How to Connect Shapes with Connectors in Java

This guide shows how to connect shapes in PowerPoint slides using Aspose.Slides FOSS for Java. Connectors are line shapes that attach to connection sites on other shapes. When you move a connected shape, the connector endpoint moves with it. The most common connector type is BENT_CONNECTOR3, which routes around obstacles with a single elbow bend.

Prerequisites

Add the following dependency to your pom.xml to include the Aspose.Slides FOSS library:

<dependency>
  <groupId>org.aspose.slides.foss</groupId>
  <artifactId>aspose-slides-foss</artifactId>
  <version>1.0.0</version>
</dependency>

Connection Site Indexes

Every shape has four numbered connection sites:

Index	Position
`0`	Top center
`1`	Left center
`2`	Bottom center
`3`	Right center

Connect Two Shapes

Create the two shapes, add a connector with slide.getShapes().addConnector(), then call setStartShapeConnectedTo() and setEndShapeConnectedTo() to link them:

import org.aspose.slides.foss.Presentation;
import org.aspose.slides.foss.ISlide;
import org.aspose.slides.foss.IShape;
import org.aspose.slides.foss.IAutoShape;
import org.aspose.slides.foss.IConnector;
import org.aspose.slides.foss.ILineFormat;
import org.aspose.slides.foss.Connector;
import org.aspose.slides.foss.ShapeType;
import org.aspose.slides.foss.export.SaveFormat;
import org.aspose.slides.foss.drawing.Color;

try (Presentation prs = new Presentation()) {
    ISlideCollection slides = prs.getSlides();
    ISlide slide = slides.get(0);

    // Add two rectangles
    IAutoShape box1 = slide.getShapes().addAutoShape(
        ShapeType.RECTANGLE, 50, 200, 200, 100
    );
    IAutoShape box2 = slide.getShapes().addAutoShape(
        ShapeType.RECTANGLE, 450, 200, 200, 100
    );

    box1.addTextFrame("Start");
    box2.addTextFrame("End");

    // Add a bent connector (initial bounds are overwritten by the connection)
    IConnector conn = slide.getShapes().addConnector(
        ShapeType.BENT_CONNECTOR3, 0, 0, 10, 10
    );

    // Connect right side of box1 (site 3) to left side of box2 (site 1)
    conn.setStartShapeConnectedTo(box1);
    conn.setStartShapeConnectionSiteIndex(3);
    conn.setEndShapeConnectedTo(box2);
    conn.setEndShapeConnectionSiteIndex(1);

    prs.save("connected.pptx", SaveFormat.PPTX);
}

The placeholder bounds (0, 0, 10, 10) passed to addConnector are ignored once the connection endpoints are set; PowerPoint re-routes the connector to the attached shapes.

Connector Types

Use ShapeType constants to select the connector routing style. Common options include straight lines, single-elbow, and double-elbow connectors:

import org.aspose.slides.foss.ShapeType;

// Straight line
ShapeType.STRAIGHT_CONNECTOR1

// Single elbow (L-shape)
ShapeType.BENT_CONNECTOR2

// Double elbow (Z-shape): most common
ShapeType.BENT_CONNECTOR3

// Curved connector
ShapeType.CURVED_CONNECTOR3

Style the Connector Line

Set the connector’s line color, width, and dash style via conn.getLineFormat() after creating the connector:

import org.aspose.slides.foss.Presentation;
import org.aspose.slides.foss.ISlide;
import org.aspose.slides.foss.IShape;
import org.aspose.slides.foss.IAutoShape;
import org.aspose.slides.foss.IConnector;
import org.aspose.slides.foss.ILineFormat;
import org.aspose.slides.foss.Connector;
import org.aspose.slides.foss.ShapeType;
import org.aspose.slides.foss.export.SaveFormat;
import org.aspose.slides.foss.drawing.Color;

try (Presentation prs = new Presentation()) {
    ISlideCollection slides = prs.getSlides();
    ISlide slide = slides.get(0);

    IAutoShape box1 = slide.getShapes().addAutoShape(
        ShapeType.RECTANGLE, 50, 150, 180, 80
    );
    IAutoShape box2 = slide.getShapes().addAutoShape(
        ShapeType.RECTANGLE, 500, 300, 180, 80
    );

