Create a design tools plugin

This new plugin is contains:
- the designer module
- the nav-editor module
- the compose-designer module
- the customview module
- the layoutlib module
- the layoutlib jar
That corresponds to everything that needs direct access to layoutlib
classes.

It depends on the android plugin, and implements a new extension point,
layoutLibraryProvider, defined in LayoutLibraryLoader. That allows the
android plugin to still have access to a LayoutLibrary, while preventing
it from accessing the internals of layoutlib.

Bug: 187316741
Test: existing tests
Change-Id: I264d82e14cb206fa7e1443cb85a0e2bc1f79c200

9 files changed, 347 insertions, 8 deletions

diff --git a/layoutlib/BUILD b/layoutlib/BUILD
index 1aefed9ec93..7e56559133a 100644
--- a/layoutlib/BUILD
+++ b/layoutlib/BUILD
@@ -10,6 +10,21 @@ iml_module(
     deps = [
         "//prebuilts/studio/intellij-sdk:studio-sdk",
         "//tools/base/layoutlib-api:studio.android.sdktools.layoutlib-api[module]",
+        "//tools/adt/idea/layoutlib-loader:intellij.android.layoutlib-loader[module]",
         "//tools/adt/idea/.idea/libraries:layoutlib",
     ],
 )
+
+# managed by go/iml_to_build
+iml_module(
+    name = "intellij.android.layoutlib.tests",
+    iml_files = ["intellij.android.layoutlib.tests.iml"],
+    test_srcs = ["testSrc"],
+    visibility = ["//visibility:public"],
+    # do not sort: must match IML order
+    deps = [
+        "//prebuilts/studio/intellij-sdk:studio-sdk",
+        "//tools/adt/idea/layoutlib:intellij.android.layoutlib[module, test]",
+        "//tools/adt/idea/.idea/libraries:layoutlib[test]",
+    ],
+)
diff --git a/layoutlib/intellij.android.layoutlib.iml b/layoutlib/intellij.android.layoutlib.iml
index d6ed5c8a505..070e027727f 100644
--- a/layoutlib/intellij.android.layoutlib.iml
+++ b/layoutlib/intellij.android.layoutlib.iml
@@ -9,6 +9,7 @@
     <orderEntry type="library" name="studio-sdk" level="project" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="module" module-name="android.sdktools.layoutlib-api" />
+    <orderEntry type="module" module-name="intellij.android.layoutlib-loader" />
     <orderEntry type="library" name="layoutlib" level="project" />
   </component>
 </module>
\ No newline at end of file
diff --git a/layoutlib/intellij.android.layoutlib.tests.iml b/layoutlib/intellij.android.layoutlib.tests.iml
new file mode 100644
index 00000000000..a4ef8d3eeaa
--- /dev/null
+++ b/layoutlib/intellij.android.layoutlib.tests.iml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$/testSrc">
+      <sourceFolder url="file://$MODULE_DIR$/testSrc" isTestSource="true" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="studio-sdk" level="project" />
+    <orderEntry type="module" module-name="intellij.android.layoutlib" scope="TEST" />
+    <orderEntry type="library" scope="TEST" name="layoutlib" level="project" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/layoutlib/src/META-INF/plugin.xml b/layoutlib/src/META-INF/layoutlib.xml
index 5b0b1b975f7..3cb64d86951 100644
--- a/layoutlib/src/META-INF/plugin.xml
+++ b/layoutlib/src/META-INF/layoutlib.xml
@@ -1,5 +1,5 @@
 <!--
-  ~ Copyright (C) 2019 The Android Open Source Project
+  ~ Copyright (C) 2021 The Android Open Source Project
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
   ~ you may not use this file except in compliance with the License.
@@ -14,12 +14,9 @@
   ~ limitations under the License.
   -->
 <idea-plugin>
-  <id>com.android.layoutlib</id>
-  <name>Layoutlib</name>
-  <version>1.0</version>
-  <vendor>Google</vendor>
-
-  <description>Provides a library for rendering Android resources</description>
+  <extensions defaultExtensionNs="com.android.tools.idea.layoutlib">
+    <layoutLibraryProvider implementation="com.android.layoutlib.LayoutlibProvider"/>
+  </extensions>
 
