[Xamarin.Android.Build.Tasks] Add Support for AndroidJavaSource to Bindings

.vscode/settings.json

@@ -1,8 +1,6 @@
 {
     "nxunitExplorer.modules": [
-        "bin/TestDebug/MSBuildDeviceIntegration/net472/MSBuildDeviceIntegration.dll",
-        "bin/TestDebug/net472/Xamarin.Android.Build.Tests.dll",
-        "bin/TestRelease/MSBuildDeviceIntegration/net472/MSBuildDeviceIntegration.dll",
+        "bin/Test*/**/net472/*.dll",
     ],
     "cmake.configureOnOpen": false,
     "dotnetCoreExplorer.searchpatterns": "bin/Test{Debug,Release}/**/net6.0/{Xamarin.Android.Build.Tests,MSBuildDeviceIntegration}.dll",

Documentation/guides/BindingJavaSource.md

@@ -0,0 +1,103 @@
+---
+id:
+title: "Binding Java Source"
+dateupdated: 2021-05-21
+---
+
+# Overview
+
+With .net 6 Bindings can be done on not only `.jar` and `.aar` files
+but also raw `.java` code. This will allow developers of bindings
+or applications to write custom API's for underlying bindings
+and expose them easily to the developer.
+
+Applications already had the ability to include
+[`AndroidJavaSource`](https://docs.microsoft.com/en-us/xamarin/android/deploy-test/building-apps/build-items#androidjavasource)
+items in them, these would then be compiled into the final `classes.dex`.
+However this custom java source code was not "bound" and if users wanted
+to call these classes they would need to do that manually.
+
+Starting with .NET 7, all `*.java` files within the project directory are
+automatically added to the `AndroidJavaSource` item group.  Additionally,
+`AndroidJavaSource` now supports `Bind` item metadata. This will instruct
+the build system to not only compile the code but also produce a C# API for it.
+
+The `%(Bind)` attribute metadata is `True` by default. If you do not want
+to bind the Java code, set `%(Bind)` to `False`.
+
+```xml
+<ItemGroup>
+    <AndroidJavaSource Update="MyClass.java" Bind="False" />
+</ItemGroup>
+```
+
+# Example
+
+Consider the following Java code.
+
+```java
+package com.xamarin.test;
+
+class MyClass {
+    public boolean isDave (String name)
+    {
+        return name.equals ("Dave");
+    }
+}
+```
+
+We want to bind this into a C# API in our app project. By default
+the app project will pick up ALL `.java` files and add them to
+the `AndroidJavaSource` ItemGroup. The `Bind` attribute is `true`
+by default as well so it will be automatically bound.
+
+```xml
+<!-- No changes needed in .NET 7; `MyClass.java` is automatically included. -->
+```
+
+When we build the app, the java code will be compiled into a
+`.jar` file which matches the application project name.
+This `.jar` will then be bound and the generated C# API will end
+up being something like this.
+
+```csharp
+using System;
+
+namespace Com.Xamarin.Test {
+    public class MyClass : Java.Lang.Object {
+        public virtual bool IsDave (string name) => …;
+    }
+}
+```
+
+All this will happen before the main C# code is compiled. The binding
+code will be included in the C# compile process, so you can use the
+code directly in your app.
+
+```csharp
+public class MainActivity : Activity {
+    public override void OnCreate()
+    {
+        var c = new MyClass ();
+        c.IsDave ("Bob");
+    }
+}
+```
+
+
+# Limitations
+
+This feature is only available in .NET 7.
+
+You will be limited to standard java types and any types that
+are available in a `.jar` or `.aar` which you reference.
+
+You *should not* use Java Generics. The Binding process currently does not
+really support Java Generic very well. Stick to primitive types
+or normal classes as much as possible, so that you don't need to use
+[`metadata.xml`](https://docs.microsoft.com/en-us/xamarin/android/platform/binding-java-library/customizing-bindings/java-bindings-metadata)
+to alter the API of the Java class.
+
+Because of the point at which the Java compilation happens
+(before the `<Csc/>` task), you will not be able to access any of the
+`R.*` Resource types either.  This may be addressed in a later release.

