blob: cfd6754cc439a17b4354352d029979f18ba04296 [file] [log] [blame]
/*
* Copyright (C) 2010 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.widget;
import static android.widget.SuggestionsAdapter.getColumnString;
import com.android.internal.R;
import android.app.SearchManager;
import android.app.SearchableInfo;
import android.content.Context;
import android.content.Intent;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.TextView.OnEditorActionListener;
import java.util.WeakHashMap;
/**
* Provides the user interface elements for the user to enter a search query and submit a
* request to a search provider. Shows a list of query suggestions or results, if
* available and allows the user to pick a suggestion or result to launch into.
*/
public class SearchView extends LinearLayout {
private static final boolean DBG = false;
private static final String LOG_TAG = "SearchView";
private OnQueryChangeListener mOnQueryChangeListener;
private OnCloseListener mOnCloseListener;
private OnFocusChangeListener mOnQueryTextFocusChangeListener;
private OnSuggestionSelectionListener mOnSuggestionListener;
private boolean mIconifiedByDefault;
private boolean mIconified;
private CursorAdapter mSuggestionsAdapter;
private View mSearchButton;
private View mSubmitButton;
private View mCloseButton;
private View mSearchEditFrame;
private AutoCompleteTextView mQueryTextView;
private boolean mSubmitButtonEnabled;
private CharSequence mQueryHint;
private boolean mQueryRefinement;
private boolean mClearingFocus;
private SearchableInfo mSearchable;
// A weak map of drawables we've gotten from other packages, so we don't load them
// more than once.
private final WeakHashMap<String, Drawable.ConstantState> mOutsideDrawablesCache =
new WeakHashMap<String, Drawable.ConstantState>();
/**
* Callbacks for changes to the query text.
*/
public interface OnQueryChangeListener {
/**
* Called when the user submits the query. This could be due to a key press on the
* keyboard or due to pressing a submit button.
* The listener can override the standard behavior by returning true
* to indicate that it has handled the submit request. Otherwise return false to
* let the SearchView handle the submission by launching any associated intent.
*
* @param query the query text that is to be submitted
*
* @return true if the query has been handled by the listener, false to let the
* SearchView perform the default action.
*/
boolean onSubmitQuery(String query);
/**
* Called when the query text is changed by the user.
*
* @param newText the new content of the query text field.
*
* @return false if the SearchView should perform the default action of showing any
* suggestions if available, true if the action was handled by the listener.
*/
boolean onQueryTextChanged(String newText);
}
public interface OnCloseListener {
/**
* The user is attempting to close the SearchView.
*
* @return true if the listener wants to override the default behavior of clearing the
* text field and dismissing it, false otherwise.
*/
boolean onClose();
}
/**
* Callback interface for selection events on suggestions. These callbacks
* are only relevant when a SearchableInfo has been specified by {@link #setSearchableInfo}.
*/
public interface OnSuggestionSelectionListener {
/**
* Called when a suggestion was selected by navigating to it.
* @param position the absolute position in the list of suggestions.
*
* @return true if the listener handles the event and wants to override the default
* behavior of possibly rewriting the query based on the selected item, false otherwise.
*/
boolean onSuggestionSelected(int position);
/**
* Called when a suggestion was clicked.
* @param position the absolute position of the clicked item in the list of suggestions.
*
* @return true if the listener handles the event and wants to override the default
* behavior of launching any intent or submitting a search query specified on that item.
* Return false otherwise.
