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Scaled BufferedImage woes  RSS feed

 
Greenhorn
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Okay, here's a tuffy:
At work I'm creating an app that displays binary data on a raster display. I am using a BufferedImage to store the raster that I create by hand using information from a byte array (the format of the data and how it is processed is unimportant to the question).
Since the user will be looking at data that are represented by a single pixel, I thought it would be nice to have a 1x, 2x, 4x zoom option to "blow up" the data (e.g., at 4x one pixel is rendered as a 4x4 sqaure). To do this, I am using Image.getScaledInstance() to increase/decrease the size of the image over the same amount of JPanel real-estate.
Okay, here's the problem/question: The JPanel I display the image on is scrolled by a JScrollPane. When the zoom factor is 1x (i.e., no zoom), the scrollbars work correctly. However, when I apply a 2x or 4x zoom, the scrollbars still believe the image size is 1x resulting in the inability to display part of the image.
So how do I tell the scrollbars that the image is now two or four times the actual size of the original? I've tried JScrollPane.setViewport() and JScrollPane.setViewportView(), but they seem to only send a repaint() after validating the JScrollPane. Any ideas?
Sorry no code, but I think the question is abstract enough to respond without it. If you REALLY want to see it, let me know and I'll drag it up.
Thanks folks,
randya
 
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