Update: the changes discussed in this post were implemented in Polydia 0.8.6. The aspect ratio settings can now be found in Shape Styles under the Dimension section.

There are a couple of changes planned for Polydia in the next month or so that may impact existing diagrams and it seemed prudent to provide some advance notice before the changes occur as well as providing an opportunity for you to give feedback if anything has been overlooked regarding these changes.

There are two properties at the shape level that currently feel out of place: 'Width = Height' and 'Use image aspect ratio' (for images). These two settings need to reside at the same level as they are mutually exclusive. Months ago when Polydia was in alpha, these settings were in shape styles rather than their current home in the shapes themselves. In retrospect, a somewhat arbitrary decision was made at the time and they were moved to the shape level thinking that this would provide some additional flexibility. As time goes by, it has become apparent that there seem to be more benefits in moving these properties back to shape styles rather than keeping them where they are. This means that both of these settings will be removed from the shape properties and added back to the shape style properties.

The first argument in favor of making this change is the experience gained having created numerous templates and documents over the last several months: having these settings in shape properties seems to almost always create more work than if they were in the shape styles. The second is that there are some features that would be great to add to Polydia, but can't be as long as these are shape properties.

However, the downside to making this move is that it requires making some assumptions about existing documents in order to migrate them and may require some minor editing of your existing documents. The current plan is that when this change occurs and an existing document is opened, majority rules in determining what setting to set on the shape style. In the event of a tie, preference will be given to 'Use image aspect ratio' first, 'Width = Height' second, and neither third. So let's say you have a document with five shapes using a given style: two of them are set to 'Use image aspect ratio', two of them are set to 'Width = Height', and one set to neither. In this case the style would be set to have all of the shapes using this style to 'Use image aspect ratio'. Hopefully this will result in no need for changes for most, if not all, of your existing documents. In the worst-case scenario, you might need to create one or two additional styles in order to maintain the exact same behavior as your document has currently.

If you see this as creating a problem with your existing documents or think of something that has been overlooked, please respond in the Google+ thread.