Documentation/guides/building-apps/build-items.md

@@ -6,7 +6,7 @@ ms.assetid: 5EBEE1A5-3879-45DD-B1DE-5CD4327C2656
 ms.technology: xamarin-android
 author: jonpryor
 ms.author: jopryo
-ms.date: 03/29/2022
+ms.date: 05/11/2022
 ---
 
 # Build Items
@@ -89,6 +89,13 @@ package.
 Files with a Build action of `AndroidJavaSource` are Java source code which
 will be included in the final Android package.
 
+Starting with .NET 7, all `**\*.java` files within the project directory
+automatically have a Build action of `AndroidJavaSource`, *and* will be
+bound prior to the Assembly build.  This allows C# code to easily use
+types and members present within the `**\*.java` files.
+
+Set `%(AndroidJavaSource.Bind)` to False to disable this behavior.
+
 ## AndroidLibrary
 
 **AndroidLibrary** is a new build action for simplifying how

build-tools/installers/create-installers.targets

@@ -288,6 +288,7 @@
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.Android.DX.targets"     ExcludeFromAndroidNETSdk="true" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.Android.EmbeddedResource.targets" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.Android.FSharp.targets" ExcludeFromAndroidNETSdk="true" />
+    <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.Android.Javac.targets" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.Android.Legacy.targets" ExcludeFromAndroidNETSdk="true" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.Android.PCLSupport.props"                                    ExcludeFromAndroidNETSdk="true" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.Android.PCLSupport.targets"                                  ExcludeFromAndroidNETSdk="true" />

src/Xamarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.AvailableItems.targets

@@ -66,6 +66,9 @@ This item group populates the Build Action drop-down in IDEs.
       <Bind>true</Bind>
       <Pack Condition=" '$(UsingAndroidNETSdk)' == 'true' ">true</Pack>
     </AndroidLibrary>
+    <AndroidJavaSource>
+      <Bind Condition=" '$(UsingAndroidNETSdk)' == 'true' ">true</Bind>
+    </AndroidJavaSource>
     <AndroidAarLibrary>
       <!-- NOTE: .aar items should skip %(AndroidSkipResourceProcessing) by default -->
       <AndroidSkipResourceProcessing>true</AndroidSkipResourceProcessing>

src/Xamarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Bindings.ClassParse.targets

@@ -52,7 +52,7 @@ This file is only used by binding projects.
       <FileWrites Include="$(IntermediateOutputPath)class-parse.rsp" />
       <!-- Created by <BindingGenerator /> -->
       <FileWrites Condition="Exists ('$(IntermediateOutputPath)java-resolution-report.log')" Include="$(IntermediateOutputPath)java-resolution-report.log" />
-    </ItemGroup>    
+    </ItemGroup>
   </Target>
 
   <Target Name="_GetJavaSourceJarJavadocFiles"

src/Xamarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Bindings.Core.targets

@@ -20,7 +20,7 @@ It is shared between "legacy" binding projects and .NET 5 projects.
     <GeneratedOutputPath        Condition=" '$(GeneratedOutputPath)' == '' ">$(IntermediateOutputPath)generated\</GeneratedOutputPath>
     <AndroidJavadocVerbosity    Condition=" '$(AndroidJavadocVerbosity)' == '' ">intellisense</AndroidJavadocVerbosity>
     <ApiOutputFile              Condition=" '$(ApiOutputFile)' == '' ">$(IntermediateOutputPath)api.xml</ApiOutputFile>
-    <_GeneratorStampFile>$(IntermediateOutputPath)generator.stamp</_GeneratorStampFile>
+    <_GeneratorStampFile>$(_AndroidStampDirectory)generator.stamp</_GeneratorStampFile>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(_UseLegacyJavadocImport)' != 'true' ">
@@ -29,7 +29,7 @@ It is shared between "legacy" binding projects and .NET 5 projects.
   </PropertyGroup>
 
