Java Swing scrollpane在滚动超过某一点时发出通知
伙计们。我需要关于如何最好地实施某事的建议。我的节目: 我有一个swing程序,它读取一个包含多条不同类型记录的文件。我将这些记录读入java对象,用它们的标题和内容制作JTable(因此每个表只有标题和1条记录),将这些表添加到面板,并将面板添加到滚动窗格。有很多记录,大约70000条,所以我不能一次把所有的东西都载入内存 我的计划是通过一次只显示100条记录来分页显示,如果滚动到某个点,比如说表格NR50,它将加载接下来的100个表格并将它们添加到滚动窗格中 这就引出了我的问题 1) 我不知道如何通知自己我已经滚动到某个点了。因此,假设我有100个JTables连接到一个JPanel,并连接到一个滚动窗格。我如何添加一个监听器来通知用户何时滚动到Jtable 50以获取参数 2) 我遇到的另一个问题与我如何将表格放入面板有关。我使用的swingworker如下所示:Java Swing scrollpane在滚动超过某一点时发出通知,java,swing,pagination,swingworker,Java,Swing,Pagination,Swingworker,伙计们。我需要关于如何最好地实施某事的建议。我的节目: 我有一个swing程序,它读取一个包含多条不同类型记录的文件。我将这些记录读入java对象,用它们的标题和内容制作JTable(因此每个表只有标题和1条记录),将这些表添加到面板,并将面板添加到滚动窗格。有很多记录,大约70000条,所以我不能一次把所有的东西都载入内存 我的计划是通过一次只显示100条记录来分页显示,如果滚动到某个点,比如说表格NR50,它将加载接下来的100个表格并将它们添加到滚动窗格中 这就引出了我的问题 1) 我不知
private class TableRun extends SwingWorker<Void, JTable> {
private ArrayDeque<FileRecord> fileRecords;
private final GridBagConstraints gc;
private final JPanel parentPanel;
int counter = 1;
TableRun(ArrayDeque<FileRecord> fileRecords, GridBagConstraints gc, JPanel parentPanel) {
this.fileRecords = fileRecords;
this.gc = gc;
this.parentPanel = parentPanel;
}
@Override
protected Void doInBackground() {
Iterator<FileRecord> iterator = fileRecords.iterator();
while (iterator.hasNext()) {
publish(getTabel(iterator.next()));
}
return null;
}
@Override
protected void process(final List<JTable> tables) {
Iterator<JTable> iterator = tables.iterator();
while(iterator.hasNext()) {
JTable table = iterator.next();
gc.fill = 1;
parentPanel.add(table.getTableHeader(), gc);
gc.gridy++;
parentPanel.add(table,gc);
gc.gridy++;
//validate takes a long time so i try to not do it too often.
if(counter == 50 || (counter % 5000) ==0 || (counter == fileRecords.size())) {
validate();
}
System.out.println("Sequence Nr : " + table.getModel().getValueAt(0,1) + " - Counter :" + counter++);
}
}
}
私有类TableRun扩展SwingWorker{
私人ArrayDeque文件记录;
私人终审法院;
私人最终JPanel家长小组;
int计数器=1;
TableRun(ArrayQue文件记录、GridBagConstraints gc、JPanel parentPanel){
this.fileRecords=fileRecords;
this.gc=gc;
this.parentPanel=parentPanel;
}
@凌驾
受保护的Void doInBackground(){
迭代器迭代器=fileRecords.Iterator();
while(iterator.hasNext()){
发布(getTabel(iterator.next());
}
返回null;
}
@凌驾
受保护的作废流程(最终列表表){
迭代器迭代器=tables.Iterator();
while(iterator.hasNext()){
JTable table=iterator.next();
gc.fill=1;
parentPanel.add(table.getTableHeader(),gc);
gc.gridy++;
parentPanel.add(表,gc);
gc.gridy++;
//验证需要很长时间,所以我尽量不太频繁地进行验证。
如果(计数器==50 | |(计数器%5000)==0 | |(计数器==fileRecords.size()){
验证();
}
System.out.println(“序列号:“+table.getModel().getValueAt(0,1)+”-计数器:“+Counter++”);
}
}
}
我将记录对象馈送给swingworker。然后,它将记录转换为具有所有必要格式的JTable,然后将它们添加到面板中。它有时调用validate来显示表,否则就不显示它们。(不确定是否有更好的方法进行此操作?)
