Allow for x-y coordinates to be negative and subtract from width-height

[andymeneely]

Cairo doesn't do that normally. Maybe make this a configurable setting in config.yml so it's easier to place.

[andymeneely]

After playing around with this, I'm not sure I like it. I would rather run the layout.yml through ERB so we can do stuff like:

title:
  x: <%=@width-75%>

[scraimer]

Ooh, ERB for layouts would be awesome! It would move much of my positioning code out of the deck.rb and into the layout, where it belongs!

For example, If I want to draw a circle around some text. I could easily use ruby expressions to offset the circle so that its origin is positioned correctly to make the circle go around the text.

SomeText:
   x: 50
   y: 50
   width: 150
   height: 150

SomeTextCircle:
    x: <%=@x - 20%>
    y: <%=@y - 20%>

[andymeneely]

Actually, you don't need ERB for that situation - use extends:

SomeText:
  x: 50
  y: 50
SomeTextCircle:
  extends: SomeText
  x: -= 20 # in yaml this is a string, but it gets processed as a part of processing "extends"
  y: -= 20

http://andymeneely.github.io/squib/doc/file.README.html#Special_key__extends

But... there are other situations where ERB would be helpful. The issue I created for that is #36.

[scraimer]

Good point!