Reduce usage of fmt in serialization and error reporting
`format!` and `write!` create a somewhat-heavyweight `Formatting` struct and use dynamic dispatch to call into impls of `Dispaly` and related traits. The former also allocates an intermediate string that is sometimes unnecessary.
I started looking into this from https://bugzilla.mozilla.org/show_bug.cgi?id=1355599, but I expect the impact there will be small to insignificant. It might be a slightly less so on parsing (error reporting).
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I want to play with autogenerating style structs, and color is the smallest
struct out there.
However, moving it out of the mako file is a requirement. This patch does that.
Properly set default direction of prefixed linear gradients
The default linear gradient direction is `to bottom`. This correspondes to
`top` keyword in prefixed linear gradients. We should preserve the default value.
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The default linear gradient direction is `to bottom`. This correspondes to
`top` keyword in prefixed linear gradients. We should preserve the default value.
Handle single X keyword value in LegacyPosition
This is reviewed by emilio in bugzilla.
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We need to use enum instead of Either since we can't interpolate stroke-* between
unitless length and unit length(e.g. '5' -> '10px').
This coomit make following:
* Introduce SVGLengthOrPercentageOrNumber on computed and specified values.
* Make SVGLengthOrPercentageOrNumber animatable.
* Make stroke-dasharray not-accumulate.
Introduce ComputedUrl
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Use the new `ComputedUrl` type for computed types and `SpecifiedUrl` for specified types instead of using the `SpecifiedUrl` implementation for both.
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As silly as it may seem to specify font-sizes using viewport units, we weren't
handling zoom for them correctly either.
Bug: 1388588
Reviewed-by: Manishearth
MozReview-Commit-ID: 3Q6phYAu5CE
stylo: Bug 1374233 - Clamp interpolated values for properties which need to be restricted
Some properties only accept non-negative values, or values greater than or equal to one. It is possible to produce an negative interpolated values while using negative timing functions, so we have to apply a restriction to these values to avoid getting invalid values.
For example, line-height must be non-negative, but the output progress of some timing functions (e,g. cubic-bezier(0.25, -2, 0.75, 1)) may be a negative value, so the interpolated result of line-height is also negative.
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