DataSourceRequest#

Added in version 1.1.

class DataSourceRequest(**properties: Any)#

Superclasses: Object

Represents a request to a DataSource for a tile.

Data sources can return a tile multiple times. For example, a 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, start_request is available, which returns a DataSourceRequest whose properties, data and error, update as data becomes available. The notify signal can be used to watch for these changes. When the request is done and no more data will be returned, completed is set to True.

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

Constructors#

class DataSourceRequest
classmethod new(x: int, y: int, zoom_level: int) → DataSourceRequest#

Creates a new DataSourceRequest.

Only implementations of start_request should need to construct a new request object.

Added in version 1.1.

Parameters:

  • x – X coordinate of the requested tile

  • y – Y coordinate of the requested tile

  • zoom_level – Zoom level of the requested tile

Methods#

class DataSourceRequest
complete() → None#

Marks the request as complete. No more data or errors may be emitted.

This can only be called if data has been emitted. If there is no data, use emit_error instead, which will automatically complete the request.

Added in version 1.1.

emit_data(data: Bytes, complete: bool) → None#

Emits tile data as a response to the request. This sets the data property.

If complete is True, then completed is set to True as well.

Added in version 1.1.

Parameters:

  • data – the data to emit

  • complete – True to also complete the request, False otherwise

emit_error(error: GError) → None#

Emits a fatal error in response to the request. This completes the request, so no more data or errors can be emitted after this. Non-fatal errors should not be reported.

If data was previously set, it will be cleared.

Added in version 1.1.

Parameters:

error – an error

get_data() → Bytes | None#

Gets the latest data from the request.

Added in version 1.1.

get_error() → GError | None#

Gets the latest error from the request.

Added in version 1.1.

get_x() → int#

Gets the X coordinate of the requested tile.

Added in version 1.1.

get_y() → int#

Gets the Y coordinate of the requested tile.

Added in version 1.1.

get_zoom_level() → int#

Gets the zoom level of the requested tile.

Added in version 1.1.

is_completed() → bool#

Gets whether the request has been completed. Completed requests will not receive new data or errors.

Added in version 1.1.

Properties#

class DataSourceRequest
props.completed: bool#

The type of the None singleton.

Added in version 1.1.

props.data: Bytes#

The type of the None singleton.

Added in version 1.1.

props.error: GError#

The type of the None singleton.

Added in version 1.1.

props.x: int#

The type of the None singleton.

Added in version 1.1.

props.y: int#

The type of the None singleton.

Added in version 1.1.

props.zoom_level: int#

The type of the None singleton.

Added in version 1.1.

Fields#

class DataSourceRequest
parent_instance#