X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?p=android_pandora.git;a=blobdiff_plain;f=apps%2FAndroidSupportV2%2Fsrc%2Fandroid%2Fsupport%2Fv2%2Fwidget%2FCursorAdapter.java;fp=apps%2FAndroidSupportV2%2Fsrc%2Fandroid%2Fsupport%2Fv2%2Fwidget%2FCursorAdapter.java;h=dd4bcfe09cd0679e99864b929f9b6b0dc401b5c1;hp=0000000000000000000000000000000000000000;hb=811a5a4a3091f65fef340acafe62d6355b13c44f;hpb=4401ca4aa1b3938939c6c371dfda57aa0652696f diff --git a/apps/AndroidSupportV2/src/android/support/v2/widget/CursorAdapter.java b/apps/AndroidSupportV2/src/android/support/v2/widget/CursorAdapter.java new file mode 100644 index 0000000..dd4bcfe --- /dev/null +++ b/apps/AndroidSupportV2/src/android/support/v2/widget/CursorAdapter.java @@ -0,0 +1,484 @@ +/* + * Copyright (C) 2011 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.support.v2.widget; + +import android.content.Context; +import android.database.ContentObserver; +import android.database.Cursor; +import android.database.DataSetObserver; +import android.os.Handler; +import android.util.Config; +import android.util.Log; +import android.view.View; +import android.view.ViewGroup; +import android.widget.BaseAdapter; +import android.widget.Filter; +import android.widget.FilterQueryProvider; +import android.widget.Filterable; + +/** + * Static library support version of the framework's {@link android.widget.CursorAdapter}. + * Used to write apps that run on platforms prior to Android 3.0. When running + * on Android 3.0 or above, this implementation is still used; it does not try + * to switch to the framework's implementation. See the framework SDK + * documentation for a class overview. + */ +public abstract class CursorAdapter extends BaseAdapter implements Filterable, + CursorFilter.CursorFilterClient { + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected boolean mDataValid; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected boolean mAutoRequery; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected Cursor mCursor; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected Context mContext; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected int mRowIDColumn; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected ChangeObserver mChangeObserver; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected DataSetObserver mDataSetObserver; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected CursorFilter mCursorFilter; + /** + * This field should be made private, so it is hidden from the SDK. + * {@hide} + */ + protected FilterQueryProvider mFilterQueryProvider; + + /** + * If set the adapter will call requery() on the cursor whenever a content change + * notification is delivered. Implies {@link #FLAG_REGISTER_CONTENT_OBSERVER}. + * + * @deprecated This option is discouraged, as it results in Cursor queries + * being performed on the application's UI thread and thus can cause poor + * responsiveness or even Application Not Responding errors. As an alternative, + * use {@link android.app.LoaderManager} with a {@link android.content.CursorLoader}. + */ + @Deprecated + public static final int FLAG_AUTO_REQUERY = 0x01; + + /** + * If set the adapter will register a content observer on the cursor and will call + * {@link #onContentChanged()} when a notification comes in. Be careful when + * using this flag: you will need to unset the current Cursor from the adapter + * to avoid leaks due to its registered observers. This flag is not needed + * when using a CursorAdapter with a + * {@link android.content.CursorLoader}. + */ + public static final int FLAG_REGISTER_CONTENT_OBSERVER = 0x02; + + /** + * Constructor that always enables auto-requery. + * + * @deprecated This option is discouraged, as it results in Cursor queries + * being performed on the application's UI thread and thus can cause poor + * responsiveness or even Application Not Responding errors. As an alternative, + * use {@link android.app.LoaderManager} with a {@link android.content.CursorLoader}. + * + * @param c The cursor from which to get the data. + * @param context The context + */ + @Deprecated + public CursorAdapter(Context context, Cursor c) { + init(context, c, FLAG_AUTO_REQUERY); + } + + /** + * Constructor that allows control over auto-requery. It is recommended + * you not use this, but instead {@link #CursorAdapter(Context, Cursor, int)}. + * When using this constructor, {@link #FLAG_REGISTER_CONTENT_OBSERVER} + * will always be set. + * + * @param c The cursor from which to get the data. + * @param context The context + * @param autoRequery If true the adapter will call requery() on the + * cursor whenever it changes so the most recent + * data is always displayed. Using true here is discouraged. + */ + public CursorAdapter(Context context, Cursor c, boolean autoRequery) { + init(context, c, autoRequery ? FLAG_AUTO_REQUERY : FLAG_REGISTER_CONTENT_OBSERVER); + } + + /** + * Recommended constructor. + * + * @param c The cursor from which to get the data. + * @param context The context + * @param flags Flags used to determine the behavior of the adapter; may + * be any combination of {@link #FLAG_AUTO_REQUERY} and + * {@link #FLAG_REGISTER_CONTENT_OBSERVER}. + */ + public CursorAdapter(Context context, Cursor c, int flags) { + init(context, c, flags); + } + + /** + * @deprecated Don't use this, use the normal constructor. This will + * be removed in the future. + */ + @Deprecated + protected void init(Context context, Cursor c, boolean autoRequery) { + init(context, c, autoRequery ? FLAG_AUTO_REQUERY : FLAG_REGISTER_CONTENT_OBSERVER); + } + + void init(Context context, Cursor c, int flags) { + if ((flags & FLAG_AUTO_REQUERY) == FLAG_AUTO_REQUERY) { + flags |= FLAG_REGISTER_CONTENT_OBSERVER; + mAutoRequery = true; + } else { + mAutoRequery = false; + } + boolean cursorPresent = c != null; + mCursor = c; + mDataValid = cursorPresent; + mContext = context; + mRowIDColumn = cursorPresent ? c.getColumnIndexOrThrow("_id") : -1; + if ((flags & FLAG_REGISTER_CONTENT_OBSERVER) == FLAG_REGISTER_CONTENT_OBSERVER) { + mChangeObserver = new ChangeObserver(); + mDataSetObserver = new MyDataSetObserver(); + } else { + mChangeObserver = null; + mDataSetObserver = null; + } + + if (cursorPresent) { + if (mChangeObserver != null) c.registerContentObserver(mChangeObserver); + if (mDataSetObserver != null) c.registerDataSetObserver(mDataSetObserver); + } + } + + /** + * Returns the cursor. + * @return the cursor. + */ + public Cursor getCursor() { + return mCursor; + } + + /** + * @see android.widget.ListAdapter#getCount() + */ + public int getCount() { + if (mDataValid && mCursor != null) { + return mCursor.getCount(); + } else { + return 0; + } + } + + /** + * @see android.widget.ListAdapter#getItem(int) + */ + public Object getItem(int position) { + if (mDataValid && mCursor != null) { + mCursor.moveToPosition(position); + return mCursor; + } else { + return null; + } + } + + /** + * @see android.widget.ListAdapter#getItemId(int) + */ + public long getItemId(int position) { + if (mDataValid && mCursor != null) { + if (mCursor.moveToPosition(position)) { + return mCursor.getLong(mRowIDColumn); + } else { + return 0; + } + } else { + return 0; + } + } + + @Override + public boolean hasStableIds() { + return true; + } + + /** + * @see android.widget.ListAdapter#getView(int, View, ViewGroup) + */ + public View getView(int position, View convertView, ViewGroup parent) { + if (!mDataValid) { + throw new IllegalStateException("this should only be called when the cursor is valid"); + } + if (!mCursor.moveToPosition(position)) { + throw new IllegalStateException("couldn't move cursor to position " + position); + } + View v; + if (convertView == null) { + v = newView(mContext, mCursor, parent); + } else { + v = convertView; + } + bindView(v, mContext, mCursor); + return v; + } + + @Override + public View getDropDownView(int position, View convertView, ViewGroup parent) { + if (mDataValid) { + mCursor.moveToPosition(position); + View v; + if (convertView == null) { + v = newDropDownView(mContext, mCursor, parent); + } else { + v = convertView; + } + bindView(v, mContext, mCursor); + return v; + } else { + return null; + } + } + + /** + * Makes a new view to hold the data pointed to by cursor. + * @param context Interface to application's global information + * @param cursor The cursor from which to get the data. The cursor is already + * moved to the correct position. + * @param parent The parent to which the new view is attached to + * @return the newly created view. + */ + public abstract View newView(Context context, Cursor cursor, ViewGroup parent); + + /** + * Makes a new drop down view to hold the data pointed to by cursor. + * @param context Interface to application's global information + * @param cursor The cursor from which to get the data. The cursor is already + * moved to the correct position. + * @param parent The parent to which the new view is attached to + * @return the newly created view. + */ + public View newDropDownView(Context context, Cursor cursor, ViewGroup parent) { + return newView(context, cursor, parent); + } + + /** + * Bind an existing view to the data pointed to by cursor + * @param view Existing view, returned earlier by newView + * @param context Interface to application's global information + * @param cursor The cursor from which to get the data. The cursor is already + * moved to the correct position. + */ + public abstract void bindView(View view, Context context, Cursor cursor); + + /** + * Change the underlying cursor to a new cursor. If there is an existing cursor it will be + * closed. + * + * @param cursor The new cursor to be used + */ + public void changeCursor(Cursor cursor) { + Cursor old = swapCursor(cursor); + if (old != null) { + old.close(); + } + } + + /** + * Swap in a new Cursor, returning the old Cursor. Unlike + * {@link #changeCursor(Cursor)}, the returned old Cursor is not + * closed. + * + * @param newCursor The new cursor to be used. + * @return Returns the previously set Cursor, or null if there wasa not one. + * If the given new Cursor is the same instance is the previously set + * Cursor, null is also returned. + */ + public Cursor swapCursor(Cursor newCursor) { + if (newCursor == mCursor) { + return null; + } + Cursor oldCursor = mCursor; + if (oldCursor != null) { + if (mChangeObserver != null) oldCursor.unregisterContentObserver(mChangeObserver); + if (mDataSetObserver != null) oldCursor.unregisterDataSetObserver(mDataSetObserver); + } + mCursor = newCursor; + if (newCursor != null) { + if (mChangeObserver != null) newCursor.registerContentObserver(mChangeObserver); + if (mDataSetObserver != null) newCursor.registerDataSetObserver(mDataSetObserver); + mRowIDColumn = newCursor.getColumnIndexOrThrow("_id"); + mDataValid = true; + // notify the observers about the new cursor + notifyDataSetChanged(); + } else { + mRowIDColumn = -1; + mDataValid = false; + // notify the observers about the lack of a data set + notifyDataSetInvalidated(); + } + return oldCursor; + } + + /** + *

Converts the cursor into a CharSequence. Subclasses should override this + * method to convert their results. The default implementation returns an + * empty String for null values or the default String representation of + * the value.

