Added in API level 1

AbstractCursor


abstract class AbstractCursor : CrossProcessCursor
kotlin.Any
   ↳ android.database.AbstractCursor

This is an abstract cursor class that handles a lot of the common code that all cursors need to deal with and is provided for convenience reasons.

Summary

Nested classes
open

Cursors use this class to track changes others make to their URI.

Public constructors

Public methods
open Unit

Closes the Cursor, releasing all of its resources and making it completely invalid.

open Unit
copyStringToBuffer(columnIndex: Int, buffer: CharArrayBuffer!)

Retrieves the requested column text and stores it in the buffer provided.

open Unit

Deactivates the Cursor, making all calls on it fail until requery is called.

open Unit
fillWindow(position: Int, window: CursorWindow!)

Copies cursor data into the window.

open ByteArray!
getBlob(column: Int)

Returns the value of the requested column as a byte array.

open Int

Return total number of columns

open Int
getColumnIndex(columnName: String!)

Returns the zero-based index for the given column name, or -1 if the column doesn't exist.

open Int

Returns the zero-based index for the given column name, or throws IllegalArgumentException if the column doesn't exist.

open String!
getColumnName(columnIndex: Int)

Returns the column name at the given zero-based column index.

abstract Array<String!>!

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

Returns the numbers of rows in the cursor.

abstract Double
getDouble(column: Int)

Returns the value of the requested column as a double.

open Bundle!

Returns a bundle of extra values.

abstract Float
getFloat(column: Int)

Returns the value of the requested column as a float.

abstract Int
getInt(column: Int)

Returns the value of the requested column as an int.

abstract Long
getLong(column: Int)

Returns the value of the requested column as a long.

open Uri!

Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUri.

open MutableList<Uri!>?

Return the URIs at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUris.

Int

Returns the current position of the cursor in the row set.

abstract Short
getShort(column: Int)

Returns the value of the requested column as a short.

abstract String!
getString(column: Int)

Returns the value of the requested column as a String.

open Int
getType(column: Int)

Returns data type of the given column's value.

open Boolean

onMove() will only be called across processes if this method returns true.

open CursorWindow!

If the cursor is backed by a CursorWindow, returns a pre-filled window with the contents of the cursor, otherwise null.

Boolean

Returns whether the cursor is pointing to the position after the last row.

Boolean

Returns whether the cursor is pointing to the position before the first row.

open Boolean

return true if the cursor is closed

Boolean

Returns whether the cursor is pointing to the first row.

Boolean

Returns whether the cursor is pointing to the last row.

abstract Boolean
isNull(column: Int)

Returns true if the value in the indicated column is null.

Boolean
move(offset: Int)

Move the cursor by a relative amount, forward or backward, from the current position.

Boolean

Move the cursor to the first row.

Boolean

Move the cursor to the last row.

Boolean

Move the cursor to the next row.

Boolean
moveToPosition(position: Int)

Move the cursor to an absolute position.

Boolean

Move the cursor to the previous row.

open Boolean
onMove(oldPosition: Int, newPosition: Int)

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.

open Unit

Register an observer that is called when changes happen to the content backing this cursor.

open Unit

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().

open Boolean

Performs the query that created the cursor again, refreshing its contents.

open Bundle!
respond(extras: Bundle!)

This is an out-of-band way for the user of a cursor to communicate with the cursor.

open Unit
setExtras(extras: Bundle!)

Sets a Bundle that will be returned by getExtras().

open Unit

Specifies a content URI to watch for changes.

open Unit

Similar to setNotificationUri(android.content.ContentResolver,android.net.Uri), except this version allows to watch multiple content URIs for changes.

open Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

open Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

Protected methods
open Unit

This function throws CursorIndexOutOfBoundsException if the cursor position is out of bounds.

open Unit

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

open Any!
getUpdatedField(columnIndex: Int)

open Boolean
isFieldUpdated(columnIndex: Int)

open Unit
onChange(selfChange: Boolean)

Subclasses must call this method when they finish committing updates to notify all observers.

Properties
Boolean

ContentResolver!

Int

Public constructors

AbstractCursor

Added in API level 1
AbstractCursor()

Public methods

close

Added in API level 1
open fun close(): Unit

Closes the Cursor, releasing all of its resources and making it completely invalid. Unlike deactivate() a call to requery() will not make the Cursor valid again.

