Image Map Empty

[joelwyland]

I'm trying to generate an Image Map for an XYPlot. I've looked through ImageMapDemo3.java in the src distribution and I believe I'm doing it right, but my map file is still empty:

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<MAP NAME="chart">
</MAP>

Here is what essentially I'm doing in my chart generator (I had to change the names and stuff for NDA reasons):

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MyCustomXYItemRenderer r = new MyCustomXYItemRenderer();
r.setToolTipGenerator(new MyCustomToolTipGenerator());
r.setLabelGenerator(new MyCustomXYLabelGenerator());
r.setURLGenerator(new StandardXYURLGenerator("prefix"));
chart.getXYPlot().getRenderer(r);

In my servlet, I'm writing the chart out as a PNG and then writing the map out as a text file. Any thoughts?

Kenny

[nova]

Your ToolTipGenerator is empty... try something like this:
simpleDateFormat_sdf is a formatted date i from a table (source maybe SQL DB etc...)

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StandardXYToolTipGenerator sXYTTG_ttg = new StandardXYToolTipGenerator(StandardXYToolTipGenerator.DEFAULT_TOOL_TIP_FORMAT, simpleDateFormat_sdf, NumberFormat.getInstance());
TimeSeriesURLGenerator urlg = new TimeSeriesURLGenerator(simpleDateFormat_sdf, "details.jsp", "value1", "value2");

[Guest]

Are you sure? I've used this code to generate a chart in a Swing app before and I go ToolTips to show up there. I will definitely double check to make sure the tool tips are working, but I really think they are and I'm not sure why they would affect the links.

Thanks for the reply

[nova]

no the links was a little bit too much code, they have no effect on the tooltips...
if I create an empty ttg I get empty tooltips, maybe depending on the graph used you can use an empty constructor I'm not sure, but in my case it was exactly like your problem...

[richard_atkinson]

Here is a critical section from ImageMapDemo3 that you may have missed.

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            final ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
            final File file1 = new File("xychart100.png");
            ChartUtilities.saveChartAsPNG(file1, chart, 600, 400, info);

Unless you pass ChartRenderingInfo object in when rendering your chart the ToolTip/URL will not be collected, which will result in an empty image map. Hope this helps.

Regards,
Richard...

[joelwyland]

Here is a critical section from ImageMapDemo3 that you may have missed.

Code: Select all

            final ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
            final File file1 = new File("xychart100.png");
            ChartUtilities.saveChartAsPNG(file1, chart, 600, 400, info);

Unless you pass ChartRenderingInfo object in when rendering your chart the ToolTip/URL will not be collected, which will result in an empty image map. Hope this helps.

Regards,
Richard...

Thanks Richard, that seems to have done the trick, thank you for catching my error. So, my question is.. ist he ChartRenderingInfo something that is doing work for the rendering or is it just a data structure that is collecting that rendered info along the way? I saw that there were functions with exactly the same signature (except that it didn't require a ChartRenderingInfo object) and used those.

[richard_atkinson]

Passing the ChartRenderingInfo object basically tells the Renderer to collect information relating to ToolTips and URLs. Collecting the tooltip and URL information is pretty memory / processor intensive, so if you do not need them using the shorter method signatures speeds up the rendering quite significantly.

Regards,
Richard...