Add an experimental search widget

chrome/android/java/src/org/chromium/chrome/browser/searchwidget/SearchWidgetProvider.java

Index: chrome/android/java/src/org/chromium/chrome/browser/searchwidget/SearchWidgetProvider.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/searchwidget/SearchWidgetProvider.java b/chrome/android/java/src/org/chromium/chrome/browser/searchwidget/SearchWidgetProvider.java
new file mode 100644
index 0000000000000000000000000000000000000000..a5a17a2579aa154ba0b3b1d13cb47136df6cd203
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/searchwidget/SearchWidgetProvider.java
@@ -0,0 +1,281 @@
+// Copyright 2017 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.searchwidget;
+
+import android.app.PendingIntent;
+import android.appwidget.AppWidgetManager;
+import android.appwidget.AppWidgetProvider;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.graphics.Rect;
+import android.net.Uri;
+import android.os.Bundle;
+import android.support.v4.app.ActivityOptionsCompat;
+import android.text.TextUtils;
+import android.widget.RemoteViews;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ContextUtils;
+import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.library_loader.LibraryLoader;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.IntentHandler;
+import org.chromium.chrome.browser.init.AsyncInitializationActivity;
+import org.chromium.chrome.browser.search_engines.TemplateUrlService;
+import org.chromium.chrome.browser.search_engines.TemplateUrlService.LoadListener;
+import org.chromium.chrome.browser.search_engines.TemplateUrlService.TemplateUrlServiceObserver;
+
+/**
+ * Widget that lets the user search using the default search engine in Chrome.
+ * Because this is a BroadcastReceiver, it dies immediately after it runs.  A new one is created
+ * for each new broadcast.
+ */
+public class SearchWidgetProvider extends AppWidgetProvider {
+    /** Monitors the TemplateUrlService for changes, updating the widget when necessary. */
+    private static final class SearchWidgetTemplateUrlServiceObserver
+            implements LoadListener, TemplateUrlServiceObserver {
+        @Override
+        public void onTemplateUrlServiceLoaded() {
+            TemplateUrlService.getInstance().unregisterLoadListener(this);
+            updateCachedEngineName();
+        }
+
+        @Override
+        public void onTemplateURLServiceChanged() {
+            updateCachedEngineName();
+        }
+    }
+
+    static final int INVALID_WIDGET_ID = -1;
+
+    static final boolean ANIMATE_TRANSITION = false;
+
+    private static final String ACTION_START_TEXT_QUERY =
+            "org.chromium.chrome.browser.searchwidget.START_TEXT_QUERY";
+    private static final String ACTION_START_VOICE_QUERY =
+            "org.chromium.chrome.browser.searchwidget.START_VOICE_QUERY";
+    private static final String ACTION_UPDATE_ALL_WIDGETS =
+            "org.chromium.chrome.browser.searchwidget.UPDATE_ALL_WIDGETS";
+
+    static final String EXTRA_START_VOICE_SEARCH =
+            "org.chromium.chrome.browser.searchwidget.START_VOICE_SEARCH";
+    private static final String EXTRA_WIDGET_ID =
+            "org.chromium.chrome.browser.searchwidget.WIDGET_ID";
+
+    private static final String PREF_LAUNCHING_WIDGET_ID =
+            "org.chromium.chrome.browser.searchwidget.LAUNCHING_WIDGET_ID";
+    private static final String PREF_SEARCH_ENGINE_SHORTNAME =
+            "org.chromium.chrome.browser.searchwidget.SEARCH_ENGINE_SHORTNAME";
+    static final String PREF_USE_HERB_TAB = "org.chromium.chrome.browser.searchwidget.USE_HERB_TAB";
+
+    private static final String TAG = "searchwidget";
+    private static final Object OBSERVER_LOCK = new Object();
+
+    private static SearchWidgetTemplateUrlServiceObserver sObserver;
+    private static String sCachedSearchEngineName;
+
+    /**
+     * Creates the singleton instance of the observer that will monitor for search engine changes.
+     * The native library and the browser process must have been fully loaded before calling this,
+     * after {@link AsyncInitializationActivity#finishNativeInitialization}.
