How to provide the user in an APEX application with low-vision apex option

Question

Hi I've a small problem I'm trying to solve but can't seem to find anything on this.
The issue is this I've developed an application and the user can log on and use it successfully. For those users that are visually impared I need a link on my main application to a High Contrast version of the same application.
Is this even possible.
I don't want to have to create a new application using a high contrast theme, as I would need to maintain 2 applications in the end.
Is there a way of changing the colors at run time to a higher contrast version.
Many thanks.

Answer 1

Hi,
I just wanted to add to this discussion with some functionality introduced in APEX 4.1 that may help here. In APEX 4.1, we introduced a new 'High Contrast Mode' which basically identifies sessions as optimized for high contrast in the APEX development environment and websheet runtime. This allowed us to get around some issues we were having when a user was running in 'Windows High Contrast Mode' (where CSS background images are ignored) and also some issues with insufficent contrast. To read more about this mode, please see the 'About Constrast Mode' section in the 'Accessibility in Oracle Application Express' appendix here:
http://download.oracle.com/docs/cd/E23903_01/doc/doc.41/e21674/accessibility002.htm#BABBCIJD
Now, although this mode is available for use within your own database applications, it really only provides the framework for you to provision the mode and importantly, will not make any changes to your application (that's still up to you). But I think the framework is still useful and provides some nice API's to help you turn the mode on or off and also determine the status of the mode.
I have setup a simple example to show you how this works:
http://apex.oracle.com/pls/apex/f?p=11005:1
It's rudimentary, just showing 1 region if High Contrast Mode is on, and another if it's off. This page has the following:
1) Select list to select whether the mode is on or off.
2) Page process to set the mode, depending on the select list value. This performs the following PL/SQL (showing the APIs you can use to switch the mode on or off):
if :P1_HIGH_CONTRAST = 'Y' then
  apex_util.set_session_high_contrast_on;
elsif :P1_HIGH_CONTRAST = 'N' then
  apex_util.set_session_high_contrast_off;
end if;3) The region's have 'PL/SQL Expression' conditions that call another API that you can use to check if the current session is running in HC Mode. For example:
apex_util.is_high_contrast_sessionOnce the mode is enabled, it will remain enabled for the length of the current session (or until it is switched off). To understand more about how you can use HC Mode, please see here:
http://download.oracle.com/docs/cd/E23903_01/doc/doc.41/e21674/advnc001.htm#CIJCDGII
So as I said, the example I gave as kinda simple. But you could easily extend this to say include an additional CSS file when running in HC Mode (containing the CSS styles and properties that would give you the increased contrast). You could do this by adding a page zero page process to run before header, that calls the apex_util.is_high_contrast_session API to determine if the current session is in HC mode, then include the CSS file if so. To see an example of this, please see here:
http://download.oracle.com/docs/cd/E23903_01/doc/doc.41/e21676/apex_util.htm#autoId71
I hope this helps, at least with the framework side of things, if you can upgrade to 4.1 at all.
Regards,
Anthony.