Observer Support for DistilledPagePrefs

These changes provide support for observers for DistilledPagePrefs
to listen to changes in DistilledPagePrefs.

BUG=383630

Review URL: https://codereview.chromium.org/403323005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285109 0039d316-1c4b-4281-b951-d872f2087c98

base/android/java/src/org/chromium/base/NativeCall.java

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.base;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * @NativeCall is used by the JNI generator to create the necessary JNI bindings
+ * so a native function can be bound to a Java inner class. The native class for
+ * which the JNI method will be generated is specified by the first parameter.
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.CLASS)
+public @interface NativeCall {
+    /*
+     * Value determines which native class the method should map to.
+     */
+    public String value() default "";
+}

chrome/android/javatests/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsTest.java

@@ -7,36 +7,110 @@ package org.chromium.chrome.browser.dom_distiller;
 import android.test.suitebuilder.annotation.SmallTest;
 import android.test.UiThreadTest;
 
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.Feature;
 import org.chromium.chrome.browser.profiles.Profile;
 import org.chromium.chrome.shell.ChromeShellTestBase;
 import org.chromium.components.dom_distiller.core.DistilledPagePrefs;
 import org.chromium.components.dom_distiller.core.DomDistillerService;
 import org.chromium.components.dom_distiller.core.Theme;
+import org.chromium.content.browser.test.util.UiUtils;
 
 /**
  * Test class for {@link DistilledPagePrefs}.
  */
 public class DistilledPagePrefsTest extends ChromeShellTestBase {
 
+    private DistilledPagePrefs mDistilledPagePrefs;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+        startChromeBrowserProcessSync(getInstrumentation().getTargetContext());
+        getDistilledPagePrefs();
+    }
+
+    private void getDistilledPagePrefs() {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            public void run() {
+                DomDistillerService domDistillerService = DomDistillerServiceFactory.
+                        getForProfile(Profile.getLastUsedProfile());
+                mDistilledPagePrefs = domDistillerService.getDistilledPagePrefs();
+            }
+        });
+    }
+
     @SmallTest
     @UiThreadTest
     @Feature({"DomDistiller"})
     public void testGetAndSetPrefs() throws InterruptedException {
-        startChromeBrowserProcessSync(getInstrumentation().getTargetContext());
-        DomDistillerService service = DomDistillerServiceFactory.
-            getForProfile(Profile.getLastUsedProfile());
-        assertNotNull(service);
-        DistilledPagePrefs distilledPagePrefs = service.getDistilledPagePrefs();
-        assertNotNull(distilledPagePrefs);
-        // Check default theme.
-        assertEquals(distilledPagePrefs.getTheme(), Theme.LIGHT);
+        // Check the default theme.
+        assertEquals(mDistilledPagePrefs.getTheme(), Theme.LIGHT);
         // Check that theme can be correctly set.
-        distilledPagePrefs.setTheme(Theme.DARK);
-        assertEquals(Theme.DARK, distilledPagePrefs.getTheme());
-        distilledPagePrefs.setTheme(Theme.LIGHT);
-        assertEquals(Theme.LIGHT, distilledPagePrefs.getTheme());
-        distilledPagePrefs.setTheme(Theme.SEPIA);
-        assertEquals(Theme.SEPIA, distilledPagePrefs.getTheme());
+        mDistilledPagePrefs.setTheme(Theme.DARK);
+        assertEquals(Theme.DARK, mDistilledPagePrefs.getTheme());
+        mDistilledPagePrefs.setTheme(Theme.LIGHT);
+        assertEquals(Theme.LIGHT, mDistilledPagePrefs.getTheme());
+        mDistilledPagePrefs.setTheme(Theme.SEPIA);
+        assertEquals(Theme.SEPIA, mDistilledPagePrefs.getTheme());
+    }
+
+    @SmallTest
+    @Feature({"DomDistiller"})
+    public void testSingleObserver() throws InterruptedException {
+        TestingObserver testObserver = new TestingObserver();
+        mDistilledPagePrefs.addObserver(testObserver);
+
+        setTheme(Theme.DARK);
+        // Assumes that callback does not occur immediately.
+        assertNull(testObserver.getTheme());
+        UiUtils.settleDownUI(getInstrumentation());
+        // Check that testObserver's theme has been updated,
+        assertEquals(Theme.DARK, testObserver.getTheme());
+        mDistilledPagePrefs.removeObserver(testObserver);
+    }
+
+    @SmallTest
+    @Feature({"DomDistiller"})
+    public void testMultipleObservers() throws InterruptedException {
+        TestingObserver testObserverOne = new TestingObserver();
+        mDistilledPagePrefs.addObserver(testObserverOne);
+        TestingObserver testObserverTwo = new TestingObserver();
+        mDistilledPagePrefs.addObserver(testObserverTwo);
+
+        setTheme(Theme.SEPIA);
+        UiUtils.settleDownUI(getInstrumentation());
+        assertEquals(Theme.SEPIA, testObserverOne.getTheme());
+        assertEquals(Theme.SEPIA, testObserverTwo.getTheme());
+        mDistilledPagePrefs.removeObserver(testObserverOne);
+
+        setTheme(Theme.DARK);
+        UiUtils.settleDownUI(getInstrumentation());
+        // Check that testObserverOne's theme is not changed but testObserverTwo's is.
+        assertEquals(Theme.SEPIA, testObserverOne.getTheme());
+        assertEquals(Theme.DARK, testObserverTwo.getTheme());
+        mDistilledPagePrefs.removeObserver(testObserverTwo);
+    }
+
+    private static class TestingObserver implements DistilledPagePrefs.Observer {
+        private Theme mTheme;
+
+        public TestingObserver() {}
+
+        public Theme getTheme() {
+            return mTheme;
+        }
+
+        public void onChangeTheme(Theme theme) {
+            mTheme = theme;
+        }
+    }
+
+    private void setTheme(final Theme theme) {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            public void run() {
+                mDistilledPagePrefs.setTheme(theme);
+            }
+        });
     }
 }

