可调整大小的JScrollPane的内容具有最小宽度。如果JScrollPane小于此宽度,则应显示水平滚动条。如果它大于此宽度,则视口内容应该展开以填充整个视口。JScrollpane调整可变大小内容的大小
似乎是一个简单的概念,我已经得到的东西的工作,但感觉像一个黑客:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
public class SSBTest {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
final Component view = new MyView();
final JScrollPane jScrollPane = new JScrollPane(view);
jScrollPane.addComponentListener(new ComponentAdapter() {
@Override
public void componentResized(final ComponentEvent e) {
final Dimension minimumSize = view.getMinimumSize();
final int width = Math.max(minimumSize.width, jScrollPane.getViewport().getWidth());
view.setPreferredSize(new Dimension(width, minimumSize.height));
}
});
showInDialog(jScrollPane);
}
});
}
private static void showInDialog(final JScrollPane jScrollPane) {
final JDialog dialog = new JOptionPane(jScrollPane).createDialog("JScrollPane Resize Test");
dialog.setResizable(true);
dialog.setModal(true);
dialog.setVisible(true);
System.exit(0);
}
private static final class MyView extends JPanel {
@Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.drawString("Dimensions are " + getSize(), 10, 20);
g.drawRect(0, 0, getMinimumSize().width-1, getMinimumSize().height-1);
g.setColor(Color.BLUE);
g.drawRect(0, 0, getPreferredSize().width-1, getPreferredSize().height-1);
}
@Override
public Dimension getMinimumSize() {
return new Dimension(200, 200);
}
@Override
public Dimension getPreferredSize() {
return super.getPreferredSize();
}
}
}
调整大小的对话框触发的ComponentListener,其中明确规定视景的首选大小,触发组件验证。但是,调整大小会导致抖动滚动条。有没有更干净的方法来做到这一点?
编辑:感谢camickr为ScrollablePanel链接,我修改了我的JPanel类来实现Scrollable,并动态地改变了getScrollableTracksViewportWidth()的返回值。
当视口很大时,我返回true
为getScrollableTracksViewportWidth()
,告诉JScrollPane使用我的组件填充视图。当视口很小时,我返回false
,滚动条出现。
import javax.swing.*;
import java.awt.*;
public class SSBTest {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
final Component view = new MyView();
final JScrollPane jScrollPane = new JScrollPane(view);
showInDialog(jScrollPane);
}
});
}
private static void showInDialog(final JScrollPane jScrollPane) {
final JDialog dialog = new JOptionPane(jScrollPane).createDialog("JScrollPane Resize Test");
dialog.setResizable(true);
dialog.setModal(true);
dialog.setVisible(true);
System.exit(0);
}
private static final class MyView extends JPanel implements Scrollable {
@Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.drawString("MyView: " + getWidth() + "x" + getHeight(), 10, 20);
g.drawRect(0, 0, getMinimumSize().width-1, getMinimumSize().height-1);
g.setColor(Color.BLUE);
g.drawRect(0, 0, getPreferredSize().width-1, getPreferredSize().height-1);
g.drawString("Preferred/Minimum Size", 10, getPreferredSize().height/2);
g.setColor(Color.GREEN);
g.drawLine(0, 0, getWidth(), getHeight());
}
@Override
public Dimension getMinimumSize() {
return new Dimension(200, 200);
}
@Override
public Dimension getPreferredSize() {
return getMinimumSize();
}
public Dimension getPreferredScrollableViewportSize() {
return getPreferredSize();
}
public int getScrollableUnitIncrement(final Rectangle visibleRect, final int orientation, final int direction) {
return 10;
}
public int getScrollableBlockIncrement(final Rectangle visibleRect, final int orientation, final int direction) {
return visibleRect.width;
}
public boolean getScrollableTracksViewportWidth() {
final Container viewport = getParent();
return viewport.getWidth() > getMinimumSize().width;
}
public boolean getScrollableTracksViewportHeight() {
return true;
}
}
}
完美!我没有使用ScrollablePanel类,但是该页面上的动态更改Scrollable#getScrollableTracksViewportWidth的返回值的建议正在完美工作。 – 2011-02-10 17:47:08