[英]JScrollPane minimum width inside JSplitPane
我正在嘗試JSplitPane
與幾個可滾動的並排JTable
s。
但是,根據 gif,我正在嘗試JScrollPane
收縮太多的行為。
注意左邊的組件,除了最小width
為250px
外,它還在繼續縮小。
相關代碼是
final var objetsTable = new JTable();
final var objectsScrollPane = new JScrollPane(objetsTable);
objectsScrollPane.setMinimumSize(new Dimension(250, 0));
objectsScrollPane.setPreferredSize(new Dimension(400, 300));
final var stepsTable = new JTable();
final var stepsScrollPane = new JScrollPane(stepsTable);
stepsScrollPane.setMinimumSize(new Dimension(150, 0));
stepsScrollPane.setPreferredSize(new Dimension(200, 300));
final var splitPane = new JSplitPane();
splitPane.setLeftComponent(objectsScrollPane);
splitPane.setRightComponent(stepsScrollPane);
splitPane.setResizeWeight(1.0);
在這種情況下,如何避免JScrollPane
縮小太多?
在JSplitPane
上調用的getMinimumSize
返回一個大小,該大小實際上考慮了其左右Component
的最小大小,加上分隔符大小。 因此,可能解決您的問題的一種方法是讓您的JSplitPane
實現Scrollable
(以使其尊重自身的最小大小)並將其添加到JScrollPane
。 通過這種方式,您可以確保遵守最小尺寸,並且當用戶繼續將Scrollable
JSplitPane
縮小到超過其最小尺寸時,將顯示滾動條。
這是一些工作代碼:
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Rectangle;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JViewport;
import javax.swing.Scrollable;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
public class Main {
private static class MyScrollableSplitPane extends JSplitPane implements Scrollable {
private int maxUnitIncrement = 10;
public void setMaxUnitIncrement(final int pixels) {
maxUnitIncrement = pixels;
}
public int getMaxUnitIncrement() {
return maxUnitIncrement;
}
/**
* This is being constantly checked by the scroll pane instead of the
* getPreferredScrollableViewportSize...
*/
@Override
public Dimension getPreferredSize() {
final Dimension minSz = getMinimumSize(),
curSz = getSize();
curSz.width = Math.max(curSz.width, minSz.width);
curSz.height = Math.max(curSz.height, minSz.height);
return curSz;
}
/**
* This is only checked once (at the beginning).
*/
@Override
public Dimension getPreferredScrollableViewportSize() {
return super.getPreferredSize();
}
/**
* Source: https://docs.oracle.com/javase/tutorial/uiswing/components/scrollpane.html .
*/
@Override
public int getScrollableUnitIncrement(Rectangle visibleRect,
int orientation,
int direction) {
//Get the current position.
int currentPosition;
if (orientation == SwingConstants.HORIZONTAL) {
currentPosition = visibleRect.x;
} else {
currentPosition = visibleRect.y;
}
//Return the number of pixels between currentPosition
//and the nearest tick mark in the indicated direction.
if (direction < 0) {
int newPosition = currentPosition -
(currentPosition / maxUnitIncrement)
* maxUnitIncrement;
return (newPosition == 0) ? maxUnitIncrement : newPosition;
} else {
return ((currentPosition / maxUnitIncrement) + 1)
* maxUnitIncrement
- currentPosition;
}
}
/**
* Source: https://docs.oracle.com/javase/tutorial/uiswing/components/scrollpane.html .
*/
@Override
public int getScrollableBlockIncrement(Rectangle visibleRect,
int orientation,
int direction) {
if (orientation == SwingConstants.HORIZONTAL) {
return visibleRect.width - maxUnitIncrement;
} else {
return visibleRect.height - maxUnitIncrement;
}
}
@Override
public boolean getScrollableTracksViewportWidth() {
final Container parent = getParent();
return (parent instanceof JViewport) && (getMinimumSize().width < ((JViewport) parent).getWidth());
}
@Override
public boolean getScrollableTracksViewportHeight() {
final Container parent = getParent();
return (parent instanceof JViewport) && (getMinimumSize().height < ((JViewport) parent).getHeight());
}
}
private static void createAndShowGUI() {
/*Since I don't add any Components to the 'left' and 'right' panels, I am going to set the
preferred size of them. This is only for demonstrating the concept. Setting the minimum size
though is somewhat required by the JSplitPane itself.*/
final JPanel left = new JPanel();
left.setMinimumSize(new Dimension(150, 100));
left.setPreferredSize(new Dimension(200, 200));
final JPanel right = new JPanel();
right.setMinimumSize(new Dimension(300, 100));
right.setPreferredSize(new Dimension(400, 200));
final JSplitPane split = new MyScrollableSplitPane();
split.setBorder(BorderFactory.createLineBorder(Color.CYAN.darker(), 3));
split.setOrientation(JSplitPane.HORIZONTAL_SPLIT);
split.setLeftComponent(left);
split.setRightComponent(right);
final JFrame frame = new JFrame("MyScrollableSplitPane demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new JScrollPane(split));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(final String[] args) {
SwingUtilities.invokeLater(Main::createAndShowGUI);
}
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.