How to collapse all issues in the Xcode issue navigator

I am porting a huge C++ project to OS X. After my initial compile with Xcode I have multiple errors in many files I want to investigate.

Problem is that the issue navigator shows all files non collapsed after each compile:

So I have to collapse all of them by hand (there a a lot of files) after each compile to have an overview of a files which need fixing.

Is there a hotkey or a setting to collapse all files?

Solution 1:

cmd ⌘-click one of the little disclosure triangles to collapse (or expand) all rows.

Solution 2:

let me add some extra info, when tapping a main item

hold ⌘ to : close a type of warnings

hold shift & ⌘ to : close all types of warnings