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.
Have a function first called before the children, and then the main function
called after the children if they did not accept the event. This will allow
processing the Flickable gesture properly
Remove the pos parameter to the render functions and instead let
the item renderer apply the transformation on the rendere (femtovg
canvas or QPainter).
So `draw_*` functions in the backend now always operate in item local
coordinates.
Don't use the item's rendering cache to determine the image size, as
that's soley for rendering. The Qt backend doesn't use the item cache
and the GL backend neither after this change. Instead both backends have
a cache for decoded images.
This allows filling glyphs with gradients. However femtovg
appears to apply the start/end position per-glyph
instead of globally - resulting in a different result than Qt.
Due to stretch using rounding, it may happen that the minimum width will
rounded down, and then later when we draw the text with the calculated width,
we have no choice but cut off the last letter.
Fixes#151
* Rename logo to the more generic meta as keyboard modifier.
* Use control as the real modifier and map command key to it with
winit and keep Qt semantics as-is.
This will give a nicer API to expose to .60. If the struct weren't
repr(C) then the booleans would be nicely packed, but alas that's not
happening. On the other hand we're not keeping many instances of them
around.
Fold CharacterInput into KeyPressed/KeyReleased and store the "key" as a string.
Also, instead of exposing the KeyCode we're encoding special characters
into the string.
The GL backend uses the item graphics cache for the image size function,
which uses a PropertyTracker. That tracker must have the Image's source
included in its dependencies, to avoid that when loading a HTML image
for example, the cache isn't invalidated when the source is changed
before the HTML image was loaded async. That's why the get() call on the
source property must happen from within the PropertyTracker's callback.
For all other items the default is the empty size.
This also required three fixes for the HTML image loading:
* The upload_pending property value was inverted, it needs to start
out as true (pending yes) and be set to false when it finished
loading (not pending anymore)
* Mark the upload_pending property as dirty before scheduling the
redraw, in case it's sync
* Pass the item rendering cache to the image_size function to ensure
that the Rc<CachedImage> is not only weak inside the image_cache
of the GLRendererData but also strong on the item.
Represent a non-specified pixel size and font weight through a None option.
This is cleaner and has the added benefit that the backend can now
easily decide what the default size/weight should be.
For the GL backend a resolved font is just a handle (femtovg::FontId)
and we can cache that. Consequently we don't really need Rc<dyn Font>
but can let `fn font(...)` on the backend return a "resolved" font that
includes the pixel size, which in turn simplifies the Font trait
signatures.
The only caveat is that because on the item level we don't know what the
chosen backend type is, we can only receive a `dyn Font`, which means
it's wrapped - for now - in a Box.
Create the font request on the text item side to reduce duplication and
remove the fallback logic from the font_weight accessor, in preparation
for automatic generation of that getter.
This means going back to an immutable renderer reference and interior
mutability for the canvas and the gpu cache. This is because while
traversing the item tree for rendering we may end up destroying
other items due to the lazyness of the models.
