DataSourceRequest

DataSourceRequest

Object Hierarchy:

Description:

[ CCode ( type_id = "shumate_data_source_request_get_type ()" ) ]
[ Version ( since = "1.1" ) ]
public class DataSourceRequest : Object

Represents a request to a [class@DataSource] for a tile.

Data sources can return a tile multiple times. For example, a [class@TileDownloader] may return cached data first, then later return data from a network service when it arrives. This allows the map to be rendered as quickly as possible without waiting for the network unnecessarily.

Conventional async/finish method pairs don't support multiple returns. Instead, [method@DataSource.start_request] is available, which returns a [class@DataSourceRequest] whose properties, [property@DataSourceRequest:data] and [property@DataSourceRequest:error], update as data becomes available. The [signal@GObject.Object:ShumateDataSourceRequest:notify] signal can be used to watch for these changes. When the request is done and no more data will be returned, [property@DataSourceRequest:completed] is set to true.

[class@DataSource] implementations can use a subclass of [class@DataSourceRequest], but the base class should be sufficient in most cases.

Namespace: Shumate

Package: shumate-1.0

Content:

Properties:

public bool completed { get; }
true if the request has been completed, otherwise false.
public Bytes data { get; }
The most recent data for the tile, if available.
public Error error { get; }
The error that occurred during the request, if any.
public int x { get; construct; }
The X coordinate of the requested tile.
public int y { get; construct; }
The Y coordinate of the requested tile.
public int zoom_level { get; construct; }
The zoom level of the requested tile.

Creation methods:

public DataSourceRequest (int x, int y, int zoom_level)
Creates a new [class@DataSourceRequest].

Methods:

public void complete ()
Marks the request as complete.
public void emit_data (Bytes data, bool complete)
Emits tile data as a response to the request.
public void emit_error (Error error)
Emits a fatal error in response to the request.
public unowned Bytes? get_data ()
Gets the latest data from the request.
public unowned Error? get_error ()
Gets the latest error from the request.
public int get_x ()
Gets the X coordinate of the requested tile.
public int get_y ()
Gets the Y coordinate of the requested tile.
public int get_zoom_level ()
Gets the zoom level of the requested tile.
public bool is_completed ()
Gets whether the request has been completed.

Inherited Members:

All known members inherited from class GLib.Object