Exceptions
java.lang.Exception if this resource cannot be closed
java.io.IOException if an I/O error occurs

copyStringToBuffer

Added in API level 1
open fun copyStringToBuffer(
    columnIndex: Int,
    buffer: CharArrayBuffer!
): Unit

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.

deactivate

Added in API level 1
open fun deactivate(): Unit

Deactivates the Cursor, making all calls on it fail until requery is called. Inactive Cursors use fewer resources than active Cursors. Calling requery will make the cursor active again.

fillWindow

Added in API level 1
open fun fillWindow(
    position: Int,
    window: CursorWindow!
): Unit

Copies cursor data into the window.

Clears the window and fills it with data beginning at the requested row position until all of the data in the cursor is exhausted or the window runs out of space.

The filled window uses the same row indices as the original cursor. For example, if you fill a window starting from row 5 from the cursor, you can query the contents of row 5 from the window just by asking it for row 5 because there is a direct correspondence between the row indices used by the cursor and the window.

The current position of the cursor, as returned by getPosition, is not changed by this method.

Parameters
position Int: The zero-based index of the first row to copy into the window.
window CursorWindow!: The window to fill.

getBlob

Added in API level 1
open fun getBlob(column: Int): ByteArray!

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 the zero-based index of the target column.
Value is 0 or greater
Return
ByteArray! the value of that column as a byte array.

getColumnCount

Added in API level 1
open fun getColumnCount(): Int

Return total number of columns

Return
Int number of columns.
Value is 0 or greater

getColumnIndex

Added in API level 1
open fun getColumnIndex(columnName: String!): Int

Returns the zero-based index for the given column name, or -1 if the column doesn't exist. If you expect the column to exist use getColumnIndexOrThrow(java.lang.String) instead, which will make the error more clear.

Parameters
columnName String!: the name of the target column.
Return
Int the zero-based column index for the given column name, or -1 if the column name does not exist.
Value is -1 or greater

getColumnIndexOrThrow

Added in API level 1
open fun getColumnIndexOrThrow(columnName: String!): Int

Returns the zero-based index for the given column name, or throws IllegalArgumentException if the column doesn't exist. If you're not sure if a column will exist or not use getColumnIndex(java.lang.String) and check for -1, which is more efficient than catching the exceptions.

Parameters
columnName String!: the name of the target column.
Return
Int the zero-based column index for the given column name.
Value is 0 or greater
Exceptions
java.lang.IllegalArgumentException if the column does not exist

getColumnName

Added in API level 1
open fun getColumnName(columnIndex: Int): String!

Returns the column name at the given zero-based column index.

Parameters
columnIndex Int: the zero-based index of the target column.
Value is 0 or greater
Return
String! the column name for the given column index.

getColumnNames

Added in API level 1
abstract fun getColumnNames(): Array<String!>!

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.

Return
Array<String!>! the names of the columns returned in this query.

getCount

Added in API level 1
abstract fun getCount(): Int

Returns the numbers of rows in the cursor.

Return
Int the number of rows in the cursor.
Value is 0 or greater

getDouble

Added in API level 1
abstract fun getDouble(column: Int): Double

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 the zero-based index of the target column.
Value is 0 or greater
Return
Double the value of that column as a double.

getExtras

Added in API level 1
open fun getExtras(): Bundle!

Returns a bundle of extra values. This is an optional way for cursors to provide out-of-band metadata to their users. One use of this is for reporting on the progress of network requests that are required to fetch data for the cursor.

These values may only change when requery is called.

Return
Bundle! cursor-defined values, or Bundle.EMPTY if there are no values. Never null.

getFloat

Added in API level 1
abstract fun getFloat(column: Int): Float

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 the zero-based index of the target column.
Value is 0 or greater
Return
Float the value of that column as a float.

getInt

Added in API level 1
abstract fun getInt(column: Int): Int

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 the zero-based index of the target column.
Value is 0 or greater
Return
Int the value of that column as an int.

getLong

Added in API level 1
abstract fun getLong(column: Int): Long

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 the zero-based index of the target column.
Value is 0 or greater
Return
Long the value of that column as a long.

getNotificationUri

Added in API level 11
open fun getNotificationUri(): Uri!

Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUri.

Return
Uri! Returns a URI that can be used with ContentResolver.registerContentObserver to find out about changes to this Cursor's data. May be null if no notification URI has been set.

getNotificationUris

Added in API level 29
open fun getNotificationUris(): MutableList<Uri!>?

Return the URIs at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUris.

If this is not implemented, this is equivalent to calling getNotificationUri().

