JAVA Swing中JScrollPanle自定义带标尺的JScrollPanel

Swing中JScrollPanel的结构与组成如下图：

分为四个角与四个边，中间蓝色矩形为View窗口，可以通过调用JScrollPanel的

getViewport().setView(view)完成对现实内容的设置。

最常见的自定义JScrollPanel是改写默认的Column  Header View与Row Header View

下面是我做的一个关于瓷砖排列显示的UI，实现了一个标尺化的JScrollPanel，可以很好

的度量与说明空间大小与瓷砖需求的关系，实现效果如下：

自定义的列与行标尺View的代码如下：

package com.gloomyfish.swing.custom.ui;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.geom.Line2D;

import java.awt.geom.Rectangle2D;

import javax.swing.JComponent;

public class RuleView extends JComponent {

/**

*

*/

private static final long serialVersionUID = 1L;

public static final int HORIZONTAL = 0;

public static final int VERTICAL = 1;

private int SIZE = 600;

public int orientation;

public boolean isMetric;

private double increment;

private double units;

private int width;

private int height;

public RuleView(int o, boolean m) {

orientation = o;

isMetric = m;

setIncrementAndUnits();

if(orientation == HORIZONTAL)

{

width = SIZE;

}

else

{

height = SIZE;

}

}

private void setIncrementAndUnits() {

}

public void setPreferredHeight(int ph) {

this.height = ph;

setPreferredSize(new Dimension(SIZE, ph));

}

public void setPreferredWidth(int pw) {

this.width = pw;

setPreferredSize(new Dimension(pw, SIZE));

}

protected void paintComponent(Graphics g) {

Graphics2D g2d = (Graphics2D) g;

System.out.println("width = " + width);

System.out.println("Height = " + height);

// background color

g2d.setColor(new Color(102, 255, 255));

Rectangle2D rect2d = new Rectangle2D.Double(0, 0, width, height);

g2d.fill(rect2d);

int count = 0;

increment = 0;

// unit and text symbol

g2d.setPaint(new Color(0,0,204));

if(orientation == HORIZONTAL)

{

units = width / 10.0;

for(int i=0; i<=units; i++)

{

double rowOff = i * 10.0;

Line2D line = new Line2D.Double(rowOff, height*0.7, rowOff, height);

g2d.draw(line);

if(count == 10)

{

count = 0;

increment += 1;

Line2D bigLine = new Line2D.Double(rowOff, height*0.4, rowOff, height);

g2d.draw(bigLine);

g2d.drawString(increment + "", (int)rowOff-3, (int)(height/3.0));

}

count++;

}

}

else

{

units = height / 10.0;

for(int i=0; i<=units; i++)

{

double colOff = i * 10.0;

Line2D line = new Line2D.Double(width*0.7, colOff, width, colOff);

g2d.draw(line);

if(count == 10)

{

count = 0;

increment += 1;

Line2D bigLine = new Line2D.Double(width*0.5, colOff, width, colOff);

g2d.draw(bigLine);

g2d.drawString(increment + "", 0, (int)colOff);

}

count++;

}

}

g2d.setPaint(Color.RED);

}

}

自定义的JScrollPanel的代码如下：

package com.gloomyfish.swing.custom.ui;

import java.awt.Color;

import java.awt.FlowLayout;

import java.awt.Font;

import javax.swing.JComponent;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JScrollPane;

import javax.swing.border.LineBorder;

public class JCustomScrollPane extends JScrollPane {

/**

*

*/

private static final long serialVersionUID = 1L;

private RuleView columnView;

private RuleView rowView;

private JLabel cornerLabel;

public JCustomScrollPane(int rowSize, int columnSize)

{

super();

JPanel buttonCorner = new JPanel(); // use FlowLayout

cornerLabel = new JLabel("单位:米");

cornerLabel.setForeground(Color.BLUE);

cornerLabel.setFont(new Font("Serif", Font.PLAIN, 8));

buttonCorner.setLayout(new FlowLayout(FlowLayout.LEFT));

buttonCorner.add(cornerLabel);

setCorner(JScrollPane.UPPER_LEFT_CORNER, buttonCorner);

columnView = new RuleView(RuleView.HORIZONTAL, true);

columnView.setPreferredHeight(30);

rowView = new RuleView(RuleView.VERTICAL, true);

rowView.setPreferredWidth(30);

setColumnHeaderView(columnView);

setRowHeaderView(rowView);

setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

setViewportBorder(new LineBorder(Color.RED));

}

public void setImagePanel(JComponent view)

{

this.getViewport().setView(view);

}

}

最后说一下，Swing 是非常灵活的UI组件，提供了非常多的自定义接口

怎么合理运用就看个人啦！