*/
boolean onSuggestionClicked(int position);
}
public SearchView(Context context) {
this(context, null);
}
public SearchView(Context context, AttributeSet attrs) {
super(context, attrs);
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.search_view, this, true);
mSearchButton = findViewById(R.id.search_button);
mQueryTextView = (AutoCompleteTextView) findViewById(R.id.search_src_text);
mSearchEditFrame = findViewById(R.id.search_edit_frame);
mSubmitButton = findViewById(R.id.search_go_btn);
mCloseButton = findViewById(R.id.search_close_btn);
mSearchButton.setOnClickListener(mOnClickListener);
mCloseButton.setOnClickListener(mOnClickListener);
mSubmitButton.setOnClickListener(mOnClickListener);
mQueryTextView.addTextChangedListener(mTextWatcher);
mQueryTextView.setOnEditorActionListener(mOnEditorActionListener);
mQueryTextView.setOnItemClickListener(mOnItemClickListener);
mQueryTextView.setOnItemSelectedListener(mOnItemSelectedListener);
// Inform any listener of focus changes
mQueryTextView.setOnFocusChangeListener(new OnFocusChangeListener() {
public void onFocusChange(View v, boolean hasFocus) {
if (mOnQueryTextFocusChangeListener != null) {
mOnQueryTextFocusChangeListener.onFocusChange(SearchView.this, hasFocus);
}
}
});
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SearchView, 0, 0);
setIconifiedByDefault(a.getBoolean(R.styleable.SearchView_iconifiedByDefault, true));
a.recycle();
updateViewsVisibility(mIconifiedByDefault);
}
/**
* Sets the SearchableInfo for this SearchView. Properties in the SearchableInfo are used
* to display labels, hints, suggestions, create intents for launching search results screens
* and controlling other affordances such as a voice button.
*
* @param searchable a SearchableInfo can be retrieved from the SearchManager, for a specific
* activity or a global search provider.
*/
public void setSearchableInfo(SearchableInfo searchable) {
mSearchable = searchable;
if (mSearchable != null) {
updateSearchAutoComplete();
}
updateViewsVisibility(mIconifiedByDefault);
}
/** @hide */
@Override
public boolean requestFocus(int direction, Rect previouslyFocusedRect) {
if (mClearingFocus) return false;
boolean result = mQueryTextView.requestFocus(direction, previouslyFocusedRect);
if (result && !isIconified()) {
setImeVisibility(true);
}
return result;
}
/** @hide */
@Override
public void clearFocus() {
mClearingFocus = true;
super.clearFocus();
mQueryTextView.clearFocus();
setImeVisibility(false);
mClearingFocus = false;
}
/**
* Sets a listener for user actions within the SearchView.
*
* @param listener the listener object that receives callbacks when the user performs
* actions in the SearchView such as clicking on buttons or typing a query.
*/
public void setOnQueryChangeListener(OnQueryChangeListener listener) {
mOnQueryChangeListener = listener;
}
/**
* Sets a listener to inform when the user closes the SearchView.
*
* @param listener the listener to call when the user closes the SearchView.
*/
public void setOnCloseListener(OnCloseListener listener) {
mOnCloseListener = listener;
}
/**
* Sets a listener to inform when the focus of the query text field changes.
*
* @param listener the listener to inform of focus changes.
*/
public void setOnQueryTextFocusChangeListener(OnFocusChangeListener listener) {
mOnQueryTextFocusChangeListener = listener;
}
/**
* Sets a listener to inform when a suggestion is focused or clicked.
*
* @param listener the listener to inform of suggestion selection events.
*/
public void setOnSuggestionSelectionListener(OnSuggestionSelectionListener listener) {
mOnSuggestionListener = listener;
}
/**
* Sets a query string in the text field and optionally submits the query as well.
*
* @param query the query string. This replaces any query text already present in the
* text field.
* @param submit whether to submit the query right now or only update the contents of
* text field.
*/
public void setQuery(CharSequence query, boolean submit) {
mQueryTextView.setText(query);
// If the query is not empty and submit is requested, submit the query
if (submit && !TextUtils.isEmpty(query)) {
onSubmitQuery();
}
}
/**
* Sets the hint text to display in the query text field. This overrides any hint specified
* in the SearchableInfo.
*
* @param hint the hint text to display
*/
public void setQueryHint(CharSequence hint) {
mQueryHint = hint;
updateQueryHint();
}
/**
* Sets the default or resting state of the search field. If true, a single search icon is
* shown by default and expands to show the text field and other buttons when pressed. Also,
* if the default state is iconified, then it collapses to that state when the close button
* is pressed. Changes to this property will take effect immediately.
