GUI: How can I find out if certain Unicode characters are supported?

Question

I noticed that Metal L&F doesn't support certain arrow characters from Unicode, while Nimbus and GTK L&Fs do support them.

Unsupported characters are just displayed as: ...

Can I

1. either look up (manually), which L&F supports which Unicode chars,
2. or find it out at runtime?

EDIT: Or, should it only depend on the L&F's default font, my question perhaps should be:
"how do I find out, which Java font supports which Unicode characters?"

Answer 1

You can use the canDisplay method to test if a java.awt.Font object can display a given character. You can typically get the font from GUI components using the getFont() method.

Answer 2

If you know which unicode block contains the arrows you need, you can look it up here . Unfortunately there doesn't seem to be a page for newer JDK's.

Answer 3

使用这段代码几乎可以使用每个Unicode ta.setFont（new java.awt.Font（“Segoe UI Emoji”，1,20））;