   <Target Name="_SetAndroidGenerateManagedBindings"
-      Condition=" '@(InputJar->Count())' != '0' Or '@(EmbeddedJar->Count())' != '0' Or '@(LibraryProjectZip->Count())' != '0' ">
+      Condition=" '@(InputJar->Count())' != '0' Or '@(EmbeddedJar->Count())' != '0' Or '@(LibraryProjectZip->Count())' != '0' Or '@(_JavaBindingSource->Count())' != '0' ">
     <PropertyGroup>
       <!-- Used throughout to determine if C# binding-related targets should skip -->
       <_AndroidGenerateManagedBindings>true</_AndroidGenerateManagedBindings>
@@ -115,15 +115,17 @@ It is shared between "legacy" binding projects and .NET 5 projects.
     <Delete Files="$(_GeneratorStampFile)" />
     <Delete Files="@(IntermediateAssembly->'$(OutputPath)%(filename).xml')" />
     <Delete Files="@(IntermediateAssembly->'$(IntermediateOutputPath)%(filename).xml')" />
+    <Delete Files="$(_AndroidIntermediateBindingClassesZip)" />
     <RemoveDirFixed Directories="$(GeneratedOutputPath)" />
-    <RemoveDirFixed Directories="$(_AndroidStampDirectory)" />
     <RemoveDirFixed Directories="$(IntermediateOutputPath)docs" />
     <RemoveDirFixed Directories="$(IntermediateOutputPath)javadocs" />
     <RemoveDirFixed Directories="$(IntermediateOutputPath)javasources" />
+    <RemoveDirFixed Directories="$(_AndroidIntermediateBindingJavaClassDirectory)" />
   </Target>
-  
+
   <Target Name="CleanLibraryProjectIntermediaries">
     <Delete Files="$(IntermediateOutputPath)__AndroidLibraryProjects__.zip" />
+    <Delete Files="$(_AndroidStampDirectory)_ResolveLibraryProjectImports.stamp" />
     <Delete Files="$(_AndroidLibraryImportsCache)" />
     <Delete Files="$(_AndroidLibraryProjectImportsCache)" />
     <Delete Files="$(_AndroidLibrayProjectAssemblyMapFile)" />

