src/com/android/globalsearch/SearchSettings.java - platform/packages/apps/GlobalSearch - Git at Google

 /*
  * Copyright (C) 2009 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 com.android.globalsearch;

 import android.app.AlertDialog;
 import android.app.Dialog;
 import android.app.SearchManager;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.content.res.Resources;
 import android.os.Bundle;
 import android.preference.CheckBoxPreference;
 import android.preference.ListPreference;
 import android.preference.Preference;
 import android.preference.PreferenceActivity;
 import android.preference.PreferenceGroup;
 import android.preference.PreferenceScreen;
 import android.preference.Preference.OnPreferenceChangeListener;
 import android.preference.Preference.OnPreferenceClickListener;
 import android.provider.Settings;
 import android.provider.Settings.SettingNotFoundException;
 import android.server.search.SearchableInfo;
 import android.server.search.Searchables;
 import android.util.Log;

 import java.util.ArrayList;
 import java.util.List;

 /**
  * Activity for setting global search preferences. Changes to search preferences trigger a broadcast
  * intent that causes all SuggestionSources objects to be updated.
  */
 public class SearchSettings extends PreferenceActivity
         implements OnPreferenceClickListener, OnPreferenceChangeListener {

     private static final boolean DBG = false;
     private static final String TAG = "SearchSettings";

     // Only used to find the preferences after inflating
     private static final String CLEAR_SHORTCUTS_PREF = "clear_shortcuts";
     private static final String SEARCH_ENGINE_SETTINGS_PREF = "search_engine_settings";
     private static final String SEARCH_SOURCES_PREF = "search_sources";

     private SearchManager mSearchManager;

     // These instances are not shared with SuggestionProvider
     private SuggestionSources mSources;
     private ShortcutRepository mShortcuts;

     // References to the top-level preference objects
     private Preference mClearShortcutsPreference;
     private ListPreference mWebSourcePreference;
     private PreferenceScreen mSearchEngineSettingsPreference;
     private PreferenceGroup mSourcePreferences;

     // Dialog ids
     private static final int CLEAR_SHORTCUTS_CONFIRM_DIALOG = 0;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         mSearchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);

         mSources = new SuggestionSources(this);
         mSources.load();
         mShortcuts = ShortcutRepositoryImplLog.create(this);
         getPreferenceManager().setSharedPreferencesName(SuggestionSources.PREFERENCES_NAME);

         addPreferencesFromResource(R.xml.preferences);

         PreferenceScreen preferenceScreen = getPreferenceScreen();
         mClearShortcutsPreference = preferenceScreen.findPreference(CLEAR_SHORTCUTS_PREF);
         mWebSourcePreference = (ListPreference) preferenceScreen.findPreference(
                 SuggestionSources.WEB_SEARCH_SOURCE_PREF);
         mSearchEngineSettingsPreference = (PreferenceScreen) preferenceScreen.findPreference(
                 SEARCH_ENGINE_SETTINGS_PREF);
         mSourcePreferences = (PreferenceGroup) getPreferenceScreen().findPreference(
                 SEARCH_SOURCES_PREF);

         mClearShortcutsPreference.setOnPreferenceClickListener(this);

         // Note: If a new preference was added to this UI, please set the onchange listener on the
         // new preference here.
         mWebSourcePreference.setOnPreferenceChangeListener(this);

         updateClearShortcutsPreference();
         populateWebSourcePreference();
         populateSourcePreference();
         updateSearchEnginePreferences(mWebSourcePreference.getValue());
     }

     @Override
     protected void onDestroy() {
         mSources.close();
         mShortcuts.close();
         super.onDestroy();
     }

     /**
      * Fills in the web search source pop-up list.
      */
     private void populateWebSourcePreference() {
         SuggestionSource defWebSearch = mSources.getSelectedWebSearchSource();
         ComponentName defComponentName = null;
         if (defWebSearch != null) {
             defComponentName = defWebSearch.getComponentName();
         }

         // Get the list of all packages handling intent action web search, these are the providers
         // that we display in the selection list.
         List<SearchableInfo> webSearchActivities = mSearchManager.getSearchablesForWebSearch();
         PackageManager pm = getPackageManager();

         ArrayList<String> labels = new ArrayList<String>();
         ArrayList<String> values = new ArrayList<String>();
         final int count = webSearchActivities.size();
         Log.i(TAG, "Number of web search activities = " + count);
         for (int i = 0; i < count; ++i) {
             SearchableInfo searchable = webSearchActivities.get(i);
             if (searchable == null) continue;

