| /* |
| * 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. |
| * <p> |
| * The cursor owns the cursor window it uses. When the cursor is closed, |
| * its window is also closed. Likewise, when the window used by the cursor is |
| * changed, its old window is closed. This policy of strict ownership ensures |
| * that cursor windows are not leaked. |
| * </p><p> |
| * Subclasses are responsible for filling the cursor window with data during |
| * {@link #onMove(int, int)}, allocating a new cursor window if necessary. |
| * During {@link #requery()}, the existing cursor window should be cleared and |
| * filled with new data. |
| * </p><p> |
| * If the contents of the cursor change or become invalid, the old window must be closed |
| * (because it is owned by the cursor) and set to null. |
| * </p> |
| */ |
| public abstract class AbstractWindowedCursor extends AbstractCursor { |
| /** |
| * The cursor window owned by this cursor. |
| */ |
| protected CursorWindow mWindow; |
| |
| @Override |
| public byte[] getBlob(int columnIndex) { |
| checkPosition(); |
| return mWindow.getBlob(mPos, columnIndex); |
| } |
| |
| @Override |
| public String getString(int columnIndex) { |
| checkPosition(); |
| return mWindow.getString(mPos, columnIndex); |
| } |
| |
| @Override |
| public void copyStringToBuffer(int columnIndex, CharArrayBuffer buffer) { |
| checkPosition(); |
| mWindow.copyStringToBuffer(mPos, columnIndex, buffer); |
| } |
| |
| @Override |
| public short getShort(int columnIndex) { |
| checkPosition(); |
| return mWindow.getShort(mPos, columnIndex); |
| } |
| |
| @Override |
| public int getInt(int columnIndex) { |
| checkPosition(); |
| return mWindow.getInt(mPos, columnIndex); |
| } |
| |
| @Override |
| public long getLong(int columnIndex) { |
| checkPosition(); |
| return mWindow.getLong(mPos, columnIndex); |
| } |
| |
| @Override |
| public float getFloat(int columnIndex) { |
| checkPosition(); |
| return mWindow.getFloat(mPos, columnIndex); |
| } |
| |
| @Override |
| public double getDouble(int columnIndex) { |
| checkPosition(); |
| return mWindow.getDouble(mPos, columnIndex); |
| } |
| |
| @Override |
| public boolean isNull(int columnIndex) { |
| checkPosition(); |
| return mWindow.getType(mPos, columnIndex) == Cursor.FIELD_TYPE_NULL; |
| } |
| |
| /** |
| * @deprecated Use {@link #getType} |
| */ |
| @Deprecated |
| public boolean isBlob(int columnIndex) { |
| return getType(columnIndex) == Cursor.FIELD_TYPE_BLOB; |
| } |
| |
| /** |
| * @deprecated Use {@link #getType} |
| */ |
| @Deprecated |
| public boolean isString(int columnIndex) { |
| return getType(columnIndex) == Cursor.FIELD_TYPE_STRING; |
| } |
| |
| /** |
| * @deprecated Use {@link #getType} |
| */ |
| @Deprecated |
| public boolean isLong(int columnIndex) { |
| return getType(columnIndex) == Cursor.FIELD_TYPE_INTEGER; |
| } |
| |
| /** |
| * @deprecated Use {@link #getType} |
| */ |
| @Deprecated |
| public boolean isFloat(int columnIndex) { |
| return getType(columnIndex) == Cursor.FIELD_TYPE_FLOAT; |
| } |
| |
| @Override |
| public int getType(int columnIndex) { |
| checkPosition(); |
| return mWindow.getType(mPos, columnIndex); |
| } |
| |
| @Override |
| protected void checkPosition() { |
| super.checkPosition(); |
| |
| if (mWindow == null) { |
| throw new StaleDataException("Attempting to access a closed CursorWindow." + |
| "Most probable cause: cursor is deactivated prior to calling this method."); |
| } |
| } |
| |
| @Override |
| public CursorWindow getWindow() { |
| return mWindow; |
| } |
| |
| /** |
| * Sets a new cursor window for the cursor to use. |
| * <p> |
| * The cursor takes ownership of the provided cursor window; the cursor window |
| * will be closed when the cursor is closed or when the cursor adopts a new |
| * cursor window. |
| * </p><p> |
| * If the cursor previously had a cursor window, then it is closed when the |
| * new cursor window is assigned. |
| * </p> |
| * |
| * @param window The new cursor window, typically a remote cursor window. |
| */ |
| public void setWindow(CursorWindow window) { |
| if (window != mWindow) { |
| closeWindow(); |
| mWindow = window; |
| } |
| } |
| |
| /** |
| * Returns true if the cursor has an associated cursor window. |
| * |
| * @return True if the cursor has an associated cursor window. |
| */ |
| public boolean hasWindow() { |
| return mWindow != null; |
| } |
| |
| /** |
| * Closes the cursor window and sets {@link #mWindow} to null. |
| * @hide |
| */ |
| protected void closeWindow() { |
| if (mWindow != null) { |
| mWindow.close(); |
| mWindow = null; |
| } |
| } |
| |
| /** |
| * If there is a window, clear it. |
| * Otherwise, creates a new window. |
| * |
| * @param name The window name. |
| * @hide |
| */ |
| protected void clearOrCreateWindow(String name) { |
| if (mWindow == null) { |
| mWindow = new CursorWindow(name); |
| } else { |
| mWindow.clear(); |
| } |
| } |
| |
| /** @hide */ |
| @Override |
| protected void onDeactivateOrClose() { |
| super.onDeactivateOrClose(); |
| closeWindow(); |
| } |
| } |