将Graphics2d调整为JScrollPane [英] Resize Graphics2d into JScrollPane

问题描述

关于问题调整组件大小而不重新绘制是我的问题在表单中创建可重新定义的自定义Graphics2d

In connection with question Resizing a component without repainting is my question how to create resiziable custom Graphics2d in form

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ZoomWithSelectionInViewport implements MouseWheelListener {

    private JComponent b;
    private int hexSize = 3;
    private int zoom = 80;
    private JScrollPane view;

    public ZoomWithSelectionInViewport() throws Exception {
        b = new JComponent() {

            private static final long serialVersionUID = 1L;

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(700, 700);
            }

            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2d = ((Graphics2D) g);
                int vertOffsetX, vertOffsetY, horizOffsetX, horizOffsetY;
                vertOffsetX = (int) ((double) hexSize * Math.sqrt(3.0f));
                vertOffsetY = (int) ((double) -hexSize - 1 * Math.sqrt(3.0f) / 2.0f);
                horizOffsetX = (int) ((double) hexSize * Math.sqrt(3.0f));
                horizOffsetY = (int) ((double) hexSize + 1 * Math.sqrt(3.0f) / 2.0f);
                for (int x = 0; x < 50; x++) {
                    for (int y = 0; y < 50; y++) {
                        int[] xcoords = new int[6];
                        int[] ycoords = new int[6];
                        for (int i = 0; i < 6; i++) {
                            xcoords[i] = (int) ((hexSize + x * horizOffsetX + y * vertOffsetX)
                                    + (double) hexSize * Math.cos(i * 2 * Math.PI / 6));
                            ycoords[i] = (int) (((getSize().height / 2) + x * horizOffsetY
                                    + y * vertOffsetY) + (double) hexSize * Math.sin(i * 2 * Math.PI / 6));
                        }
                        g2d.setStroke(new BasicStroke(hexSize / 2.5f));
                        g2d.setColor(Color.GRAY);
                        g2d.drawPolygon(xcoords, ycoords, 6);
                    }
                }
            }
        };
        view = new JScrollPane(b);
        b.addMouseWheelListener(this);
        JFrame f = new JFrame();
        f.setLocation(10, 10);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(view);
        f.setPreferredSize(b.getPreferredSize());
        f.pack();
        f.setVisible(true);
    }

    public void mouseWheelMoved(MouseWheelEvent e) {
        zoom = 100 * -Integer.signum(e.getWheelRotation());
        if (hexSize - Integer.signum(e.getWheelRotation()) > 0) {
            hexSize -= Integer.signum(e.getWheelRotation());
        }
        Dimension targetSize = new Dimension(b.getWidth() + zoom, b.getHeight() + zoom);
        b.setPreferredSize(targetSize);
        b.setSize(targetSize);
        b.revalidate();
        b.repaint();
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                try {
                    ZoomWithSelectionInViewport example = new ZoomWithSelectionInViewport();
                } catch (Exception ex) {
                    //
                }
            }
        });
    }
}

推荐答案

如果我理解正确，您希望滚动窗格的滚动条反映当前的缩放状态。我看到两种选择：

If I understand correctly, you want the scroll pane's scroll bars to reflect the current zoom state. I see two alternatives:

• 不要覆盖 getPreferredSize（） 在组件中，并调整鼠标侦听器中的首选大小以包含缩放图像;它似乎在右侧略微截断。

• Don't override getPreferredSize() in the component, and adjust the preferred size in the mouse listener to include the zoomed image; it appears slightly truncated on the right.

执行覆盖 getPreferredSize（）在组件中，并调整返回的维度（现在是一个常量），以包含隐含在 paintComponent（）。

Do override getPreferredSize() in the component, and adjust the returned Dimension (now a constant) to include the zoomed boundary implicit in paintComponent().

我更喜欢后者。我还发现编写显式转换函数来转换缩放和非缩放坐标很有帮助，如图所示这里。还可以使用此处显示的逆 AffineTransform 。

I'd prefer the latter. I've also found it helpful to write explicit transformation functions to convert zoomed and un-zoomed coordinates, as shown here. An inverse AffineTransform, shown here, is also possible.

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