Java Cursor.registerContentObserver方法代码示例

import android.database.Cursor; //导入方法依赖的package包/类
public void changeCursor(Cursor cursor) {
    if (cursor == mCursor) {
        return;
    }

    if (mCursor != null) {
        mCursor.unregisterContentObserver(mChangeObserver);
        mCursor.unregisterDataSetObserver(mDataSetObserver);
        mCursor.close();
    }
    mCursor = cursor;
    resetCache();
    findGroups();

    if (cursor != null) {
        cursor.registerContentObserver(mChangeObserver);
        cursor.registerDataSetObserver(mDataSetObserver);
        mRowIdColumnIndex = cursor.getColumnIndexOrThrow("_id");
        notifyDataSetChanged();
    } else {
        // notify the observers about the lack of a data set
        notifyDataSetInvalidated();
    }

}
 

import android.database.Cursor; //导入方法依赖的package包/类
private void init(Context context, Cursor c, int flags) {
    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);
        }
    }
    setHasStableIds(true);
}
 

import android.database.Cursor; //导入方法依赖的package包/类
void init(Context context, Cursor c, int flags) {

        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);
        }
        setHasStableIds(true);
    }
 

import android.database.Cursor; //导入方法依赖的package包/类
@Override
public Cursor loadInBackground() {
  Cursor newCursor = getCursor();
  if (newCursor != null) {
    newCursor.getCount();
    newCursor.registerContentObserver(observer);
  }
  return newCursor;
}
 

import android.database.Cursor; //导入方法依赖的package包/类
/**
     * Swap in a new Cursor, returning the old Cursor.  Unlike
     * {@link #changeCursor(Cursor)}, the returned old Cursor is <em>not</em>
     * 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
            notifyDataSetChanged();
//            notifyDataSetInvalidated();
        }
        return oldCursor;
    }
 

import android.database.Cursor; //导入方法依赖的package包/类
/**
     * Swap in a new Cursor, returning the old Cursor.  Unlike
     * {@link #changeCursor(Cursor)}, the returned old Cursor is <em>not</em>
     * 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
            notifyDataSetChanged();
//            notifyDataSetInvalidated();
        }
        return oldCursor;
    }
 

import android.database.Cursor; //导入方法依赖的package包/类
public Cursor loadInBackground() {
    Cursor cursor = null;
    try {
        cursor = getContext().getContentResolver().query(this.mUri, this.mProjection, this.mSelection, this.mSelectionArgs, this.mSortOrder);
        if (cursor != null) {
            cursor.getCount();
            cursor.registerContentObserver(this.mObserver);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return cursor;
}
 

import android.database.Cursor; //导入方法依赖的package包/类
/**
 * Swap in a new Cursor, returning the old Cursor.  Unlike
 * {@link #changeCursor(Cursor)}, the returned old Cursor is <em>not</em>
 * 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();
        notifyItemRangeRemoved(0, oldCursor.getCount());
    }
    return oldCursor;
}
 

import android.database.Cursor; //导入方法依赖的package包/类
public Cursor swapCursor(Cursor newCursor) {
    if (newCursor == this.mCursor) {
        return null;
    }
    Cursor oldCursor = this.mCursor;
    if (oldCursor != null) {
        if (this.mChangeObserver != null) {
            oldCursor.unregisterContentObserver(this.mChangeObserver);
        }
        if (this.mDataSetObserver != null) {
            oldCursor.unregisterDataSetObserver(this.mDataSetObserver);
        }
    }
    this.mCursor = newCursor;
    if (newCursor != null) {
        if (this.mChangeObserver != null) {
            newCursor.registerContentObserver(this.mChangeObserver);
        }
        if (this.mDataSetObserver != null) {
            newCursor.registerDataSetObserver(this.mDataSetObserver);
        }
        this.mRowIDColumn = newCursor.getColumnIndexOrThrow("_id");
        this.mDataValid = true;
        notifyDataSetChanged();
        return oldCursor;
    }
    this.mRowIDColumn = -1;
    this.mDataValid = false;
    notifyDataSetInvalidated();
    return oldCursor;
}
 

import android.database.Cursor; //导入方法依赖的package包/类
public Cursor loadInBackground() {
    Cursor cursor;
    synchronized (this) {
        if (isLoadInBackgroundCanceled()) {
            throw new OperationCanceledException();
        }
        this.mCancellationSignal = new CancellationSignal();
    }
    try {
        cursor = ContentResolverCompat.query(getContext().getContentResolver(), this.mUri, this.mProjection, this.mSelection, this.mSelectionArgs, this.mSortOrder, this.mCancellationSignal);
        if (cursor != null) {
            cursor.getCount();
            cursor.registerContentObserver(this.mObserver);
        }
        synchronized (this) {
            this.mCancellationSignal = null;
        }
        return cursor;
    } catch (RuntimeException ex) {
        cursor.close();
        throw ex;
    } catch (Throwable th) {
        synchronized (this) {
            this.mCancellationSignal = null;
        }
    }
}
 

import android.database.Cursor; //导入方法依赖的package包/类
void init(Context context, Cursor c, int flags) {
    boolean cursorPresent = true;
    if ((flags & 1) == 1) {
        flags |= 2;
        this.mAutoRequery = true;
    } else {
        this.mAutoRequery = false;
    }
    if (c == null) {
        cursorPresent = false;
    }
    this.mCursor = c;
    this.mDataValid = cursorPresent;
    this.mContext = context;
    this.mRowIDColumn = cursorPresent ? c.getColumnIndexOrThrow("_id") : -1;
    if ((flags & 2) == 2) {
        this.mChangeObserver = new ChangeObserver();
        this.mDataSetObserver = new MyDataSetObserver();
    } else {
        this.mChangeObserver = null;
        this.mDataSetObserver = null;
    }
    if (cursorPresent) {
        if (this.mChangeObserver != null) {
            c.registerContentObserver(this.mChangeObserver);
        }
        if (this.mDataSetObserver != null) {
            c.registerDataSetObserver(this.mDataSetObserver);
        }
    }
}
 

