Java tutorial
package io.github.vomitcuddle.SearchViewAllowEmpty; /* * Copyright (C) 2013 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. */ import android.app.SearchManager; import android.app.SearchableInfo; import android.content.ComponentName; import android.content.ContentResolver; import android.content.Context; import android.content.pm.ActivityInfo; import android.content.pm.PackageManager; import android.content.pm.PackageManager.NameNotFoundException; import android.content.res.ColorStateList; import android.content.res.Resources; import android.database.Cursor; import android.graphics.drawable.Drawable; import android.net.Uri; import android.os.Bundle; import android.support.v4.widget.ResourceCursorAdapter; import android.text.Spannable; import android.text.SpannableString; import android.text.TextUtils; import android.text.style.TextAppearanceSpan; import android.util.Log; import android.util.TypedValue; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.TextView; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.util.List; import java.util.WeakHashMap; /** * Provides the contents for the suggestion drop-down list.in {@link SearchView}. * @hide */ class SuggestionsAdapter extends ResourceCursorAdapter implements OnClickListener { private static final boolean DBG = false; private static final String LOG_TAG = "SuggestionsAdapter"; private static final int QUERY_LIMIT = 50; static final int REFINE_NONE = 0; static final int REFINE_BY_ENTRY = 1; static final int REFINE_ALL = 2; private SearchManager mSearchManager; private SearchView mSearchView; private SearchableInfo mSearchable; private Context mProviderContext; private WeakHashMap<String, Drawable.ConstantState> mOutsideDrawablesCache; private boolean mClosed = false; private int mQueryRefinement = REFINE_BY_ENTRY; // URL color private ColorStateList mUrlColor; static final int INVALID_INDEX = -1; // Cached column indexes, updated when the cursor changes. private int mText1Col = INVALID_INDEX; private int mText2Col = INVALID_INDEX; private int mText2UrlCol = INVALID_INDEX; private int mIconName1Col = INVALID_INDEX; private int mIconName2Col = INVALID_INDEX; private int mFlagsCol = INVALID_INDEX; // private final Runnable mStartSpinnerRunnable; // private final Runnable mStopSpinnerRunnable; public SuggestionsAdapter(Context context, SearchView searchView, SearchableInfo searchable, WeakHashMap<String, Drawable.ConstantState> outsideDrawablesCache) { super(context, R.layout.abc_search_dropdown_item_icons_2line, null, // no initial cursor true); // auto-requery mSearchManager = (SearchManager) mContext.getSystemService(Context.SEARCH_SERVICE); mSearchView = searchView; mSearchable = searchable; // set up provider resources (gives us icons, etc.) mProviderContext = context; mOutsideDrawablesCache = outsideDrawablesCache; } /** * Enables query refinement for all suggestions. This means that an additional icon * will be shown for each entry. When clicked, the suggested text on that line will be * copied to the query text field. * <p> * * @param refineWhat which queries to refine. Possible values are {@link #REFINE_NONE}, * {@link #REFINE_BY_ENTRY}, and {@link #REFINE_ALL}. */ public void setQueryRefinement(int refineWhat) { mQueryRefinement = refineWhat; } /** * Returns the current query refinement preference. * @return value of query refinement preference */ public int getQueryRefinement() { return mQueryRefinement; } /** * Overridden to always return <code>false</code>, since we cannot be sure that * suggestion sources return stable IDs. */ @Override public boolean hasStableIds() { return false; } /** * Use the search suggestions provider to obtain a live cursor. This will be called * in a worker thread, so it's OK if the query is slow (e.g. round trip for suggestions). * The results will be processed in the UI thread and changeCursor() will be called. */ @Override public Cursor runQueryOnBackgroundThread(CharSequence constraint) { if (DBG) Log.d(LOG_TAG, "runQueryOnBackgroundThread(" + constraint + ")"); String query = (constraint == null) ? "" : constraint.toString(); /** * for in app search we show the progress spinner until the cursor is returned with * the results. */ Cursor cursor = null; if (mSearchView.getVisibility() != View.VISIBLE || mSearchView.getWindowVisibility() != View.VISIBLE) { return null; } try { cursor = getSearchManagerSuggestions(mSearchable, query, QUERY_LIMIT); // trigger fill window so the spinner stays up until the results are copied over and // closer to being ready if (cursor != null) { cursor.getCount(); return cursor; } } catch (RuntimeException e) { Log.w(LOG_TAG, "Search suggestions query threw an exception.", e); } // If cursor is null or an exception was thrown, stop the spinner and return null. // changeCursor doesn't get called if cursor is null return null; } public void close() { if (DBG) Log.d(LOG_TAG, "close()"); changeCursor(null); mClosed = true; } @Override public void notifyDataSetChanged() { if (DBG) Log.d(LOG_TAG, "notifyDataSetChanged"); super.notifyDataSetChanged(); updateSpinnerState(getCursor()); } @Override public void notifyDataSetInvalidated() { if (DBG) Log.d(LOG_TAG, "notifyDataSetInvalidated"); super.notifyDataSetInvalidated(); updateSpinnerState(getCursor()); } private void updateSpinnerState(Cursor cursor) { Bundle extras = cursor != null ? cursor.getExtras() : null; if (DBG) { Log.d(LOG_TAG, "updateSpinnerState - extra = " + (extras != null ? extras.getBoolean(SearchManager.CURSOR_EXTRA_KEY_IN_PROGRESS) : null)); } // Check if the Cursor indicates that the query is not complete and show the spinner if (extras != null && extras.getBoolean(SearchManager.CURSOR_EXTRA_KEY_IN_PROGRESS)) { return; } // If cursor is null or is done, stop the spinner } /** * Cache columns. */ @Override public void changeCursor(Cursor c) { if (DBG) Log.d(LOG_TAG, "changeCursor(" + c + ")"); if (mClosed) { Log.w(LOG_TAG, "Tried to change cursor after adapter was closed."); if (c != null) c.close(); return; } try { super.changeCursor(c); if (c != null) { mText1Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_1); mText2Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_2); mText2UrlCol = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_TEXT_2_URL); mIconName1Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_ICON_1); mIconName2Col = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_ICON_2); mFlagsCol = c.getColumnIndex(SearchManager.SUGGEST_COLUMN_FLAGS); } } catch (Exception e) { Log.e(LOG_TAG, "error changing cursor and caching columns", e); } } /** * Tags the view with cached child view look-ups. */ @Override public View newView(Context context, Cursor cursor, ViewGroup parent) { View v = super.newView(context, cursor, parent); v.setTag(new ChildViewCache(v)); return v; } /** * Cache of the child views of drop-drown list items, to avoid looking up the children * each time the contents of a list item are changed. */ private final static class ChildViewCache { public final TextView mText1; public final TextView mText2; public final ImageView mIcon1; public final ImageView mIcon2; public final ImageView mIconRefine; public ChildViewCache(View v) { mText1 = (TextView) v.findViewById(android.R.id.text1); mText2 = (TextView) v.findViewById(android.R.id.text2); mIcon1 = (ImageView) v.findViewById(android.R.id.icon1); mIcon2 = (ImageView) v.findViewById(android.R.id.icon2); mIconRefine = (ImageView) v.findViewById(R.id.edit_query); } } @Override public void bindView(View view, Context context, Cursor cursor) { ChildViewCache views = (ChildViewCache) view.getTag(); int flags = 0; if (mFlagsCol != INVALID_INDEX) { flags = cursor.getInt(mFlagsCol); } if (views.mText1 != null) { String text1 = getStringOrNull(cursor, mText1Col); setViewText(views.mText1, text1); } if (views.mText2 != null) { // First check TEXT_2_URL CharSequence text2 = getStringOrNull(cursor, mText2UrlCol); if (text2 != null) { text2 = formatUrl(text2); } else { text2 = getStringOrNull(cursor, mText2Col); } // If no second line of text is indicated, allow the first line of text // to be up to two lines if it wants to be. if (TextUtils.isEmpty(text2)) { if (views.mText1 != null) { views.mText1.setSingleLine(false); views.mText1.setMaxLines(2); } } else { if (views.mText1 != null) { views.mText1.setSingleLine(true); views.mText1.setMaxLines(1); } } setViewText(views.mText2, text2); } if (views.mIcon1 != null) { setViewDrawable(views.mIcon1, getIcon1(cursor), View.INVISIBLE); } if (views.mIcon2 != null) { setViewDrawable(views.mIcon2, getIcon2(cursor), View.GONE); } if (mQueryRefinement == REFINE_ALL || (mQueryRefinement == REFINE_BY_ENTRY && (flags & SearchManager.FLAG_QUERY_REFINEMENT) != 