Manage Connectors in Presentations with Python

What this page is about

Learn how to add, attach, reroute, adjust, and inspect straight, bent, and curved PowerPoint connectors with Aspose.Slides for Python via .NET.

Overview

A connector is a line that can remain attached to two shapes when either shape moves. Its ends attach to connection sites, represented by green dots in PowerPoint. Some bent and curved connectors also expose adjustment points, represented by orange dots, that control the position of individual connector segments.

Aspose.Slides represents connectors through the IConnector interface. You can create them, attach their ends to shapes, choose connection sites, reroute them, and modify the geometry of connectors that have adjustment points.

Connector Types

The ShapeType enumeration includes straight, bent, and curved connector presets. The following table shows the available connector geometries and the number of adjustment points defined by each preset.

Connector	Image	Number of adjustment points
`ShapeType.LINE`		0
`ShapeType.STRAIGHT_CONNECTOR1`		0
`ShapeType.BENT_CONNECTOR2`		0
`ShapeType.BENT_CONNECTOR3`		1
`ShapeType.BENT_CONNECTOR4`		2
`ShapeType.BENT_CONNECTOR5`		3
`ShapeType.CURVED_CONNECTOR2`		0
`ShapeType.CURVED_CONNECTOR3`		1
`ShapeType.CURVED_CONNECTOR4`		2
`ShapeType.CURVED_CONNECTOR5`		3

The number and meaning of adjustment points are part of the selected connector preset. Do not assume that two different connector types expose the same collection layout.

Connect Two Shapes

Use IShapeCollection.add_connector to add a connector, and assign its start_shape_connected_to and end_shape_connected_to properties. After both ends are attached, IConnector.reroute selects a short route between the shapes.

The following example connects an ellipse and a rectangle with a bent connector:

import aspose.slides as slides

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    ellipse = slide.shapes.add_auto_shape(slides.ShapeType.ELLIPSE, 40, 80, 120, 80)
    rectangle = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 320, 240, 140, 80)
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR2, 0, 0, 10, 10)

    connector.start_shape_connected_to = ellipse
    connector.end_shape_connected_to = rectangle
    connector.reroute()

    presentation.save("connected-shapes.pptx", slides.export.SaveFormat.PPTX)

Warning

Calling reroute can change the start_shape_connection_site_index and end_shape_connection_site_index values. Assign specific connection sites after rerouting if those sites must remain fixed.

Choose a Connection Site

Each connectable shape reports its number of sites through connection_site_count. Validate a preferred zero-based site index before assigning it to a connector end; site counts vary by shape geometry.

This example attaches the connector to a particular site on the ellipse when that site exists:

import aspose.slides as slides

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    ellipse = slide.shapes.add_auto_shape(slides.ShapeType.ELLIPSE, 40, 80, 120, 80)
    rectangle = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 320, 240, 140, 80)
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR3, 0, 0, 10, 10)

    connector.start_shape_connected_to = ellipse
    connector.end_shape_connected_to = rectangle

    preferred_site_index = 2
    if preferred_site_index < ellipse.connection_site_count:
        connector.start_shape_connection_site_index = preferred_site_index
    else:
        print(f"The ellipse has only {ellipse.connection_site_count} connection sites.")

    presentation.save("specific-connection-site.pptx", slides.export.SaveFormat.PPTX)

Adjust a Connector Point

Connectors with adjustment points expose them through IGeometryShape.adjustments. Inspect every IAdjustValue and check its type before changing its raw_value. For general shape manipulation, see Shape Manipulation.

The number, order, meaning, and valid value range of connector adjustments depend on the connector preset. The type property is read-only, while the adjustment value is writable. The read-only name property provides additional identification when a connector contains more than one adjustment of the same semantic type.