+ * + * @param cursor the cursor to convert to a CharSequence + * @return a CharSequence representing the value + */ + public CharSequence convertToString(Cursor cursor) { + return cursor == null ? "" : cursor.toString(); + } + + /** + * Runs a query with the specified constraint. This query is requested + * by the filter attached to this adapter. + * + * The query is provided by a + * {@link android.widget.FilterQueryProvider}. + * If no provider is specified, the current cursor is not filtered and returned. + * + * After this method returns the resulting cursor is passed to {@link #changeCursor(Cursor)} + * and the previous cursor is closed. + * + * This method is always executed on a background thread, not on the + * application's main thread (or UI thread.) + * + * Contract: when constraint is null or empty, the original results, + * prior to any filtering, must be returned. + * + * @param constraint the constraint with which the query must be filtered + * + * @return a Cursor representing the results of the new query + * + * @see #getFilter() + * @see #getFilterQueryProvider() + * @see #setFilterQueryProvider(android.widget.FilterQueryProvider) + */ + public Cursor runQueryOnBackgroundThread(CharSequence constraint) { + if (mFilterQueryProvider != null) { + return mFilterQueryProvider.runQuery(constraint); + } + + return mCursor; + } + + public Filter getFilter() { + if (mCursorFilter == null) { + mCursorFilter = new CursorFilter(this); + } + return mCursorFilter; + } + + /** + * Returns the query filter provider used for filtering. When the + * provider is null, no filtering occurs. + * + * @return the current filter query provider or null if it does not exist + * + * @see #setFilterQueryProvider(android.widget.FilterQueryProvider) + * @see #runQueryOnBackgroundThread(CharSequence) + */ + public FilterQueryProvider getFilterQueryProvider() { + return mFilterQueryProvider; + } + + /** + * Sets the query filter provider used to filter the current Cursor. + * The provider's + * {@link android.widget.FilterQueryProvider#runQuery(CharSequence)} + * method is invoked when filtering is requested by a client of + * this adapter. + * + * @param filterQueryProvider the filter query provider or null to remove it + * + * @see #getFilterQueryProvider() + * @see #runQueryOnBackgroundThread(CharSequence) + */ + public void setFilterQueryProvider(FilterQueryProvider filterQueryProvider) { + mFilterQueryProvider = filterQueryProvider; + } + + /** + * Called when the {@link ContentObserver} on the cursor receives a change notification. + * The default implementation provides the auto-requery logic, but may be overridden by + * sub classes. + * + * @see ContentObserver#onChange(boolean) + */ + protected void onContentChanged() { + if (mAutoRequery && mCursor != null && !mCursor.isClosed()) { + if (Config.LOGV) Log.v("Cursor", "Auto requerying " + mCursor + " due to update"); + mDataValid = mCursor.requery(); + } + } + + private class ChangeObserver extends ContentObserver { + public ChangeObserver() { + super(new Handler()); + } + + @Override + public boolean deliverSelfNotifications() { + return true; + } + + @Override + public void onChange(boolean selfChange) { + onContentChanged(); + } + } + + private class MyDataSetObserver extends DataSetObserver { + @Override + public void onChanged() { + mDataValid = true; + notifyDataSetChanged(); + } + + @Override + public void onInvalidated() { + mDataValid = false; + notifyDataSetInvalidated(); + } + } + +}