             ComponentName component = searchable.getSearchActivity();
             // If both GoogleSearch and EnhancedGoogleSearch are present, the former is hidden from
             // our list because the latter is a superset of the former.
             if (component.flattenToShortString().equals(Searchables.GOOGLE_SEARCH_COMPONENT_NAME)) {
                 try {
                     ComponentName enhancedGoogleSearch = ComponentName.unflattenFromString(
                             Searchables.ENHANCED_GOOGLE_SEARCH_COMPONENT_NAME);
                     pm.getActivityInfo(enhancedGoogleSearch, 0);

                     // Control comes here if EnhancedGoogleSearch is installed, in which case it
                     // overrides the GoogleSearch package in the web source list.
                     continue;
                 } catch (PackageManager.NameNotFoundException e) {
                     // Nothing to do as EnhancedGoogleSearch is not installed. Continue below and
                     // add this source to the list.
                 }
             }

             try {
                 // Add the localised display name and index of the activity within our array as the
                 // label and value for each item. The index will be used to identify which item was
                 // selected by the user.
                 ActivityInfo activityInfo = pm.getActivityInfo(component, 0);
                 Resources res = pm.getResourcesForApplication(activityInfo.applicationInfo);
                 int labelRes = (activityInfo.labelRes != 0)
                         ? activityInfo.labelRes : activityInfo.applicationInfo.labelRes;
                 String name = res.getString(labelRes);
                 String value = component.flattenToShortString();
                 labels.add(name);
                 values.add(value);
                 if (DBG) Log.d(TAG, "Listing web search source: " + name);
                 if (defComponentName != null
                         && defComponentName.getClassName().equals(activityInfo.name)) {
                     if (DBG) Log.d(TAG, "Default web search source: " + name);
                     mWebSourcePreference.setValue(value);
                 }
             } catch (PackageManager.NameNotFoundException exception) {
                 // Skip this entry and continue to list other activities.
                 Log.w(TAG, "Web search source not found: " + component);
             } catch (Resources.NotFoundException exception) {
                 Log.w(TAG, "No name for web search source: " + component);
             }
         }

         // Check if EnhancedGoogleSearch or GoogleSearch are available, and if so insert it at the
         // first position.
         for (int i = 1; i < values.size(); ++i) {
             String value = values.get(i);
             if (value.equals(Searchables.GOOGLE_SEARCH_COMPONENT_NAME) ||
                     value.equals(Searchables.ENHANCED_GOOGLE_SEARCH_COMPONENT_NAME)) {
                 values.add(0, values.remove(i));
                 labels.add(0, labels.remove(i));
                 break;
             }
         }

         try {
             String[] labelsArray = new String[labels.size()];
             String[] valuesArray = new String[values.size()];
             labels.toArray(labelsArray);
             values.toArray(valuesArray);
             mWebSourcePreference.setEntries(labelsArray);
             mWebSourcePreference.setEntryValues(valuesArray);
         } catch (ArrayStoreException exception) {
             // In this case we will end up displaying an empty list.
             Log.e(TAG, "Error loading web search sources", exception);
         }
     }

     /**
      * Enables/disables the "Clear search shortcuts" preference depending
      * on whether there is any search history.
      */
     private void updateClearShortcutsPreference() {
         boolean hasHistory = mShortcuts.hasHistory();
         if (DBG) Log.d(TAG, "hasHistory()=" + hasHistory);
         mClearShortcutsPreference.setEnabled(hasHistory);
     }

     /**
      * Updates the search engine preferences depending on the name of the currently
      * selected search engine and whether it has settings to expose or not.
      *
      * @param webSourcePreferenceValue the web source preference value to use
      */
     private void updateSearchEnginePreferences(String webSourcePreferenceValue) {
         if (webSourcePreferenceValue == null) return;

         // Get the package name of the current activity chosen for web search.
         ComponentName component = ComponentName.unflattenFromString(webSourcePreferenceValue);

         // Now find out if this package contains an activity which satisfies the
         // WEB_SEARCH_SETTINGS intent, and if so, point the "search engine settings"
         // item there.

