Update and extend readme

Author: ole

DemoApp/README.md

@@ -1,25 +1,12 @@
-#  SwiftUI Layout Inspector
-
-Ole Begemann, 2022-09
-
-Based on: [objc.io, Swift Talk episode 318, Inspecting SwiftUI's Layout Process (2022-08)](https://talk.objc.io/episodes/S01E318-inspecting-swiftui-s-layout-process)
-
-Inspect the layout algorithm of SwiftUI views, i.e. what sizes views propose to
-their children and what sizes they return to their parents.
-
-![Layout Inspector screenshot on iPhone simulator](assets/LayoutInspector-screenshot.png)
-
-## Requirements
-
-iOS 16.0 or macOS 13.0 (requires the `Layout` protocol).
+#  SwiftUI Layout Inspector Demo App
 
 ## Instructions
 
 1.  Edit the `subject: some View` property in `ContentView`. It should contain
     the view tree you want to inspect.
 
-2.  Add `.debugLayout()` at each point in the view tree where you want to inspect
-    the layout algorithm (what sizes are being proposed and returned). 
+2.  Add `.debugLayout()` at each point in the view tree where you want to
+    inspect the layout algorithm (what sizes are being proposed and returned). 
 
     Example of a `subject` property with a few inspection points:
 

README.md

@@ -1,23 +1,62 @@
-# DebugLayout
+# SwiftUI Layout Inspector
 
-Ole Begemann, 2022-09
+By [Ole Begemann](https://oleb.net/)
 
-Based on: [objc.io, Swift Talk episode 318, Inspecting SwiftUI's Layout Process (2022-08)](https://talk.objc.io/episodes/S01E318-inspecting-swiftui-s-layout-process)
+A Swift library (and demo app) for learning how the SwiftUI layout system works,
+and for debugging your own layout code. Inspect the layout behavior of SwiftUI
+views, i.e. what sizes views propose to their children and how a view determines
+its own size.
 
-Inspect the layout algorithm of SwiftUI views, i.e. what sizes views propose to
-their children and what sizes they return to their parents.
+![Layout Inspector screenshot on iPhone simulator](assets/LayoutInspector-screenshot.png)
+
+## Motivation
+
+At its core, SwiftUI’s layout algorithm is wonderfully simple:
+
+1.  Each parent view proposes a size to its child view(s). Width and height are
+    both optional values; either one (or both) can be `nil`.
+
+2.  The child view determines its own size, taking the proposed size into
+    account, as well as the sizes of its own children (it’s a recursive
+    process).
+    
+3.  The child reports its size back to its parent. The parent cannot change the
+    size: in SwiftUI, each view determines its own size.
+    
+4.  The parent view positions its children.
+
+Complex layouts in SwiftUI can be achieved by composing built-in views and view
+modifiers. The tricky part about understanding the SwiftUI layout system is
+learning the layout behavior of the built-in views. This package aims to help
+you learn.
+
+## Components
+
+Layout Inspector consists of:
+
+- The `LayoutInspector` library, provided as a SwiftPM package. Add it to your
+  own SwiftUI app to debug your layout code.
+
+- The `LayoutInspectorDemo` app, an iOS and Mac app that shows Layout Inspector
+  in action.
 
 ## Requirements
 
 iOS 16.0 or macOS 13.0 (requires the `Layout` protocol).
 
 ## Instructions
 
-1.  `import DebugLayout`
+1.  `import LayoutInspector`
 
 2.  Add `.debugLayout()` at each point in a view tree where you want to inspect
     the layout algorithm (what sizes are being proposed and returned).
 
 3.  At the top of the view tree you want to inspect, add `.startDebugLayout()`.
 
-See the README of the sample app for a complete example.
+See the README of the demo app for a complete example.
+
+## Acknowledgements
+
+Idea and initial code based on: [objc.io, Swift Talk episode 318, Inspecting SwiftUI's Layout Process (2022-08-19)](https://talk.objc.io/episodes/S01E318-inspecting-swiftui-s-layout-process)
+
+Runtime warnings in Xcode: [Point-Free, Unobtrusive runtime warnings for libraries (2022-01-03)](https://www.pointfree.co/blog/posts/70-unobtrusive-runtime-warnings-for-libraries)