Return
MutableList<Uri!>? Returns URIs that can be used with ContentResolver.registerContentObserver to find out about changes to this Cursor's data. May be null if no notification URI has been set.

getPosition

Added in API level 1
fun getPosition(): Int

Returns the current position of the cursor in the row set. The value is zero-based. When the row set is first returned the cursor will be at positon -1, which is before the first row. After the last row is returned another call to next() will leave the cursor past the last entry, at a position of count().

Return
Int the current cursor position.
Value is -1 or greater

getShort

Added in API level 1
abstract fun getShort(column: Int): Short

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 the zero-based index of the target column.
Value is 0 or greater
Return
Short the value of that column as a short.

getString

Added in API level 1
abstract fun getString(column: Int): String!

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 the zero-based index of the target column.
Value is 0 or greater
Return
String! the value of that column as a String.

getType

Added in API level 11
open fun getType(column: Int): Int

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 the zero-based index of the target column.
Value is 0 or greater
Return
Int column value type.
Value is one of the following:

getWantsAllOnMoveCalls

Added in API level 1
open fun getWantsAllOnMoveCalls(): Boolean

onMove() will only be called across processes if this method returns true.

Return
Boolean whether all cursor movement should result in a call to onMove().

getWindow

Added in API level 1
open fun getWindow(): CursorWindow!

If the cursor is backed by a CursorWindow, returns a pre-filled window with the contents of the cursor, otherwise null.

Return
CursorWindow! The pre-filled window that backs this cursor, or null if none.

isAfterLast

Added in API level 1
fun isAfterLast(): Boolean

Returns whether the cursor is pointing to the position after the last row.

Return
Boolean whether the cursor is after the last result.

isBeforeFirst

Added in API level 1
fun isBeforeFirst(): Boolean

Returns whether the cursor is pointing to the position before the first row.

Return
Boolean whether the cursor is before the first result.

isClosed

Added in API level 1
open fun isClosed(): Boolean

return true if the cursor is closed

Return
Boolean true if the cursor is closed.

isFirst

Added in API level 1
fun isFirst(): Boolean

Returns whether the cursor is pointing to the first row.

Return
Boolean whether the cursor is pointing at the first entry.

isLast

Added in API level 1
fun isLast(): Boolean

Returns whether the cursor is pointing to the last row.

Return
Boolean whether the cursor is pointing at the last entry.

isNull

Added in API level 1
abstract fun isNull(column: Int): Boolean

Returns true if the value in the indicated column is null.

Parameters
columnIndex the zero-based index of the target column.
Value is 0 or greater
Return
Boolean whether the column value is null.

move

Added in API level 1
fun move(offset: Int): Boolean

Move the cursor by a relative amount, forward or backward, from the current position. Positive offsets move forwards, negative offsets move backwards. If the final position is outside of the bounds of the result set then the resultant position will be pinned to -1 or count() depending on whether the value is off the front or end of the set, respectively.

This method will return true if the requested destination was reachable, otherwise, it returns false. For example, if the cursor is at currently on the second entry in the result set and move(-5) is called, the position will be pinned at -1, and false will be returned.

Parameters
offset Int: the offset to be applied from the current position.
Return
Boolean whether the requested move fully succeeded.

moveToFirst

Added in API level 1
fun moveToFirst(): Boolean

Move the cursor to the first row.

This method will return false if the cursor is empty.

Return
Boolean whether the move succeeded.

moveToLast

Added in API level 1
fun moveToLast(): Boolean

Move the cursor to the last row.

This method will return false if the cursor is empty.

Return
Boolean whether the move succeeded.

moveToNext

Added in API level 1
fun moveToNext(): Boolean

Move the cursor to the next row.

This method will return false if the cursor is already past the last entry in the result set.

Return
Boolean whether the move succeeded.

moveToPosition

Added in API level 1
fun moveToPosition(position: Int): Boolean

Move the cursor to an absolute position. The valid range of values is -1 <= position <= count.

This method will return true if the request destination was reachable, otherwise, it returns false.

Parameters
position Int: the zero-based position to move to.
Value is -1 or greater
Return
Boolean whether the requested move fully succeeded.

moveToPrevious

Added in API level 1
fun moveToPrevious(): Boolean

Move the cursor to the previous row.

This method will return false if the cursor is already before the first entry in the result set.

Return
Boolean whether the move succeeded.

onMove

Added in API level 1
open fun onMove(
    oldPosition: Int,
    newPosition: Int
): Boolean

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. If it returns false the move function will also do so and the cursor will scroll to the beforeFirst position.

