Add FeedbackReporter for reporting distillation quality.

chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/FeedbackReporter.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.chrome.browser.dom_distiller;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.JNINamespace;
+import org.chromium.chrome.browser.EmptyTabObserver;
+import org.chromium.chrome.browser.Tab;
+import org.chromium.chrome.browser.TabObserver;
+import org.chromium.content.browser.ContentView;
+import org.chromium.content_public.browser.WebContents;
+
+/**
+ * Java implementation of FeedbackReporterAndroid.
+ */
+@JNINamespace("dom_distiller::android")
+public final class FeedbackReporter implements FeedbackReportingView.FeedbackObserver {
+
+    private final long mNativePointer;
+    private final Tab mTab;
+    private ContentView mContentView;
+    private FeedbackReportingView mFeedbackReportingView;
+    private String mOverlayUrl;
+
+    /**
+     * @return whether the DOM Distiller feature is enabled.
+     */
+    public static boolean isEnabled() {
+        return nativeIsEnabled();
+    }
+
+    /**
+     * Records feedback for the distilled content.
+     *
+     * @param good whether the perceived quality of the distillation of a web page was good.
+     */
+    private static void recordQuality(boolean good) {
+        nativeReportQuality(good);
+    }
+
+    /**
+     * Creates the FeedbackReporter, adds itself as a TabObserver, and ensures
+     * references to ContentView and WebContents are up to date.
+     *
+     * @param tab the tab where the overlay should be displayed.
+     */
+    public FeedbackReporter(Tab tab) {
+        mNativePointer = nativeInit();
+        mTab = tab;
+        mTab.addObserver(createTabObserver());
+        updatePointers();
+    }
+
+    @Override
+    public void onYesPressed(FeedbackReportingView view) {
+        if (view != mFeedbackReportingView) return;
+        recordQuality(true);
+        dismissOverlay();
+    }
+
+    @Override
+    public void onNoPressed(FeedbackReportingView view) {
+        if (view != mFeedbackReportingView) return;
+        recordQuality(false);
+        dismissOverlay();
+    }
+
+    /**
+     * Start showing the overlay.
+     */
+    private void showOverlay() {
+        mFeedbackReportingView = FeedbackReportingView.create(mContentView, this);
+    }
+
+    @CalledByNative
+    private void dismissOverlay() {
+        if (mFeedbackReportingView != null) mFeedbackReportingView.dismiss();
+        mOverlayUrl = null;
+        mFeedbackReportingView = null;
+    }
+
+    /**
+     * Dismiss the overlay which is currently being displayed.
+     */
+    @CalledByNative
+    private String getCurrentOverlayUrl() {
+        return mOverlayUrl;
+    }
+
+    /**
+     * Updates which ContentView and WebContents the FeedbackReporter is monitoring.
+     */
+    private void updatePointers() {
+        mContentView = mTab.getContentView();
+        nativeReplaceWebContents(mNativePointer, mTab.getWebContents());
+    }
+
+    /**
+     * Creates a TabObserver for monitoring a Tab, used to react to changes in the ContentView
+     * or to trigger its own destruction.
+     *
+     * @return TabObserver that can be used to monitor a Tab.
+     */
+    private TabObserver createTabObserver() {
+        return new EmptyTabObserver() {
+            @Override
+            public void onWebContentsSwapped(Tab tab, boolean didStartLoad,
+                                             boolean didFinishLoad) {
+                updatePointers();
+            }
+
+            @Override
+            public void onContentChanged(Tab tab) {
+                updatePointers();
+            }
+
+            @Override
+            public void onUpdateUrl(Tab tab, String url) {
+                boolean reportable = nativeIsReportableUrl(url);
+                if (reportable) {
+                    mOverlayUrl = url;
+                    showOverlay();
+                } else {
+                    dismissOverlay();
+                }
+            }
+
+            @Override
+            public void onDestroyed(Tab tab) {
+                nativeDestroy(mNativePointer);
+                mContentView = null;
+            }
+        };
+    }
+
+    private static native boolean nativeIsEnabled();
+
+    private static native boolean nativeIsReportableUrl(String url);
+
+    private static native void nativeReportQuality(boolean good);
+
+    private native long nativeInit();
+
+    private native void nativeDestroy(long nativeFeedbackReporterAndroid);
+
+    private native void nativeReplaceWebContents(
+            long nativeFeedbackReporterAndroid, WebContents webContents);
+}