SVG in KDE

"Commitment" is one of the words that have never been used in this blog. Which is pretty impressive given that I've managed to use such words as sheep, llamas, raspberries, ninjas, donkeys, crack or woodchuck quite extensively (especially impressive in a technology centric blog).

That's because commitment implies that whatever it is one is committed to plays an important role in their life. It's a word that goes beyond the paper or the medium on which it was written. It enters the cold reality that surrounds us.

But today is all about commitment. It's about commitment that KDE made to a technology broadly refereed to as Scalable Vector Graphics. I took some time off this week and came to Germany where I talked about usage of SVG in KDE.

The paper about, what I like to call, the Freedom of Beauty, is available here:

https://www.svgopen.org/2008/papers/104-SVG_in_KDE/

It talks about the history of SVG in KDE, the rendering model used by KDE, it lists ways in which we use SVG and finally shows some problems which have been exposed by such diverse usage of SVG in a desktop environment. Please read it if you're interested in KDE or SVG.

Hopefully this paper marks a start of a more proactive role KDE is going to be playing in shaping of the SVG standard.

Gradient bounds

The most unfriendly thing about rendering gradients with Qt has been the fact that you had to specify gradients in coordinates of the shape they were to be rendered on. It wasn't ideal especially for all applications which included any kind of animations or were rendering large number of items because it meant that the gradient had to be individually created for each and every one of items/frames. I've fixed that two days ago by adding a coordinate-mode property to QGradient, which now accepts ObjectBoundingMode. Object bounding mode, just like in SVG, means that the gradient coordinates are percentages of bounding box of the shape that the gradient is about to fill. So all the coordinates are between 0 and 1 and Qt automatically adjusts the bounds for gradient when it's being rendered. This makes it possible to easily use QGradient's with QPalette. An example where I'm drawing a bunch of rectangles and animate them along while the gradient is set only once with (0,0, 1, 1) coordinate box (meaning starting at the topleft and ending at the bottom right corner of each rectangle).
And since it's an animation (including a widget show/hide effect) here's a movie showing it in action.