I know a lot of you don’t want to mess with Xcode BUT there are some really handy things it can help you with and you don’t have to write any Swift or Objective-C code.
Since you can drop a plist into Xojo to supplement or replace certain keys at some point you may need to create one. Xcode has an excellent editor for plists.
If you start Xcode and select File > New > File and scroll down there is a section that lists various kinds of files that you can edit. In this list is a Plist.
Select that template and edit and you have a plist ready to add to your Xojo project.
But thats only the beginning.
Perhaps the handiest things Xcode can do is examine the view hierarchy of ANY application. In Cocoa every control is a kind of “view” and your entire UI is composed of multiple views one on top of the other and composited together.
If you’re having issues getting things to appear correctly this can be very handy to know whats above or below what in the entire view hierarchy that macOS uses to create what you see on screen.
We’ll work thought a quick example.
Start Xcode. Start a new empty macOS project. Use the Cocoa App template. It doesn’t matter what you call it just that Xcode wont work for this without an open project. Save that project in a new folder on your desktop since we’re going to throw it away when done.
Start Activity Monitor so you can get the the PID of your running application. I’m going to select Xojo since everyone reading this should have a copy.
I happened to show the Memory usage but other views like CPU time also have a PID column. The number in that column is what you need.
Now back to Xcode.
Select Debug > Attach to Process by PID or Name. A small panel should appear and in here you can put the PID from Activity Monitor. Nothing else will appear to change.
However there are new options available.
Select Debug > View Debugging > Capture View Hierarchy. Once you do that you get what appears to be a 2-D wire frame drawing of the user interface views. However, this is NOT just a 2D view. You can slick and drag in the view area and Xcode will reveal the various layers used to composite the image you see on screen.
There are scrollers on the bottom left to adjust the separation of the layers so its easier to see them. You can, in this view, see what is in front of or behind something else and that can help you resolve weird drawing issues and may help reveal how other applications achieve specific affects like the translucency seen in the Finders left hand navigation panes.
As well in this view you can right click on any view and select the “Print description of” menu item. This wont always tell you something really useful in the lower panes. But it does tell you what Cocoa UI element an object is in case you need to use declares to manipulate it.
There are lots of other things you can do in Xcode once you have attached to a process to examine it. Observing the view hierarchy is just one really useful one.