Scheme Link (link)

Scheme Link

class orangecanvas.scheme.link.SchemeLink(source_node, source_channel, sink_node, sink_channel, enabled=True, properties=None, parent=None)

Bases: PyQt5.QtCore.QObject

A instantiation of a link between two SchemeNode instances in a Scheme.

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)

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()

Return the type of the source channel.

Deprecated since version 0.1.5: Use source_types() instead.

source_types()

Return the type(s) of the source channel.

sink_type()

Return the type of the sink channel.

Deprecated since version 0.1.5: Use sink_types() instead.

sink_types()

Return the type(s) of the sink channel.

is_dynamic()

Is this link dynamic.

set_enabled(enabled)

Enable/disable the link.

is_enabled()

Is this link enabled.

enabled: bool

Is this link enabled.

set_dynamic_enabled(enabled)

Enable/disable the dynamic link. Has no effect if the link is not dynamic.

is_dynamic_enabled()

Is this a dynamic link and is dynamic_enabled set to True

dynamic_enabled: bool

Is this a dynamic link and is dynamic_enabled set to True

set_runtime_state(state)

Set the link’s runtime state.

Parameters

state (SchemeLink.State) –

runtime_state()

Returns

state

Return type

SchemeLink.State

set_runtime_state_flag(flag, on)

Set/unset runtime state flag.

Parameters

• flag (SchemeLink.State) –

• on (bool) –

test_runtime_state(flag)

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

bool

set_tool_tip(tool_tip)

Set the link tool tip.

tool_tip: str

Link tool tip.