From fae4578311970afadca8ee28a47e1e11df00eedd Mon Sep 17 00:00:00 2001
From: Keisuke Kuroyanagi <ksk@google.com>
Date: Wed, 24 Feb 2016 18:53:00 -0800
Subject: [PATCH] Make drag&drop be atomic for undo/redo.

For undo/redo, drag&drop is recorded as a 2 operations, paste and
delete. This CL makes drag&drop be atomic operation to be properly
undoed/redoed.

Bug: 27268820
Change-Id: Ia38d663f046c2c65f348985934f5cfa054b0437e
---
 core/java/android/widget/Editor.java          | 34 +++++++++++++------
 .../android/widget/TextViewActivityTest.java  |  7 ++++
 2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/core/java/android/widget/Editor.java b/core/java/android/widget/Editor.java
index 406dc2b2baa9f..69591371aa35b 100644
--- a/core/java/android/widget/Editor.java
+++ b/core/java/android/widget/Editor.java
@@ -2395,17 +2395,22 @@ public class Editor {
                 dragSourceEnd += shift;
             }
 
-            // Delete original selection
-            mTextView.deleteText_internal(dragSourceStart, dragSourceEnd);
+            mUndoInputFilter.setForceMerge(true);
+            try {
+                // Delete original selection
+                mTextView.deleteText_internal(dragSourceStart, dragSourceEnd);
 
-            // Make sure we do not leave two adjacent spaces.
-            final int prevCharIdx = Math.max(0,  dragSourceStart - 1);
-            final int nextCharIdx = Math.min(mTextView.getText().length(), dragSourceStart + 1);
-            if (nextCharIdx > prevCharIdx + 1) {
-                CharSequence t = mTextView.getTransformedText(prevCharIdx, nextCharIdx);
-                if (Character.isSpaceChar(t.charAt(0)) && Character.isSpaceChar(t.charAt(1))) {
-                    mTextView.deleteText_internal(prevCharIdx, prevCharIdx + 1);
+                // Make sure we do not leave two adjacent spaces.
+                final int prevCharIdx = Math.max(0,  dragSourceStart - 1);
+                final int nextCharIdx = Math.min(mTextView.getText().length(), dragSourceStart + 1);
+                if (nextCharIdx > prevCharIdx + 1) {
+                    CharSequence t = mTextView.getTransformedText(prevCharIdx, nextCharIdx);
+                    if (Character.isSpaceChar(t.charAt(0)) && Character.isSpaceChar(t.charAt(1))) {
+                        mTextView.deleteText_internal(prevCharIdx, prevCharIdx + 1);
+                    }
                 }
+            } finally {
+                mUndoInputFilter.setForceMerge(false);
             }
         }
     }
@@ -5497,6 +5502,9 @@ public class Editor {
         // rotates the screen during composition.
         private boolean mHasComposition;
 
+        // Whether to merge events into one operation.
+        private boolean mForceMerge;
+
         public UndoInputFilter(Editor editor) {
             mEditor = editor;
         }
@@ -5511,6 +5519,10 @@ public class Editor {
             mHasComposition = parcel.readInt() != 0;
         }
 
+        public void setForceMerge(boolean forceMerge) {
+            mForceMerge = forceMerge;
+        }
+
         /**
          * Signals that a user-triggered edit is starting.
          */
@@ -5570,7 +5582,7 @@ public class Editor {
                 // Otherwise the user inserted the composition.
                 String newText = TextUtils.substring(source, start, end);
                 EditOperation edit = new EditOperation(mEditor, "", dstart, newText);
-                recordEdit(edit, false /* forceMerge */);
+                recordEdit(edit, mForceMerge);
                 return true;
             }
 
@@ -5584,7 +5596,7 @@ public class Editor {
             // the initial input filters run (e.g. a credit card formatter that adds spaces to a
             // string). This results in multiple filter() calls for what the user considers to be
             // a single operation. Always undo the whole set of changes in one step.
-            final boolean forceMerge = isInTextWatcher();
+            final boolean forceMerge = mForceMerge || isInTextWatcher();
 
             // Build a new operation with all the information from this edit.
             String newText = TextUtils.substring(source, start, end);
diff --git a/core/tests/coretests/src/android/widget/TextViewActivityTest.java b/core/tests/coretests/src/android/widget/TextViewActivityTest.java
index 5dae4a878bf43..844eadbae692b 100644
--- a/core/tests/coretests/src/android/widget/TextViewActivityTest.java
+++ b/core/tests/coretests/src/android/widget/TextViewActivityTest.java
@@ -44,6 +44,7 @@ import static android.support.test.espresso.matcher.ViewMatchers.withText;
 
 import com.android.frameworks.coretests.R;
 
+import android.support.test.espresso.action.EspressoKey;
 import android.test.ActivityInstrumentationTestCase2;
 import android.test.suitebuilder.annotation.SmallTest;
 import android.view.KeyEvent;
@@ -172,6 +173,12 @@ public class TextViewActivityTest extends ActivityInstrumentationTestCase2<TextV
         onView(withId(R.id.textview)).check(hasSelection(""));
         assertNoSelectionHandles();
         onView(withId(R.id.textview)).check(hasInsertionPointerAtIndex("abc ghi.def".length()));
+
+        // Test undo returns to the original state.
+        onView(withId(R.id.textview)).perform(pressKey(
+                (new EspressoKey.Builder()).withCtrlPressed(true).withKeyCode(KeyEvent.KEYCODE_Z)
+                        .build()));
+        onView(withId(R.id.textview)).check(matches(withText(text)));
     }
 
     @SmallTest