Scheme Link (link
)¶
Scheme Link¶
- class orangecanvas.scheme.link.SchemeLink(source_node, source_channel, sink_node, sink_channel, enabled=True, properties=None, parent=None)[source]¶
Bases:
PyQt5.QtCore.QObject
A instantiation of a link between two
SchemeNode
instances in aScheme
.- Parameters
source_node (
SchemeNode
) – Source node.source_channel (
OutputSignal
) – The source widget’s signal.sink_node (
SchemeNode
) – The sink node.sink_channel (
InputSignal
) – The sink widget’s input signal.properties (dict) – Additional link properties.
- enabled_changed(enabled)¶
The link enabled state has changed
- dynamic_enabled_changed(enabled)¶
The link dynamic enabled state has changed.
- state_changed¶
Runtime link state has changed
- class State(value)[source]¶
Bases:
enum.IntEnum
Flags indicating the runtime state of a link
- NoState = 0¶
The link has no associated state (e.g. is not associated with any execution contex)
- Empty = 1¶
A link is empty when it has no value on it.
- Active = 2¶
A link is active when the source node provides a value on output.
- Pending = 4¶
A link is pending when it’s sink node has not yet been notified of a change (note that Empty|Pending is a valid state)
- Invalidated = 8¶
The link’s source node has invalidated the source channel. The execution manager should not propagate this links source value until this flag is cleared.
New in version 0.1.8.
- source_type()[source]¶
Return the type of the source channel.
Deprecated since version 0.1.5: Use
source_types()
instead.
- sink_type()[source]¶
Return the type of the sink channel.
Deprecated since version 0.1.5: Use
sink_types()
instead.
- set_dynamic_enabled(enabled)[source]¶
Enable/disable the dynamic link. Has no effect if the link is not dynamic.
- set_runtime_state(state)[source]¶
Set the link’s runtime state.
- Parameters
state (SchemeLink.State) –
- set_runtime_state_flag(flag, on)[source]¶
Set/unset runtime state flag.
- Parameters
flag (SchemeLink.State) –
on (bool) –
- test_runtime_state(flag)[source]¶
Test if runtime state flag is on/off
- Parameters
flag (SchemeLink.State) – State flag to test
- Returns
on – True if flag is set; False otherwise.
- Return type