+     */
+    public static void initialize() {
+        ThreadUtils.assertOnUiThread();
+        assert LibraryLoader.isInitialized();
+
+        // Set up an observer to monitor for changes.
+        synchronized (OBSERVER_LOCK) {
+            if (sObserver != null) return;
+            sObserver = new SearchWidgetTemplateUrlServiceObserver();
+
+            TemplateUrlService service = TemplateUrlService.getInstance();
+            service.addObserver(sObserver);
+            if (!service.isLoaded()) {
+                service.registerLoadListener(sObserver);
+                service.load();
+            }
+        }
+        updateCachedEngineName();
+    }
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        if (IntentHandler.isIntentChromeOrFirstParty(intent)) {
+            if (ACTION_START_TEXT_QUERY.equals(intent.getAction())) {
+                startSearchActivity(context, intent, false);
+                return;
+            } else if (ACTION_START_VOICE_QUERY.equals(intent.getAction())) {
+                startSearchActivity(context, intent, true);
+                return;
+            }
+        } else if (ACTION_UPDATE_ALL_WIDGETS.equals(intent.getAction())) {
+            performUpdate(context);
+            return;
+        }
+        super.onReceive(context, intent);
+    }
+
+    private void startSearchActivity(Context context, Intent intent, boolean startVoiceSearch) {
+        int widgetId = getLaunchingWidgetIdFromIntent(intent);
+        SearchWidgetProvider.setLaunchingWidgetId(widgetId);
+        Log.d(TAG, "Launching SearchActivity: ID=" + widgetId + " VOICE=" + startVoiceSearch);
+
+        // Launch the SearchActivity.
+        Intent searchIntent = new Intent();
+        searchIntent.setClassName(context, SearchActivity.class.getName());
+        searchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        searchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_DOCUMENT);
+        searchIntent.putExtra(EXTRA_START_VOICE_SEARCH, startVoiceSearch);
+
+        Bundle optionsBundle;
+        if (ANIMATE_TRANSITION) {
+            // Pass the widget's bounds along to allow moving the box into place.
+            Rect rect = intent.getSourceBounds();
+            if (rect != null) searchIntent.setSourceBounds(rect);
+            optionsBundle = ActivityOptionsCompat.makeCustomAnimation(context, 0, 0).toBundle();
+        } else {
+            optionsBundle = ActivityOptionsCompat
+                                    .makeCustomAnimation(context, R.anim.activity_open_enter, 0)
+                                    .toBundle();
+        }
+        context.startActivity(searchIntent, optionsBundle);
+    }
+
+    @Override
+    public void onUpdate(Context context, AppWidgetManager manager, int[] ids) {
+        performUpdate(context, ids);
+        super.onUpdate(context, manager, ids);
+    }
+
+    private void performUpdate(Context context) {
+        AppWidgetManager manager = AppWidgetManager.getInstance(context);
+        performUpdate(context, getAllSearchWidgetIds(manager));
+    }
+
+    private void performUpdate(Context context, int[] ids) {
+        for (int id : ids) updateWidget(context, id);
+    }
+
+    private void updateWidget(Context context, int id) {
+        int launchingWidgetId = ANIMATE_TRANSITION ? getLaunchingWidgetId() : INVALID_WIDGET_ID;
+
+        AppWidgetManager manager = AppWidgetManager.getInstance(context);
+        RemoteViews views = new RemoteViews(context.getPackageName(),
+                id == launchingWidgetId ? R.layout.text_box_template_transparent
+                                        : R.layout.text_box_template);
+
+        // Clicking on the widget fires an Intent back at this BroadcastReceiver, allowing control
+        // over how the Activity is animated when it starts up.
+        Intent textIntent = createStartQueryIntent(context, ACTION_START_TEXT_QUERY, id);
+        views.setOnClickPendingIntent(R.id.text_container,
+                PendingIntent.getBroadcast(
+                        context, 0, textIntent, PendingIntent.FLAG_UPDATE_CURRENT));
+
+        Intent voiceIntent = createStartQueryIntent(context, ACTION_START_VOICE_QUERY, id);
+        views.setOnClickPendingIntent(R.id.microphone_icon,
+                PendingIntent.getBroadcast(
+                        context, 0, voiceIntent, PendingIntent.FLAG_UPDATE_CURRENT));
+
+        // Update what string is displayed by the widget.
