the old version of Accessor::access() is redundant,
we replaced it with set().
It's still under the beta, we can remove it immediately.
Note that we've planned to promote them official APIs in v0.9.
Newly changed, tagging beta again...w
It supports data parameters that
can pass user data to the callback function.
std::unique_ptr<Picture> access(std::unique_ptr<Picture> picture, bool(*func)(const Paint* paint, void* data), void* data) noexcept;
Basically, this Accessor is a utility to debug the Scene structure,
by traversing the scene-tree by users.
You can search specific nodes to read the property information,
figure out the structure of the scene tree and its size.
We actually don't recommend you to touch the property unless you really
know the each paint's position and role because it's not visible, difficult to
understand its anatomy.
Also, You must underatnd that modifying the nodes of the scene will be going
well with both the art-design structure and the prorgram logic.
In this first version, Accessor only supports for the Picture class.
@example:
auto picture = tvg::Picture::gen();
picture->load("test.svg");
//The callback function from lambda expression.
//This function will be called for every paint nodes of the tree.
auto f = [](const tvg::Paint* paint) -> bool
{
if (paint->identifier() == Shape::identifier()) {
//override properties?
uint8_t r, g, b, a;
paint->fillColor(&r, &g, &b, &a);
paint->fill(r / 2, g / 2, b / 2, a);
}
//You can return false, to stop traversing immediately.
return true;
};
auto accessor = tvg::Accessor::gen();
picture = accessor->access(move(picture), f);
...
@Issue: https://github.com/Samsung/thorvg/issues/693
