The default size for label is always a compromise, no matter what value
is chosen, some layouts will require local manual overrides.
Having the preferred size be opportunistic_grow in both directions seems
like it's currently the option that works without modification in most
cases.
This commit adds some finagling and shrinking of the corner bitmap
to handle drawing shadows on elements where the shadow radius >
half the width or height of the element. Previously things would
go horribly wrong when this happend.
There could still be some edge cases, but things seem to be working
fairly well now.
This fixes a issue due to the background/border painting using
.to_rounded<int>() to get an IntRect, but shadow painting was using
enclosing_int_rect().
enclosing_int_rect() uses some floors/ceils and does not always match
.to_rounded<int>().
This now allows passing a 'fill_color' to the blur, any fully
transparent pixels will be replaced with this color (with the alpha
set to 0).
For box-shadows, if this color is set to the same as the shadow,
the issues around the fringes are fixed. This also fixes some places
where dark shadows appeared light / the wrong color.
With this change the blur no longer dominates the profile. On my PC
it is down to 27% (which is the same as the AA ellipse painting).
The box-shadow.html test page now also feels more responsive.
This adds an implementation of StackBlur which is a very efficient
blur that closely approximates a gaussian blur. It has a number of
benefits over the existing FastBoxBlurFilter:
1. It's faster (~half the pixel lookups of a single box blur pass)
2. It only requires a single pass over image to produce good results
- (Rather than the 3 the box blur requires)
3. It only needs to allocate a buffer of `blur_radius * 2 + 1` colors
- These easily fits on the stack for any reasonable radius
For a detailed explanation of the algorithm check out this link:
https://observablehq.com/@jobleonard/mario-klingemans-stackblur
Previously we forwarded all event handler attributes to Window from
these two elements, however, we are only supposed to forward blur,
error, focus, load, resize and scroll.
Before this, the spacers were handled as just another child widget, and
as such could take away space from real widgets when growing.
This also fixes the problem of effectively 0 sized spacers, that doubled
the spacing between the widgets they were placed between.
Effective sizes are the ones that are actually to be used for layout.
They are just their respective propertys value, or the value returned
by the calculated_<min/preferred>_size, when the respective property
is set to shrink or fit.
The "calculated" values in turn are specific to the widget. Container
widgets for example can calculate their values depending on their
layout and child widget requirement.
Simple widgets like labels and buttons can for example calculate their
values based upon their current text.
This allows HTMLCanvasElement and WebGL rendering contexts to share
their lifetime, as JS allows them to arbitrarily access them at any
time and WebGLRCB.canvas expects a non-null return value.
