -1d);
    return at;
  }
}
}}

* 解説 [#explanation]
- `VerticalFlipLayerUI`
-- `JLayer`を使用して水平`JSlider`とその内部の`MouseEvent`の上下を反転
-- ラベルの数字も上下反転してしまう
-- `Ubuntu 20.04.4 LTS`で`JLayer`が表示されない場合がある？
--- このサンプルでは`BorderLayout.NORTH`で表示されて`BorderLayout.SOUTH`で非表示になる？
- `UpArrowThumbSliderUI`
-- `BasicSliderUI`の`calculateTrackRect()`、`calculateTickRect()`、`calculateLabelRect()`をオーバーライドしてこの`3`つの領域の描画位置を入れ替える
-- つまみの矢印は`BasicSliderUI#paintThumb()`をオーバーライドしてその場で上下反転描画
-- `MetalLookAndFeel`%%や`WindowsLookAndFeel`%%ではつまみだけ反転するのは難しい？

#code{{
class UpArrowThumbSliderUI extends BasicSliderUI {
  protected UpArrowThumbSliderUI(JSlider slider) {
    super(slider);
  }

  @Override protected void calculateTrackRect() {
    if (slider.getOrientation() == SwingConstants.HORIZONTAL) {
      int centerSpacing = thumbRect.height;
      if (slider.getPaintTicks()) {
        centerSpacing -= getTickLength();
      }
      if (slider.getPaintLabels()) {
        centerSpacing -= getHeightOfTallestLabel();
      }
      trackRect.x = contentRect.x + trackBuffer;
      trackRect.y = contentRect.y + (contentRect.height + centerSpacing + 1) / 2;
      trackRect.width = contentRect.width - (trackBuffer * 2);
      trackRect.height = thumbRect.height;
    } else {
      super.calculateTrackRect();
    }
  }

  @Override protected void calculateTickRect() {
    if (slider.getOrientation() == SwingConstants.HORIZONTAL) {
      tickRect.x = trackRect.x;
      // tickRect.y = trackRect.y + trackRect.height;
      tickRect.y = trackRect.y;
      tickRect.width = trackRect.width;
      tickRect.height = slider.getPaintTicks() ? getTickLength() : 0;
    } else {
      super.calculateTickRect();
    }
  }

  @Override protected void calculateLabelRect() {
    if (slider.getPaintLabels()) {
      if (slider.getOrientation() == SwingConstants.HORIZONTAL) {
        labelRect.width = tickRect.width + (trackBuffer * 2);
        labelRect.height = getHeightOfTallestLabel();
        labelRect.x = tickRect.x - trackBuffer;
        labelRect.y = tickRect.y - labelRect.height;
      } else {
        super.calculateLabelRect();
      }
    } else {
      if (slider.getOrientation() == SwingConstants.HORIZONTAL) {
        labelRect.x = tickRect.x;
        labelRect.y = tickRect.y; // + tickRect.height;
        labelRect.width = tickRect.width;
        labelRect.height = 0;
      } else {
        super.calculateLabelRect();
      }
    }
  }

  @Override public void paintThumb(Graphics g) {
    if (slider.getOrientation() == SwingConstants.HORIZONTAL) {
      Graphics2D g2 = (Graphics2D) g.create();
      g2.translate(0, contentRect.y + contentRect.height + thumbRect.height);
      g2.scale(1d, -1d);
      super.paintThumb(g2);
      g2.dispose();
    } else {
      super.paintThumb(g);
    }
  }
}
}}

* 参考リンク [#reference]
- [[JSliderの順序を反転>Swing/InvertedSlider]]
-- 垂直`JSlider`の目盛りをデフォルトの右側から左側に変更する場合は`JSlider#setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT)`が使用可能

* コメント [#comment]
#comment
#comment