   <application-components>
     <component>
@@ -27,5 +24,4 @@
       <headless-implementation-class/>
     </component>
   </application-components>
-
 </idea-plugin>
\ No newline at end of file
diff --git a/layoutlib/src/com/android/layoutlib/LayoutlibClassLoader.java b/layoutlib/src/com/android/layoutlib/LayoutlibClassLoader.java
new file mode 100644
index 00000000000..35790f71062
--- /dev/null
+++ b/layoutlib/src/com/android/layoutlib/LayoutlibClassLoader.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.layoutlib;
+
+import android.os._Original_Build;
+import com.google.common.annotations.VisibleForTesting;
+import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.util.text.StringUtil;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.org.objectweb.asm.ClassReader;
+import org.jetbrains.org.objectweb.asm.ClassWriter;
+import org.jetbrains.org.objectweb.asm.commons.ClassRemapper;
+import org.jetbrains.org.objectweb.asm.commons.Remapper;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Deque;
+import java.util.LinkedList;
+import java.util.function.BiConsumer;
+
+/**
+ * {@link ClassLoader} used for Layoutlib. Currently it only generates {@code android.os.Build} dynamically by copying the class in
+ * {@link _Original_Build}.
+ * By generating {@code android.os.Build} dynamically, we avoid to have it in the classpath of the plugins. Some plugins check for the
+ * existence of the class in order to detect if they are running Android. This is just a workaround for that.
+ */
+public class LayoutlibClassLoader extends ClassLoader {
+  private static final Logger LOG = Logger.getInstance(LayoutlibClassLoader.class);
+
+  LayoutlibClassLoader(@NotNull ClassLoader parent) {
+    super(parent);
+
+    // Define the android.os.Build and all inner classes by renaming everything in android.os._Original_Build
+    generate(_Original_Build.class, (className, classBytes) -> defineClass(className, classBytes, 0, classBytes.length));
+  }
+
+  @NotNull
+  private static String toBinaryClassName(@NotNull String name) {
+    return name.replace('.', '/');
+  }
+
+  @NotNull
+  private static String toClassName(@NotNull String name) {
+    return name.replace('/', '.');
+  }
+
+  /**
+   * Creates a copy of the passed class, replacing its name with "android.os.Build".
+   */
+  @VisibleForTesting
+  static void generate(@NotNull Class<?> originalBuildClass, @NotNull BiConsumer<String, byte[]> defineClass) {
+    ClassLoader loader = originalBuildClass.getClassLoader();
+    String originalBuildClassName = originalBuildClass.getName();
+    String originalBuildBinaryClassName = toBinaryClassName(originalBuildClassName);
+    Deque<String> pendingClasses = new LinkedList<>();
+    pendingClasses.push(originalBuildClassName);
+
+    Remapper remapper = new Remapper() {
+      @Override
+      public String map(String typeName) {
+        if (typeName.startsWith(originalBuildBinaryClassName)) {
+          return "android/os/Build" + StringUtil.trimStart(typeName, originalBuildBinaryClassName);
+        }
+
+        return typeName;
+      }
+    };
+
+    while (!pendingClasses.isEmpty()) {
+      String name = pendingClasses.pop();
+
+      String newName = "android.os.Build" + StringUtil.trimStart(name, originalBuildClassName);
+      String binaryName = toBinaryClassName(name);
+
+      try (InputStream is = loader.getResourceAsStream(binaryName + ".class")) {
+        ClassWriter writer = new ClassWriter(0);
+        ClassReader reader = new ClassReader(is);
+        ClassRemapper classRemapper = new ClassRemapper(writer, remapper) {
+          @Override
+          public void visitInnerClass(String name, String outerName, String innerName, int access) {
+            if (outerName != null && outerName.startsWith(binaryName)) {
+              pendingClasses.push(toClassName(name));
+            }
+            super.visitInnerClass(name, outerName, innerName, access);
+          }
+        };
+        reader.accept(classRemapper, 0);
+        defineClass.accept(newName, writer.toByteArray());
+      }
+      catch (IOException e) {
+        LOG.warn("Unable to define android.os.Build", e);
+      }
+    }
+  }
+}
diff --git a/layoutlib/src/com/android/layoutlib/LayoutlibProvider.kt b/layoutlib/src/com/android/layoutlib/LayoutlibProvider.kt
new file mode 100644
index 00000000000..93d531ee89f
--- /dev/null
+++ b/layoutlib/src/com/android/layoutlib/LayoutlibProvider.kt
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.layoutlib
+
+import com.android.layoutlib.bridge.Bridge
+import com.android.tools.idea.layoutlib.LayoutLibrary
+import com.android.tools.idea.layoutlib.LayoutLibraryLoader
+
+class LayoutlibProvider : LayoutLibraryLoader.LayoutLibraryProvider() {
+  override fun getLibrary(): LayoutLibrary {
+    return LayoutLibrary.load(Bridge(), LayoutlibClassLoader(LayoutlibProvider::class.java.classLoader))
+  }
+
+  override fun getFrameworkRClass(): Class<*> {
+    return com.android.internal.R::class.java
+  }
+}
\ No newline at end of file
diff --git a/layoutlib/testSrc/com/android/layoutlib/LayoutlibClassLoaderTest.java b/layoutlib/testSrc/com/android/layoutlib/LayoutlibClassLoaderTest.java
new file mode 100644
index 00000000000..f7919e750be
--- /dev/null
+++ b/layoutlib/testSrc/com/android/layoutlib/LayoutlibClassLoaderTest.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.layoutlib;