         ResolveInfo matchedInfo = findWebSearchSettingsActivity(component);

         // If we found a match, that means this web search source provides some settings,
         // so enable the link to its settings. If not, then disable this preference.
         mSearchEngineSettingsPreference.setEnabled(matchedInfo != null);

         PackageManager pm = getPackageManager();
         String engineName = getWebSourceLabel(pm, component);

         // Set the correct summary and intent information for the matched activity, if any.
         int summaryStringRes;
         Intent intent;
         if (matchedInfo != null) {
             summaryStringRes = R.string.search_engine_settings_summary_enabled;
             intent = createWebSearchSettingsIntent(matchedInfo);
         } else {
             summaryStringRes = R.string.search_engine_settings_summary_disabled;
             intent = null;
         }

         // If for some reason the engine name could not be found, just don't set a summary.
         if (engineName != null) {
             mWebSourcePreference.setSummary(
                     getResources().getString(R.string.web_search_source_summary, engineName));
             mSearchEngineSettingsPreference.setSummary(
                     getResources().getString(summaryStringRes, engineName));
         } else {
             mWebSourcePreference.setSummary(null);
             mSearchEngineSettingsPreference.setSummary(null);
         }

         mSearchEngineSettingsPreference.setIntent(intent);
     }

     /**
      * Gets the name of the web source represented in the provided ResolveInfo.
      */
     private String getWebSourceLabel(PackageManager pm, ComponentName component) {
         try {
             ActivityInfo activityInfo = pm.getActivityInfo(component, 0);
             Resources res = pm.getResourcesForApplication(activityInfo.applicationInfo);
             int labelRes = (activityInfo.labelRes != 0) ?
                     activityInfo.labelRes : activityInfo.applicationInfo.labelRes;
             return res.getString(labelRes);
         } catch (PackageManager.NameNotFoundException exception) {
             Log.e(TAG, "Error loading web search source from activity "
                     + component, exception);
             return null;
         }
     }

     /**
      * Returns the activity in the provided package that satisfies the
      * {@link SearchManager#INTENT_ACTION_WEB_SEARCH_SETTINGS} intent, or null
      * if none.
      */
     private ResolveInfo findWebSearchSettingsActivity(ComponentName component) {
         // Get all the activities which satisfy the WEB_SEARCH_SETTINGS intent.
         PackageManager pm = getPackageManager();
         Intent intent = new Intent(SearchManager.INTENT_ACTION_WEB_SEARCH_SETTINGS);
         List<ResolveInfo> activitiesWithWebSearchSettings = pm.queryIntentActivities(intent, 0);

         String packageName = component.getPackageName();
         String name = component.getClassName();

         // Iterate through them and see if any of them are the activity we're looking for.
         for (ResolveInfo resolveInfo : activitiesWithWebSearchSettings) {
             if (packageName.equals(resolveInfo.activityInfo.packageName)
                     && name.equals(resolveInfo.activityInfo.name)) {
                 return resolveInfo;
             }
         }

         // If there is no exact match, look for one in the right package
         for (ResolveInfo resolveInfo : activitiesWithWebSearchSettings) {
             if (packageName.equals(resolveInfo.activityInfo.packageName)) {
                 return resolveInfo;
             }
         }

         return null;
     }

     /**
      * Creates an intent for accessing the web search settings from the provided ResolveInfo
      * representing an activity.
      */
     private Intent createWebSearchSettingsIntent(ResolveInfo info) {
         Intent intent = new Intent(SearchManager.INTENT_ACTION_WEB_SEARCH_SETTINGS);
         intent.setComponent(
                 new ComponentName(info.activityInfo.packageName, info.activityInfo.name));
         return intent;
     }

     /**
      * Fills the suggestion source list.
      */
     private void populateSourcePreference() {
         for (SuggestionSource source : mSources.getSuggestionSources()) {
             Preference pref = createSourcePreference(source);
             if (pref != null) {
                 if (DBG) Log.d(TAG, "Adding search source: " + source);
                 mSourcePreferences.addPreference(pref);
             }
         }
     }

     /**
      * Adds a suggestion source to the list of suggestion source checkbox preferences.
      */
     private Preference createSourcePreference(SuggestionSource source) {
         CheckBoxPreference sourcePref = new CheckBoxPreference(this);
         sourcePref.setKey(mSources.getSourceEnabledPreference(source));
         sourcePref.setDefaultValue(mSources.isSourceDefaultEnabled(source));
         sourcePref.setOnPreferenceChangeListener(this);
         String label = source.getLabel();
         sourcePref.setTitle(label);
         sourcePref.setSummaryOn(source.getSettingsDescription());
         sourcePref.setSummaryOff(source.getSettingsDescription());
         return sourcePref;
     }