0)) { views.mIconRefine.setVisibility(View.VISIBLE); views.mIconRefine.setTag(views.mText1.getText()); views.mIconRefine.setOnClickListener(this); } else { views.mIconRefine.setVisibility(View.GONE); } } public void onClick(View v) { Object tag = v.getTag(); if (tag instanceof CharSequence) { mSearchView.onQueryRefine((CharSequence) tag); } } private CharSequence formatUrl(CharSequence url) { if (mUrlColor == null) { // Lazily get the URL color from the current theme. TypedValue colorValue = new TypedValue(); mContext.getTheme().resolveAttribute(R.attr.textColorSearchUrl, colorValue, true); mUrlColor = mContext.getResources().getColorStateList(colorValue.resourceId); } SpannableString text = new SpannableString(url); text.setSpan(new TextAppearanceSpan(null, 0, 0, mUrlColor, null), 0, url.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); return text; } private void setViewText(TextView v, CharSequence text) { // Set the text even if it's null, since we need to clear any previous text. v.setText(text); if (TextUtils.isEmpty(text)) { v.setVisibility(View.GONE); } else { v.setVisibility(View.VISIBLE); } } private Drawable getIcon1(Cursor cursor) { if (mIconName1Col == INVALID_INDEX) { return null; } String value = cursor.getString(mIconName1Col); Drawable drawable = getDrawableFromResourceValue(value); if (drawable != null) { return drawable; } return getDefaultIcon1(cursor); } private Drawable getIcon2(Cursor cursor) { if (mIconName2Col == INVALID_INDEX) { return null; } String value = cursor.getString(mIconName2Col); return getDrawableFromResourceValue(value); } /** * Sets the drawable in an image view, makes sure the view is only visible if there * is a drawable. */ private void setViewDrawable(ImageView v, Drawable drawable, int nullVisibility) { // Set the icon even if the drawable is null, since we need to clear any // previous icon. v.setImageDrawable(drawable); if (drawable == null) { v.setVisibility(nullVisibility); } else { v.setVisibility(View.VISIBLE); // This is a hack to get any animated drawables (like a 'working' spinner) // to animate. You have to setVisible true on an AnimationDrawable to get // it to start animating, but it must first have been false or else the // call to setVisible will be ineffective. We need to clear up the story // about animated drawables in the future, see http://b/1878430. drawable.setVisible(false, false); drawable.setVisible(true, false); } } /** * Gets the text to show in the query field when a suggestion is selected. * * @param cursor The Cursor to read the suggestion data from. The Cursor should already * be moved to the suggestion that is to be read from. * @return The text to show, or <code>null</code> if the query should not be * changed when selecting this suggestion. */ @Override public CharSequence convertToString(Cursor cursor) { if (cursor == null) { return null; } String query = getColumnString(cursor, SearchManager.SUGGEST_COLUMN_QUERY); if (query != null) { return query; } if (mSearchable.shouldRewriteQueryFromData()) { String data = getColumnString(cursor, SearchManager.SUGGEST_COLUMN_INTENT_DATA); if (data != null) { return data; } } if (mSearchable.shouldRewriteQueryFromText()) { String text1 = getColumnString(cursor, SearchManager.SUGGEST_COLUMN_TEXT_1); if (text1 != null) { return text1; } } return null; } /** * This method is overridden purely to provide a bit of protection against * flaky content providers. * * @see android.widget.ListAdapter#getView(int, View, ViewGroup) */ @Override public View getView(int position, View convertView, ViewGroup parent) { try { return super.getView(position, convertView, parent); } catch (RuntimeException e) { Log.w(LOG_TAG, "Search suggestions cursor threw exception.", e); // Put exception string in item title View v = newView(mContext, mCursor, parent); if (v != null) { ChildViewCache views = (ChildViewCache) v.getTag(); TextView tv = views.mText1; tv.setText(e.toString()); } return v; } } /** * Gets a drawable given a value provided by a suggestion provider. * * This value could be just the string value of a resource id * (e.g., "2130837524"), in which case we will try to retrieve a drawable from * the provider's resources. If the value is not an integer, it is * treated as a Uri and opened with * {@link ContentResolver#openOutputStream(android.net.Uri, String)}. * * All resources and URIs are read using the suggestion provider's