    IConnector conn = slide.getShapes().addConnector(
        ShapeType.BENT_CONNECTOR3, 0, 0, 10, 10
    );
    conn.setStartShapeConnectedTo(box1);
    conn.setStartShapeConnectionSiteIndex(2);   // bottom of box1
    conn.setEndShapeConnectedTo(box2);
    conn.setEndShapeConnectionSiteIndex(0);     // top of box2

    // Style: 2 pt width, blue color
    ILineFormat lf = conn.getLineFormat();
    lf.setWidth(2.0);
    lf.getFillFormat().getSolidFillColor().setColor(
        Color.fromArgb(255, 0, 0, 255)
    );

    prs.save("styled-connector.pptx", SaveFormat.PPTX);
}

Flowchart with Multiple Connectors

Build a multi-step flowchart by creating several shapes and adding a connector between each pair of consecutive steps:

import org.aspose.slides.foss.Presentation;
import org.aspose.slides.foss.ISlide;
import org.aspose.slides.foss.IShape;
import org.aspose.slides.foss.IAutoShape;
import org.aspose.slides.foss.IConnector;
import org.aspose.slides.foss.ILineFormat;
import org.aspose.slides.foss.Connector;
import org.aspose.slides.foss.ShapeType;
import org.aspose.slides.foss.export.SaveFormat;
import org.aspose.slides.foss.drawing.Color;

try (Presentation prs = new Presentation()) {
    ISlideCollection slides = prs.getSlides();
    ISlide slide = slides.get(0);

    // Three-step flowchart
    IAutoShape step1 = slide.getShapes().addAutoShape(
        ShapeType.RECTANGLE, 350, 50, 200, 70
    );
    IAutoShape step2 = slide.getShapes().addAutoShape(
        ShapeType.RECTANGLE, 350, 220, 200, 70
    );
    IAutoShape step3 = slide.getShapes().addAutoShape(
        ShapeType.RECTANGLE, 350, 390, 200, 70
    );

    step1.addTextFrame("Step 1");
    step2.addTextFrame("Step 2");
    step3.addTextFrame("Step 3");

    // Connect step1 -> step2
    IConnector conn1 = slide.getShapes().addConnector(
        ShapeType.BENT_CONNECTOR3, 0, 0, 10, 10
    );
    conn1.setStartShapeConnectedTo(step1);
    conn1.setStartShapeConnectionSiteIndex(2);   // bottom
    conn1.setEndShapeConnectedTo(step2);
    conn1.setEndShapeConnectionSiteIndex(0);     // top

    // Connect step2 -> step3
    IConnector conn2 = slide.getShapes().addConnector(
        ShapeType.BENT_CONNECTOR3, 0, 0, 10, 10
    );
    conn2.setStartShapeConnectedTo(step2);
    conn2.setStartShapeConnectionSiteIndex(2);
    conn2.setEndShapeConnectedTo(step3);
    conn2.setEndShapeConnectionSiteIndex(0);

    prs.save("flowchart.pptx", SaveFormat.PPTX);
}

Read Connector Properties

Load an existing presentation and inspect each connector’s start and end shape connections by casting shapes to IConnector:

import org.aspose.slides.foss.Presentation;
import org.aspose.slides.foss.ISlide;
import org.aspose.slides.foss.IShape;
import org.aspose.slides.foss.IAutoShape;
import org.aspose.slides.foss.IConnector;
import org.aspose.slides.foss.ILineFormat;
import org.aspose.slides.foss.Connector;
import org.aspose.slides.foss.ShapeType;
import org.aspose.slides.foss.export.SaveFormat;
import org.aspose.slides.foss.drawing.Color;

try (Presentation prs = new Presentation("connected.pptx")) {
    for (IShape shape : prs.getSlides().get(0).getShapes()) {
        if (shape instanceof Connector) {
            IConnector conn = (IConnector) shape;
            IShape start = conn.getStartShapeConnectedTo();
            IShape end = conn.getEndShapeConnectedTo();
            System.out.println("Connector: "
                + (start != null ? start.getName() : "?")
                + " -> "
                + (end != null ? end.getName() : "?"));
        }
    }
}