This change adds support for rendering static SVG images using the
`resvg` crate, allowing svg sources in the `img` tag and in CSS
`background` and `content` properties. There are some limitations in
using resvg:
1. There is no support for animations or interactivity as these would
require implementing the full DOM layer of SVG specification.
2. Only system fonts can be used for text rendering. There is some
mechanism to provide a custom font resolver to usvg, but that is not
explored in this change.
3. resvg's handling of certain edge cases involving lack of explicit
`width` and `height` on the root svg element deviates from what the
specification expects from browsers. For example, resvg uses the values
in `viewBox` to derive the missing width or height dimension, but
without scaling that dimension to preserve the aspect ratio. It also
doesn't allow overriding this behavior.
Demo screenshot:
<details>
<summary>Source</summary>
```
<style>
#svg1 {
border: 1px solid red;
}
#svg2 {
border: 1px solid red;
width: 300px;
}
#svg3 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: contain;
}
#svg4 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: cover;
}
#svg5 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: fill;
}
#svg6 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: none;
}
</style>
</head>
<body>
<div>
<img id="svg1" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
</div>
<div>
<img id="svg2" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
<img id="svg3" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
<img id="svg4" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
</div>
<div>
<img id="svg5" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
<img id="svg6" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
</div>
</body>
```
</details>
---------
Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
This is the last big change necessary to create the
`constellation_traits` crate. This moves the data structure for messages
that originate from the `ScriptThread` and are sent to the
`Contellation` to `constellation_traits`, effectively splitting
`script_traits` in half. Before, `script_traits` was responsible for
exposing the API of both the `ScriptThread` and the `Constellation` to
the rest of Servo.
- Data structures that are used by `ScriptToConstellationMsg` are moved
to `constellation_traits`. The dependency graph looks a bit like this:
`script_layout_interface` depends on `script_traits` depends on
`constellation_traits` depends on `embedder_traits`.
- Data structures that are used in the embedding layer
(`UntrustedNodeAddress`, `CompositorHitTestResult`, `TouchEventResult`
and `AnimationState`) are moved to embedder_traits, to avoid a
dependency cycle between `webrender_traits` and
`constellation_traits`.
- Types dealing with MessagePorts and serialization are moved to
`constellation_traits::message_port`.
Testing: This is covered by existing tests as it just moves types
around.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
