Re: Calculator applet questions
<yingjian.ma1955@gmail.com> wrote in message
news:1146021347.725598.184020@i39g2000cwa.googlegroups.com...
I have a Calculator applet. The code works and I have some questions
about the code in public Calc(). Thank you in advance for help me.
1. In IE 6, it displays both the text box and keys. Since I did not
use the second argument in pCalc.add(), it should display the keys only
(it did in an applet viewer).
If you don't want the textbox to display, perhaps you shouldn't add it
at all.
2. It does not have init() or start(), how does IE know where to
start?
See
http://java.sun.com/docs/books/tutorial/deployment/applet/appletMethods.html
<quote>
Not every applet needs to override every one of these methods. Some very
simple applets override none of them. For example, the HelloWorld applet at
the beginning of this section doesn't override any of these methods, since
it doesn't do anything except draw itself.
</quote>
3. The components did not set their size. Does IE sets the size for
the keys and the panels?
Components like JButton will emit a preferred size depending on the text
label associated with them. The rest is up to the layout managers.
4. How can I display red color outside the keys and text box? It only
display a red bar beneath the text box.
There's some problems with your code in that you're not using the
BorderLayout properly. Fix that first by going through Sun's GUI tutorial at
http://java.sun.com/docs/books/tutorial/uiswing/index.html
Also, you'll probably have to call setOpaque(true) on the stuff for
which you are setting the background colors on.
- Oliver