     /**
      * Handles clicks on the "Clear search shortcuts" preference.
      */
     public synchronized boolean onPreferenceClick(Preference preference) {
         if (preference == mClearShortcutsPreference) {
             showDialog(CLEAR_SHORTCUTS_CONFIRM_DIALOG);
             return true;
         }
         return false;
     }

     @Override
     protected Dialog onCreateDialog(int id) {
         switch (id) {
             case CLEAR_SHORTCUTS_CONFIRM_DIALOG:
                 return new AlertDialog.Builder(this)
                         .setTitle(R.string.clear_shortcuts)
                         .setMessage(R.string.clear_shortcuts_prompt)
                         .setPositiveButton(R.string.agree, new DialogInterface.OnClickListener() {
                             public void onClick(DialogInterface dialog, int whichButton) {
                                 if (DBG) Log.d(TAG, "Clearing history...");
                                 mShortcuts.clearHistory();
                                 updateClearShortcutsPreference();
                             }
                         })
                         .setNegativeButton(R.string.disagree, null).create();
             default:
                 Log.e(TAG, "unknown dialog" + id);
                 return null;
         }
     }

     /**
      * Inform our listeners (SuggestionSources objects) about the updated settings data.
      */
     private void broadcastSettingsChanged() {
         // We use a message broadcast since the listeners could be in multiple processes.
         Intent intent = new Intent(SearchManager.INTENT_ACTION_SEARCH_SETTINGS_CHANGED);
         Log.i(TAG, "Broadcasting: " + intent);
         sendBroadcast(intent);
     }

     public synchronized boolean onPreferenceChange(Preference preference, Object newValue) {
         if (preference == mWebSourcePreference) {
             String valueStr = (String)newValue;
             ComponentName activity = ComponentName.unflattenFromString(valueStr);
             if (DBG) Log.i(TAG, "Setting default web search source as " + valueStr);

             mSearchManager.setDefaultWebSearch(activity);
             updateSearchEnginePreferences(valueStr);
         }

         broadcastSettingsChanged();

         return true;  // to update the selection in the list if the user brings it up again.
     }
 }
	/*
	* Copyright (C) 2009 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 com.android.globalsearch;

	import android.app.AlertDialog;
	import android.app.Dialog;
	import android.app.SearchManager;
	import android.content.ComponentName;
	import android.content.Context;
	import android.content.DialogInterface;
	import android.content.Intent;
	import android.content.pm.ActivityInfo;
	import android.content.pm.PackageManager;
	import android.content.pm.ResolveInfo;
	import android.content.res.Resources;
	import android.os.Bundle;
	import android.preference.CheckBoxPreference;
	import android.preference.ListPreference;
	import android.preference.Preference;
	import android.preference.PreferenceActivity;
	import android.preference.PreferenceGroup;
	import android.preference.PreferenceScreen;
	import android.preference.Preference.OnPreferenceChangeListener;
	import android.preference.Preference.OnPreferenceClickListener;
	import android.provider.Settings;
	import android.provider.Settings.SettingNotFoundException;
	import android.server.search.SearchableInfo;
	import android.server.search.Searchables;
	import android.util.Log;

	import java.util.ArrayList;
	import java.util.List;

	/**
	* Activity for setting global search preferences. Changes to search preferences trigger a broadcast
	* intent that causes all SuggestionSources objects to be updated.
	*/
	public class SearchSettings extends PreferenceActivity
	implements OnPreferenceClickListener, OnPreferenceChangeListener {

	private static final boolean DBG = false;
	private static final String TAG = "SearchSettings";

	// Only used to find the preferences after inflating
	private static final String CLEAR_SHORTCUTS_PREF = "clear_shortcuts";
	private static final String SEARCH_ENGINE_SETTINGS_PREF = "search_engine_settings";
	private static final String SEARCH_SOURCES_PREF = "search_sources";

	private SearchManager mSearchManager;

	// These instances are not shared with SuggestionProvider
	private SuggestionSources mSources;
	private ShortcutRepository mShortcuts;

	// References to the top-level preference objects
	private Preference mClearShortcutsPreference;
	private ListPreference mWebSourcePreference;
	private PreferenceScreen mSearchEngineSettingsPreference;
	private PreferenceGroup mSourcePreferences;