Route Around an Obstacle

In the following layout, a ShapeType.BENT_CONNECTOR5 connector between two shapes passes through a third shape:

connector-obstruction

This code creates the obstructed connector:

import aspose.slides as slides
import aspose.pydrawing as draw

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 300, 150, 150, 75)
    source_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 500, 400, 100, 50)
    target_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 100, 70, 30)
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR5, 20, 20, 400, 300)

    connector.line_format.end_arrowhead_style = slides.LineArrowheadStyle.TRIANGLE
    connector.line_format.fill_format.fill_type = slides.FillType.SOLID
    connector.line_format.fill_format.solid_fill_color.color = draw.Color.black
    connector.start_shape_connected_to = source_shape
    connector.end_shape_connected_to = target_shape
    connector.start_shape_connection_site_index = 2

    presentation.save("connector-obstruction.pptx", slides.export.SaveFormat.PPTX)

Moving the vertical bend changes the route so that the connector bypasses the obstacle:

connector-obstruction-fixed

Instead of assuming that collection index 1 always represents the vertical bend, this example searches for ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y and changes it only when the expected semantic type is present:

import aspose.slides as slides
import aspose.pydrawing as draw

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 300, 150, 150, 75)
    source_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 500, 400, 100, 50)
    target_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 100, 70, 30)
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR5, 20, 20, 400, 300)

    connector.line_format.end_arrowhead_style = slides.LineArrowheadStyle.TRIANGLE
    connector.line_format.fill_format.fill_type = slides.FillType.SOLID
    connector.line_format.fill_format.solid_fill_color.color = draw.Color.black
    connector.start_shape_connected_to = source_shape
    connector.end_shape_connected_to = target_shape
    connector.start_shape_connection_site_index = 2

    vertical_bend = None
    for adjustment_index in range(len(connector.adjustments)):
        adjustment = connector.adjustments[adjustment_index]
        print(f"{adjustment.name}: {adjustment.type}, raw value = {adjustment.raw_value}")
        if adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y:
            vertical_bend = adjustment
            break

    if vertical_bend is None:
        print("The connector does not expose a vertical bend adjustment.")
    else:
        vertical_bend.raw_value = 60000
        presentation.save("connector-obstruction-fixed.pptx", slides.export.SaveFormat.PPTX)

A ShapeType.BENT_CONNECTOR5 has two ShapeAdjustmentType.CONNECTOR_BEND_POSITION_X adjustments and one ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y adjustment. If the type you need occurs more than once, inspect name and the known geometry of that preset before selecting one. If an adjustment reports ShapeAdjustmentType.CUSTOM, treat its meaning and range as preset-specific and do not change it until that contract is known.

Relate Adjustment Values to Connector Geometry

For bent connectors, adjustment values can be used to estimate the positions of individual segments. These calculations are specific to the connector preset:

ShapeType.BENT_CONNECTOR4 normally exposes one ShapeAdjustmentType.CONNECTOR_BEND_POSITION_X and one ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y adjustment.
For these bend positions, raw_value / 100000 produces the fraction of the connector frame width or height used by the examples below.
A connector frame can be rotated or flipped, so frame coordinates must be transformed before they are compared with slide coordinates.

The following examples use type to identify the adjustments first. They do not treat collection indexes as portable identifiers.

Unrotated Connector

The initial layout contains two text shapes connected by a ShapeType.BENT_CONNECTOR4:

connector-shape-complex

This example inspects the connector and obtains its horizontal and vertical bend adjustments:

import aspose.slides as slides
import aspose.pydrawing as draw

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    source_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 100, 60, 25)
    source_shape.text_frame.text = "From"
    target_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 500, 100, 60, 25)
    target_shape.text_frame.text = "To"
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR4, 20, 20, 400, 300)

    connector.line_format.end_arrowhead_style = slides.LineArrowheadStyle.TRIANGLE
    connector.line_format.fill_format.fill_type = slides.FillType.SOLID
    connector.line_format.fill_format.solid_fill_color.color = draw.Color.crimson
    connector.line_format.width = 3
    connector.start_shape_connected_to = source_shape
    connector.start_shape_connection_site_index = 3
    connector.end_shape_connected_to = target_shape
    connector.end_shape_connection_site_index = 2

    for adjustment_index in range(len(connector.adjustments)):
        adjustment = connector.adjustments[adjustment_index]
        print(f"{adjustment.name}: {adjustment.type}, raw value = {adjustment.raw_value}")

