自定义边界外的java组件绘制
在这个自定义边框类中,我定义了一个RoundRectangle2D
形状。此对象用于绘制边界。不幸的是,由于JComponent
的paint
方法在paintBorder
之前调用paintComponent
,因此将Graphics
剪辑设置为RoundRectangle2D
形状没有效果;即使我发repaint
。因此,组件将在其边界外涂漆,这是可以理解的不可取的
所以,我想知道:如何让组件在自定义边框内以独占方式绘制
我考虑的一种方法是在paintComponent
方法中获取组件的Border
对象。然后将这个对象投射到适当的类中,我定义了影响剪辑的参数。但这似乎不是一个“合理”的设计
编辑-
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.RenderingHints;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.border.AbstractBorder;
class JRoundedCornerBorder extends AbstractBorder
{
private static final long serialVersionUID = 7644739936531926341L;
private static final int THICKNESS = 2;
JRoundedCornerBorder()
{
super();
}
@Override
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height)
{
Graphics2D g2 = (Graphics2D)g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if(c.hasFocus())
{
g2.setColor(Color.BLUE);
}
else
{
g2.setColor(Color.BLACK);
}
g2.setStroke(new BasicStroke(THICKNESS, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
g2.drawRoundRect(THICKNESS, THICKNESS, width - THICKNESS - 2, height - THICKNESS - 2, 20, 20);
g2.dispose();
}
@Override
public Insets getBorderInsets(Component c)
{
return new Insets(THICKNESS, THICKNESS, THICKNESS, THICKNESS);
}
@Override
public Insets getBorderInsets(Component c, Insets insets)
{
insets.left = insets.top = insets.right = insets.bottom = THICKNESS;
return insets;
}
public boolean isBorderOpaque() {
return false;
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new FlowLayout());
// Add button with custom border
final JButton button = new JButton("Hello");
button.setBorder(new JRoundedCornerBorder());
button.setBackground(Color.YELLOW);
button.setPreferredSize(new Dimension(200, 200));
frame.add(button);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
红色圆圈突出显示组件超出其边界的位置
共 (0) 个答案