The font resolution function querying fontdb is fast now, so we can
always call it when rendering text. That way we don't need all the
indirection in the text_size(), etc. functions, we don't need an entry
in the item graphics cache for the font and we can avoid a lot of
property dependencies.
Unfortunately the text property was not included in the property dependency chain
for the cached Font.
This is fixed by delaying that with a getter function, but in the mid term
we should be able to remove this again once
femtovg learns lazy font resolution.
As tests/cases/examples/image_rendering.60 itself demonstrates, the png file
should be loaded into the CPU side image cache once, but the two textures
should be cached independently.
cc #465
Like CSS image-rendering it has "smooth" and "pixelated" options.
Only OpenGL has been tested right now, have not tested WASM or Qt.
Right now the first instance of a @image-url() will set the scaling
for that specific image. The same image used from memory on the otherhand
can all have a different scaling property.
- Have the cursor at the right place when clicking on end of line
- make sure not to render new lines if there are some when in single-line mode
- Enter should make a new line
since there is only one function in it, just put that function in the Window
then there is no need to heap alocate a dyn FontMetrics just to call this function.
In preparation of having mutiple-lines TextInput, we will need to give more
data to this function so it no longer belong in FontMetrics
Also remove the unused FontMetric::line_height()
The cursor navigation left/right (and subsequently text selection) needs
to respect grapheme boundaries. Since we already depend on the
unicode-segmentation crate through femtovg, we might as well use the
functionality for determining grapheme boundaries from there.
The only place where the cursor navigation is allowed to break that is
when using backspace, as that allows the user to break glyph clusters.
That's all it is nowadays, it's a wrapper around Rc<Window>. It's not an
alias because we need to also "wrap" it to C++ via cbindgen, but that's
about it.
When replacing the text, it may happen that the cursor position becomes outdated.
As per #331 we should make sure that this is handled also on an API level,
but this patch at least avoids the panic triggered by using editing.
This requires the image size query to be window independent and go
through the backend instead.
This implies minor changes for the Qt backend and bigger ones for the GL
backend:
* There exists now a thread-local IMAGE_CACHE, which is used by the
backend's image_size() function as well as by the renderer for
loading CPU side images.
* The image remain as decoded images in there (including SVG tree)
and the window now has a texture_cache, which holds CachedImage
with ImageData::Texture.
* Rendering an image item therefore fetches the CPU side image,
calls upload_to_gpu() on it, which creates a new Rc<CachedImage>
and that's stored in the texture_cache.
* The texture cache continues to be pruned when hiding the window.
Split the vertical and horizontal pass into different property cache
This will allow to implement "height for with"
This patch does not port the Rust or C++ binding yet
When a Text element has wrapping enabled, it should not have zero
minimum size. Otherwise the layout will give it a height of zero in the
layout in the test case and that'll make the text disappear. There are
different options but this patch goes for minimum height as if no
wrapping was enabled (so at least one line plus forced line breaks).
Fixes#246
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.
Pass everything needed for delayed evaluation for
`PlatformWindow::font_metrics()` to permit caching the font matching
result in the Text/TextInput's rendering cache.
We query text metrics frequently for text items, for example when in
layouts. This requires font resolution, which is about to become more
much more expensive due to analysis of the underlying text. To speed
this up, the objective is to use the item rendering cache. Making that
work in turn requires querying all related properties inside a property
tracker. That means we need to delay querying anything related to that,
including the font request needed for the `font_metrics()` function on
the PlatformWindow trait.
