Is there any documentation for building/customizing custom UI controls? I need to customize an existing out-of-box control (OpportunityCoverageUserPersonPicker.control), but there does not seem to be any GUI or documentation on what any of the properties do.
More specifically, I am trying to make the select popup of OpportunityCoverageUserPersonPicker.control (CoverageUserCustomPicker.screen) launch with a specific where clause, but no properties I have tried work (I have tried selectPopupWhere and selectPopupSearchWhere, not knowing if either of these properties are even valid due to lack of documentation handy).
I found that adding the searchWhere parameter only applies a filter to the typeahead feature on the custom picker control and does not apply the filter to the select popup screen launched from the custom picker control. The select popup is what I need to have the filter.