AbstractWindowedCursor
public
abstract
class
AbstractWindowedCursor
extends AbstractCursor
A base class for Cursors that store their data in CursorWindow
s.
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.
Subclasses are responsible for filling the cursor window with data during
AbstractCursor.onMove(int, int)
, allocating a new cursor window if necessary.
During AbstractCursor.requery()
, the existing cursor window should be cleared and
filled with new data.
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.
Summary
Public methods |
void
|
copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)
Retrieves the requested column text and stores it in the buffer provided.
|
byte[]
|
getBlob(int columnIndex)
Returns the value of the requested column as a byte array.
|
double
|
getDouble(int columnIndex)
Returns the value of the requested column as a double.
|
float
|
getFloat(int columnIndex)
Returns the value of the requested column as a float.
|
int
|
getInt(int columnIndex)
Returns the value of the requested column as an int.
|
long
|
getLong(int columnIndex)
Returns the value of the requested column as a long.
|
short
|
getShort(int columnIndex)
Returns the value of the requested column as a short.
|
String
|
getString(int columnIndex)
Returns the value of the requested column as a String.
|
int
|
getType(int columnIndex)
Returns data type of the given column's value.
|
CursorWindow
|
getWindow()
If the cursor is backed by a CursorWindow , returns a pre-filled
window with the contents of the cursor, otherwise null.
|
boolean
|
hasWindow()
Returns true if the cursor has an associated cursor window.
|
boolean
|
isBlob(int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
|
boolean
|
isFloat(int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
|
boolean
|
isLong(int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
|
boolean
|
isNull(int columnIndex)
Returns true if the value in the indicated column is null.
|
boolean
|
isString(int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
|
void
|
setWindow(CursorWindow window)
Sets a new cursor window for the cursor to use.
|
Protected methods |
void
|
checkPosition()
This function throws CursorIndexOutOfBoundsException if
the cursor position is out of bounds.
|
Inherited methods |
From class
android.database.AbstractCursor
void
|
checkPosition()
This function throws CursorIndexOutOfBoundsException if
the cursor position is out of bounds.
|
void
|
close()
Closes the Cursor, releasing all of its resources and making it completely invalid.
|
void
|
copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)
Retrieves the requested column text and stores it in the buffer provided.
|
void
|
deactivate()
Deactivates the Cursor, making all calls on it fail until requery() is called.
|
void
|
fillWindow(int position, CursorWindow window)
Copies cursor data into the window.
|
void
|
finalize()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
|
byte[]
|
getBlob(int column)
Returns the value of the requested column as a byte array.
|
int
|
getColumnCount()
Return total number of columns
|
int
|
getColumnIndex(String columnName)
Returns the zero-based index for the given column name, or -1 if the column doesn't exist.
|
int
|
getColumnIndexOrThrow(String columnName)
Returns the zero-based index for the given column name, or throws
IllegalArgumentException if the column doesn't exist.
|
String
|
getColumnName(int columnIndex)
Returns the column name at the given zero-based column index.
|
abstract
String[]
|
getColumnNames()
Returns a string array holding the names of all of the columns in the
result set in the order in which they were listed in the result.
|
abstract
int
|
getCount()
Returns the numbers of rows in the cursor.
|
abstract
double
|
getDouble(int column)
Returns the value of the requested column as a double.
|
Bundle
|
getExtras()
Returns a bundle of extra values.
|
abstract
float
|
getFloat(int column)
Returns the value of the requested column as a float.
|
abstract
int
|
getInt(int column)
Returns the value of the requested column as an int.
|
abstract
long
|
getLong(int column)
Returns the value of the requested column as a long.
|
Uri
|
getNotificationUri()
Return the URI at which notifications of changes in this Cursor's data
will be delivered, as previously set by setNotificationUri(ContentResolver, Uri) .
|
List<Uri>
|
getNotificationUris()
Return the URIs at which notifications of changes in this Cursor's data
will be delivered, as previously set by setNotificationUris(ContentResolver, List) .
|
final
int
|
getPosition()
Returns the current position of the cursor in the row set.
|
abstract
short
|
getShort(int column)
Returns the value of the requested column as a short.
|
abstract
String
|
getString(int column)
Returns the value of the requested column as a String.
|
int
|
getType(int column)
Returns data type of the given column's value.
|
Object
|
getUpdatedField(int columnIndex)
This method was deprecated
in API level 15.