src/Xamarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Javac.targets

@@ -0,0 +1,141 @@
+<!--
+***********************************************************************************************
+Xamarin.Android.Javac.targets
+
+This file contains the core MSBuild logic for Xamarin.Android Java Invocations.
+
+It is shared between "legacy" binding projects and .NET 7+ projects.
+
+***********************************************************************************************
+-->
+
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <UsingTask TaskName="Xamarin.Android.Tasks.AdjustJavacVersionArguments" AssemblyFile="Xamarin.Android.Build.Tasks.dll" />
+  <UsingTask TaskName="Xamarin.Android.Tasks.DetermineJavaLibrariesToCompile" AssemblyFile="Xamarin.Android.Build.Tasks.dll" />
+  <UsingTask TaskName="Xamarin.Android.Tasks.Javac" AssemblyFile="Xamarin.Android.Build.Tasks.dll" />
+
+  <PropertyGroup>
+    <_AndroidIntermediateBindingJavaClassDirectory>$(IntermediateOutputPath)binding\bin\classes\</_AndroidIntermediateBindingJavaClassDirectory>
+    <_AndroidIntermediateBindingJavaSourceDirectory>$(IntermediateOutputPath)binding\src</_AndroidIntermediateBindingJavaSourceDirectory>
+    <_AndroidIntermediateBindingClassesZip>$(IntermediateOutputPath)binding\bin\$(MSBuildProjectName).jar</_AndroidIntermediateBindingClassesZip>
+    <_AndroidCompileJavaStampFile>$(_AndroidStampDirectory)_CompileJava.stamp</_AndroidCompileJavaStampFile>
+    <_AndroidCompileBindingJavaStampFile>$(_AndroidStampDirectory)_CompileBindingJava.stamp</_AndroidCompileBindingJavaStampFile>
+  </PropertyGroup>
+
+  <Target Name="_AdjustJavacVersionArguments">
+    <AdjustJavacVersionArguments
+        Condition=" '$(JavacTargetVersion)' == '' or '$(JavacSourceVersion)' == '' "
+        JdkVersion="$(_JdkVersion)"
+        DefaultJdkVersion="$(_DefaultJdkVersion)"
+        SkipJavacVersionCheck="$(AndroidSkipJavacVersionCheck)"
+        EnableProguard="$(AndroidEnableProguard)"
+        EnableMultiDex="$(AndroidEnableMultiDex)">
+      <Output TaskParameter="TargetVersion" PropertyName="JavacTargetVersion" />
+      <Output TaskParameter="SourceVersion" PropertyName="JavacSourceVersion" />
+    </AdjustJavacVersionArguments>
+  </Target>
+
+  <Target Name="_DetermineBindingJavaLibrariesToCompile" Condition=" '@(_JavaBindingSource->Count())' != '0' ">
+    <DetermineJavaLibrariesToCompile
+        MonoPlatformJarPaths="$(MonoPlatformJarPath);$(_RuntimeJar)"
+        JavaSourceFiles="@(_JavaBindingSource)"
+        JavaLibraries="@(AndroidJavaLibrary);@(EmbeddedJar)"
+        ExternalJavaLibraries="@(AndroidExternalJavaLibrary)"
+        LibraryProjectJars="@(ExtractedJarImports)"
+        DoNotPackageJavaLibraries="@(_ResolvedDoNotPackageAttributes)"
+        EnableInstantRun="$(_InstantRunEnabled)">
+      <Output TaskParameter="JavaLibrariesToCompile" ItemName="_BindingJavaLibrariesToCompile" />
+      <Output TaskParameter="ReferenceJavaLibraries" ItemName="_ReferenceJavaLibs" />
+    </DetermineJavaLibrariesToCompile>
+  </Target>
+
+  <Target Name="_DetermineJavaLibrariesToCompile">
+
+    <DetermineJavaLibrariesToCompile
+        MonoPlatformJarPaths="$(MonoPlatformJarPath);$(_RuntimeJar)"
+        JavaSourceFiles="@(AndroidJavaSource)"
+        JavaLibraries="@(AndroidJavaLibrary)"
+        ExternalJavaLibraries="@(AndroidExternalJavaLibrary)"
+        LibraryProjectJars="@(ExtractedJarImports)"
+        DoNotPackageJavaLibraries="@(_ResolvedDoNotPackageAttributes)"
+        EnableInstantRun="$(_InstantRunEnabled)">
+      <Output TaskParameter="JavaLibrariesToCompile" ItemName="_JavaLibrariesToCompile" />
+      <Output TaskParameter="ReferenceJavaLibraries" ItemName="_ReferenceJavaLibs" />
+    </DetermineJavaLibrariesToCompile>
+
+    <ItemGroup>
+      <_JavaLibrariesToCompileForApp Include="@(_JavaLibrariesToCompile)" Condition=" '$(_InstantRunEnabled)' != 'True' " />
+      <AndroidExternalJavaLibrary    Include="@(_JavaLibrariesToCompile)" Condition=" '$(_InstantRunEnabled)' == 'True' " />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_CollectJavaSourceForBinding">
+    <ItemGroup>
+      <_JavaBindingSource Include="@(AndroidJavaSource)" Condition=" '%(AndroidJavaSource.Bind)' == 'True' " />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_CollectJavaSource">
