Save port positions in the elk graph by LudoBroche · Pull Request #20 · ewoks-kit/ewoksdraw

LudoBroche · 2026-07-24T16:25:57Z

Tip

The Feature

As a: Developer integrating ewoksdraw with pyelk for automatic graph layout
I want to: Include computed task input/output positions in the ELK graph
So that: SVG links can use the actual I/O anchors instead of generic box edges

Note

Scope & Boundaries

In Scope: Extracting TaskIOPosition values and converting them into fixed WEST input and EAST output ports with x/y coordinates
Out of Scope: map_all_data, mappings without source_output, layout algorithm changes, and manual port repositioning

Important

Acceptance Criteria

Every task input/output becomes an ELK port with its computed x/y position
Supported data-mapping edges connect the corresponding output and input ports
Unsupported mappings emit a warning and are not drawn
SVG and ELK conversion tests pass

codecov · 2026-07-24T16:29:56Z

Codecov Report

❌ Patch coverage is 98.73418% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/ewoksdraw/svg/svg_task_io.py	83.33%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

LudoBroche · 2026-08-06T09:45:35Z

+task_io_positions: TaskIOPositions = svg_task_group.extract_io_positions()
+elk_graph: ElkGraph = convert_ewoks_to_elk_graph(
+    ewoks_graph, task_sizes, task_io_positions
+)

 pprint(dict(ewoks_graph.graph.nodes(data=True)))
 pprint(list(ewoks_graph.graph.edges(data=True)))
 pprint(task_sizes)
+pprint(task_io_positions)
 pprint(elk_graph)


New method to extract io_positions returning a TaskIOPositions.
Example:

{ 'task1': [ TaskIOPosition(name='a', io_type='input', x=0.0, y=20.0), TaskIOPosition(name='b', io_type='input', x=0.0, y=28.0), TaskIOPosition(name='delay', io_type='input', x=0.0, y=36.0), TaskIOPosition(name='result', io_type='output', x=39.56, y=47.0)], 'task2': [ TaskIOPosition(name='a', io_type='input', x=0.0, y=20.0), TaskIOPosition(name='b', io_type='input', x=0.0, y=28.0), TaskIOPosition(name='delay', io_type='input', x=0.0, y=36.0), TaskIOPosition(name='result', io_type='output', x=39.56, y=47.0)] }

The elk_graph representation now includes the TaskIOPositions (called "Ports" in ELK semantic).
Example:

{'children': [{'height': 55.0, 'id': 'task1', 'layoutOptions': {'org.eclipse.elk.portConstraints': 'FIXED_POS'}, 'ports': [{'height': 0, 'id': 'task1.input.a', 'layoutOptions': {'org.eclipse.elk.port.borderOffset': 0, 'org.eclipse.elk.port.index': 0, 'org.eclipse.elk.port.side': 'WEST'}, 'width': 0, 'x': 0.0, 'y': 20.0}, .... {'height': 0, 'id': 'task1.output.result', 'layoutOptions': {'org.eclipse.elk.port.borderOffset': 0, 'org.eclipse.elk.port.index': 0, 'org.eclipse.elk.port.side': 'EAST'}, 'width': 0, 'x': 39.56, 'y': 47.0}], .... 'edges': [{'id': 'edge_0_task1_task3', 'sources': ['task1.output.result'], 'targets': ['task3.input.a']}, {'id': 'edge_1_task2_task4', 'sources': ['task2.output.result'], 'targets': ['task4.input.a']}, {'id': 'edge_2_task3_task5', 'sources': ['task3.output.result'], 'targets': ['task5.input.a']}, {'id': 'edge_3_task4_task5', 'sources': ['task4.output.result'], 'targets': ['task5.input.b']}, {'id': 'edge_4_task5_task6', 'sources': ['task5.output.result'], 'targets': ['task6.input.a']}],

LudoBroche · 2026-08-06T11:03:41Z

+        for mapping in link_attrs.get("data_mapping", []):
+            source_output = mapping.get("source_output")
+            if not source_output:
+                warnings.warn(


I'm also ignoring links that have source_input but no source_output in the mapping.

What is source_input? Did you mean target_input?