所以我的问题与滚动有关。如果我最初只将70000条记录中的100条提供给我的swinworker,它显然会创建一个滚动窗格,认为只有100条记录。所以滚动条不是很小(很明显你不能滚动很远)。我真正想要的是,尽管我只显示100条记录,但我希望滚动窗格的大小是70000条记录的大小,以便您可以根据滚动条查看记录的大小。如果将滚动条拖动到底部的某个点,则需要将这些记录拉出来并显示出来。如何创建滚动窗格的大小大于其中的实际组件,但基于它们的大小
希望我的问题有意义
谢谢
我如何添加一个监听器来通知用户何时滚动过页面
为了便于讨论,Jtable 50
例如(一种可能的方法,您可以测试),(向我道歉)其他问题不可回答,请注意,您必须将鼠标事件(鼠标滚轮)从父对象(JScrollPane包含JPanel)重新修补到子对象包含JTables
import java.awt.*;
导入java.awt.event.ActionEvent;
导入java.awt.image.buffereImage;
导入javax.swing.*;
导入javax.swing.repaitmanager;
导入javax.swing.event.ChangeEvent;
导入javax.swing.event.ChangeListener;
导入javax.swing.table.TableModel;
//http://stackoverflow.com/a/8249353/714968
公共类视口闪烁原始{
私有JFrame=新JFrame(“表格”);
私有JViewport viewport=新JViewport();
私有矩形RECT=新矩形();
私有矩形RECT1=新矩形();
专用JTable表=新JTable(50,3);
私有javax.swing.Timer;
私有整数计数=0;
私有布尔topOrBottom=false;
private GradientViewPortOriginal tableViewPort;
公共视口闪烁原始(){
tableViewPort=新的GradientViewPortOriginal(表格);
viewport=tableViewPort.getViewport();
viewport.addChangeListener(新的ChangeListener(){
@凌驾
公共无效状态已更改(更改事件e){
如果(tableViewPort.bolStart){
RECT=table.getCellRect(0,0,true);
RECT1=table.getCellRect(table.getRowCount()-1,0,true);
矩形viewRect=viewport.getViewRect();
if(视图矩形相交(矩形)){
System.out.println(“可见矩形->”+RECT);
tableViewPort.paintBackGround(新颜色(250150150));
}else if(视图矩形相交(矩形1)){
System.out.println(“可见的RECT1->”+RECT1);
tableViewPort.paintBackGround(新颜色(150250150));
}否则{
System.out.println(“可见矩形->?”;
助教
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import javax.swing.*;
import javax.swing.RepaintManager;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.table.TableModel;
//http://stackoverflow.com/a/8249353/714968
public class ViewPortFlickeringOriginal {
private JFrame frame = new JFrame("Table");
private JViewport viewport = new JViewport();
private Rectangle RECT = new Rectangle();
private Rectangle RECT1 = new Rectangle();
private JTable table = new JTable(50, 3);
private javax.swing.Timer timer;
private int count = 0;
private boolean topOrBottom = false;
private GradientViewPortOriginal tableViewPort;
public ViewPortFlickeringOriginal() {
tableViewPort = new GradientViewPortOriginal(table);
viewport = tableViewPort.getViewport();
viewport.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
if (tableViewPort.bolStart) {
RECT = table.getCellRect(0, 0, true);
RECT1 = table.getCellRect(table.getRowCount() - 1, 0, true);
Rectangle viewRect = viewport.getViewRect();
if (viewRect.intersects(RECT)) {
System.out.println("Visible RECT -> " + RECT);
tableViewPort.paintBackGround(new Color(250, 150, 150));
} else if (viewRect.intersects(RECT1)) {
System.out.println("Visible RECT1 -> " + RECT1);
tableViewPort.paintBackGround(new Color(150, 250, 150));
} else {
System.out.println("Visible RECT1 -> ???? ");
tableViewPort.paintBackGround(new Color(150, 150, 250));
}
}
}
});
frame.add(tableViewPort);
frame.setPreferredSize(new Dimension(600, 300));
frame.pack();
frame.setLocation(50, 100);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
