There's only one place where we need this ourselves and that's also
easily done by hand. Otherwise the `as_bytes(_mut)()` accessor provides the
functionality along with `width()` and `height()`.
Other than that the API is mostly consuming, given that `sixtyfps::Image`
has no way of extracting the data again.
This adds an ImageBuffer and PixelBuffer type for SharedVector
backed images. The documentation explains how to use this
with low-level rendering functions and the popular image crate.
Fixes#387
This requires some gymnastics to get right as the information
need to be passed to the compiler despite having no direct dependency
between the compiler and the runtime or backends.
So use a file in the build directory to tell the default style
cc: #83
Setting the value of the native_padding_{left, right, top, bottom}
properties *during* the layout_info() call is too late, as the calling
compute_layout implementation has already queried for those properties.
Instead, this patch moves the padding calculation into a shared property
binding that's queried from bindings to the individual native_padding_*
properties and layout_info() just uses the properties, too.
Currently the Qt backend still redirect everything to the GL backend,
but the goal is to use QPainter and QWindow
This also adds a "default" backend, whose goal is to select the proper
backend at compile time