components/dom_distiller/android/java/src/org/chromium/components/dom_distiller/core/DistilledPagePrefs.java

@@ -4,7 +4,12 @@
 
 package org.chromium.components.dom_distiller.core;
 
+import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
+import org.chromium.base.NativeCall;
+
+import java.util.HashMap;
+import java.util.Map;
 
 /**
  * Wrapper for the dom_distiller::DistilledPagePrefs.
@@ -13,25 +18,85 @@ import org.chromium.base.JNINamespace;
 public final class DistilledPagePrefs {
 
     private final long mDistilledPagePrefsAndroid;
+    private Map<Observer, DistilledPagePrefsObserverWrapper> mObserverMap;
+
+    /**
+     * Observer interface for observing DistilledPagePrefs changes.
+     */
+    public interface Observer {
+        void onChangeTheme(Theme theme);
+    }
+
+    /**
+     * Wrapper for dom_distiller::android::DistilledPagePrefsObserverAndroid.
+     */
+    private static class DistilledPagePrefsObserverWrapper {
+        private final Observer mDistilledPagePrefsObserver;
+        private final long mNativeDistilledPagePrefsObserverAndroidPtr;
+
+        public DistilledPagePrefsObserverWrapper(Observer observer) {
+            mNativeDistilledPagePrefsObserverAndroidPtr = nativeInitObserverAndroid();
+            mDistilledPagePrefsObserver = observer;
+        }
+
+        @CalledByNative("DistilledPagePrefsObserverWrapper")
+        private void onChangeTheme(int theme) {
+            mDistilledPagePrefsObserver.onChangeTheme(Theme.getThemeForValue(theme));
+        }
+
+        public void destroy() {
+            nativeDestroyObserverAndroid(mNativeDistilledPagePrefsObserverAndroidPtr);
+        }
+
+        public long getNativePtr() {
+            return mNativeDistilledPagePrefsObserverAndroidPtr;
+        }
+
+        @NativeCall("DistilledPagePrefsObserverWrapper")
+        private native long nativeInitObserverAndroid();
+
+        @NativeCall("DistilledPagePrefsObserverWrapper")
+        private native void nativeDestroyObserverAndroid(
+                long nativeDistilledPagePrefsObserverAndroid);
+    }
 