+    <ItemGroup>
+      <_JavaSource Include="@(AndroidJavaSource)" Condition=" '%(AndroidJavaSource.Bind)' != 'True' " />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_CompileBindingJava"
+      Condition=" '@(_JavaBindingSource->Count())' != '0' "
+      DependsOnTargets="$(_CompileBindingJavaDependsOnTargets)"
+      Inputs="@(_AndroidMSBuildAllProjects);$(MonoPlatformJarPath);@(_JavaBindingSource)"
+      Outputs="$(_AndroidCompileBindingJavaStampFile)">
+
+    <!-- remove existing <Javac /> outputs, since *.class files and classes.zip could contain old files -->
+    <RemoveDirFixed Directories="$(_AndroidIntermediateBindingJavaClassDirectory)" Condition="Exists('$(_AndroidIntermediateBindingJavaClassDirectory)')" />
+    <Delete Files="$(_AndroidIntermediateBindingClassesZip)" Condition="Exists('$(_AndroidIntermediateBindingClassesZip)')" />
+    <!-- Compile java code -->
+    <Javac
+        Condition=" '@(_JavaBindingSource->Count())' != '0' "
+        JavaPlatformJarPath="$(JavaPlatformJarPath)"
+        ClassesOutputDirectory="$(_AndroidIntermediateBindingJavaClassDirectory)"
+        ClassesZip="$(_AndroidIntermediateBindingClassesZip)"
+        StubSourceDirectory="$(_AndroidIntermediateBindingJavaSourceDirectory)"
+        JavaSourceFiles="@(_JavaBindingSource)"
+        ToolPath="$(JavacToolPath)"
+        ToolExe="$(JavacToolExe)"
+        Jars="@(_BindingJavaLibrariesToCompile);@(_ReferenceJavaLibs)"
+        JavacTargetVersion="$(JavacTargetVersion)"
+        JavacSourceVersion="$(JavacSourceVersion)"
+    />
+    <Touch Files="$(_AndroidCompileBindingJavaStampFile)" AlwaysCreate="true" />
+    <ItemGroup>
+      <EmbeddedJar Include="$(_AndroidIntermediateBindingClassesZip)" Condition="Exists('$(_AndroidIntermediateBindingClassesZip)')" />
+      <AndroidJavaLibrary Include="$(_AndroidIntermediateBindingClassesZip)" Condition="Exists('$(_AndroidIntermediateBindingClassesZip)')" />
+      <FileWrites Include="$(_AndroidIntermediateBindingClassesZip)" Condition="Exists('$(_AndroidIntermediateBindingClassesZip)')" />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_CompileJava"
+    DependsOnTargets="$(_CompileJavaDependsOnTargets);_CollectJavaSource"
+    Inputs="@(_AndroidMSBuildAllProjects);$(MonoPlatformJarPath);@(_JavaStubFiles);@(_JavaSource)"
+    Outputs="$(_AndroidCompileJavaStampFile)">
+
+    <!-- remove existing <Javac /> outputs, since *.class files and classes.zip could contain old files -->
+    <RemoveDirFixed Directories="$(_AndroidIntermediateJavaClassDirectory)" />
+    <Delete Files="$(_AndroidIntermediateClassesZip)" />
+
+    <!-- Compile java code -->
+    <Javac
+        JavaPlatformJarPath="$(JavaPlatformJarPath)"
+        ClassesOutputDirectory="$(_AndroidIntermediateJavaClassDirectory)"
+        ClassesZip="$(_AndroidIntermediateClassesZip)"
+        StubSourceDirectory="$(_AndroidIntermediateJavaSourceDirectory)"
+        JavaSourceFiles="@(_JavaSource)"
+        ToolPath="$(JavacToolPath)"
+        ToolExe="$(JavacToolExe)"
+        Jars="@(_JavaLibrariesToCompile);@(_InstantRunJavaReference);@(_ReferenceJavaLibs)"
+        JavacTargetVersion="$(JavacTargetVersion)"
+        JavacSourceVersion="$(JavacSourceVersion)"
+    />
+
+    <Touch Files="$(_AndroidCompileJavaStampFile)" AlwaysCreate="true" />
+  </Target>
+</Project>

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/Sdk/AutoImport.props

@@ -48,6 +48,7 @@ https://github.com/dotnet/designs/blob/4703666296f5e59964961464c25807c727282cae/
     <AndroidLibrary       Include="**\*.aar" Exclude="$(DefaultItemExcludes);$(DefaultExcludesInProjectFolder)" />
     <AndroidNativeLibrary Include="**\*.so"  Exclude="$(DefaultItemExcludes);$(DefaultExcludesInProjectFolder)" />
     <JavaSourceJar        Include="$(_DefaultJavaSourceJarPattern)"   Exclude="$(DefaultItemExcludes);$(DefaultExcludesInProjectFolder)" />
+    <AndroidJavaSource    Include="**\*.java" Exclude="$(DefaultItemExcludes);$(DefaultExcludesInProjectFolder)" />
   </ItemGroup>
 
 </Project>

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.AndroidLibraries.targets

@@ -113,4 +113,8 @@ projects.
     <Touch Files="$(_AndroidStampDirectory)_ExtractAar.stamp" AlwaysCreate="true" />
   </Target>
 
+  <Target Name="_CleanAarCache">
+    <Delete Files="$(_AarCacheFile)" />
+  </Target>
+
 </Project>