JSplitPane SetDividerLocation Problem

问题

I have a JSplitPane which when shown should split the pane by 50%.

Now on giving an argument of 0.5 (as suggested) to setDividerLocation, Java seems to treat it as a normal number instead of a percentage. As in, the divider, instead of going to the middle of the pane, is almost at the start of the left pane (the pane is vertically split). Any work arounds?

回答1:

Am I missing something? There seem to be a lot of rather convoluted answers to this question... but I think a simple setResizeWeight(0.5) would solve the issue ... it's described in the SplitPane Tutorial

回答2:

The setDividerLocation( double ) method only works on a "realized" frame, which means after you've packed or made the frame visible.

The setDividerLocation( int ) method can be used at any time.

回答3:

You can only set the split pane divider's location as a percentage when the split pane is visible. You can tap into the split pane owner's events to determine when its OK to set the divider's location. For example:

public class MyFrame extends JFrame {

  public MyFrame() {

    final JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
    // ... set up the split pane, and add to the frame ...

    // Listen for the frame's "shown" event.

    addComponentListener(new ComponentAdapter() {

      @Override
      public void componentShown(ComponentEvent componentEvent) {

        // Set the divider location to 20%.
        // This works because we know the pane is visible.

        splitPane.setDividerLocation(.2);

        // Stop listening for "shown" events.

        removeComponentListener(this);
      }

    });

    pack();
  }
}

回答4:

this fixes it:

public class JSplitPane3 extends JSplitPane {
    private boolean hasProportionalLocation = false;
    private double proportionalLocation = 0.5;
    private boolean isPainted = false;

    public void setDividerLocation(double proportionalLocation) {
        if (!isPainted) {
            hasProportionalLocation = true;
            this.proportionalLocation = proportionalLocation;
        } else {
            super.setDividerLocation(proportionalLocation);
        }
    }

    public void paint(Graphics g) {
        super.paint(g);
        if (!isPainted) {
            if (hasProportionalLocation) {
                super.setDividerLocation(proportionalLocation);
            }
            isPainted = true;
        }
    }

}

回答5:

If you're happy for the divider to move to the middle every time you resize the pane, you could add a ComponentListener and have its componentResized method call setDividerLocation(0.5).

回答6:

This works for me, based on Dave Rays link.

/**
 * Set JSplitPane proportional divider location
 * 
 * @param jsplitpane JSplitPane to set
 * @param proportionalLocation double <0.0; 1.0>
 */
public static void setJSplitPaneDividerLocation(final JSplitPane jsplitpane, final double proportionalLocation)
{
    if (jsplitpane.isShowing())
    {
        if (jsplitpane.getWidth() > 0 && jsplitpane.getHeight() > 0)
        {
            jsplitpane.setDividerLocation(proportionalLocation);
        }
        else
        {
            jsplitpane.addComponentListener(new ComponentAdapter()
            {
                @Override
                public void componentResized(ComponentEvent ce)
                {
                    jsplitpane.removeComponentListener(this);
                    setJSplitPaneDividerLocation(jsplitpane, proportionalLocation);
                }
            });
        }
    }
    else
    {
        jsplitpane.addHierarchyListener(new HierarchyListener()
        {
            @Override
            public void hierarchyChanged(HierarchyEvent e)
            {
                if ((e.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) != 0 && jsplitpane.isShowing())
                {
                    jsplitpane.removeHierarchyListener(this);
                    setJSplitPaneDividerLocation(jsplitpane, proportionalLocation);
                }
            }
        });
    }
}

回答7:

use setResizeWeight(double);

回答8:

I found the combination of setResizeWeight and setDividerLocation invoked later provides the behavior one would expect:

_splitPane.setResizeWeight(0.5);

SwingUtilities.invokeLater(new Runnable() {
    @Override
    public void run() {
        _splitPane.setDividerLocation(0.5);
    }
});

回答9:

There's a solution here that is a simple function that doesn't require sub-classing or any other changes to your splitpane.

回答10:

The following in the Component with the JSplitPane does it too:

@Override
public void setVisible(final boolean b) {
    super.setVisible(b);
    SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            AppFrame.this.jSplitPane.setDividerLocation(0.9d);
        }

    });
}

来源：https://stackoverflow.com/questions/1879091/jsplitpane-setdividerlocation-problem

标签

java

jsplitpane