Always returns null since Cursors do not support updating rows
|
boolean
|
getWantsAllOnMoveCalls()
onMove() will only be called across processes if this method returns true.
|
CursorWindow
|
getWindow()
If the cursor is backed by a CursorWindow , returns a pre-filled
window with the contents of the cursor, otherwise null.
|
final
boolean
|
isAfterLast()
Returns whether the cursor is pointing to the position after the last
row.
|
final
boolean
|
isBeforeFirst()
Returns whether the cursor is pointing to the position before the first
row.
|
boolean
|
isClosed()
return true if the cursor is closed
|
boolean
|
isFieldUpdated(int columnIndex)
This method was deprecated
in API level 15.
Always returns false since Cursors do not support updating rows
|
final
boolean
|
isFirst()
Returns whether the cursor is pointing to the first row.
|
final
boolean
|
isLast()
Returns whether the cursor is pointing to the last row.
|
abstract
boolean
|
isNull(int column)
Returns true if the value in the indicated column is null.
|
final
boolean
|
move(int offset)
Move the cursor by a relative amount, forward or backward, from the
current position.
|
final
boolean
|
moveToFirst()
Move the cursor to the first row.
|
final
boolean
|
moveToLast()
Move the cursor to the last row.
|
final
boolean
|
moveToNext()
Move the cursor to the next row.
|
final
boolean
|
moveToPosition(int position)
Move the cursor to an absolute position.
|
final
boolean
|
moveToPrevious()
Move the cursor to the previous row.
|
void
|
onChange(boolean selfChange)
Subclasses must call this method when they finish committing updates to notify all
observers.
|
boolean
|
onMove(int oldPosition, int newPosition)
This function is called every time the cursor is successfully scrolled
to a new position, giving the subclass a chance to update any state it
may have.
|
void
|
registerContentObserver(ContentObserver observer)
Register an observer that is called when changes happen to the content backing this cursor.
|
void
|
registerDataSetObserver(DataSetObserver observer)
Register an observer that is called when changes happen to the contents
of the this cursors data set, for example, when the data set is changed via
requery() , deactivate() , or close() .
|
boolean
|
requery()
Performs the query that created the cursor again, refreshing its
contents.
|
Bundle
|
respond(Bundle extras)
This is an out-of-band way for the user of a cursor to communicate with the cursor.
|
void
|
setExtras(Bundle extras)
Sets a Bundle that will be returned by getExtras() .
|
void
|
setNotificationUri(ContentResolver cr, Uri notifyUri)
Specifies a content URI to watch for changes.
|
void
|
setNotificationUris(ContentResolver cr, List<Uri> notifyUris)
Similar to setNotificationUri(android.content.ContentResolver, android.net.Uri) , except this version allows
to watch multiple content URIs for changes.
|
void
|
unregisterContentObserver(ContentObserver observer)
Unregister an observer that has previously been registered with this
cursor via registerContentObserver(ContentObserver) .
|
void
|
unregisterDataSetObserver(DataSetObserver observer)
Unregister an observer that has previously been registered with this
cursor via registerContentObserver(ContentObserver) .
|
|
From class
java.lang.Object
Object
|
clone()
Creates and returns a copy of this object.
|
boolean
|
equals(Object obj)
Indicates whether some other object is "equal to" this one.
|
void
|
finalize()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
|
final
Class<?>
|
getClass()
Returns the runtime class of this Object .
|
int
|
hashCode()
Returns a hash code value for the object.
|
final
void
|
notify()
Wakes up a single thread that is waiting on this object's
monitor.
|
final
void
|
notifyAll()
Wakes up all threads that are waiting on this object's monitor.
|
String
|
toString()
Returns a string representation of the object.
|
final
void
|
wait(long timeoutMillis, int nanos)
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted, or until a
certain amount of real time has elapsed.
|
final
void
|
wait(long timeoutMillis)
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted, or until a
certain amount of real time has elapsed.
|
final
void
|
wait()
Causes the current thread to wait until it is awakened, typically
by being notified or interrupted.
|
|
From interface
android.database.CrossProcessCursor
abstract
void
|
fillWindow(int position, CursorWindow window)
Copies cursor data into the window.
|
abstract
CursorWindow
|
getWindow()
Returns a pre-filled window that contains the data within this cursor.
|
abstract
boolean
|
onMove(int oldPosition, int newPosition)
This function is called every time the cursor is successfully scrolled
to a new position, giving the subclass a chance to update any state it
may have.
|
|
From interface
android.database.Cursor
abstract
void
|
close()
Closes the Cursor, releasing all of its resources and making it completely invalid.
|
abstract
void
|
copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)
Retrieves the requested column text and stores it in the buffer provided.
|
abstract
void
|
deactivate()
This method was deprecated
in API level 16.
