User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0 Build ID: 20150525141253 Steps to reproduce: 1. Open debugger 2. Toggle right side panel to close it 3. Move mouse to right side border, press left mouse button and move mouse to the left Actual results: Panel was moved out, but the toggle button on toolbar still suggest to OPEN it Watch video if STR are not clear: https://dl.dropboxusercontent.com/s/cqu8l24vepuwdot/Panel%20in%20Debugger%20can%20be%20moved%20out%20without%20toggling%20state.webm?dl=0

I figured out that another panels in DevTools behave in the same way. This include: right panels on Inspector, Debugger and Network tabs

Reproduced this on latest nightly 42.0a1 The dragger between the left pane and right pane should be hidden while right pane is collapsed

>>> My Info: Win7_64, Nightly 48, 32bit, ID 20160412050029 While testing bug 1260053, I noticed that breadcrumbs widget twitches by 1px to the bottom when Inspector switches to vertical mode. Plus button "Toggle sidebar" and filter field "Search HTML" twitch by 1px to the right when Inspector switches to horizontal mode. > screencast: https://dl.dropboxusercontent.com/s/b0q6ccc7r967ggm/bug%201171449%20comment%203.webm That happens because when splitter is visible, it shifts content on the left/top to the right/bottom because of margin-left/margin-top == -3px. I think that this bug should be modified to: (1) handle visibility of splitter (2) fix alignment of content to the left/top (3) prevent twitching at the very start of transition when openning sidebar If (3) is unclear, see attachment 8706156 [details] (you need to watch 1st demo and click on the page)

Hi Julian, Have you started to work on this ? If not, I can dive in I hope. It might be very easy to you, but I could learn something if I get the chance to work on this Thanks

(In reply to [:Towkir] Ahmed from comment #5) > Hi Julian, > Have you started to work on this ? If not, I can dive in I hope. > It might be very easy to you, but I could learn something if I get the > chance to work on this > Thanks When I started working on this, most of the issues were related to the XUL splitter. Since then, we started migrating the devtools from XUL to HTML. In particular we have Bug 1260552 which is about finding a replacement for the XUL Splitter. Since Bug 1260552 is currently assigned and being worked on, I would wait for it to land before reviewing this bug. Otherwise we will probably end up having to implement this twice. Unassigning myself in the meantime.