Inkscape: How to symetrically adjust handles on two nodes of the same path?

Question

On a symmetrical path, I'd like to adjust two nodes while maintaining the symmetry.

I understand I can move the nodes horizontally using < and shift-< using the center point as the symmetry point of a scaling operation. What if I want to adjust the handles only (changing the angle or the length)?

Inkscape 0.91, Windows 7.

Answer 1

The handles can't be moved together but you can place them in a position individually which maintains the symmetric look (explained at the bottom)

Drawing a symmetric path

In this method you will draw half of the path, clone it, flip the clone, place it next to each other and join the 2 paths to form the symmetric shape (the instructions below looks like this is a very tedious thing to do, but it isn't, hence this straight forward summary)

1. Start with a (horizontal or vertical) guide that marks as the centre of the object

2. Start with one side of the guide and draw one half roughly, you can edit it later

3. Clone that path(go to Edit –> Clone –> Create Clone or press ALT + D), flip it (horizontally or vertically, as required) and drag it to the other side of the guide while pressing the CTRL key
4. Make edits in the original path, the changes will be reflected in the cloned object and the symmetry will be maintained
5. Once you are satisfied with the final look, unlink the cloned path(go to Edit –> Clone –> Unlink Clone or press SHIFT + ALT + D) and unite the two objects by selecting the 2 paths and performing the Union path operation (CTRL + + or go to Path –> Union in the menu)

Editing an existing symmetric path

Method 1

In this method you will divide the existing path into 2, delete one half, clone the other half, flip it, place it next to each other, make edits and finally join them together.

1. Drag a guide from the ruler and snap it(make sure snapping is enabled) to the middle of the object.
2. Draw a straight line by plotting 2 nodes using the bezier tool along the guide, make sure the line covers the entire symmetric object
3. Select the line and the symmetric path and perform the Division path operation(CTRL + / or go to Path –> Division in the menu)
4. Select any one side of the 2 divided objects and delete it
5. Clone the other path(go to Edit –> Clone –> Create Clone or press ALT + D), flip it and drag it to the other side of the guide while pressing the CTRL key
6. Make edits in the original path, the changes will be reflected in the cloned object and the symmetry will be maintained

Method 2

This method is not so straight forward as the one above but it deals with positioning the handles as desired.

In this method the handle of one node is altered, then it's position is identified from the centre(a common point for both the side of the symmetric shape) then the same position is plotted on the other side using guides and a lines.

1. Start with a guide that marks as the centre of the object along the symmetry
2. position the handle of one node in a place you want
3. Drag another guide to the handle, the guide origin won't snap with the handle, so drag it as close as possible,then snap the handle to the guide origin(make sure to enable snapping)
4. use the bezier path tool and place a node on top of the handle(guide origin) and second one anywhere at the centre guide that is in the middle of the object and press Enter or Return Key.
5. Duplicate(or copy and paste) the line and and flip it, drag it (while pressing CTRL) to the other side of the middle guide.
6. Drag the handle on the 2nd node so that the handle snaps to the corner of the flipped line.