New UndoManager.

Basic implementation of an undo manager.  Supports
multi-level undo/redo, building on the top undo state
as edits occur, managing multiple distinct entities in
the undo state (such as embedded objects in a document),
and saving/restoring the full undo state.  Still some
work remaining on correctly dealing with dependencies
between undo states that hold multiple owners.

Also do a simple implementation of undo state in TextView
to see how things actually work.  The implementation here
is very primitive: it needs a lot more work to correctly
identify when to merge undo ops, is not trying to do
anything smart with style spans, etc.

Change-Id: Ie30f4e133351e2f569ffb48c6c44a2b19cadee27

1 files changed, 75 insertions, 0 deletions

diff --git a/core/java/android/os/ParcelableParcel.java b/core/java/android/os/ParcelableParcel.java
new file mode 100644
index 0000000..11785f1
--- /dev/null
+++ b/core/java/android/os/ParcelableParcel.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2013 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 android.os;
+
+/**
+ * Parcelable containing a raw Parcel of data.
+ * @hide
+ */
+public class ParcelableParcel implements Parcelable {
+    final Parcel mParcel;
+    final ClassLoader mClassLoader;
+
+    public ParcelableParcel(ClassLoader loader) {
+        mParcel = Parcel.obtain();
+        mClassLoader = loader;
+    }
+
+    public ParcelableParcel(Parcel src, ClassLoader loader) {
+        mParcel = Parcel.obtain();
+        mClassLoader = loader;
+        int size = src.readInt();
+        int pos = src.dataPosition();
+        mParcel.appendFrom(src, src.dataPosition(), size);
+        src.setDataPosition(pos + size);
+    }
+
+    public Parcel getParcel() {
+        mParcel.setDataPosition(0);
+        return mParcel;
+    }
+
+    public ClassLoader getClassLoader() {
+        return mClassLoader;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(mParcel.dataSize());
+        dest.appendFrom(mParcel, 0, mParcel.dataSize());
+    }
+
+    public static final Parcelable.ClassLoaderCreator<ParcelableParcel> CREATOR
+            = new Parcelable.ClassLoaderCreator<ParcelableParcel>() {
+        public ParcelableParcel createFromParcel(Parcel in) {
+            return new ParcelableParcel(in, null);
+        }
+
+        public ParcelableParcel createFromParcel(Parcel in, ClassLoader loader) {
+            return new ParcelableParcel(in, loader);
+        }
+
+        public ParcelableParcel[] newArray(int size) {
+            return new ParcelableParcel[size];
+        }
+    };
+}