     DistilledPagePrefs(long distilledPagePrefsPtr) {
         mDistilledPagePrefsAndroid = nativeInit(distilledPagePrefsPtr);
+        mObserverMap = new HashMap<Observer, DistilledPagePrefsObserverWrapper>();
+    }
+
+    public void addObserver(Observer obs) {
+        DistilledPagePrefsObserverWrapper wrappedObserver =
+                new DistilledPagePrefsObserverWrapper(obs);
+        nativeAddObserver(mDistilledPagePrefsAndroid, wrappedObserver.getNativePtr());
+        mObserverMap.put(obs, wrappedObserver);
+    }
+
+    public void removeObserver(Observer obs) {
+        DistilledPagePrefsObserverWrapper wrappedObserver = mObserverMap.remove(obs);
+        if (wrappedObserver != null) {
+            nativeRemoveObserver(mDistilledPagePrefsAndroid, wrappedObserver.getNativePtr());
+            wrappedObserver.destroy();
+        }
     }
 
-    // TODO(sunangel): Add observer support from this Java class to native
-    // counterpart so UI can be updated across tabs.
     public void setTheme(Theme theme) {
         nativeSetTheme(mDistilledPagePrefsAndroid, theme.asNativeEnum());
     }
 
     public Theme getTheme() {
-        return Theme.getThemeForValue(
-            nativeGetTheme(mDistilledPagePrefsAndroid));
+        return Theme.getThemeForValue(nativeGetTheme(mDistilledPagePrefsAndroid));
     }
 
     private native long nativeInit(long distilledPagePrefPtr);
-    private native void nativeSetTheme(long nativeDistilledPagePrefsAndroid,
-        int theme);
-    private native int nativeGetTheme(
-        long nativeDistilledPagePrefsAndroid);
+
+    private native void nativeSetTheme(long nativeDistilledPagePrefsAndroid, int theme);
+
+    private native int nativeGetTheme(long nativeDistilledPagePrefsAndroid);
+
+    private native void nativeAddObserver(long nativeDistilledPagePrefsAndroid,
+            long nativeObserverPtr);
+
+    private native void nativeRemoveObserver(long nativeDistilledPagePrefsAndroid,
+            long nativeObserverPtr);
 }

components/dom_distiller/core/BUILD.gn

@@ -17,6 +17,10 @@ static_library("core") {
     "distiller.h",
     "distiller_page.cc",
     "distiller_page.h",
+    "distilled_page_prefs.cc",
+    "distilled_page_prefs.h",
+    "distilled_page_prefs_android.cc",
+    "distilled_page_prefs_android.h",
     "distiller_url_fetcher.cc",
     "distiller_url_fetcher.h",
     "dom_distiller_constants.cc",

components/dom_distiller/core/distilled_page_prefs_android.cc

@@ -9,13 +9,14 @@
 #include "jni/DistilledPagePrefs_jni.h"
 
 namespace dom_distiller {
+
 namespace android {
 
 DistilledPagePrefsAndroid::DistilledPagePrefsAndroid(
     JNIEnv* env,
     jobject obj,
-    DistilledPagePrefs* distillerPagePrefsPtr)
-    : distilled_page_prefs_(distillerPagePrefsPtr) {
+    DistilledPagePrefs* distilled_page_prefs_ptr)
+    : distilled_page_prefs_(distilled_page_prefs_ptr) {
 }
 
 DistilledPagePrefsAndroid::~DistilledPagePrefsAndroid() {
@@ -29,11 +30,11 @@ jint DistilledPagePrefsAndroid::GetTheme(JNIEnv* env, jobject obj) {
   return (int)distilled_page_prefs_->GetTheme();
 }
 
-jlong Init(JNIEnv* env, jobject obj, jlong distilledPagePrefsPtr) {
-  DistilledPagePrefs* distilledPagePrefs =
-      reinterpret_cast<DistilledPagePrefs*>(distilledPagePrefsPtr);
+jlong Init(JNIEnv* env, jobject obj, jlong distilled_page_prefs_ptr) {
+  DistilledPagePrefs* distilled_page_prefs =
+      reinterpret_cast<DistilledPagePrefs*>(distilled_page_prefs_ptr);
   DistilledPagePrefsAndroid* distilled_page_prefs_android =
-      new DistilledPagePrefsAndroid(env, obj, distilledPagePrefs);
+      new DistilledPagePrefsAndroid(env, obj, distilled_page_prefs);
   return reinterpret_cast<intptr_t>(distilled_page_prefs_android);
 }
 