	// Dialog ids
	private static final int CLEAR_SHORTCUTS_CONFIRM_DIALOG = 0;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);

	mSearchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);

	mSources = new SuggestionSources(this);
	mSources.load();
	mShortcuts = ShortcutRepositoryImplLog.create(this);
	getPreferenceManager().setSharedPreferencesName(SuggestionSources.PREFERENCES_NAME);

	addPreferencesFromResource(R.xml.preferences);

	PreferenceScreen preferenceScreen = getPreferenceScreen();
	mClearShortcutsPreference = preferenceScreen.findPreference(CLEAR_SHORTCUTS_PREF);
	mWebSourcePreference = (ListPreference) preferenceScreen.findPreference(
	SuggestionSources.WEB_SEARCH_SOURCE_PREF);
	mSearchEngineSettingsPreference = (PreferenceScreen) preferenceScreen.findPreference(
	SEARCH_ENGINE_SETTINGS_PREF);
	mSourcePreferences = (PreferenceGroup) getPreferenceScreen().findPreference(
	SEARCH_SOURCES_PREF);

	mClearShortcutsPreference.setOnPreferenceClickListener(this);

	// Note: If a new preference was added to this UI, please set the onchange listener on the
	// new preference here.
	mWebSourcePreference.setOnPreferenceChangeListener(this);

	updateClearShortcutsPreference();
	populateWebSourcePreference();
	populateSourcePreference();
	updateSearchEnginePreferences(mWebSourcePreference.getValue());
	}

	@Override
	protected void onDestroy() {
	mSources.close();
	mShortcuts.close();
	super.onDestroy();
	}

	/**
	* Fills in the web search source pop-up list.
	*/
	private void populateWebSourcePreference() {
	SuggestionSource defWebSearch = mSources.getSelectedWebSearchSource();
	ComponentName defComponentName = null;
	if (defWebSearch != null) {
	defComponentName = defWebSearch.getComponentName();
	}

	// Get the list of all packages handling intent action web search, these are the providers
	// that we display in the selection list.
	List<SearchableInfo> webSearchActivities = mSearchManager.getSearchablesForWebSearch();
	PackageManager pm = getPackageManager();

	ArrayList<String> labels = new ArrayList<String>();
	ArrayList<String> values = new ArrayList<String>();
	final int count = webSearchActivities.size();
	Log.i(TAG, "Number of web search activities = " + count);
	for (int i = 0; i < count; ++i) {
	SearchableInfo searchable = webSearchActivities.get(i);
	if (searchable == null) continue;

	ComponentName component = searchable.getSearchActivity();
	// If both GoogleSearch and EnhancedGoogleSearch are present, the former is hidden from
	// our list because the latter is a superset of the former.
	if (component.flattenToShortString().equals(Searchables.GOOGLE_SEARCH_COMPONENT_NAME)) {
	try {
	ComponentName enhancedGoogleSearch = ComponentName.unflattenFromString(
	Searchables.ENHANCED_GOOGLE_SEARCH_COMPONENT_NAME);
	pm.getActivityInfo(enhancedGoogleSearch, 0);

	// Control comes here if EnhancedGoogleSearch is installed, in which case it
	// overrides the GoogleSearch package in the web source list.
	continue;
	} catch (PackageManager.NameNotFoundException e) {
	// Nothing to do as EnhancedGoogleSearch is not installed. Continue below and
	// add this source to the list.
	}
	}

	try {
	// Add the localised display name and index of the activity within our array as the
	// label and value for each item. The index will be used to identify which item was
	// selected by the user.
	ActivityInfo activityInfo = pm.getActivityInfo(component, 0);
	Resources res = pm.getResourcesForApplication(activityInfo.applicationInfo);
	int labelRes = (activityInfo.labelRes != 0)
	? activityInfo.labelRes : activityInfo.applicationInfo.labelRes;
	String name = res.getString(labelRes);
	String value = component.flattenToShortString();
	labels.add(name);
	values.add(value);
	if (DBG) Log.d(TAG, "Listing web search source: " + name);
	if (defComponentName != null
	&& defComponentName.getClassName().equals(activityInfo.name)) {
	if (DBG) Log.d(TAG, "Default web search source: " + name);
	mWebSourcePreference.setValue(value);
	}
	} catch (PackageManager.NameNotFoundException exception) {
	// Skip this entry and continue to list other activities.
	Log.w(TAG, "Web search source not found: " + component);
	} catch (Resources.NotFoundException exception) {
	Log.w(TAG, "No name for web search source: " + component);
	}
	}