*
* <p>The default value is false.</p>
*
* @param iconified whether the search field should be iconified by default
*/
public void setIconifiedByDefault(boolean iconified) {
mIconifiedByDefault = iconified;
updateViewsVisibility(iconified);
setImeVisibility(!iconified);
}
/**
* Returns the default iconified state of the search field.
* @return
*/
public boolean isIconfiedByDefault() {
return mIconifiedByDefault;
}
/**
* Iconifies or expands the SearchView. Any query text is cleared when iconified. This is
* a temporary state and does not override the default iconified state set by
* {@link #setIconifiedByDefault(boolean)}. If the default state is iconified, then
* a false here will only be valid until the user closes the field. And if the default
* state is expanded, then a true here will only clear the text field and not close it.
*
* @param iconify a true value will collapse the SearchView to an icon, while a false will
* expand it.
*/
public void setIconified(boolean iconify) {
if (iconify) {
onCloseClicked();
} else {
onSearchClicked();
}
}
/**
* Returns the current iconified state of the SearchView.
*
* @return true if the SearchView is currently iconified, false if the search field is
* fully visible.
*/
public boolean isIconified() {
return mIconified;
}
/**
* Enables showing a submit button when the query is non-empty. In cases where the SearchView
* is being used to filter the contents of the current activity and doesn't launch a separate
* results activity, then the submit button should be disabled.
*
* @param enabled true to show a submit button for submitting queries, false if a submit
* button is not required.
*/
public void setSubmitButtonEnabled(boolean enabled) {
mSubmitButton.setVisibility(enabled ? VISIBLE : GONE);
mSubmitButtonEnabled = enabled;
}
/**
* Returns whether the submit button is enabled when necessary or never displayed.
*
* @return whether the submit button is enabled automatically when necessary
*/
public boolean isSubmitButtonEnabled() {
return mSubmitButtonEnabled;
}
/**
* Specifies if a query refinement button should be displayed alongside each suggestion
* or if it should depend on the flags set in the individual items retrieved from the
* suggestions provider. Clicking on the query refinement button will replace the text
* in the query text field with the text from the suggestion. This flag only takes effect
* if a SearchableInfo has been specified with {@link #setSearchableInfo(SearchableInfo)}
* and not when using a custom adapter.
*
* @param enable true if all items should have a query refinement button, false if only
* those items that have a query refinement flag set should have the button.
*
* @see SearchManager#SUGGEST_COLUMN_FLAGS
* @see SearchManager#FLAG_QUERY_REFINEMENT
*/
public void setQueryRefinementEnabled(boolean enable) {
mQueryRefinement = enable;
if (mSuggestionsAdapter instanceof SuggestionsAdapter) {
((SuggestionsAdapter) mSuggestionsAdapter).setQueryRefinement(
enable ? SuggestionsAdapter.REFINE_ALL : SuggestionsAdapter.REFINE_BY_ENTRY);
}
}
/**
* Returns whether query refinement is enabled for all items or only specific ones.
* @return true if enabled for all items, false otherwise.
*/
public boolean isQueryRefinementEnabled() {
return mQueryRefinement;
}
/**
* You can set a custom adapter if you wish. Otherwise the default adapter is used to
* display the suggestions from the suggestions provider associated with the SearchableInfo.
*
* @see #setSearchableInfo(SearchableInfo)
*/
public void setSuggestionsAdapter(CursorAdapter adapter) {
mSuggestionsAdapter = adapter;
mQueryTextView.setAdapter(mSuggestionsAdapter);
}
/**
* Returns the adapter used for suggestions, if any.
