Doodling with Cairo...

Hi,

 

I’ve been experimenting with the various Cairo bits and pieces trying to figure out how to get a nice looking tree/UI – some interesting stuff! (thanks for the previous pointers, everyone).

 

One of which is the Gizmo – which on first impression I wondered what’s with all these pink rectangles?

 

But delving deeper it looks like a pretty cool open ended framework – I’ve been experimenting with nesting and it sort of works, but not sure if I’m configuring it correctly.

 

The Cairo Wrapper Kit is a piece of art, but I’m struggling to get my head around it – wrapper hell?

 

Anyway, I was wondering where the “Doodle Layout Algorithm” came from? – all I can find are references to a constraint based object visualization system from the mid 90’s.

 

BTW, I know Smalltalk is generally self documenting code, but some “big picture” class/package documentation with these lovely experiments would make them a lot more accessible!

 

Cheers,

 

Stewart

 

 

Gizmo>>layoutFromIndex: index

            "** The Doodle Layout Algorithm **

1) Use desiredLayoutBlock to find out what we want as our bounds inside the availableExtent given to us. Store this in @desired.

2) Figure out what extent we want to offer our children based on our @desired bounds. Store this in @offered.

            @desired may contain a width/height of BlockClosure. In this case, we offer the

            available space for that dimension to our children

3) Offer the @offered space to each child, storing their @requested space

4) Keep a record of the @maximum extent that our children reach inside us so that we can decide how to clip correctly.

5) <pluggable> Use our child layout algorithm to position and size the @requested space as the @bounds of the child

6) Return our @desired bounds to our parent as a requested space replacing any BlockClosure with details from our children's @maximum extent.

."

 

 

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Hi Michael,

 

Thanks for making Gizmo available – I’ve discovered the clocks, and have experimented with nesting them – quite funky seeing the Dr Who, alongside yours and Travis’ clock in one window.

 

I was wondering whether you could provide a few more details on “we have other plans there using a constraint based solver that has been proven in production code both in Smalltalk and in other languages.”? Sounds interesting…

 

Yeah, it is inspiring what people have done with Cairo in VW. I’ve been working through various examples/frameworks etc trying to get my head around it all. I’m now trying to apply it to develop my own cool looking UI. A lot of work, but experiments etc such as yours and others are a great help – thanks.

The Cairo Wrapper Kit is a piece of art, but I’m struggling to get my head around it – wrapper hell?

Am 09.01.2008 um 16:34 schrieb Stewart MacLean <[hidden email]>:

The Cairo Wrapper Kit is a piece of art, but I’m struggling to get my head around it – wrapper hell?

Stewart,

if you meant the package "CairoGraphics-Wrappers", then it's my fault. :-)  

<base href="x-msg://359/">

Resending as didn’t appear on list… I’ve also subsequently tried your code and the improvement is fantastic!

 

Hi Henrik,

 

Thank you, thank you!

 

I’ve been digging into the GF/ST Framework (please see clunky object model below – deleted as message didn’t appear on vwnc list) and had figured that GFScalingPen was what I should reimplement, but was wilting at the prospect of all those primitives (Cairo details are still a mystery to me, and I don’t have much spare time to delve into it).

 

I was going to tackle it within the various GFGraphicObject subclasses that I needed, but this is a way better approach. I should be able to expand on your “primitive set” as required, given your kick start.

 

From what I understand, zooming should be possible using matrix transformations, but hey I’m getting ahead of myself!

 

Thanks again,

 

Cheers,

 

Stewart