@@ -41,5 +42,48 @@ bool DistilledPagePrefsAndroid::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
+void DistilledPagePrefsAndroid::AddObserver(JNIEnv* env,
+                                            jobject obj,
+                                            jlong observer_ptr) {
+  DistilledPagePrefsObserverAndroid* distilled_page_prefs_observer_wrapper =
+      reinterpret_cast<DistilledPagePrefsObserverAndroid*>(observer_ptr);
+  distilled_page_prefs_->AddObserver(distilled_page_prefs_observer_wrapper);
+}
+
+void DistilledPagePrefsAndroid::RemoveObserver(JNIEnv* env,
+                                               jobject obj,
+                                               jlong observer_ptr) {
+  DistilledPagePrefsObserverAndroid* distilled_page_prefs_observer_wrapper =
+      reinterpret_cast<DistilledPagePrefsObserverAndroid*>(observer_ptr);
+  distilled_page_prefs_->RemoveObserver(distilled_page_prefs_observer_wrapper);
+}
+
+DistilledPagePrefsObserverAndroid::DistilledPagePrefsObserverAndroid(
+    JNIEnv* env,
+    jobject obj) {
+  java_ref_.Reset(env, obj);
+}
+
+DistilledPagePrefsObserverAndroid::~DistilledPagePrefsObserverAndroid() {}
+
+void DistilledPagePrefsObserverAndroid::DestroyObserverAndroid(JNIEnv* env,
+                                                               jobject obj) {
+  delete this;
+}
+
+void DistilledPagePrefsObserverAndroid::OnChangeTheme(
+    DistilledPagePrefs::Theme new_theme) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_DistilledPagePrefsObserverWrapper_onChangeTheme(
+      env, java_ref_.obj(), (int)new_theme);
+}
+
+jlong InitObserverAndroid(JNIEnv* env, jobject obj) {
+  DistilledPagePrefsObserverAndroid* observer_android =
+      new DistilledPagePrefsObserverAndroid(env, obj);
+  return reinterpret_cast<intptr_t>(observer_android);
+}
+
 }  // namespace android
+
 }  // namespace dom_distiller

components/dom_distiller/core/distilled_page_prefs_android.h

@@ -17,11 +17,13 @@ class DistilledPagePrefsAndroid {
  public:
   DistilledPagePrefsAndroid(JNIEnv* env,
                             jobject obj,
-                            DistilledPagePrefs* distillerPagePrefsPtr);
+                            DistilledPagePrefs* distilled_page_prefs_ptr);
   virtual ~DistilledPagePrefsAndroid();
   static bool Register(JNIEnv* env);
   void SetTheme(JNIEnv* env, jobject obj, jint theme);
   jint GetTheme(JNIEnv* env, jobject obj);
+  void AddObserver(JNIEnv* env, jobject obj, jlong obs);
+  void RemoveObserver(JNIEnv* env, jobject obj, jlong obs);
 
  private:
   DistilledPagePrefs* distilled_page_prefs_;
@@ -29,6 +31,20 @@ class DistilledPagePrefsAndroid {
   DISALLOW_COPY_AND_ASSIGN(DistilledPagePrefsAndroid);
 };
 
+class DistilledPagePrefsObserverAndroid : public DistilledPagePrefs::Observer {
+ public:
+  DistilledPagePrefsObserverAndroid(JNIEnv* env, jobject obj);
+  virtual ~DistilledPagePrefsObserverAndroid();
+
+  // DistilledPagePrefs::Observer implementation.
+  virtual void OnChangeTheme(DistilledPagePrefs::Theme new_theme) OVERRIDE;
+
+  virtual void DestroyObserverAndroid(JNIEnv* env, jobject obj);
+
+ private:
+  base::android::ScopedJavaGlobalRef<jobject> java_ref_;
+};
+
 }  // namespace android
 }  // namespace dom_distiller