Don't execute binding when the root view is detached.

Also add tests for memory leaks. The binder should be deleted
when the root view is deleted.

Change-Id: Ifcb24feb80791e64cdfd7203d071d9b1453f6f70

3 files changed, 189 insertions, 2 deletions

diff --git a/tools/data-binding/integration-tests/TestApp/app/src/androidTest/java/android/databinding/testapp/LeakTest.java b/tools/data-binding/integration-tests/TestApp/app/src/androidTest/java/android/databinding/testapp/LeakTest.java
new file mode 100644
index 0000000..bb0576d
--- /dev/null
+++ b/tools/data-binding/integration-tests/TestApp/app/src/androidTest/java/android/databinding/testapp/LeakTest.java
@@ -0,0 +1,126 @@
+/*
+ * 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 android.databinding.testapp;
+
+import android.databinding.testapp.generated.LeakTestBinding;
+import android.test.ActivityInstrumentationTestCase2;
+import android.util.Log;
+import android.widget.FrameLayout;
+
+import java.lang.ref.WeakReference;
+
+public class LeakTest extends ActivityInstrumentationTestCase2<TestActivity> {
+    WeakReference<LeakTestBinding> mWeakReference = new WeakReference<LeakTestBinding>(null);
+
+    public LeakTest() {
+        super(TestActivity.class);
+    }
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+
+        try {
+            getActivity().runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    try {
+                        LeakTestBinding binding = LeakTestBinding.inflate(getActivity());
+                        getActivity().setContentView(binding.getRoot());
+                        mWeakReference = new WeakReference<LeakTestBinding>(binding);
+                        binding.setName("hello world");
+                        binding.executePendingBindings();
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                        throw e;
+                    }
+                }
+            });
+            getInstrumentation().waitForIdleSync();
+        } catch (Throwable t) {
+            throw new Exception(t);
+        }
+    }
+
+    public void testBindingLeak() throws Throwable {
+        assertNotNull(mWeakReference.get());
+        runTestOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                getActivity().setContentView(new FrameLayout(getActivity()));
+            }
+        });
+        System.gc();
+        assertNull(mWeakReference.get());
+    }
+
+    // Test to ensure that when the View is detached that it doesn't rebind
+    // the dirty Views. The rebind should happen only after the root view is
+    // reattached.
+    public void testNoChangeWhenDetached() throws Throwable {
+        final LeakTestBinding binding = mWeakReference.get();
+        final AnimationWatcher watcher = new AnimationWatcher();
+
+        runTestOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                getActivity().setContentView(new FrameLayout(getActivity()));
+                binding.setName("goodbye world");
+                binding.getRoot().postOnAnimation(watcher);
+            }
+        });
+
+        watcher.waitForAnimationThread();
+
+        runTestOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                assertEquals("hello world", binding.getTextView().getText().toString());
+                getActivity().setContentView(binding.getRoot());
+                binding.getRoot().postOnAnimation(watcher);
+            }
+        });
+
+        watcher.waitForAnimationThread();
+
+        runTestOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                assertEquals("goodbye world", binding.getTextView().getText().toString());
+            }
+        });
+    }
+
+    private static class AnimationWatcher implements Runnable {
+        private boolean mWaiting = true;
+
+        public void waitForAnimationThread() throws InterruptedException {
+            synchronized (this) {
+                while (mWaiting) {
+                    this.wait();
+                }
+                mWaiting = true;
+            }
+        }
+
+
+        @Override
+        public void run() {
+            synchronized (this) {
+                mWaiting = false;
+                this.notifyAll();
+            }
+        }
+    }
+}
diff --git a/tools/data-binding/integration-tests/TestApp/app/src/main/res/layout/leak_test.xml b/tools/data-binding/integration-tests/TestApp/app/src/main/res/layout/leak_test.xml
new file mode 100644
index 0000000..3dbf2f5
--- /dev/null
+++ b/tools/data-binding/integration-tests/TestApp/app/src/main/res/layout/leak_test.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ 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.
+  -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+              android:orientation="vertical"
+              android:layout_width="match_parent"
+              android:layout_height="match_parent">
+    <variable name="name" type="String"/>
+    <TextView
+            android:id="@+id/textView"
+            android:layout_width="wrap_content" android:layout_height="wrap_content"
+            android:text="@{name}"/>
+</LinearLayout>
\ No newline at end of file
diff --git a/tools/data-binding/library/src/main/java/android/databinding/ViewDataBinding.java b/tools/data-binding/library/src/main/java/android/databinding/ViewDataBinding.java
index 6cc28571..e4bb2f4 100644
--- a/tools/data-binding/library/src/main/java/android/databinding/ViewDataBinding.java
+++ b/tools/data-binding/library/src/main/java/android/databinding/ViewDataBinding.java
@@ -16,10 +16,13 @@
 
 package android.databinding;
 
+import android.annotation.TargetApi;
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
+import android.util.Log;
 import android.util.SparseIntArray;
 import android.view.View;
+import android.view.View.OnAttachStateChangeListener;
 import android.view.ViewGroup;
 
 import java.lang.ref.WeakReference;
@@ -71,6 +74,29 @@ public abstract class ViewDataBinding {
         }
     };
 
+    private static final OnAttachStateChangeListener ROOT_REATTACHED_LISTENER;
+
+    static {
+        if (VERSION.SDK_INT < VERSION_CODES.KITKAT) {
+            ROOT_REATTACHED_LISTENER = null;
+        } else {
+            ROOT_REATTACHED_LISTENER = new OnAttachStateChangeListener() {
+                @TargetApi(VERSION_CODES.KITKAT)
+                @Override
+                public void onViewAttachedToWindow(View v) {
+                    // execute the pending bindings.
+                    ViewDataBinding binding = (ViewDataBinding) v.getTag();
+                    v.post(binding.mRebindRunnable);
+                    v.removeOnAttachStateChangeListener(this);
+                }
+
+                @Override
+                public void onViewDetachedFromWindow(View v) {
+                }
+            };
+        }
+    }
+
     /**
      * Runnable executed on animation heartbeat to rebind the dirty Views.
      */
@@ -78,8 +104,19 @@ public abstract class ViewDataBinding {
         @Override
         public void run() {
             if (mPendingRebind) {
-                mPendingRebind = false;
-                executePendingBindings();
+                boolean rebind = true;
+                if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {
+                    rebind = mRoot.isAttachedToWindow();
+                    if (!rebind) {
+                        // Don't execute the pending bindings until the View
+                        // is attached again.
+                        mRoot.addOnAttachStateChangeListener(ROOT_REATTACHED_LISTENER);
+                    }
+                }
+                if (rebind) {
+                    mPendingRebind = false;
+                    executePendingBindings();
+                }
             }
         }
     };