Since requery() is deprecated, so too is this.
|
abstract
byte[]
|
getBlob(int columnIndex)
Returns the value of the requested column as a byte array.
|
abstract
int
|
getColumnCount()
Return total number of columns
|
abstract
int
|
getColumnIndex(String columnName)
Returns the zero-based index for the given column name, or -1 if the column doesn't exist.
|
abstract
int
|
getColumnIndexOrThrow(String columnName)
Returns the zero-based index for the given column name, or throws
IllegalArgumentException if the column doesn't exist.
|
abstract
String
|
getColumnName(int columnIndex)
Returns the column name at the given zero-based column index.
|
abstract
String[]
|
getColumnNames()
Returns a string array holding the names of all of the columns in the
result set in the order in which they were listed in the result.
|
abstract
int
|
getCount()
Returns the numbers of rows in the cursor.
|
abstract
double
|
getDouble(int columnIndex)
Returns the value of the requested column as a double.
|
abstract
Bundle
|
getExtras()
Returns a bundle of extra values.
|
abstract
float
|
getFloat(int columnIndex)
Returns the value of the requested column as a float.
|
abstract
int
|
getInt(int columnIndex)
Returns the value of the requested column as an int.
|
abstract
long
|
getLong(int columnIndex)
Returns the value of the requested column as a long.
|
abstract
Uri
|
getNotificationUri()
Return the URI at which notifications of changes in this Cursor's data
will be delivered, as previously set by setNotificationUri(ContentResolver, Uri) .
|
default
List<Uri>
|
getNotificationUris()
Return the URIs at which notifications of changes in this Cursor's data
will be delivered, as previously set by setNotificationUris(ContentResolver, List) .
|
abstract
int
|
getPosition()
Returns the current position of the cursor in the row set.
|
abstract
short
|
getShort(int columnIndex)
Returns the value of the requested column as a short.
|
abstract
String
|
getString(int columnIndex)
Returns the value of the requested column as a String.
|
abstract
int
|
getType(int columnIndex)
Returns data type of the given column's value.
|
abstract
boolean
|
getWantsAllOnMoveCalls()
onMove() will only be called across processes if this method returns true.
|
abstract
boolean
|
isAfterLast()
Returns whether the cursor is pointing to the position after the last
row.
|
abstract
boolean
|
isBeforeFirst()
Returns whether the cursor is pointing to the position before the first
row.
|
abstract
boolean
|
isClosed()
return true if the cursor is closed
|
abstract
boolean
|
isFirst()
Returns whether the cursor is pointing to the first row.
|
abstract
boolean
|
isLast()
Returns whether the cursor is pointing to the last row.
|
abstract
boolean
|
isNull(int columnIndex)
Returns true if the value in the indicated column is null.
|
abstract
boolean
|
move(int offset)
Move the cursor by a relative amount, forward or backward, from the
current position.
|
abstract
boolean
|
moveToFirst()
Move the cursor to the first row.
|
abstract
boolean
|
moveToLast()
Move the cursor to the last row.
|
abstract
boolean
|
moveToNext()
Move the cursor to the next row.
|
abstract
boolean
|
moveToPosition(int position)
Move the cursor to an absolute position.
|
abstract
boolean
|
moveToPrevious()
Move the cursor to the previous row.
|
abstract
void
|
registerContentObserver(ContentObserver observer)
Register an observer that is called when changes happen to the content backing this cursor.
|
abstract
void
|
registerDataSetObserver(DataSetObserver observer)
Register an observer that is called when changes happen to the contents
of the this cursors data set, for example, when the data set is changed via
requery() , deactivate() , or close() .
|
abstract
boolean
|
requery()
This method was deprecated
in API level 15.
Don't use this. Just request a new cursor, so you can do this
asynchronously and update your list view once the new cursor comes back.
|
abstract
Bundle
|
respond(Bundle extras)
This is an out-of-band way for the user of a cursor to communicate with the cursor.
|
abstract
void
|
setExtras(Bundle extras)
Sets a Bundle that will be returned by getExtras() .
|
abstract
void
|
setNotificationUri(ContentResolver cr, Uri uri)
Register to watch a content URI for changes.
|
default
void
|
setNotificationUris(ContentResolver cr, List<Uri> uris)
Similar to setNotificationUri(android.content.ContentResolver, android.net.Uri) , except this version allows
to watch multiple content URIs for changes.
|
abstract
void
|
unregisterContentObserver(ContentObserver observer)
Unregister an observer that has previously been registered with this
cursor via registerContentObserver(ContentObserver) .
|
abstract
void
|
unregisterDataSetObserver(DataSetObserver observer)
Unregister an observer that has previously been registered with this
cursor via registerContentObserver(ContentObserver) .
|
|
From interface
java.io.Closeable
abstract
void
|
close()
Closes this stream and releases any system resources associated
with it.
|
|
|
Fields
mWindow
protected CursorWindow mWindow
The cursor window owned by this cursor.
