From 654ed880e273af6f8be96f2dc6bfc11c25793037 Mon Sep 17 00:00:00 2001
From: Jonathan Pobst <jonathan.pobst@microsoft.com>
Date: Thu, 5 Mar 2020 14:48:38 -0600
Subject: [PATCH] [Mono.Android] Allow interfaces to contain nested types
 starting with API-30.

---
 src/Mono.Android/Mono.Android.targets |  2 +-
 src/Mono.Android/metadata             | 40 +++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/Mono.Android/Mono.Android.targets b/src/Mono.Android/Mono.Android.targets
index 373e64eac0f..c71d8083a93 100644
--- a/src/Mono.Android/Mono.Android.targets
+++ b/src/Mono.Android/Mono.Android.targets
@@ -98,7 +98,7 @@
       <_Api>$(IntermediateOutputPath)mcw\api.xml</_Api>
       <_Dirs>--enumdir=$(IntermediateOutputPath)mcw</_Dirs>
       <_FullIntermediateOutputPath>$([System.IO.Path]::GetFullPath('$(IntermediateOutputPath)'))</_FullIntermediateOutputPath>
-      <_LangFeatures Condition="$(AndroidApiLevel) &gt;= 30">--lang-features=default-interface-methods</_LangFeatures>
+      <_LangFeatures Condition="$(AndroidApiLevel) &gt;= 30">--lang-features=default-interface-methods,nested-interface-types</_LangFeatures>
     </PropertyGroup>
     <Exec
         Command="$(ManagedRuntime) $(ManagedRuntimeArgs) $(Generator) $(_GenFlags) $(_ApiLevel) $(_Out) $(_Codegen) $(_Fixup) $(_Enums1) $(_Enums2) $(_Versions) $(_Annotations) $(_Assembly) $(_TypeMap) $(_LangFeatures) $(_Dirs) $(_Api)"
diff --git a/src/Mono.Android/metadata b/src/Mono.Android/metadata
index 4d95c431e4a..3cddd17ae43 100644
--- a/src/Mono.Android/metadata
+++ b/src/Mono.Android/metadata
@@ -1560,4 +1560,44 @@
   <remove-node api-since="30" path="/api/package[@name='android.animation']/interface[@name='Animator.AnimatorListener']/method[@name='onAnimationStart' and count(parameter)=2]" />
   <remove-node api-since="30" path="/api/package[@name='android.animation']/interface[@name='Animator.AnimatorListener']/method[@name='onAnimationEnd' and count(parameter)=2]" />
 
+  <!-- Starting with API added in API-30, we are going to allow interfaces to contain nested types.
+       To preserve backwards compatibility, we need to "un-nest" anything added before API-30 -->
+  
+  <!-- Handle everything that has always existed (no @merge.SourceFile) -->
+  <attr api-since="30" path="/api/package/interface[not(@merge.SourceFile)]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[not(@merge.SourceFile)]" name="unnest">true</attr>
+
+  <!-- Need these for each platform prior to 30 -->
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-10.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-10.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-15.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-15.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-16.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-16.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-17.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-17.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-18.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-18.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-19.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-19.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-20.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-20.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-21.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-21.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-22.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-22.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-23.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-23.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-24.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-24.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-25.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-25.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-26.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-26.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-27.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-27.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-28.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-28.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/interface[contains(@merge.SourceFile,'api-29.xml.in')]" name="unnest">true</attr>
+  <attr api-since="30" path="/api/package/class[contains(@merge.SourceFile,'api-29.xml.in')]" name="unnest">true</attr>
 </metadata>