+        String engineName = getCachedEngineName();
+        String text = TextUtils.isEmpty(engineName)
+                ? context.getString(R.string.search_widget_default)
+                : context.getString(R.string.search_with_product, engineName);
+        views.setTextViewText(R.id.title, text);
+
+        manager.updateAppWidget(id, views);
+    }
+
+    /** Force all widgets to update their state. */
+    static void updateAllWidgets() {
+        Intent intent = new Intent(ACTION_UPDATE_ALL_WIDGETS);
+        intent.setPackage(ContextUtils.getApplicationContext().getPackageName());
+        ContextUtils.getApplicationContext().sendBroadcast(intent);
+    }
+
+    /** Updates the name of the user's default search engine that is cached in SharedPreferences. */
+    static void updateCachedEngineName() {
+        assert LibraryLoader.isInitialized();
+
+        // Getting an instance of the TemplateUrlService requires that the native library be
+        // loaded, but the TemplateUrlService itself needs to be initialized.
+        TemplateUrlService service = TemplateUrlService.getInstance();
+        if (!service.isLoaded()) return;
+
+        String engineName = service.getDefaultSearchEngineTemplateUrl().getShortName();
+        if (!TextUtils.equals(sCachedSearchEngineName, engineName)) {
+            sCachedSearchEngineName = engineName;
+
+            SharedPreferences.Editor editor = ContextUtils.getAppSharedPreferences().edit();
+            editor.putString(PREF_SEARCH_ENGINE_SHORTNAME, engineName);
+            editor.apply();
+
+            updateAllWidgets();
+        }
+    }
+
+    /**
+     * Returns the cached name of the user's default search engine.  Caching it in SharedPreferences
+     * prevents us from having to load the native library and the TemplateUrlService.
+     *
+     * @return The cached name of the user's default search engine.
+     */
+    private static String getCachedEngineName() {
+        if (sCachedSearchEngineName != null) return sCachedSearchEngineName;
+
+        SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
+        sCachedSearchEngineName = prefs.getString(PREF_SEARCH_ENGINE_SHORTNAME, null);
+        return sCachedSearchEngineName;
+    }
+
+    /** Get the IDs of all of Chrome's search widgets. */
+    private static int[] getAllSearchWidgetIds(AppWidgetManager manager) {
+        return manager.getAppWidgetIds(new ComponentName(
+                ContextUtils.getApplicationContext(), SearchWidgetProvider.class.getName()));
+    }
+
+    private int getLaunchingWidgetId() {
+        int launchingWidgetId = INVALID_WIDGET_ID;
+
+        // If the SearchActivity isn't in the foreground, the user must have exited it.
+        if (ApplicationStatus.getLastTrackedFocusedActivity() instanceof SearchActivity) {
+            launchingWidgetId = ContextUtils.getAppSharedPreferences().getInt(
+                    PREF_LAUNCHING_WIDGET_ID, INVALID_WIDGET_ID);
+        }
+
+        return launchingWidgetId;
+    }
+
+    /** Cache the ID of the widget that was used to launch the SearchActivity. */
+    static void setLaunchingWidgetId(int id) {
+        SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
+        SharedPreferences.Editor editor = prefs.edit();
+        editor.putInt(PREF_LAUNCHING_WIDGET_ID, id);
+        editor.apply();
+    }
+
+    /** Parse out which widget launched the Activity from the given Intent. */
+    private static int getLaunchingWidgetIdFromIntent(Intent intent) {
+        String data = intent.getData() == null ? null : intent.getData().toString();
+        if (data == null) return INVALID_WIDGET_ID;
+
+        try {
+            return Integer.parseInt(data);
+        } catch (NumberFormatException e) {
+            return INVALID_WIDGET_ID;
+        }
+    }
+
+    /** Creates a trusted Intent that lets the user begin performing queries. */
+    private Intent createStartQueryIntent(Context context, String action, int widgetId) {
+        Intent intent = new Intent(action, Uri.parse(String.valueOf(widgetId)));
+        intent.setClass(context, getClass());
+        IntentHandler.addTrustedIntentExtras(intent);
+        return intent;
+    }
+}