An ugly hack to render CalendarView. [DO NOT MERGE]

This is an ugly hack to switch the field
android.widget.SimpleMonthView.mDayFormatter from
java.text.SimpleDateFormat to icu's version of the same class. The hack
is only for the L version of the LayoutLib. It's done in a better way in
M and even better in N.

Change-Id: Id84a1d32040211c46b20cdaf3a77119676e748b6

3 files changed, 100 insertions, 1 deletions

diff --git a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmAnalyzer.java b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmAnalyzer.java
index c8b2b84..d37a93e 100644
--- a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmAnalyzer.java
+++ b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmAnalyzer.java
@@ -112,6 +112,8 @@ public class AsmAnalyzer {
             mGen.setDeps(deps);
             mGen.setCopyFiles(filesFound);
             mGen.setRewriteMethodCallClasses(mReplaceMethodCallClasses);
+            // hack hack hack
+            mGen.mSimpleMonthViewReader = zipClasses.get(AsmGenerator.SIMPLE_MONTH_VIEW);
         }
     }
 
diff --git a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmGenerator.java b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmGenerator.java
index f6c2626..2bfceb4 100644
--- a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmGenerator.java
+++ b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/AsmGenerator.java
@@ -77,6 +77,9 @@ public class AsmGenerator {
     /** Methods to inject. FQCN of class in which method should be injected => runnable that does
      * the injection. */
     private final Map<String, ICreateInfo.InjectMethodRunnable> mInjectedMethodsMap;
+    // A hack to do some modifications to simple month view.
+    static final String SIMPLE_MONTH_VIEW = "android/widget/SimpleMonthView";
+    ClassReader mSimpleMonthViewReader;
 
     /**
      * Creates a new generator that can generate the output JAR with the stubbed classes.
@@ -204,7 +207,7 @@ public class AsmGenerator {
      * Utility that returns the internal ASM class name from a fully qualified binary class
      * name. E.g. it returns android/view/View from android.view.View.
      */
-    String binaryToInternalClassName(String className) {
+    static String binaryToInternalClassName(String className) {
         if (className == null) {
             return null;
         } else {
@@ -380,6 +383,10 @@ public class AsmGenerator {
             }
         }
 
+        if (SIMPLE_MONTH_VIEW.equals(className)) {
+            cv = new SimpleMonthViewAdapter(cv);
+        }
+
         cr.accept(cv, 0);
         return cw.toByteArray();
     }
diff --git a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/SimpleMonthViewAdapter.java b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/SimpleMonthViewAdapter.java
new file mode 100644
index 0000000..49fd456
--- /dev/null
+++ b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/SimpleMonthViewAdapter.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2015 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.tools.layoutlib.create;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.FieldVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+
+import java.text.SimpleDateFormat;
+
+import static com.android.tools.layoutlib.create.AsmGenerator.binaryToInternalClassName;
+
+/**
+ * A very ugly hack to transform all references to {@link java.text.SimpleDateFormat} in {@code
+ * android.widget.SimpleMonthView} to {@code com.ibm.icu.text.SimpleDateFormat}.
+ */
+public class SimpleMonthViewAdapter extends ClassVisitor {
+
+    private static final String JAVA_SDF_DESC = Type.getDescriptor(SimpleDateFormat.class);
+    private static final String JAVA_SDF_INTERNAL_NAME =
+            binaryToInternalClassName(SimpleDateFormat.class.getName());
+    private static final String ICU_SDF_INTERNAL_NAME = "com/ibm/icu/text/SimpleDateFormat";
+
+    public SimpleMonthViewAdapter(ClassVisitor cv) {
+        super(Opcodes.ASM4, cv);
+    }
+
+    @Override
+    public FieldVisitor visitField(int access, String name, String desc, String signature,
+            Object value) {
+        if (JAVA_SDF_DESC.equals(desc)) {
+            desc = "L" + ICU_SDF_INTERNAL_NAME + ";";
+        }
+        return super.visitField(access, name, desc, signature, value);
+    }
+
+    @Override
+    public MethodVisitor visitMethod(int access, String name, String desc, String signature,
+            String[] exceptions) {
+        return new MyMethodVisitor(super.visitMethod(access, name, desc, signature, exceptions));
+    }
+
+    private static class MyMethodVisitor extends MethodVisitor {
+        public MyMethodVisitor(MethodVisitor mv) {
+            super(Opcodes.ASM4, mv);
+        }
+
+        @Override
+        public void visitTypeInsn(int opcode, String type) {
+            if (JAVA_SDF_INTERNAL_NAME.equals(type) && opcode == Opcodes.NEW) {
+                type = ICU_SDF_INTERNAL_NAME;
+            }
+            super.visitTypeInsn(opcode, type);
+        }
+
+        @Override
+        public void visitMethodInsn(int opcode, String owner, String name, String desc) {
+            if (JAVA_SDF_INTERNAL_NAME.equals(owner)) {
+                owner = ICU_SDF_INTERNAL_NAME;
+            }
+            super.visitMethodInsn(opcode, owner, name, desc);
+        }
+
+        @Override
+        public void visitFieldInsn(int opcode, String owner, String name, String desc) {
+            if (JAVA_SDF_DESC.equals(desc) &&
+                    (opcode == Opcodes.PUTFIELD || opcode == Opcodes.GETFIELD) &&
+                    name.equals("mDayFormatter")) {
+                desc = "L" + ICU_SDF_INTERNAL_NAME + ";";
+            }
+            super.visitFieldInsn(opcode, owner, name, desc);
+        }
+    }
+}