在调整JXMultiSplitPane中的分割器期间，我似乎经常得到重新绘制请求。 （见下面的程序）
为什么呢？
我有setContinuousLayout(false)。
只是为了澄清：我知道重新调整分割窗格后，会在之后发生重绘。但在分割器调整期间，没有任何内容正在调整大小;分离器在屏幕上移动。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Rectangle;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import org.jdesktop.swingx.JXMultiSplitPane;
import org.jdesktop.swingx.MultiSplitLayout;
public class MultiVerticalPane<T extends Component> extends JPanel
{
final private List<T> components;
public MultiVerticalPane(List<? extends T> components,
List<Double> weights)
{
this.components = new ArrayList<T>(components);
final int n = this.components.size();
if (weights != null && weights.size() != n)
throw new IllegalArgumentException(
"weights and components should have same length");
JXMultiSplitPane msp = new JXMultiSplitPane();
msp.setContinuousLayout(false);
msp.getMultiSplitLayout().setModel(createSplitModel(weights));
int i = 0;
for (T component : components)
{
msp.add(component, nodeTitle(i++));
}
setLayout(new BorderLayout());
add(msp, BorderLayout.CENTER);
}
private MultiSplitLayout.Split createSplitModel(
List<Double> weights)
{
LinkedList<MultiSplitLayout.Node> nodes =
new LinkedList<MultiSplitLayout.Node>();
int i = 0;
double wtot = 0;
for (double w : weights)
{
wtot += w;
}
for (double w : weights)
{
if (i > 0)
nodes.addFirst(new MultiSplitLayout.Divider());
MultiSplitLayout.Leaf leaf =
new MultiSplitLayout.Leaf(nodeTitle(i++));
leaf.setWeight(w/wtot);
nodes.addFirst(leaf);
}
MultiSplitLayout.Split split =
new MultiSplitLayout.Split();
split.setRowLayout(false);
split.setChildren(nodes);
return split;
}
private String nodeTitle(int i) {
return String.format("%02d", i);
}
/************ test methods *************/
private interface Painter
{
public void paint(Graphics g, Rectangle bounds);
}
static private class RelativeGraphics
{
final private Graphics g;
final private double xofs;
final private double yofs;
final private double xscale;
final private double yscale;
private double cx;
private double cy;
public RelativeGraphics(Graphics g, Rectangle bounds)
{
this.g = g;
this.cx = 0;
this.cy = 0;
this.xofs = bounds.getMinX();
this.yofs = bounds.getMaxY();
this.xscale = bounds.getWidth();
this.yscale = -bounds.getHeight();
}
public void moveTo(double x, double y)
{
this.cx = x;
this.cy = y;
}
public void lineTo(double x, double y)
{
this.g.drawLine(
(int)(this.cx*this.xscale+this.xofs),
(int)(this.cy*this.yscale+this.yofs),
(int)(x*this.xscale+this.xofs),
(int)(y*this.yscale+this.yofs)
);
moveTo(x,y);
}
public void rmoveTo(double dx, double dy)
{
moveTo(this.cx+dx, this.cy+dy);
}
public void rlineTo(double dx, double dy)
{
lineTo(this.cx+dx, this.cy+dy);
}
}
// adapted from http://en.wikipedia.org/wiki/Hilbert_curve#Java
static private class HilbertCurve
{
final private RelativeGraphics rg;
final private double d;
public HilbertCurve(RelativeGraphics rg, int level)
{
this.rg = rg;
double d0 = 1.0;
for (int i = level; i > 0; i--)
d0 /= 2;
this.d = d0;
rg.rmoveTo(d0/2, d0/2);
drawCurveUp(level);
}
private void drawCurveUp(int n)
{
if (n > 0) {
drawCurveLeft(n-1); this.rg.rlineTo(0, this.d);
drawCurveUp(n-1); this.rg.rlineTo(this.d, 0);
drawCurveUp(n-1); this.rg.rlineTo(0, -this.d);
drawCurveRight(n-1);
}
}
private void drawCurveLeft(int n)
{
if (n > 0) {
drawCurveUp(n-1); this.rg.rlineTo(this.d, 0);
drawCurveLeft(n-1); this.rg.rlineTo(0, this.d);
drawCurveLeft(n-1); this.rg.rlineTo(-this.d, 0);
drawCurveDown(n-1);
}
}
private void drawCurveRight(int n)
{
if (n > 0) {
drawCurveDown(n-1); this.rg.rlineTo(-this.d, 0);
drawCurveRight(n-1); this.rg.rlineTo(0, -this.d);
drawCurveRight(n-1); this.rg.rlineTo(this.d, 0);
drawCurveUp(n-1);
}
}
private void drawCurveDown(int n)
{
if (n > 0) {
drawCurveRight(n-1); this.rg.rlineTo(0, -this.d);
drawCurveDown(n-1); this.rg.rlineTo(-this.d, 0);
drawCurveDown(n-1); this.rg.rlineTo(0, this.d);
drawCurveLeft(n-1);
}
}
}
static private class HilbertPainter implements Painter
{
final private int level;
public HilbertPainter(int level) { this.level = level; }
@Override public void paint(Graphics g, Rectangle bounds) {
new HilbertCurve(
new RelativeGraphics(g,
new Rectangle(new Point(0,0),bounds.getSize())),
this.level);
}
}
static private class PainterPanel extends JPanel
{
final private Painter painter;
public PainterPanel(Painter painter)
{
this.painter = painter;
setBackground(Color.WHITE);
setForeground(Color.RED);
}
@Override public void paintComponent(Graphics g)
{
super.paintComponent(g);
this.painter.paint(g, getBounds());
}
}
public static void main(String[] args) { test(); }
private static void test()
{
JFrame frame = new JFrame("MultiVerticalPane test");
List<JPanel> panels = new ArrayList<JPanel>();
List<Double> weights = Arrays.asList(1.0,1.0,2.0,4.0,8.0);
for (int i = 0; i < 5; ++i)
{
panels.add(new PainterPanel(new HilbertPainter(i+4)
{
int count = 0;
@Override public void paint(Graphics g,
Rectangle bounds)
{
super.paint(g,
new Rectangle(bounds.getLocation(),
new Dimension(bounds.width,
bounds.height-10)));
g.drawString(String.format("%d", this.count++),
0, bounds.height);
}
}
));
}
MultiVerticalPane<Component> mvp =
new MultiVerticalPane<Component>(panels, weights);
mvp.setPreferredSize(new Dimension(360,720));
frame.setContentPane(mvp);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
答案 0 :(得分：1)
这不是一个“直接”的答案。我只是把它放在这里，因为我在评论中用完了空间。
我不认为这太频繁了？为什么你认为你将它与任何其他组件进行比较？
我认为每个调整组件的大小都会检测到它调用重绘。最重要的是布局管理器如何处理调整大小。请注意，例如，当您调整最顶部面板并将其向下拖动时，它很少重新绘制，您无法对其邻居说。向上拖动滑块时情况相反。
顺便说一句：我可能会问为什么你会担心重新划分拆分窗格的频率和部分？
请记住，我不是该组件重绘机制内部的专家，但我怀疑SwingX的人会在这方面偏离默认值。
答案 1 :(得分：1)
看起来setContinuousLayout()会影响revalidate()，而不会影响repaint()。