* @return the suggestions adapter
*/
public CursorAdapter getSuggestionsAdapter() {
return mSuggestionsAdapter;
}
private void updateViewsVisibility(final boolean collapsed) {
mIconified = collapsed;
// Visibility of views that are visible when collapsed
final int visCollapsed = collapsed ? VISIBLE : GONE;
// Visibility of views that are visible when expanded
final int visExpanded = collapsed ? GONE : VISIBLE;
// Is there text in the query
final boolean hasText = !TextUtils.isEmpty(mQueryTextView.getText());
mSearchButton.setVisibility(visCollapsed);
mSubmitButton.setVisibility(mSubmitButtonEnabled && hasText ? visExpanded : GONE);
mSearchEditFrame.setVisibility(visExpanded);
}
private void setImeVisibility(boolean visible) {
InputMethodManager imm = (InputMethodManager)
getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
// We made sure the IME was displayed, so also make sure it is closed
// when we go away.
if (imm != null) {
if (visible) {
imm.showSoftInputUnchecked(0, null);
} else {
imm.hideSoftInputFromWindow(getWindowToken(), 0);
}
}
}
/**
* Called by the SuggestionsAdapter
* @hide
*/
/* package */void onQueryRefine(CharSequence queryText) {
setQuery(queryText);
}
private final OnClickListener mOnClickListener = new OnClickListener() {
public void onClick(View v) {
if (v == mSearchButton) {
onSearchClicked();
} else if (v == mCloseButton) {
onCloseClicked();
} else if (v == mSubmitButton) {
onSubmitQuery();
}
}
};
/**
* Handles the key down event for dealing with action keys.
*
* @param keyCode This is the keycode of the typed key, and is the same value as
* found in the KeyEvent parameter.
* @param event The complete event record for the typed key
*
* @return true if the event was handled here, or false if not.
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (mSearchable == null) {
return false;
}
// if it's an action specified by the searchable activity, launch the
// entered query with the action key
SearchableInfo.ActionKeyInfo actionKey = mSearchable.findActionKey(keyCode);
if ((actionKey != null) && (actionKey.getQueryActionMsg() != null)) {
launchQuerySearch(keyCode, actionKey.getQueryActionMsg(), mQueryTextView.getText()
.toString());
return true;
}
return super.onKeyDown(keyCode, event);
}
private void updateQueryHint() {
if (mQueryHint != null) {
mQueryTextView.setHint(mQueryHint);
} else if (mSearchable != null) {
CharSequence hint = null;
int hintId = mSearchable.getHintId();
if (hintId != 0) {
hint = getContext().getString(hintId);
}
if (hint != null) {
mQueryTextView.setHint(hint);
}
}
}
/**
* Updates the auto-complete text view.
*/
private void updateSearchAutoComplete() {
// close any existing suggestions adapter
//closeSuggestionsAdapter();
mQueryTextView.setDropDownAnimationStyle(0); // no animation
// attach the suggestions adapter, if suggestions are available
// The existence of a suggestions authority is the proxy for "suggestions available here"
if (mSearchable.getSuggestAuthority() != null) {
mSuggestionsAdapter = new SuggestionsAdapter(getContext(),
this, mSearchable, mOutsideDrawablesCache);
mQueryTextView.setAdapter(mSuggestionsAdapter);
((SuggestionsAdapter) mSuggestionsAdapter).setQueryRefinement(
mQueryRefinement ? SuggestionsAdapter.REFINE_ALL
: SuggestionsAdapter.REFINE_BY_ENTRY);
}
}
private final OnEditorActionListener mOnEditorActionListener = new OnEditorActionListener() {
/**
* Called when the input method default action key is pressed.