Parameters
oldPosition Int: the position that we're moving from
newPosition Int: the position that we're moving to
Return
Boolean true if the move is successful, false otherwise

registerContentObserver

Added in API level 1
open fun registerContentObserver(observer: ContentObserver!): Unit

Register an observer that is called when changes happen to the content backing this cursor. Typically the data set won't change until requery() is called.

Parameters
observer ContentObserver!: the object that gets notified when the content backing the cursor changes.

registerDataSetObserver

Added in API level 1
open fun registerDataSetObserver(observer: DataSetObserver!): Unit

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().

Parameters
observer DataSetObserver!: the object that gets notified when the cursors data set changes.

requery

Added in API level 1
open fun requery(): Boolean

Performs the query that created the cursor again, refreshing its contents. This may be done at any time, including after a call to deactivate. Since this method could execute a query on the database and potentially take a while, it could cause ANR if it is called on Main (UI) thread. A warning is printed if this method is being executed on Main thread.

Return
Boolean true if the requery succeeded, false if not, in which case the cursor becomes invalid.

respond

Added in API level 1
open fun respond(extras: Bundle!): Bundle!

This is an out-of-band way for the user of a cursor to communicate with the cursor. The structure of each bundle is entirely defined by the cursor.

One use of this is to tell a cursor that it should retry its network request after it reported an error.

Parameters
extras Bundle!: extra values, or Bundle.EMPTY. Never null.
Return
Bundle! extra values, or Bundle.EMPTY. Never null.

setExtras

Added in API level 23
open fun setExtras(extras: Bundle!): Unit

Sets a Bundle that will be returned by getExtras().

Parameters
extras Bundle!: Bundle to set, or null to set an empty bundle.

setNotificationUri

Added in API level 1
open fun setNotificationUri(
    cr: ContentResolver!,
    notifyUri: Uri!
): Unit

Specifies a content URI to watch for changes.

Parameters
cr ContentResolver!: The content resolver from the caller's context.
uri The content URI to watch.
notifyUri Uri!: The URI to watch for changes. This can be a specific row URI, or a base URI for a whole class of content.

setNotificationUris

Added in API level 29
open fun setNotificationUris(
    cr: ContentResolver,
    notifyUris: MutableList<Uri!>
): Unit

Similar to setNotificationUri(android.content.ContentResolver,android.net.Uri), except this version allows to watch multiple content URIs for changes.

If this is not implemented, this is equivalent to calling setNotificationUri(android.content.ContentResolver,android.net.Uri) with the first URI in uris.

Calling this overrides any previous call to setNotificationUri(android.content.ContentResolver,android.net.Uri).

Parameters
cr ContentResolver: This value cannot be null.
uris The content URIs to watch.
This value cannot be null.
notifyUris MutableList<Uri!>: This value cannot be null.

unregisterContentObserver

Added in API level 1
open fun unregisterContentObserver(observer: ContentObserver!): Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

Parameters
observer ContentObserver!: the object to unregister.

unregisterDataSetObserver

Added in API level 1
open fun unregisterDataSetObserver(observer: DataSetObserver!): Unit

Unregister an observer that has previously been registered with this cursor via registerContentObserver.

Parameters
observer DataSetObserver!: the object to unregister.

Protected methods

checkPosition

Added in API level 1
protected open fun checkPosition(): Unit

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.

Exceptions
android.database.CursorIndexOutOfBoundsException

finalize

Added in API level 1
protected open fun finalize(): Unit

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the Java virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.

Exceptions
java.lang.Throwable the Exception raised by this method

getUpdatedField

Added in API level 1
Deprecated in API level 15
protected open fun getUpdatedField(columnIndex: Int): Any!

Deprecated: Always returns null since Cursors do not support updating rows

isFieldUpdated

Added in API level 1
Deprecated in API level 15
protected open fun isFieldUpdated(columnIndex: Int): Boolean

Deprecated: Always returns false since Cursors do not support updating rows

onChange

Added in API level 1
protected open fun onChange(selfChange: Boolean): Unit

Subclasses must call this method when they finish committing updates to notify all observers.

Parameters
selfChange Boolean:

Properties

mClosed

Added in API level 1
Deprecated in API level 23
protected var mClosed: Boolean

Deprecated: Use isClosed() instead.

mContentResolver

Added in API level 1
Deprecated in API level 23
protected var mContentResolver: ContentResolver!

Deprecated: Do not use.

mPos

Added in API level 1
Deprecated in API level 23
protected var mPos: Int

Deprecated: Use getPosition() instead.