To change both bends, locate each expected type and modify the values only after both have been found:

import aspose.slides as slides

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    source_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 100, 60, 25)
    target_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 500, 100, 60, 25)
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR4, 20, 20, 400, 300)
    connector.start_shape_connected_to = source_shape
    connector.start_shape_connection_site_index = 3
    connector.end_shape_connected_to = target_shape
    connector.end_shape_connection_site_index = 2

    horizontal_bend = None
    vertical_bend = None
    for adjustment_index in range(len(connector.adjustments)):
        adjustment = connector.adjustments[adjustment_index]
        if adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_X:
            horizontal_bend = adjustment
        elif adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y:
            vertical_bend = adjustment

    if horizontal_bend is None or vertical_bend is None:
        print("The connector does not expose the expected bend adjustments.")
    else:
        horizontal_bend.raw_value += 20000
        vertical_bend.raw_value += 200000
        presentation.save("connector-adjusted.pptx", slides.export.SaveFormat.PPTX)

The result is a connector whose horizontal and vertical segments have moved:

connector-adjusted-1

Once the semantic types are known, their values can be converted into connector-frame coordinates. This example draws a thin rectangle over the vertical segment controlled by the two bend adjustments:

import aspose.slides as slides

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    source_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 100, 60, 25)
    target_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 500, 100, 60, 25)
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR4, 20, 20, 400, 300)
    connector.start_shape_connected_to = source_shape
    connector.start_shape_connection_site_index = 3
    connector.end_shape_connected_to = target_shape
    connector.end_shape_connection_site_index = 2

    horizontal_bend = None
    vertical_bend = None
    for adjustment_index in range(len(connector.adjustments)):
        adjustment = connector.adjustments[adjustment_index]
        if adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_X:
            horizontal_bend = adjustment
        elif adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y:
            vertical_bend = adjustment

    if horizontal_bend is None or vertical_bend is None:
        print("The connector does not expose the expected bend adjustments.")
    else:
        x = connector.x + connector.width * horizontal_bend.raw_value / 100000
        y = connector.y
        height = connector.height * vertical_bend.raw_value / 100000
        slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, x, y, 1, height)
        presentation.save("connector-segment-guide.pptx", slides.export.SaveFormat.PPTX)

The guide shape marks the calculated segment:

connector-adjusted-2

Rotated or Flipped Connector

When the same connector geometry is oriented vertically, its frame, flip_h, and flip_v values affect the conversion from connector-frame coordinates to slide coordinates.

This example creates and adjusts the vertically oriented connector:

import aspose.slides as slides
import aspose.pydrawing as draw

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    source_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 100, 60, 25)
    source_shape.text_frame.text = "From"
    target_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 400, 60, 25)
    target_shape.text_frame.text = "To 1"
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR4, 20, 20, 400, 300)

    connector.line_format.end_arrowhead_style = slides.LineArrowheadStyle.TRIANGLE
    connector.line_format.fill_format.fill_type = slides.FillType.SOLID
    connector.line_format.fill_format.solid_fill_color.color = draw.Color.medium_aquamarine
    connector.line_format.width = 3
    connector.start_shape_connected_to = source_shape
    connector.start_shape_connection_site_index = 2
    connector.end_shape_connected_to = target_shape
    connector.end_shape_connection_site_index = 3

    for adjustment_index in range(len(connector.adjustments)):
        adjustment = connector.adjustments[adjustment_index]
        if adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_X:
            adjustment.raw_value += 20000
        elif adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y:
            adjustment.raw_value += 200000

    presentation.save("vertical-connector-adjusted.pptx", slides.export.SaveFormat.PPTX)

The adjusted connector appears vertically between the shapes:

connector-adjusted-3

For an arbitrary rotation angle alpha, rotate a connector-frame point (x, y) around the frame center (x0, y0):