Public constructors
AbstractWindowedCursor
public AbstractWindowedCursor ()
Public methods
copyStringToBuffer
public void copyStringToBuffer (int columnIndex,
CharArrayBuffer buffer)
Retrieves the requested column text and stores it in the buffer provided.
If the buffer size is not sufficient, a new char buffer will be allocated
and assigned to CharArrayBuffer.data
Parameters |
columnIndex |
int : the zero-based index of the target column.
if the target column is null, return buffer
Value is 0 or greater |
buffer |
CharArrayBuffer : the buffer to copy the text into. |
getBlob
public byte[] getBlob (int columnIndex)
Returns the value of the requested column as a byte array.
The result and whether this method throws an exception when the
column value is null or the column type is not a blob type is
implementation-defined.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
byte[] |
the value of that column as a byte array. |
getDouble
public double getDouble (int columnIndex)
Returns the value of the requested column as a double.
The result and whether this method throws an exception when the
column value is null, the column type is not a floating-point type, or the
floating-point value is not representable as a double
value is
implementation-defined.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
double |
the value of that column as a double. |
getFloat
public float getFloat (int columnIndex)
Returns the value of the requested column as a float.
The result and whether this method throws an exception when the
column value is null, the column type is not a floating-point type, or the
floating-point value is not representable as a float
value is
implementation-defined.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
float |
the value of that column as a float. |
getInt
public int getInt (int columnIndex)
Returns the value of the requested column as an int.
The result and whether this method throws an exception when the
column value is null, the column type is not an integral type, or the
integer value is outside the range [Integer.MIN_VALUE
,
Integer.MAX_VALUE
] is implementation-defined.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
int |
the value of that column as an int. |
getLong
public long getLong (int columnIndex)
Returns the value of the requested column as a long.
The result and whether this method throws an exception when the
column value is null, the column type is not an integral type, or the
integer value is outside the range [Long.MIN_VALUE
,
Long.MAX_VALUE
] is implementation-defined.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
long |
the value of that column as a long. |
getShort
public short getShort (int columnIndex)
Returns the value of the requested column as a short.
The result and whether this method throws an exception when the
column value is null, the column type is not an integral type, or the
integer value is outside the range [Short.MIN_VALUE
,
Short.MAX_VALUE
] is implementation-defined.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
short |
the value of that column as a short. |
getString
public String getString (int columnIndex)
Returns the value of the requested column as a String.
The result and whether this method throws an exception when the
column value is null or the column type is not a string type is
implementation-defined.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
String |
the value of that column as a String. |
getType
public int getType (int columnIndex)
Returns data type of the given column's value.
The preferred type of the column is returned but the data may be converted to other types
as documented in the get-type methods such as getInt(int)
, getFloat(int)
etc.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
getWindow
public CursorWindow getWindow ()
If the cursor is backed by a CursorWindow
, returns a pre-filled
window with the contents of the cursor, otherwise null.
Returns |
CursorWindow |
The pre-filled window that backs this cursor, or null if none. |
hasWindow
public boolean hasWindow ()
Returns true if the cursor has an associated cursor window.
Returns |
boolean |
True if the cursor has an associated cursor window. |
isBlob
public boolean isBlob (int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
Parameters |
columnIndex |
int |
isFloat
public boolean isFloat (int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
Parameters |
columnIndex |
int |
isLong
public boolean isLong (int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
Parameters |
columnIndex |
int |
isNull
public boolean isNull (int columnIndex)
Returns true
if the value in the indicated column is null.
Parameters |
columnIndex |
int : the zero-based index of the target column.
Value is 0 or greater |
Returns |
boolean |
whether the column value is null. |
isString
public boolean isString (int columnIndex)
This method was deprecated
in API level 15.
Use getType(int)
Parameters |
columnIndex |
int |
setWindow
public void setWindow (CursorWindow window)
Sets a new cursor window for the cursor to use.
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.
If the cursor previously had a cursor window, then it is closed when the
new cursor window is assigned.
Parameters |
window |
CursorWindow : The new cursor window, typically a remote cursor window. |
Protected methods
checkPosition
protected void checkPosition ()
This function throws CursorIndexOutOfBoundsException if
the cursor position is out of bounds. Subclass implementations of
the get functions should call this before attempting
to retrieve data.