Android example source code file (AbstractWindowedCursor.java)

This example Android source code file (AbstractWindowedCursor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

abstractcursor, abstractwindowedcursor, access, chararraybuffer, cursorwindow, double, float, integer, long, number, object, override, staledataexception, string

The AbstractWindowedCursor.java Android example source code

/*
 * Copyright (C) 2006 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.database;

/**
 * A base class for Cursors that store their data in {@link CursorWindow}s.
 */
public abstract class AbstractWindowedCursor extends AbstractCursor
{
    @Override
    public byte[] getBlob(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                return (byte[])getUpdatedField(columnIndex);
            }
        }

        return mWindow.getBlob(mPos, columnIndex);
    }

    @Override
    public String getString(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                return (String)getUpdatedField(columnIndex);
            }
        }

        return mWindow.getString(mPos, columnIndex);
    }
    
    @Override
    public void copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)
    {
        checkPosition();
        
        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                super.copyStringToBuffer(columnIndex, buffer);
            }
        }
        
        mWindow.copyStringToBuffer(mPos, columnIndex, buffer);
    }

    @Override
    public short getShort(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Number value = (Number)getUpdatedField(columnIndex);
                return value.shortValue();
            }
        }

        return mWindow.getShort(mPos, columnIndex);
    }

    @Override
    public int getInt(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Number value = (Number)getUpdatedField(columnIndex);
                return value.intValue();
            }
        }

        return mWindow.getInt(mPos, columnIndex);
    }

    @Override
    public long getLong(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Number value = (Number)getUpdatedField(columnIndex);
                return value.longValue();
            }
        }

        return mWindow.getLong(mPos, columnIndex);
    }

    @Override
    public float getFloat(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Number value = (Number)getUpdatedField(columnIndex);
                return value.floatValue();
            }
        }

        return mWindow.getFloat(mPos, columnIndex);
    }

    @Override
    public double getDouble(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Number value = (Number)getUpdatedField(columnIndex);
                return value.doubleValue();
            }
        }

        return mWindow.getDouble(mPos, columnIndex);
    }

    @Override
    public boolean isNull(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                return getUpdatedField(columnIndex) == null;
            }
        }

        return mWindow.isNull(mPos, columnIndex);
    }

    public boolean isBlob(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Object object = getUpdatedField(columnIndex);
                return object == null || object instanceof byte[];
            }
        }

        return mWindow.isBlob(mPos, columnIndex);
    }

    public boolean isString(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Object object = getUpdatedField(columnIndex);
                return object == null || object instanceof String;
            }
        }

        return mWindow.isString(mPos, columnIndex);
    }

    public boolean isLong(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Object object = getUpdatedField(columnIndex);
                return object != null && (object instanceof Integer || object instanceof Long);
            }
        }

        return mWindow.isLong(mPos, columnIndex);
    }

    public boolean isFloat(int columnIndex)
    {
        checkPosition();

        synchronized(mUpdatedRows) {
            if (isFieldUpdated(columnIndex)) {
                Object object = getUpdatedField(columnIndex);
                return object != null && (object instanceof Float || object instanceof Double);
            }
        }

        return mWindow.isFloat(mPos, columnIndex);
    }

    @Override
    protected void checkPosition()
    {
        super.checkPosition();
        
        if (mWindow == null) {
            throw new StaleDataException("Access closed cursor");
        }
    }

    @Override
    public CursorWindow getWindow() {
        return mWindow;
    }
    
    /**
     * Set a new cursor window to cursor, usually set a remote cursor window
     * @param window cursor window
     */
    public void setWindow(CursorWindow window) {
        if (mWindow != null) {
            mWindow.close();
        }
        mWindow = window;
    }
    
    public boolean hasWindow() {
        return mWindow != null;
    }

    /**
     * This needs be updated in {@link #onMove} by subclasses, and
     * needs to be set to NULL when the contents of the cursor change.
     */
    protected CursorWindow mWindow;
}