I want to extend an existing application I made to make it set mixer volume by wheel-scrolling over it’s notification area icon.
As far as I know, the notification area doesn’t receive any WM_MOUSEWHEEL messages, but still I found an application that does exactly what I want to achieve (http://www.actualsolution.com/power_mixer). Using WinspectorSpy I’ve noticed some strange messages the application’s form receives: 0x000003d0 and 0x000003d1, but I found no references about them.
Does anyone have any idea on how I could achieve the desired functionality?
If you want to capture mouse/keyboard events outside of your application you will need Low-level Hooks.
A nice beginners article about installing a mouse hook in Delphi is How to Hook the Mouse to Catch Events Outside of your application on About.com written by Zarko Gajic.
The user which starts your application will need administrative rights to install a hook.
After you capture the message you should determine if it’s above your icon in the notification bar (which can be difficult because there is no exact api to get your position on the bar) and than process the scroll event.