Move the item graphics cache into the GraphicsWindow and then, together
with the new femtovg::TextContext, we can provide the metrics and can
stop using the window_map_pending notifier for this query.
With wasm there is no current context (can alwasy render) but we own the
winit::Window. With glutin own the ContextWrapper and have to make it
current (and resize). This patch hides all that behind the OpenGLContext
type.
This is primarly search & replace for now, slightly simplifying function
signatures.
However this paves the way to a thread-local font cache that can share
fonts across windows (not glyph atlas) and also measure without a canvas.
The follow basic example reproduces the issue that the items remain around
but the item cache has been destroyed and re-created, which causes get_mut() to fail:
```
let app = App::new();
loop {
app.run(); // now close the window via the close button in the window decoration
}
```
When we calculate the initial layout without a mapped window early on,
we end up with zero text metrics with the GL backend due to an API
limitation of femtovg.
While working on that, this patch introduces a workaround to mark the callers of
image_size() and font_metrics() as dirty when the window is mapped.
Let's keep source compatibility and define `drop-shadow-blur` to be a radius.
The CSS spec says that the standard deviation is half of the radius.
We just need to scale again and increase the shadow rect to make sure that no borders are visible.
Commit bb7b301b10 pulled in a branch of femtovg, which
had a change to its shader that used a variable in the loop condition.
That is unfortunately not supported in WebGL 1.0 / GLES 2.0.
The pinned femtovg works around that limitation.
Fixes#230
This replaces the box gradient with a new implementation that
behaves like the HTML Canvas element, by applying a gaussian
blur to the alpha of the rectangle to shadow.
The drop-shadow-blur property is changed to be now just a "level", like
the HTML Canvas shadowBlur property, which is defined to be half of the
standard deviation of the gaussian blur to be applied.
We use a weight of 900 in the demo, which results in a QFont::Weight of 100.
Unfortunately QFont::setWeight() doesn't cap itself, but brutally asserts
if the value is > 99. So let's cap ourselves.
We don't need a property reference anymore, a plain image reference is fine AFAICS.
Dirtyness of the source is tracked on the caller side of layouting_info()
or in the draw_image_impl anyway.
Use slab instead of the deprecated vec_arena, both of which appear to
use the same Vec based storage of an enum that's either the entry or an
index to the next free slot.