	// Check if EnhancedGoogleSearch or GoogleSearch are available, and if so insert it at the
	// first position.
	for (int i = 1; i < values.size(); ++i) {
	String value = values.get(i);
	if (value.equals(Searchables.GOOGLE_SEARCH_COMPONENT_NAME) \|\|
	value.equals(Searchables.ENHANCED_GOOGLE_SEARCH_COMPONENT_NAME)) {
	values.add(0, values.remove(i));
	labels.add(0, labels.remove(i));
	break;
	}
	}

	try {
	String[] labelsArray = new String[labels.size()];
	String[] valuesArray = new String[values.size()];
	labels.toArray(labelsArray);
	values.toArray(valuesArray);
	mWebSourcePreference.setEntries(labelsArray);
	mWebSourcePreference.setEntryValues(valuesArray);
	} catch (ArrayStoreException exception) {
	// In this case we will end up displaying an empty list.
	Log.e(TAG, "Error loading web search sources", exception);
	}
	}

	/**
	* Enables/disables the "Clear search shortcuts" preference depending
	* on whether there is any search history.
	*/
	private void updateClearShortcutsPreference() {
	boolean hasHistory = mShortcuts.hasHistory();
	if (DBG) Log.d(TAG, "hasHistory()=" + hasHistory);
	mClearShortcutsPreference.setEnabled(hasHistory);
	}

	/**
	* Updates the search engine preferences depending on the name of the currently
	* selected search engine and whether it has settings to expose or not.
	*
	* @param webSourcePreferenceValue the web source preference value to use
	*/
	private void updateSearchEnginePreferences(String webSourcePreferenceValue) {
	if (webSourcePreferenceValue == null) return;

	// Get the package name of the current activity chosen for web search.
	ComponentName component = ComponentName.unflattenFromString(webSourcePreferenceValue);

	// Now find out if this package contains an activity which satisfies the
	// WEB_SEARCH_SETTINGS intent, and if so, point the "search engine settings"
	// item there.

	ResolveInfo matchedInfo = findWebSearchSettingsActivity(component);

	// If we found a match, that means this web search source provides some settings,
	// so enable the link to its settings. If not, then disable this preference.
	mSearchEngineSettingsPreference.setEnabled(matchedInfo != null);

	PackageManager pm = getPackageManager();
	String engineName = getWebSourceLabel(pm, component);

	// Set the correct summary and intent information for the matched activity, if any.
	int summaryStringRes;
	Intent intent;
	if (matchedInfo != null) {
	summaryStringRes = R.string.search_engine_settings_summary_enabled;
	intent = createWebSearchSettingsIntent(matchedInfo);
	} else {
	summaryStringRes = R.string.search_engine_settings_summary_disabled;
	intent = null;
	}

	// If for some reason the engine name could not be found, just don't set a summary.
	if (engineName != null) {
	mWebSourcePreference.setSummary(
	getResources().getString(R.string.web_search_source_summary, engineName));
	mSearchEngineSettingsPreference.setSummary(
	getResources().getString(summaryStringRes, engineName));
	} else {
	mWebSourcePreference.setSummary(null);
	mSearchEngineSettingsPreference.setSummary(null);
	}

	mSearchEngineSettingsPreference.setIntent(intent);
	}

	/**
	* Gets the name of the web source represented in the provided ResolveInfo.
	*/
	private String getWebSourceLabel(PackageManager pm, ComponentName component) {
	try {
	ActivityInfo activityInfo = pm.getActivityInfo(component, 0);
	Resources res = pm.getResourcesForApplication(activityInfo.applicationInfo);
	int labelRes = (activityInfo.labelRes != 0) ?
	activityInfo.labelRes : activityInfo.applicationInfo.labelRes;
	return res.getString(labelRes);
	} catch (PackageManager.NameNotFoundException exception) {
	Log.e(TAG, "Error loading web search source from activity "
	+ component, exception);
	return null;
	}
	}

	/**
	* Returns the activity in the provided package that satisfies the
	* {@link SearchManager#INTENT_ACTION_WEB_SEARCH_SETTINGS} intent, or null
	* if none.
	*/
	private ResolveInfo findWebSearchSettingsActivity(ComponentName component) {
	// Get all the activities which satisfy the WEB_SEARCH_SETTINGS intent.
	PackageManager pm = getPackageManager();
	Intent intent = new Intent(SearchManager.INTENT_ACTION_WEB_SEARCH_SETTINGS);
	List<ResolveInfo> activitiesWithWebSearchSettings = pm.queryIntentActivities(intent, 0);

