[svg] Initial <tspan> support
Introduce classes to support text node nesting:
- TextContainer -- base class for nestable text containers
(<text>, <tspan> etc)
- TextLiteral -- actual text string/payload
Example structure mapping:
<text>Foo<tspan>Bar</tspan>Baz</text>
TextContainer[text]
TextLiteral["Foo"]
TextContainer[tspan]
TextLiteral["Bar"]
TextLiteral["Baz"]
Also add text layout state (SkSVGTextContenxt) to SkSVGRenderContext.
This will be used to track layout across a text subtree.
For now we don't touch rendering, so the output is quite garbled for
non-trivial text (no advance propagation -> things draw on top of each
other).
Bug: skia:10840
Change-Id: Ic6d3990ec8635b586f5d3d226be070fbf134e391
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/341236
Commit-Queue: Florin Malita <fmalita@google.com>
Reviewed-by: Tyler Denniston <tdenniston@google.com>
6 files changed