如何滚动两个JTextPane? [英] How to scroll two JTextPane's?

问题描述

我是使用NetBeans的Swing新手.我想垂直滚动两个并排的JTextPane.滚动应该同步，并通过单个滚动条完成.

I am a Swing novice using NetBeans. I want to vertically scroll two side-by-side JTextPane's. The scrolling should be syncronized and done through a single scrollbar.

如果我从NetBean设计器中添加JTextPanes，它们将自动放置在JScrollPane中，因此它们可以独立滚动.我删除了封闭的滚动窗格，并将其放在JPanel中，以便JPanel可以是单个JScrollPane的客户端.这似乎可行，除了当JTextPanes太长时，它们似乎在JPanel的末尾出现.我可以将面板和两个文本窗格滚动到某个点.当我到达底部时，我可以将光标放置在一个文本窗格中，并向下箭头超出我的视野.

If I add JTextPanes from the NetBean designer they are automatically put inside a JScrollPane so they scroll independently. I have deleted the enclosing scroll panes and put them in a JPanel instead so the JPanel can be the client of a single JScrollPane. This seems to work except that when the JTextPanes are very long they seem to go beyong the end of the JPanel. I can scroll the panel and both text panes to a certain point. When I reach the bottom I can put a cusor in one of the text panes and arrow down beyond my field of view.

这是我主要方法中的代码.我已经从NetBeans设计器生成的内容中复制了布局.

Here is code from my main method. I have copied the layout from something that was generated by the NetBeans designer.

java.awt.EventQueue.invokeLater(new Runnable() {
    public void run() {
topFrame aTopFrame = new topFrame();
JScrollPane scollBothDiffs = new javax.swing.JScrollPane();
JPanel bothDiffsPanel = new javax.swing.JPanel();
JTextPane leftDiffPane = diffPane1;
JTextPane rightDiffPane = diffPane2;


javax.swing.GroupLayout bothDiffsPanelLayout = new javax.swing.GroupLayout(bothDiffsPanel);
bothDiffsPanel.setLayout(bothDiffsPanelLayout);
bothDiffsPanelLayout.setHorizontalGroup(
    bothDiffsPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
    .addGroup(bothDiffsPanelLayout.createSequentialGroup()
        .addGap(20, 20, 20)
        .addComponent(leftDiffPane, javax.swing.GroupLayout.PREFERRED_SIZE, 463, javax.swing.GroupLayout.PREFERRED_SIZE)
        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
        .addComponent(rightDiffPane, javax.swing.GroupLayout.PREFERRED_SIZE, 463, javax.swing.GroupLayout.PREFERRED_SIZE)
        .addContainerGap(52, Short.MAX_VALUE))
);
bothDiffsPanelLayout.setVerticalGroup(
    bothDiffsPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, bothDiffsPanelLayout.createSequentialGroup()
        .addContainerGap()
        .addGroup(bothDiffsPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
            .addComponent(rightDiffPane, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 630, Short.MAX_VALUE)
            .addComponent(leftDiffPane, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 630, Short.MAX_VALUE))
        .addContainerGap())
);

scollBothDiffs.setViewportView(bothDiffsPanel);

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(aTopFrame.getContentPane());
aTopFrame.getContentPane().setLayout(layout);
layout.setHorizontalGroup(
    layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
    .addGroup(layout.createSequentialGroup()
        .addGap(20, 20, 20)
        .addComponent(scollBothDiffs, javax.swing.GroupLayout.DEFAULT_SIZE, 997, Short.MAX_VALUE)
        .addContainerGap())
);
layout.setVerticalGroup(
    layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
        .addContainerGap()
        .addComponent(scollBothDiffs, javax.swing.GroupLayout.DEFAULT_SIZE, 671, Short.MAX_VALUE)
        .addContainerGap())
);

aTopFrame.pack();
aTopFrame.setVisible(true);
}
});

这是显示我对第一个答案的实现的图像，其中文本窗格不限于水平显示区域.

Here is an image that shows my implementation of the first answer where the text panes are not limited to the horizontal display area.

此图像显示了水平显示区域中限制的文本窗格，但是此示例最初具有以下问题:如果文本窗格很长，则不会垂直滚动.

And this image shows the text panes limited in the horizontal display area but this example has the original issue of not scrolling vertically if the text panes are very long.

推荐答案

我之前使用的一个技巧是使用两个JScrollPanes，隐藏左侧窗格的垂直滚动条，并将其模型设置为右侧的模型滚动窗格.这样，当用户滚动右滚动条时，它会更新两个滚动窗格，因为它们共享相同的模型.这是一个示例，在底部也有两个同步的水平滚动条:

A trick I've used before is to use two JScrollPanes, hide the vertical scroll bar for the left pane, and set its model to the model for the right scroll pane. That way, when the user scrolls the right scroll bar, it updates both scroll panes, since they share the same model. Here is an example that also has dual synchronized horizontal scroll bars at the bottom:

JTextPane leftDiffPane = diffPane1;
JTextPane rightDiffPane = diffPane2;
JScrollPane spLeft = new JScrollPane(leftDiffPane, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
JScrollPane spRight = new JScrollPane(leftDiffPane, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
spLeft.getHorizontalScrollBar().setModel(spRight.getHorizontalScrollBar().getModel());
spLeft.getVerticalScrollBar().setModel(spRight.getVerticalScrollBar().getModel());

// ...

请注意，如果您的JTextPanes具有不同的大小(我没有尝试过，但是我最好的猜测是它将引起问题)，它可能无法很好地工作

Note that it might not work so well if your JTextPanes have different sizes (I haven't tried it, but my best guess is it would cause problems)

您还可以通过将滚轮事件从左侧滚动窗格重定向到右侧滚动滚轮来修复鼠标滚轮滚动:

You can also fix mouse wheel scrolling by redirecting wheel events from the left scroll pane to the right one:

spLeft.setWheelScrollingEnabled(false);
spLeft.addMouseWheelListener(new MouseWheelListener() {
    public void mouseWheelMoved(MouseWheelEvent e) {
        spRight.dispatchEvent(e);
    }
});

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