+
+import com.google.common.io.CharSource;
+import org.jetbrains.org.objectweb.asm.ClassReader;
+import org.jetbrains.org.objectweb.asm.util.TraceClassVisitor;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class LayoutlibClassLoaderTest {
+
+  /**
+   * Simplify the output from the ASM Textifier so we do not get the comments or Opcodes into the output
+   */
+  private static String simplify(String s) {
+    try {
+      return CharSource.wrap(s).readLines().stream().filter(l -> !l.trim().isEmpty() && !l.startsWith("   ") && !l.trim().startsWith("//"))
+        .collect(Collectors.joining("\n"));
+    }
+    catch (IOException e) {
+      e.printStackTrace();
+      return "";
+    }
+  }
+
+
+  @Test
+  public void generateBuildFile() {
+    Map<String, String> definedClasses = new HashMap<>();
+    LayoutlibClassLoader.generate(TestBuild.class, (name, classBytes) -> {
+      StringWriter writer = new StringWriter();
+      ClassReader reader = new ClassReader(classBytes);
+      TraceClassVisitor visitor = new TraceClassVisitor(new PrintWriter(writer));
+      reader.accept(visitor, 0);
+
+      definedClasses.put(name, simplify(writer.toString()));
+    });
+
+    Assert.assertEquals(3, definedClasses.size()); // Outer class + 2 inner classes
+    Assert.assertEquals("public class android/os/Build {\n" +
+                        "  public static INNERCLASS android/os/Build$InnerClass2 android/os/Build InnerClass2\n" +
+                        "  public static INNERCLASS android/os/Build$InnerClass android/os/Build InnerClass\n" +
+                        "  public final static Ljava/lang/String; TEST_FIELD = \"TestValue\"\n" +
+                        "  public <init>()V\n" +
+                        "  private static privateMethod()Ljava/lang/String;\n" +
+                        "  public static getSerial()Ljava/lang/String;\n" +
+                        "}",
+                        definedClasses.get("android.os.Build"));
+
+    Assert.assertEquals("public class android/os/Build$InnerClass {\n" +
+                        "  public static INNERCLASS android/os/Build$InnerClass android/os/Build InnerClass\n" +
+                        "  public final static Ljava/lang/String; TEST_INNER_FIELD = \"TestInnerValue\"\n" +
+                        "  public final static I INNER_VALUE = 1\n" +
+                        "  public <init>()V\n" +
+                        "}",
+                        definedClasses.get("android.os.Build$InnerClass"));
+
+    Assert.assertEquals("public class android/os/Build$InnerClass2 {\n" +
+                        "  public static INNERCLASS android/os/Build$InnerClass2 android/os/Build InnerClass2\n" +
+                        "  public final static Ljava/lang/String; TEST_INNER_FIELD2\n" +
+                        "  public <init>()V\n" +
+                        "  static <clinit>()V\n" +
+                        "}",
+                        definedClasses.get("android.os.Build$InnerClass2"));
+  }
+}
\ No newline at end of file
diff --git a/layoutlib/testSrc/com/android/layoutlib/LayoutlibPrebuiltTest.kt b/layoutlib/testSrc/com/android/layoutlib/LayoutlibPrebuiltTest.kt
new file mode 100644
index 00000000000..9d646de7e1c
--- /dev/null
+++ b/layoutlib/testSrc/com/android/layoutlib/LayoutlibPrebuiltTest.kt
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.layoutlib
+
+import com.android.layoutlib.bridge.BridgeConstants
+import org.junit.Test
+import java.net.URL
+import java.util.jar.JarFile
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class LayoutPrebuiltTest {
+  // Regression test for b/109738602
+  @Test
+  fun jarContents() {
+    val classUrl = BridgeConstants::class.java.getResource(BridgeConstants::class.simpleName + ".class")
+    assertEquals("jar", classUrl.protocol)
+    val jarUrl = URL(classUrl.path.substringBefore("!"))
+    val jarFile = JarFile(jarUrl.file)
+    val jarEntryNames = jarFile.entries().asSequence()
+      .map { it.name }
+      .toSet()
+
+    // Sanity check to make sure the file contains some data
+    assertTrue(jarEntryNames.contains("android/R.class"))
+    assertTrue(jarEntryNames.contains("android/R\$layout.class"))
+
+    // Check that the jar does not contain classes in sun.** or java.**zs
+    assertFalse(jarEntryNames.any {
+      it.startsWith("sun/") || it.startsWith("java/")
+    })
+  }
+}
\ No newline at end of file
diff --git a/layoutlib/testSrc/com/android/layoutlib/TestBuild.java b/layoutlib/testSrc/com/android/layoutlib/TestBuild.java
new file mode 100644
index 00000000000..5b03c78381b
--- /dev/null
+++ b/layoutlib/testSrc/com/android/layoutlib/TestBuild.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.layoutlib;
+
+public class TestBuild {
+  public static final String TEST_FIELD = "TestValue";
+
+  private static String privateMethod() {
+    return "SerialNumber";
+  }
+
+  public static String getSerial() {
+    return "#" + privateMethod();
+  }
+
+  public static class InnerClass {
+    public static final String TEST_INNER_FIELD = "TestInnerValue";
+    public static final int INNER_VALUE = 1;
+  }
+
+  public static class InnerClass2 {
+    public static final String TEST_INNER_FIELD2;
+
+    static {
+      TEST_INNER_FIELD2 = "TestInnerValue2";
+    }
+  }
+}