import android.database.Cursor; //导入方法依赖的package包/类
void init(Cursor c) {
    boolean cursorPresent = c != null;
    mCursor = c;
    mDataValid = cursorPresent;
    mRowIDColumn = cursorPresent ? c.getColumnIndexOrThrow("_id") : -1;

    mChangeObserver = new ChangeObserver();
    mDataSetObserver = new MyDataSetObserver();

    if (cursorPresent) {
        if (mChangeObserver != null) c.registerContentObserver(mChangeObserver);
        if (mDataSetObserver != null) c.registerDataSetObserver(mDataSetObserver);
    }
}
 

import android.database.Cursor; //导入方法依赖的package包/类
@Override
public void registerContentObserver(ContentObserver observer) {
    for (Cursor cursor : mCursors) {
        cursor.registerContentObserver(observer);
    }
}
 

import android.database.Cursor; //导入方法依赖的package包/类
public void testUpdateLeader() {
    // Create a new map of values, where column names are the keys
    ContentValues values = TestUtilities.createLeaderValues();

    Uri Uri = mContext.getContentResolver().
            insert(LeaderContract.LeaderEntry.CONTENT_URI, values);
    long leaderRowId = ContentUris.parseId(Uri);

    // Verify we got a row back.
    assertTrue(leaderRowId != -1);
    Log.d(LOG_TAG, "New row id: " + leaderRowId);

    ContentValues updatedValues = new ContentValues(values);
    updatedValues.put(LeaderContract.LeaderEntry._ID, leaderRowId);
    updatedValues.put(LeaderContract.LeaderEntry.COLUMN_USER_NAME, "Bob");

    // Create a cursor with observer to make sure that the content provider is notifying
    // the observers as expected
    Cursor leaderCursor = mContext.getContentResolver().query(
            LeaderContract.LeaderEntry.CONTENT_URI, null, null, null, null);

    TestUtilities.TestContentObserver tco = TestUtilities.getTestContentObserver();
    leaderCursor.registerContentObserver(tco);

    int count = mContext.getContentResolver().update(
            LeaderContract.LeaderEntry.CONTENT_URI, updatedValues, LeaderContract.LeaderEntry._ID + "= ?",
            new String[]{Long.toString(leaderRowId)});
    assertEquals(count, 1);

    // Test to make sure our observer is called.  If not, we throw an assertion.
    tco.waitForNotificationOrFail();

    leaderCursor.unregisterContentObserver(tco);
    leaderCursor.close();

    Cursor cursor = mContext.getContentResolver().query(
            LeaderContract.LeaderEntry.CONTENT_URI,
            null,
            LeaderContract.LeaderEntry._ID + " = " + leaderRowId,
            null,
            null
    );

    TestUtilities.validateCursor("testUpdateLeader.  Error validating leader entry update.",
            cursor, updatedValues);

    cursor.close();
}
 

import android.database.Cursor; //导入方法依赖的package包/类
@Test
public void testUpdateFavoriteMovie() {
    Context appContext = InstrumentationRegistry.getTargetContext();
    // Create a new map of values, where column names are the keys
    ContentValues values = TestUtilities.createTheWallValues();

    Uri quoteUri = appContext.getContentResolver().
            insert(FavoritesContract.FavoriteColumns.uriMovie, values);
    long rowId = ContentUris.parseId(quoteUri);

    // Verify we got a row back.
    assertTrue(rowId != -1);
    Log.d(LOG_TAG, "New row id: " + rowId);

    ContentValues updatedValues = new ContentValues(values);
    updatedValues.put(FavoritesContract.FavoriteColumns._ID, rowId);
    updatedValues.put(FavoritesContract.FavoriteColumns.COLUMN_VOTE_COUNT, 250);

    // Create a cursor with observer to make sure that the content provider is notifying
    // the observers as expected
    Cursor locationCursor = appContext.getContentResolver().query(
            FavoritesContract.FavoriteColumns.uriMovie, null, null, null, null);

    TestUtilities.TestContentObserver tco = TestUtilities.getTestContentObserver();
    locationCursor.registerContentObserver(tco);

    int count = appContext.getContentResolver().update(
            FavoritesContract.FavoriteColumns.uriMovie, updatedValues,
            FavoritesContract.FavoriteColumns._ID + "= ?", new String[] { Long.toString(rowId)});
    assertEquals(count, 1);

    // Test to make sure our observer is called.  If not, we throw an assertion.
    // If your code is failing here, it means that your content provider
    // isn't calling getContext().getContentResolver().notifyChange(uri, null);
    tco.waitForNotificationOrFail();

    locationCursor.unregisterContentObserver(tco);
    locationCursor.close();

    // A cursor is your primary interface to the query results.
    Cursor cursor = appContext.getContentResolver().query(
            FavoritesContract.FavoriteColumns.uriMovie,
            null,   // projection
            FavoritesContract.FavoriteColumns._ID + " = " + rowId,
            null,   // Values for the "where" clause
            null    // sort order
    );

    TestUtilities.validateCursor("testUpdateFavoriteMovie.  Error validating quote entry update.",
            cursor, updatedValues);
    cursor.close();
}