RepaintManager.setCurrentManager(new RepaintManager() {
@Override
public void addDirtyRegion(JComponent c, int x, int y, int w, int h) {
Container con = c.getParent();
while (con instanceof JComponent) {
if (!con.isVisible()) {
return;
}
if (con instanceof GradientViewPortOriginal) {
c = (JComponent) con;
x = 0;
y = 0;
w = con.getWidth();
h = con.getHeight();
}
con = con.getParent();
}
super.addDirtyRegion(c, x, y, w, h);
}
});
frame.setVisible(true);
start();
}
private void start() {
timer = new javax.swing.Timer(100, updateCol());
timer.start();
}
public Action updateCol() {
return new AbstractAction("text load action") {
private static final long serialVersionUID = 1L;
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("updating row " + (count + 1));
TableModel model = table.getModel();
int cols = model.getColumnCount();
int row = 0;
for (int j = 0; j < cols; j++) {
row = count;
table.changeSelection(row, 0, false, false);
timer.setDelay(100);
Object value = "row " + (count + 1) + " item " + (j + 1);
model.setValueAt(value, count, j);
}
count++;
if (count >= table.getRowCount()) {
timer.stop();
table.changeSelection(0, 0, false, false);
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
table.clearSelection();
tableViewPort.bolStart = true;
}
});
}
}
};
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
ViewPortFlickeringOriginal viewPortFlickering = new ViewPortFlickeringOriginal();
}
});
}
}
class GradientViewPortOriginal extends JScrollPane {
private static final long serialVersionUID = 1L;
private final int h = 50;
private BufferedImage img = null;
private BufferedImage shadow = new BufferedImage(1, h, BufferedImage.TYPE_INT_ARGB);
private JViewport viewPort;
public boolean bolStart = false;
public GradientViewPortOriginal(JComponent com) {
super(com);
viewPort = this.getViewport();
viewPort.setScrollMode(JViewport.BLIT_SCROLL_MODE);
viewPort.setScrollMode(JViewport.BACKINGSTORE_SCROLL_MODE);
viewPort.setScrollMode(JViewport.SIMPLE_SCROLL_MODE);
paintBackGround(new Color(250, 150, 150));
}
public void paintBackGround(Color g) {
Graphics2D g2 = shadow.createGraphics();
g2.setPaint(g);
g2.fillRect(0, 0, 1, h);
g2.setComposite(AlphaComposite.DstIn);
g2.setPaint(new GradientPaint(0, 0, new Color(0, 0, 0, 0f), 0, h,
new Color(0.1f, 0.8f, 0.8f, 0.5f)));
g2.fillRect(0, 0, 1, h);
g2.dispose();
}
@Override
public void paint(Graphics g) {
if (img == null || img.getWidth() != getWidth() || img.getHeight() != getHeight()) {
img = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
}
Graphics2D g2 = img.createGraphics();
super.paint(g2);
Rectangle bounds = getViewport().getVisibleRect();
g2.scale(bounds.getWidth(), -1);
int y = (getColumnHeader() == null) ? 0 : getColumnHeader().getHeight();
g2.drawImage(shadow, bounds.x, -bounds.y - y - h, null);
g2.scale(1, -1);
g2.drawImage(shadow, bounds.x, bounds.y + bounds.height - h + y, null);
g2.dispose();
g.drawImage(img, 0, 0, null);
}
}