Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Has anyone had luck using the transparency feature of color-bitmap buttons? The manual quotes: >>>> >>>>>>>>>>>> Transparent Bitmaps For 16- and 256-color bitmaps, IDL uses the color of the pixel in the lower left corner as the transparent color. All pixels of this color become transparent, allowing the button color to show through. This allows you to use bitmaps that are not rectangular. If you have a rectangular bitmap that you want to use as a button label, you must either draw a border of a different color around the bitmap or save the bitmap as 24-bit (TrueColor). If your bitmap also contains text, make sure the border you draw is a different color than the text, otherwise the text color will become transparent. <<<<<<<<<<<<<<<<< But I'm unable to see this behavior. Try: IDL> base=widget_base(/COLUMN) IDL> but=widget_button(base,VALUE=filepath('zoom.bmp',$ SUBDIR=['resource','bitmaps']),/BITMAP) IDL> widget_control, base, /realize Does the button blend into the background tranparently? On my system (x86 linux unix 5.4), it does not, despite this claim. Note that if you have a matching gray background it may appear to blend in (though without real transparency). Please note your system and version if responding. Thanks, JD