Update Layout without creating from scratch

[miquik]

Hi,
There is a way to update layout (recalculate boxes position/size when viewport is resized for example), without creating layout from scratch? Usually CSS styles and fonts doesn't change, so (for example) creating a VisualContext every time size is changed it seems a little expensive for me.

Another question related to this one: could I recalculate only a "part" of document tree? Just a subtree for example?

Thanks

[radkovo]

CSSBox was originally designed primarily for one-time rendering so that page re-rendering was actually never thoroughly tested. But in theory, for re-rendering the page, the following approach should work:

Viewport viewport = engine.getViewport();
viewport.doLayout(canvasWidth, true, true); // canvasWidth is the new canvas width
viewport.absolutePositions(); // re-compute absolute positions of sub-boxes

Similarly, a subtree rooted with a BlockBox can be theoretically recomputed like this:

BloxBox root = ... // the subtree root block box
root.doLayout(root.getAvailableContentWidth(), true, true);
root.absolutePositions()

The size of the root block itself is not recomputed. Therefore, if some element changes, I would do this for its containing block (nearest block ancestor).

[miquik]

Thanks a lot I will try

[Osiris-Team]

@radkovo Doesn't work for me. Is the root returned by DOMAnalyzer a temporary/copy representation and not the original that gets rendered? Because I modified it and tried to re-render, but the changes were not shown.

Also another question. I assume there is no support for animations then? Or animations based on input, like a mouse hover for example?

Here is the code I am working with: https://github.com/Osiris-Team/Desku/blob/ccsbox/src/test/java/com/osiris/desku/cssbox/CssBoxTest.java