How is it possible to have a link that does not have a target and a source?

Sorry, I meant the mapping has a target_input but no source_ouput
From the doc : ewokscore :

data_mapping (optional): Describe data transfer from source outputs to target input arguments. For example:

{ "data_mapping": [{"source_output": "result", "target_input": "a"}] }

If "source_output" is None or missing, the complete output of the source will be passed to the corresponding "target_input" or the target.

Gotcha. Didn't even know this was a thing

loichuder

I feel like some code would read better if we deal with inputs and outputs separately (rather than keeping a io_type flag). I identified already one place where it would simplify the code.

What do think?

loichuder · 2026-08-07T12:51:39Z

+        for mapping in link_attrs.get("data_mapping", []):
+            source_output = mapping.get("source_output")
+            if not source_output:
+                warnings.warn(


What is source_input? Did you mean target_input?

How is it possible to have a link that does not have a target and a source?

LudoBroche · 2026-08-10T11:25:57Z

 def _convert_io_positions_to_elk_ports(
-    task_id: str, io_positions: list[TaskIOPosition]
+    task_id: str, io_positions: IOPositions
+) -> list[ElkPort]:
+    ports = _convert_positions_to_elk_ports(
+        io_positions.inputs,
+        id_prefix=f"{task_id}.input",
+        elk_port_side="WEST",
+    )
+    ports.extend(
+        _convert_positions_to_elk_ports(
+            io_positions.outputs,
+            id_prefix=f"{task_id}.output",
+            elk_port_side="EAST",
+        )
+    )
+    return ports
+
+


A new split between input/output allows us to separate the two calls and avoid the constants

LudoBroche · 2026-08-10T11:27:04Z

    y: float


+class IOPositions(NamedTuple):


Instead of having a flag for input/output, we just contain both directly in a single structure

Personally, I would not used a tuple but instead passed inputs and outputs separately down the line.

But I understand this is up to personal preference.

LudoBroche · 2026-08-10T11:39:25Z

+    def get_io_positions(self) -> IOPositions:
+        """Return the task-relative positions of the task inputs and outputs."""
+        return IOPositions(
+            inputs=self._get_group_io_positions(self._inputs),
+            outputs=self._get_group_io_positions(self._outputs),
+        )
+
+    @staticmethod
+    def _get_group_io_positions(group: SvgTaskIOGroup) -> list[TaskIOPosition]:
+        positions: list[TaskIOPosition] = []
+        for io in group.elements:
+            x = group.translation.x + io.translation.x
+            y = group.translation.y + io.translation.y
+            positions.append(TaskIOPosition(name=io.name, x=x, y=y))
+        return positions


New version of the get_io_position with the I/O splits.
Two simple method calls.

loichuder · 2026-08-25T12:48:31Z

+        for mapping in link_attrs.get("data_mapping", []):
+            source_output = mapping.get("source_output")
+            if not source_output:
+                warnings.warn(


Gotcha. Didn't even know this was a thing

loichuder · 2026-08-25T12:59:08Z

    y: float


+class IOPositions(NamedTuple):


Personally, I would not used a tuple but instead passed inputs and outputs separately down the line.

But I understand this is up to personal preference.

Co-authored-by: Loïc Huder <42204205+loichuder@users.noreply.github.com>

LudoBroche · 2026-08-28T13:23:57Z

I applied your suggestions.
Mainly splitting inputs / outputs.

LudoBroche added this to the ewoksdraw 1.0 release milestone Jul 24, 2026

LudoBroche self-assigned this Jul 24, 2026

LudoBroche force-pushed the 19-feature-save-port-positions-in-the-elk-graph branch from 7f0ce2c to 0e8326c Compare July 29, 2026 12:56

Base automatically changed from 17-feature-flat-converter-from-ewoks-execution-graph-to-elk-layout-graph to main August 5, 2026 12:55

LudoBroche force-pushed the 19-feature-save-port-positions-in-the-elk-graph branch from 0e8326c to 9752500 Compare August 5, 2026 14:33

LudoBroche linked an issue Aug 6, 2026 that may be closed by this pull request

[Feature]: Save port positions in the elk graph #19

Closed