X = (x - x0) * cos(alpha) - (y - y0) * sin(alpha) + x0

Y = (x - x0) * sin(alpha) + (y - y0) * cos(alpha) + y0

The following code handles the 90-degree orientation used in this example and draws a red guide over the corresponding connector segment:

import aspose.slides as slides
import aspose.pydrawing as draw

with slides.Presentation() as presentation:
    slide = presentation.slides[0]

    source_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 100, 60, 25)
    target_shape = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, 100, 400, 60, 25)
    connector = slide.shapes.add_connector(slides.ShapeType.BENT_CONNECTOR4, 20, 20, 400, 300)
    connector.start_shape_connected_to = source_shape
    connector.start_shape_connection_site_index = 2
    connector.end_shape_connected_to = target_shape
    connector.end_shape_connection_site_index = 3

    horizontal_bend = None
    vertical_bend = None
    for adjustment_index in range(len(connector.adjustments)):
        adjustment = connector.adjustments[adjustment_index]
        if adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_X:
            horizontal_bend = adjustment
        elif adjustment.type == slides.ShapeAdjustmentType.CONNECTOR_BEND_POSITION_Y:
            vertical_bend = adjustment

    if horizontal_bend is None or vertical_bend is None:
        print("The connector does not expose the expected bend adjustments.")
    else:
        horizontal_bend.raw_value += 20000
        vertical_bend.raw_value += 200000

        x = connector.x
        y = connector.y
        if connector.frame.flip_h == slides.NullableBool.TRUE:
            x += connector.width
        if connector.frame.flip_v == slides.NullableBool.TRUE:
            y += connector.height

        x += connector.width * horizontal_bend.raw_value / 100000
        rotated_x = connector.frame.center_x - y + connector.frame.center_y
        rotated_y = x - connector.frame.center_x + connector.frame.center_y
        segment_width = connector.height * vertical_bend.raw_value / 100000
        guide = slide.shapes.add_auto_shape(slides.ShapeType.RECTANGLE, rotated_x, rotated_y, segment_width, 1)
        guide.line_format.fill_format.fill_type = slides.FillType.SOLID
        guide.line_format.fill_format.solid_fill_color.color = draw.Color.red

        presentation.save("rotated-connector-segment-guide.pptx", slides.export.SaveFormat.PPTX)

The red guide marks the calculated segment after the coordinate transformation:

connector-adjusted-4

These formulas describe the presets used in the examples, not a universal connector model. Validate the adjustment types, frame orientation, and value ranges before applying the same calculation to a different preset.

Find a Connector Direction Angle

The direction of a straight connector can be calculated from its width and height, with horizontal and vertical flips applied. The following example reports the clockwise angle from the positive horizontal axis in slide coordinates:

import math
import aspose.slides as slides

with slides.Presentation() as presentation:
    slide = presentation.slides[0]
    connector = slide.shapes.add_connector(slides.ShapeType.STRAIGHT_CONNECTOR1, 100, 100, 200, 100)

    flip_h = connector.frame.flip_h == slides.NullableBool.TRUE
    flip_v = connector.frame.flip_v == slides.NullableBool.TRUE
    delta_x = connector.width * (-1 if flip_h else 1)
    delta_y = connector.height * (-1 if flip_v else 1)
    angle = math.atan2(delta_y, delta_x) * 180.0 / math.pi

    if angle < 0:
        angle += 360

    print(f"Connector direction: {angle:.2f} degrees")

FAQ

How can I tell whether a connector can attach to a shape?

Check the shape’s connection_site_count. A positive count means the shape exposes connection sites. Validate the selected site index before assigning it to either connector end.

Can I identify a connector adjustment by its collection index?

An index is meaningful only for a known connector preset and collection layout. Check IAdjustValue.type before modifying a value, and use IAdjustValue.name as additional information when the same semantic type occurs more than once.

What happens when a connected shape is deleted?

The corresponding connector end becomes detached. The connector remains on the slide and can be deleted, positioned as a free line, or attached to another shape.

Are connector bindings preserved when a slide is copied?

Bindings are generally preserved when the connected shapes are copied with the slide. If a connector is copied without one of its target shapes, the affected end must be attached again.

Customize Shapes in Presentations with Python