CrossProcessCursor

Kotlin |Java

public interface CrossProcessCursor
implements Cursor

android.database.CrossProcessCursor

Known indirect subclasses

AbstractCursor, AbstractWindowedCursor, CrossProcessCursorWrapper, MatrixCursor, MergeCursor, SQLiteCursor

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.
AbstractWindowedCursor	A base class for Cursors that store their data in `CursorWindow`s.
CrossProcessCursorWrapper	Cursor wrapper that implements `CrossProcessCursor`.
MatrixCursor	A mutable cursor implementation backed by an array of `Object`s.
MergeCursor	A convenience class that lets you present an array of Cursors as a single linear Cursor.
SQLiteCursor	A Cursor implementation that exposes results from a query on a `SQLiteDatabase`.

A cross process cursor is an extension of a Cursor that also supports usage from remote processes.

The contents of a cross process cursor are marshalled to the remote process by filling CursorWindow objects using fillWindow(int, CursorWindow). As an optimization, the cursor can provide a pre-filled window to use via getWindow() thereby obviating the need to copy the data to yet another cursor window.

Summary

Inherited constants

From interface android.database.Cursor

`int`	`FIELD_TYPE_BLOB` Value returned by `getType(int)` if the specified column type is blob
`int`	`FIELD_TYPE_FLOAT` Value returned by `getType(int)` if the specified column type is float
`int`	`FIELD_TYPE_INTEGER` Value returned by `getType(int)` if the specified column type is integer
`int`	`FIELD_TYPE_NULL` Value returned by `getType(int)` if the specified column is null
`int`	`FIELD_TYPE_STRING` Value returned by `getType(int)` if the specified column type is string

Public methods
`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.

Inherited methods

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


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Public methods

fillWindow

Added in API level 1

public abstract void fillWindow (int position, 
                CursorWindow window)

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 Cursor.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.

getWindow

Added in API level 1

public abstract CursorWindow getWindow ()

Returns a pre-filled window that contains the data within this cursor.

In particular, the window contains the row indicated by Cursor#getPosition. The window's contents are automatically scrolled whenever the current row moved outside the range covered by the window.

Returns
`CursorWindow`	The pre-filled window, or null if none.

onMove

Added in API level 1

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

This function should be called by methods such as Cursor.moveToPosition(int), so it will typically not be called from outside of the cursor class itself.

Parameters
`oldPosition`	`int`: The position that we're moving from.
`newPosition`	`int`: The position that we're moving to.

Returns
`boolean`	True if the move is successful, false otherwise.