Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!eternal-september.org!feeder.eternal-september.org!mx04.eternal-september.org!.POSTED!not-for-mail From: Knute Johnson Newsgroups: comp.lang.java.gui Subject: Re: How do I paint on an existing Panel? Date: Wed, 18 Jan 2012 09:29:24 -0800 Organization: A noiseless patient Spider Lines: 21 Message-ID: References: <4f16f997$0$2957$fa0fcedb@news.zen.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Wed, 18 Jan 2012 17:29:26 +0000 (UTC) Injection-Info: mx04.eternal-september.org; posting-host="mz/LDSJwiWnk3Jnnqg7x+Q"; logging-data="4527"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/Nu3pCoTLqSXLPNrW647yt" User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:9.0) Gecko/20111222 Thunderbird/9.0.1 In-Reply-To: <4f16f997$0$2957$fa0fcedb@news.zen.co.uk> Cancel-Lock: sha1:WkLPuifpqONQcxUVguDBmiDKD3s= Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.gui:4963 On 1/18/2012 8:55 AM, A B wrote: > I expect this is a really obvious question; I must get round to getting > a bigger Java book! Part of my program starts by displaying a JPanel, > with an image put on it using paintComponent(). How do I then draw some > shapes over the top of that image when a particular button is clicked? I > can't just put them in paintComponent(), because they haven't to appear > at first. Would it be easier in an applet, rather than an application? > > I'm sure this comes up in the example programs in the JDK package, but > for some mysterious reason they won't work. Wrong version of IE, > probably; have to look into that. > Put all your drawing code in the paintComponent() method. One idea, you could stash your shapes in a List and in the paintComponent() method, retrieve and paint them. Press a button put a shape in the List, call repaint(). -- Knute Johnson