java - 从 JComponent 的右下角动画缩小会导致卡顿

Question

我目前正在实现一个 swing JComponent 作为图像查看器，能够缩放、旋转和显示居中的图像以及所有这些动画。我已经实现了所有这些功能，但是在从图像的右下角缩小时遇到了问题。 每次动画开始时断时续，并且仅从面板的右侧或底部边缘开始。

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g;
    if (this.workingCopy != null) {
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        Point2D center = new Point2D.Double((getPreferredSize().width) / 2, (getPreferredSize().height) / 2);
        g2d.scale(getZoom(), getZoom());
        g2d.rotate(Math.toRadians(getRotation()), (center.getX() + 0) / getZoom(), (center.getY() + 0) / getZoom());
        g2d.drawImage(this.workingCopy,
                (int) Math.round(((getPreferredSize().width - (image.getWidth() * getZoom())) / 2) / getZoom()),
                (int) Math.round(((getPreferredSize().height - (image.getHeight() * getZoom())) / 2) / getZoom()), null);
    }
}

public synchronized void setZoom(final double zoom, boolean animated, final Point point) {
    final double oldZoom = getZoom();

    final Dimension viewSize = getPreferredSize();
    final Rectangle viewRect = getVisibleRect();

    // get relative point
    double relX = viewRect.getX() / viewSize.getWidth();
    double relY = viewRect.getY() / viewSize.getHeight();

    // new size
    double newViewSizeWidth = (getImageBounds().getWidth() / oldZoom) * zoom;
    double newViewSizeHeight = (getImageBounds().getHeight() / oldZoom) * zoom;


    double deltaDiffX = (point.getX() - viewRect.getX()) / viewSize.getWidth();
    double deltaDiffY = (point.getY() - viewRect.getY()) / viewSize.getHeight();

    double newDiffX = newViewSizeWidth * deltaDiffX;
    double newDiffY = newViewSizeHeight * deltaDiffY;

    double viewPositionX = (newViewSizeWidth * relX) + newDiffX - (point.getX() - viewRect.getX());
    double viewPositionY = (newViewSizeHeight * relY) + newDiffY - (point.getY() - viewRect.getY());

    final Point newPoint = new Point((int) Math.round(viewPositionX), (int) Math.round(viewPositionY));

    if (animated && !zooming) {

        Animator animator = new Animator(getAnimationSpeed(), new TimingTargetAdapter() {

            @Override
            public void begin() {
                super.begin();
                zooming = true;
            }

            @Override
            public void timingEvent(final float fraction) {
                super.timingEvent(fraction);
                double zoomDiff = zoom - oldZoom;
                setZoom(oldZoom + (fraction * zoomDiff),
                        new Point(
                        (int) Math.round(viewRect.getX() - (viewRect.getX() - newPoint.getX()) * fraction),
                        (int) Math.round(viewRect.getY() - (viewRect.getY() - newPoint.getY()) * fraction)));
            }

            @Override
            public void end() {
                super.end();
                zooming = false;
            }
        });
        animator.start();
    } else {
        setZoom(zoom, newPoint);
    }
}

有人可以指出我做错了什么或忘记考虑缩放动画吗？ 一切正常，除了动画缩小期间的卡顿。

预先感谢您的帮助。

Answer 1

好吧，我偶然发现了这个问题。问题是 JPanel 仍然有一个 LayoutManager，这导致了从右/下角缩小时出现问题。 在我将 LayoutManager 设置为 null 后，一切正常。