Create circle-only annotation

[Valentin Marteau]

Hello,

We are looking for a way to create annotations which are circles (not ellipsis).

Is there a way to configure or extend EllipseAnnotation so that it can only draw circles ?

Thanks and best regards

Valentin

[Anthony Chen]

Hi Valenti,

It is possible.

If its from the UI, you can do the following:
When using the ellipse create tool, hold shift while dragging around.

If you want to do this programmatically, please use the following code snippet:

    Tools.EllipseCreateTool.prototype.mouseMove = function(e) {

      Tools.GenericAnnotationCreateTool.prototype.mouseMove.call(this, e);

      const annotation = this['annotation'];

      if (annotation) {

        const width = annotation['Width'];

        const height = annotation['Height'];

        const maxDimension = Math.abs(width < height ? width : height);

        annotation['Width'] = maxDimension;

        annotation['Height'] = maxDimension;

  

        // The following code ensures the annotation X and Y

        // remains fixed to point where we started drawing,

        // even as the annotation moves upwards or leftwards

        const pt0 = this['pageCoordinates'][0];

        const pt1 = this['pageCoordinates'][1];

  

        const deltaX = pt1.x - pt0.x;

        const deltaY = pt1.y - pt0.y;

  

        const absDeltaX = Math.abs(deltaX);

        const absDeltaY = Math.abs(deltaY);

  

        const offset = absDeltaX < absDeltaY ? absDeltaX : absDeltaY;

  

        if (deltaX < 0) {

          annotation['X'] = pt0.x - offset;

        }

  

        if (deltaY < 0) {

          annotation['Y'] = pt0.y - offset;

        }

  

        this.docViewer.annotationManager.redrawAnnotation(this['annotation']);

  

        // By toggling this on/off we can ensure the ellipsis remains

        // a perfect circle when it is being resized when selected

        annotation['MaintainAspectRatio'] = true;

      }

    };

Please let me know if either options were not what you were looking for.

Anthony Chen

Software Developer

PDFTron Systems Inc.

[Valentin Marteau]

Hi Anthony,

Thank you!

We were looking for a programmatic approach so we will try your solution.

Regards,

Valentin