context. * * If the string is not formatted as expected, or no drawable can be found for * the provided value, this method returns null. * * @param drawableId a string like "2130837524", * "android.resource://com.android.alarmclock/2130837524", * or "content://contacts/photos/253". * @return a Drawable, or null if none found */ private Drawable getDrawableFromResourceValue(String drawableId) { if (drawableId == null || drawableId.length() == 0 || "0".equals(drawableId)) { return null; } try { // First, see if it's just an integer int resourceId = Integer.parseInt(drawableId); // It's an int, look for it in the cache String drawableUri = ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + mProviderContext.getPackageName() + "/" + resourceId; // Must use URI as cache key, since ints are app-specific Drawable drawable = checkIconCache(drawableUri); if (drawable != null) { return drawable; } // Not cached, find it by resource ID drawable = mProviderContext.getResources().getDrawable(resourceId); // Stick it in the cache, using the URI as key storeInIconCache(drawableUri, drawable); return drawable; } catch (NumberFormatException nfe) { // It's not an integer, use it as a URI Drawable drawable = checkIconCache(drawableId); if (drawable != null) { return drawable; } Uri uri = Uri.parse(drawableId); drawable = getDrawable(uri); storeInIconCache(drawableId, drawable); return drawable; } catch (Resources.NotFoundException nfe) { // It was an integer, but it couldn't be found, bail out Log.w(LOG_TAG, "Icon resource not found: " + drawableId); return null; } } /** * Gets a drawable by URI, without using the cache. * * @return A drawable, or {@code null} if the drawable could not be loaded. */ private Drawable getDrawable(Uri uri) { try { String scheme = uri.getScheme(); if (ContentResolver.SCHEME_ANDROID_RESOURCE.equals(scheme)) { // Load drawables through Resources, to get the source density information try { return getDrawableFromResourceUri(uri); } catch (Resources.NotFoundException ex) { throw new FileNotFoundException("Resource does not exist: " + uri); } } else { // Let the ContentResolver handle content and file URIs. InputStream stream = mProviderContext.getContentResolver().openInputStream(uri); if (stream == null) { throw new FileNotFoundException("Failed to open " + uri); } try { return Drawable.createFromStream(stream, null); } finally { try { stream.close(); } catch (IOException ex) { Log.e(LOG_TAG, "Error closing icon stream for " + uri, ex); } } } } catch (FileNotFoundException fnfe) { Log.w(LOG_TAG, "Icon not found: " + uri + ", " + fnfe.getMessage()); return null; } } private Drawable checkIconCache(String resourceUri) { Drawable.ConstantState cached = mOutsideDrawablesCache.get(resourceUri); if (cached == null) { return null; } if (DBG) Log.d(LOG_TAG, "Found icon in cache: " + resourceUri); return cached.newDrawable(); } private void storeInIconCache(String resourceUri, Drawable drawable) { if (drawable != null) { mOutsideDrawablesCache.put(resourceUri, drawable.getConstantState()); } } /** * Gets the left-hand side icon that will be used for the current suggestion * if the suggestion contains an icon column but no icon or a broken icon. * * @param cursor A cursor positioned at the current suggestion. * @return A non-null drawable. */ private Drawable getDefaultIcon1(Cursor cursor) { // Check the component that gave us the suggestion Drawable drawable = getActivityIconWithCache(mSearchable.getSearchActivity()); if (drawable != null) { return drawable; } // Fall back to a default icon return mContext.getPackageManager().getDefaultActivityIcon(); } /** * Gets the activity or application icon for an activity. * Uses the local icon cache for fast repeated lookups. * * @param component Name of an activity. * @return A drawable, or {@code null} if neither the activity nor the application * has an icon set. */ private Drawable getActivityIconWithCache(ComponentName component) { // First check the icon cache String componentIconKey = component.flattenToShortString(); // Using containsKey() since we also store null values. if (mOutsideDrawablesCache.containsKey(componentIconKey)) { Drawable.ConstantState cached = mOutsideDrawablesCache.get(componentIconKey); return cached == null ? null : cached.newDrawable(mProviderContext.getResources()); } // Then try the activity or application icon Drawable