*/
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
onSubmitQuery();
return true;
}
};
private void onTextChanged(CharSequence newText) {
CharSequence text = mQueryTextView.getText();
boolean hasText = !TextUtils.isEmpty(text);
if (isSubmitButtonEnabled()) {
mSubmitButton.setVisibility(hasText ? VISIBLE : GONE);
}
if (mOnQueryChangeListener != null)
mOnQueryChangeListener.onQueryTextChanged(newText.toString());
}
private void onSubmitQuery() {
CharSequence query = mQueryTextView.getText();
if (!TextUtils.isEmpty(query)) {
if (mOnQueryChangeListener == null
|| !mOnQueryChangeListener.onSubmitQuery(query.toString())) {
if (mSearchable != null) {
launchQuerySearch(KeyEvent.KEYCODE_UNKNOWN, null, query.toString());
setImeVisibility(false);
}
}
}
}
private void onCloseClicked() {
if (mOnCloseListener == null || !mOnCloseListener.onClose()) {
CharSequence text = mQueryTextView.getText();
if (TextUtils.isEmpty(text)) {
// query field already empty, hide the keyboard and remove focus
mQueryTextView.clearFocus();
setImeVisibility(false);
} else {
mQueryTextView.setText("");
}
updateViewsVisibility(mIconifiedByDefault);
}
}
private void onSearchClicked() {
mQueryTextView.requestFocus();
updateViewsVisibility(false);
setImeVisibility(true);
}
private final OnItemClickListener mOnItemClickListener = new OnItemClickListener() {
/**
* Implements OnItemClickListener
*/
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (DBG)
Log.d(LOG_TAG, "onItemClick() position " + position);
if (mOnSuggestionListener == null
|| !mOnSuggestionListener.onSuggestionClicked(position)) {
launchSuggestion(position, KeyEvent.KEYCODE_UNKNOWN, null);
}
}
};
private final OnItemSelectedListener mOnItemSelectedListener = new OnItemSelectedListener() {
/**
* Implements OnItemSelectedListener
*/
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if (DBG)
Log.d(LOG_TAG, "onItemSelected() position " + position);
// A suggestion has been selected, rewrite the query if possible,
// otherwise the restore the original query.
if (mOnSuggestionListener == null
|| !mOnSuggestionListener.onSuggestionSelected(position)) {
rewriteQueryFromSuggestion(position);
}
}
/**
* Implements OnItemSelectedListener
*/
public void onNothingSelected(AdapterView<?> parent) {
if (DBG)
Log.d(LOG_TAG, "onNothingSelected()");
}
};
/**
* Query rewriting.
*/
private void rewriteQueryFromSuggestion(int position) {
CharSequence oldQuery = mQueryTextView.getText();
Cursor c = mSuggestionsAdapter.getCursor();
if (c == null) {
return;
}
if (c.moveToPosition(position)) {
// Get the new query from the suggestion.
CharSequence newQuery = mSuggestionsAdapter.convertToString(c);
if (newQuery != null) {
// The suggestion rewrites the query.
// Update the text field, without getting new suggestions.
setQuery(newQuery);
} else {
// The suggestion does not rewrite the query, restore the user's query.
setQuery(oldQuery);
}
} else {
// We got a bad position, restore the user's query.
setQuery(oldQuery);
}
}
/**
* Launches an intent based on a suggestion.
*
* @param position The index of the suggestion to create the intent from.
* @param actionKey The key code of the action key that was pressed,
* or {@link KeyEvent#KEYCODE_UNKNOWN} if none.
* @param actionMsg The message for the action key that was pressed,
* or <code>null</code> if none.
* @return true if a successful launch, false if could not (e.g. bad position).
*/
private boolean launchSuggestion(int position, int actionKey, String actionMsg) {
Cursor c = mSuggestionsAdapter.getCursor();
if ((c != null) && c.moveToPosition(position)) {
Intent intent = createIntentFromSuggestion(c, actionKey, actionMsg);
// launch the intent
launchIntent(intent);
return true;
}
return false;
}
/**
* Launches an intent, including any special intent handling.
*/
private void launchIntent(Intent intent) {
if (intent == null) {
return;
}
try {
// If the intent was created from a suggestion, it will always have an explicit
// component here.
getContext().startActivity(intent);
} catch (RuntimeException ex) {
Log.e(LOG_TAG, "Failed launch activity: " + intent, ex);
}
}
/**
* Sets the text in the query box, without updating the suggestions.
*/
private void setQuery(CharSequence query) {
mQueryTextView.setText(query, true);
// Move the cursor to the end
mQueryTextView.setSelection(TextUtils.isEmpty(query) ? 0 : query.length());
}
private void launchQuerySearch(int actionKey, String actionMsg, String query) {
String action = Intent.ACTION_SEARCH;
Intent intent = createIntent(action, null, null, query, actionKey, actionMsg);
getContext().startActivity(intent);
}
/**
* Constructs an intent from the given information and the search dialog state.
