How do I use the Extend or Trim tool?

[DanielMesserich]

When I trim a line I can't pick which end of the line I want to trim. Do I need to click another button or something? 

[DanPatterson_Retired]

The rule-case is set out in here http://pro.arcgis.com/en/pro-app/help/editing/extend-or-trim-polyline-features.htm

it largely describes the condition where you want to trim a line at another line or extend a line to an other line.

Are you doing the clicking on the other line?

[DanielMesserich]

Yes. I'm used to MicroStation's trim tool. I select then I want to trim then select the line to trim to. Pro usually picks the side I don't want to trim. Is there a way to choose the side you want to trim?

[DanPatterson_Retired]

The side that the other line is on, but if the line just crosses another line, have you tried clicking on the end you want to keep first?  then switch it up.  It may be the case that it trims in the direction of digitizing, so you might have to flip the line first if it doesn't work the way you want at first.

[DanielMesserich]

I couldn't get the dash line to select any side except what seemed to be the shorter side.

I found a toggle at the bottom of the Modify Feature dialog and check "Allow Extend or Trim without selection." and that seems to get the job done.