	String packageName = component.getPackageName();
	String name = component.getClassName();

	// Iterate through them and see if any of them are the activity we're looking for.
	for (ResolveInfo resolveInfo : activitiesWithWebSearchSettings) {
	if (packageName.equals(resolveInfo.activityInfo.packageName)
	&& name.equals(resolveInfo.activityInfo.name)) {
	return resolveInfo;
	}
	}

	// If there is no exact match, look for one in the right package
	for (ResolveInfo resolveInfo : activitiesWithWebSearchSettings) {
	if (packageName.equals(resolveInfo.activityInfo.packageName)) {
	return resolveInfo;
	}
	}

	return null;
	}

	/**
	* Creates an intent for accessing the web search settings from the provided ResolveInfo
	* representing an activity.
	*/
	private Intent createWebSearchSettingsIntent(ResolveInfo info) {
	Intent intent = new Intent(SearchManager.INTENT_ACTION_WEB_SEARCH_SETTINGS);
	intent.setComponent(
	new ComponentName(info.activityInfo.packageName, info.activityInfo.name));
	return intent;
	}

	/**
	* Fills the suggestion source list.
	*/
	private void populateSourcePreference() {
	for (SuggestionSource source : mSources.getSuggestionSources()) {
	Preference pref = createSourcePreference(source);
	if (pref != null) {
	if (DBG) Log.d(TAG, "Adding search source: " + source);
	mSourcePreferences.addPreference(pref);
	}
	}
	}

	/**
	* Adds a suggestion source to the list of suggestion source checkbox preferences.
	*/
	private Preference createSourcePreference(SuggestionSource source) {
	CheckBoxPreference sourcePref = new CheckBoxPreference(this);
	sourcePref.setKey(mSources.getSourceEnabledPreference(source));
	sourcePref.setDefaultValue(mSources.isSourceDefaultEnabled(source));
	sourcePref.setOnPreferenceChangeListener(this);
	String label = source.getLabel();
	sourcePref.setTitle(label);
	sourcePref.setSummaryOn(source.getSettingsDescription());
	sourcePref.setSummaryOff(source.getSettingsDescription());
	return sourcePref;
	}

	/**
	* Handles clicks on the "Clear search shortcuts" preference.
	*/
	public synchronized boolean onPreferenceClick(Preference preference) {
	if (preference == mClearShortcutsPreference) {
	showDialog(CLEAR_SHORTCUTS_CONFIRM_DIALOG);
	return true;
	}
	return false;
	}

	@Override
	protected Dialog onCreateDialog(int id) {
	switch (id) {
	case CLEAR_SHORTCUTS_CONFIRM_DIALOG:
	return new AlertDialog.Builder(this)
	.setTitle(R.string.clear_shortcuts)
	.setMessage(R.string.clear_shortcuts_prompt)
	.setPositiveButton(R.string.agree, new DialogInterface.OnClickListener() {
	public void onClick(DialogInterface dialog, int whichButton) {
	if (DBG) Log.d(TAG, "Clearing history...");
	mShortcuts.clearHistory();
	updateClearShortcutsPreference();
	}
	})
	.setNegativeButton(R.string.disagree, null).create();
	default:
	Log.e(TAG, "unknown dialog" + id);
	return null;
	}
	}

	/**
	* Inform our listeners (SuggestionSources objects) about the updated settings data.
	*/
	private void broadcastSettingsChanged() {
	// We use a message broadcast since the listeners could be in multiple processes.
	Intent intent = new Intent(SearchManager.INTENT_ACTION_SEARCH_SETTINGS_CHANGED);
	Log.i(TAG, "Broadcasting: " + intent);
	sendBroadcast(intent);
	}

	public synchronized boolean onPreferenceChange(Preference preference, Object newValue) {
	if (preference == mWebSourcePreference) {
	String valueStr = (String)newValue;
	ComponentName activity = ComponentName.unflattenFromString(valueStr);
	if (DBG) Log.i(TAG, "Setting default web search source as " + valueStr);

	mSearchManager.setDefaultWebSearch(activity);
	updateSearchEnginePreferences(valueStr);
	}

	broadcastSettingsChanged();

	return true; // to update the selection in the list if the user brings it up again.
	}
	}