*
* @param action Intent action.
* @param data Intent data, or <code>null</code>.
* @param extraData Data for {@link SearchManager#EXTRA_DATA_KEY} or <code>null</code>.
* @param query Intent query, or <code>null</code>.
* @param actionKey The key code of the action key that was pressed,
* or {@link KeyEvent#KEYCODE_UNKNOWN} if none.
* @param actionMsg The message for the action key that was pressed,
* or <code>null</code> if none.
* @param mode The search mode, one of the acceptable values for
* {@link SearchManager#SEARCH_MODE}, or {@code null}.
* @return The intent.
*/
private Intent createIntent(String action, Uri data, String extraData, String query,
int actionKey, String actionMsg) {
// Now build the Intent
Intent intent = new Intent(action);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// We need CLEAR_TOP to avoid reusing an old task that has other activities
// on top of the one we want. We don't want to do this in in-app search though,
// as it can be destructive to the activity stack.
if (data != null) {
intent.setData(data);
}
intent.putExtra(SearchManager.USER_QUERY, query);
if (query != null) {
intent.putExtra(SearchManager.QUERY, query);
}
if (extraData != null) {
intent.putExtra(SearchManager.EXTRA_DATA_KEY, extraData);
}
if (actionKey != KeyEvent.KEYCODE_UNKNOWN) {
intent.putExtra(SearchManager.ACTION_KEY, actionKey);
intent.putExtra(SearchManager.ACTION_MSG, actionMsg);
}
intent.setComponent(mSearchable.getSearchActivity());
return intent;
}
/**
* When a particular suggestion has been selected, perform the various lookups required
* to use the suggestion. This includes checking the cursor for suggestion-specific data,
* and/or falling back to the XML for defaults; It also creates REST style Uri data when
* the suggestion includes a data id.
*
* @param c The suggestions cursor, moved to the row of the user's selection
* @param actionKey The key code of the action key that was pressed,
* or {@link KeyEvent#KEYCODE_UNKNOWN} if none.
* @param actionMsg The message for the action key that was pressed,
* or <code>null</code> if none.
* @return An intent for the suggestion at the cursor's position.
*/
private Intent createIntentFromSuggestion(Cursor c, int actionKey, String actionMsg) {
try {
// use specific action if supplied, or default action if supplied, or fixed default
String action = getColumnString(c, SearchManager.SUGGEST_COLUMN_INTENT_ACTION);
if (action == null) {
action = mSearchable.getSuggestIntentAction();
}
if (action == null) {
action = Intent.ACTION_SEARCH;
}
// use specific data if supplied, or default data if supplied
String data = getColumnString(c, SearchManager.SUGGEST_COLUMN_INTENT_DATA);
if (data == null) {
data = mSearchable.getSuggestIntentData();
}
// then, if an ID was provided, append it.
if (data != null) {
String id = getColumnString(c, SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID);
if (id != null) {
data = data + "/" + Uri.encode(id);
}
}
Uri dataUri = (data == null) ? null : Uri.parse(data);
String query = getColumnString(c, SearchManager.SUGGEST_COLUMN_QUERY);
String extraData = getColumnString(c, SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA);
return createIntent(action, dataUri, extraData, query, actionKey, actionMsg);
} catch (RuntimeException e ) {
int rowNum;
try { // be really paranoid now
rowNum = c.getPosition();
} catch (RuntimeException e2 ) {
rowNum = -1;
}
Log.w(LOG_TAG, "Search Suggestions cursor at row " + rowNum +
" returned exception" + e.toString());
return null;
}
}
/**
* Callback to watch the text field for empty/non-empty
*/
private TextWatcher mTextWatcher = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int before, int after) { }
public void onTextChanged(CharSequence s, int start,
int before, int after) {
SearchView.this.onTextChanged(s);
}
public void afterTextChanged(Editable s) {
}
};
}