【发布时间】:2013-02-08 02:59:37
【问题描述】:
以下屏幕截图显示了TextBubbleBorder1 的测试。我想让矩形外部的组件的角完全透明并显示它下面的任何组件。我找到了一种方法,通过在Graphics2D 实例上设置Clip(表示圆角外的区域)并调用clearRect(),将标签的BG 颜色限制在“边框内”。这可以在Label 1 中看到。
但是,当父面板上有红色 BG(或任何非标准颜色)时,您会看到这种方法的缺点。角落默认为默认面板颜色(在Panel 2 中最容易看到)。
最终我希望它适用于父容器中的非标准颜色,但它的部分灵感来自What do I need to do to replicate this component with gradient paint?
有人知道让这些角落透明的方法吗?
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.border.*;
public class BorderTest {
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
JPanel gui = new JPanel(new GridLayout(1,0,5,5));
gui.setBorder(new EmptyBorder(10,10,10,10));
gui.setBackground(Color.RED);
AbstractBorder brdr = new TextBubbleBorder(Color.BLACK,2,16,0);
JLabel l1 = new JLabel("Label 1");
l1.setBorder(brdr);
gui.add(l1);
JLabel l2 = new JLabel("Label 2");
l2.setBorder(brdr);
l2.setBackground(Color.YELLOW);
l2.setOpaque(true);
gui.add(l2);
JPanel p1 = new JPanel();
p1.add(new JLabel("Panel 1"));
p1.setBorder(brdr);
p1.setOpaque(false);
gui.add(p1);
JPanel p2 = new JPanel();
p2.add(new JLabel("Panel 2"));
p2.setBorder(brdr);
gui.add(p2);
JOptionPane.showMessageDialog(null, gui);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
class TextBubbleBorder extends AbstractBorder {
private Color color;
private int thickness = 4;
private int radii = 8;
private int pointerSize = 7;
private Insets insets = null;
private BasicStroke stroke = null;
private int strokePad;
private int pointerPad = 4;
RenderingHints hints;
TextBubbleBorder(
Color color) {
new TextBubbleBorder(color, 4, 8, 7);
}
TextBubbleBorder(
Color color, int thickness, int radii, int pointerSize) {
this.thickness = thickness;
this.radii = radii;
this.pointerSize = pointerSize;
this.color = color;
stroke = new BasicStroke(thickness);
strokePad = thickness / 2;
hints = new RenderingHints(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int pad = radii + strokePad;
int bottomPad = pad + pointerSize + strokePad;
insets = new Insets(pad, pad, bottomPad, pad);
}
@Override
public Insets getBorderInsets(Component c) {
return insets;
}
@Override
public Insets getBorderInsets(Component c, Insets insets) {
return getBorderInsets(c);
}
@Override
public void paintBorder(
Component c,
Graphics g,
int x, int y,
int width, int height) {
Graphics2D g2 = (Graphics2D) g;
int bottomLineY = height - thickness - pointerSize;
RoundRectangle2D.Double bubble = new RoundRectangle2D.Double(
0 + strokePad,
0 + strokePad,
width - thickness,
bottomLineY,
radii,
radii);
Polygon pointer = new Polygon();
// left point
pointer.addPoint(
strokePad + radii + pointerPad,
bottomLineY);
// right point
pointer.addPoint(
strokePad + radii + pointerPad + pointerSize,
bottomLineY);
// bottom point
pointer.addPoint(
strokePad + radii + pointerPad + (pointerSize / 2),
height - strokePad);
Area area = new Area(bubble);
area.add(new Area(pointer));
g2.setRenderingHints(hints);
Area spareSpace = new Area(new Rectangle(0, 0, width, height));
spareSpace.subtract(area);
g2.setClip(spareSpace);
g2.clearRect(0, 0, width, height);
g2.setClip(null);
g2.setColor(color);
g2.setStroke(stroke);
g2.draw(area);
}
}
- 虽然
TextBubbleBorder是为Internal padding for JTextArea with background Image 设计的(并且最终使用JLabel,因为由于上述原因,文本区域一团糟),但通过将pointerSize指定为0,我们最终会得到一个'圆角矩形' 代替。
【问题讨论】:
-
边框的美妙之处在于,它们只提供插图,不提供关于那里形状的提示,因此组件实际上不可能填充边框内的区域。我过去所做的都是被骗的。本质上,我已经创建了一个具有我想要的自定义形状的面板,然后将其放置到另一个提供背景功能的组件中,例如投影或我想要实现的任何东西......
-
如果您覆盖
paint(是paint而不是paintComponent)并将剪辑设置为您想要的确切形状怎么办? -
谢谢@mKorbel,我会根据'mre+Stroke'进行一些狩猎。
-
@mKorbel 我不知道该笑还是该哭。看来这个问题是那个问题的直接重复,我什至以前看过它,并且对这个问题和 2 个答案(包括你发布的非常酷的边框)投了赞成票!如果我有任何问题会告诉你..
-
@GuillaumePolet 感谢您的提示。如果我无法在副本(由 mKorbel 链接)中获得为我工作的答案,我会检查一下。
标签: java swing awt border transparency