drawable = getActivityIcon(component); // Stick it in the cache so we don't do this lookup again. Drawable.ConstantState toCache = drawable == null ? null : drawable.getConstantState(); mOutsideDrawablesCache.put(componentIconKey, toCache); return drawable; } /** * Gets the activity or application icon for an activity. * * @param component Name of an activity. * @return A drawable, or {@code null} if neither the acitivy or the application * have an icon set. */ private Drawable getActivityIcon(ComponentName component) { PackageManager pm = mContext.getPackageManager(); final ActivityInfo activityInfo; try { activityInfo = pm.getActivityInfo(component, PackageManager.GET_META_DATA); } catch (NameNotFoundException ex) { Log.w(LOG_TAG, ex.toString()); return null; } int iconId = activityInfo.getIconResource(); if (iconId == 0) return null; String pkg = component.getPackageName(); Drawable drawable = pm.getDrawable(pkg, iconId, activityInfo.applicationInfo); if (drawable == null) { Log.w(LOG_TAG, "Invalid icon resource " + iconId + " for " + component.flattenToShortString()); return null; } return drawable; } /** * Gets the value of a string column by name. * * @param cursor Cursor to read the value from. * @param columnName The name of the column to read. * @return The value of the given column, or <code>null</null> * if the cursor does not contain the given column. */ public static String getColumnString(Cursor cursor, String columnName) { int col = cursor.getColumnIndex(columnName); return getStringOrNull(cursor, col); } private static String getStringOrNull(Cursor cursor, int col) { if (col == INVALID_INDEX) { return null; } try { return cursor.getString(col); } catch (Exception e) { Log.e(LOG_TAG, "unexpected error retrieving valid column from cursor, " + "did the remote process die?", e); return null; } } /** * Import of hidden method: ContentResolver.getResourceId(Uri). * Modified to return a drawable, rather than a hidden type. */ Drawable getDrawableFromResourceUri(Uri uri) throws FileNotFoundException { String authority = uri.getAuthority(); Resources r; if (TextUtils.isEmpty(authority)) { throw new FileNotFoundException("No authority: " + uri); } else { try { r = mContext.getPackageManager().getResourcesForApplication(authority); } catch (NameNotFoundException ex) { throw new FileNotFoundException("No package found for authority: " + uri); } } List<String> path = uri.getPathSegments(); if (path == null) { throw new FileNotFoundException("No path: " + uri); } int len = path.size(); int id; if (len == 1) { try { id = Integer.parseInt(path.get(0)); } catch (NumberFormatException e) { throw new FileNotFoundException("Single path segment is not a resource ID: " + uri); } } else if (len == 2) { id = r.getIdentifier(path.get(1), path.get(0), authority); } else { throw new FileNotFoundException("More than two path segments: " + uri); } if (id == 0) { throw new FileNotFoundException("No resource found for: " + uri); } return r.getDrawable(id); } /** * Import of hidden method: SearchManager.getSuggestions(SearchableInfo, String, int). */ Cursor getSearchManagerSuggestions(SearchableInfo searchable, String query, int limit) { if (searchable == null) { return null; } String authority = searchable.getSuggestAuthority(); if (authority == null) { return null; } Uri.Builder uriBuilder = new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority) .query("") // TODO: Remove, workaround for a bug in Uri.writeToParcel() .fragment(""); // TODO: Remove, workaround for a bug in Uri.writeToParcel() // if content path provided, insert it now final String contentPath = searchable.getSuggestPath(); if (contentPath != null) { uriBuilder.appendEncodedPath(contentPath); } // append standard suggestion query path uriBuilder.appendPath(SearchManager.SUGGEST_URI_PATH_QUERY); // get the query selection, may be null String selection = searchable.getSuggestSelection(); // inject query, either as selection args or inline String[] selArgs = null; if (selection != null) { // use selection if provided selArgs = new String[] { query }; } else { // no selection, use REST pattern uriBuilder.appendPath(query); } if (limit > 0) { uriBuilder.appendQueryParameter("limit", String.valueOf(limit)); } Uri uri = uriBuilder.build(); // finally, make the query return mContext.getContentResolver().query(uri, null, selection, selArgs, null); } }