mirrors/ladybird
0
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2025-07-29 12:19:54 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 9

LibWeb: Implement basics for OffscreenCanvas

Browse source 
This implements the basic interface, classes and functions for
OffscreenCanvas. Many are still stubbed out and have many FIXMEs in
them, but it is a basic skeleton.
This commit is contained in:
Totto16 2025-03-07 00:19:45 +01:00 • committed by Andrew Kaster
commit 2ad3ce5d37
Notes: github-actions[bot] 2025-06-30 15:47:43 +00:00
14 changed files with 1094 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

60
Libraries/LibWeb/HTML/Canvas/CanvasTextDrawingStyles.h
View file

@ -11,11 +11,14 @@
#include <LibWeb/CSS/StyleValues/ShorthandStyleValue.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/HTML/Canvas/CanvasState.h>
#include <LibWeb/HTML/OffscreenCanvas.h>
#include <LibWeb/HTML/Window.h>
#include <LibWeb/HTML/WorkerGlobalScope.h>
namespace Web::HTML {
// https://html.spec.whatwg.org/multipage/canvas.html#canvastextdrawingstyles
template<typename IncludingClass>
template<typename IncludingClass, typename CanvasType>
class CanvasTextDrawingStyles {
public:
~CanvasTextDrawingStyles() = default;
@ -40,6 +43,34 @@ public:
font_family->to_string(CSS::SerializationMode::Normal));
}
// https://html.spec.whatwg.org/multipage/canvas.html#font-style-source-object
Variant<DOM::Document*, HTML::WorkerGlobalScope*> get_font_source_for_font_style_source_object(CanvasType& font_style_source_object)
{
// Font resolution for the font style source object requires a font source. This is determined for a given object implementing CanvasTextDrawingStyles by the following steps: [CSSFONTLOAD]
if constexpr (SameAs<CanvasType, HTML::HTMLCanvasElement>) {
// 1. If object's font style source object is a canvas element, return the element's node document.
return &font_style_source_object.document();
} else {
// 2. Otherwise, object's font style source object is an OffscreenCanvas object:
// 1. Let global be object's relevant global object.
auto& global_object = HTML::relevant_global_object(font_style_source_object);
// 2. If global is a Window object, then return global's associated Document.
if (is<HTML::Window>(global_object)) {
auto& window = as<HTML::Window>(global_object);
return &(window.associated_document());
}
// 3. Assert: global implements WorkerGlobalScope.
VERIFY(is<HTML::WorkerGlobalScope>(global_object));
// 4. Return global.
return &(as<HTML::WorkerGlobalScope>(global_object));
};
}
void set_font(StringView font)
{
// The font IDL attribute, on setting, must be parsed as a CSS <'font'> value (but without supporting property-independent style sheet syntax like 'inherit'),
@ -59,13 +90,36 @@ public:
// Load font with font style value properties
auto const& font_style_value = my_drawing_state().font_style_value->as_shorthand();
auto& canvas_element = reinterpret_cast<IncludingClass&>(*this).canvas_element();
auto& font_style = *font_style_value.longhand(CSS::PropertyID::FontStyle);
auto& font_weight = *font_style_value.longhand(CSS::PropertyID::FontWeight);
auto& font_width = *font_style_value.longhand(CSS::PropertyID::FontWidth);
auto& font_size = *font_style_value.longhand(CSS::PropertyID::FontSize);
auto& font_family = *font_style_value.longhand(CSS::PropertyID::FontFamily);
auto font_list = canvas_element.document().style_computer().compute_font_for_style_values(&canvas_element, {}, font_family, font_size, font_style, font_weight, font_width);
my_drawing_state().current_font_cascade_list = font_list;
// https://drafts.csswg.org/css-font-loading/#font-source
auto font_source = get_font_source_for_font_style_source_object(canvas_element);
auto font_list = font_source.visit(
[&](DOM::Document* document) -> RefPtr<Gfx::FontCascadeList const> {
if constexpr (SameAs<CanvasType, HTML::HTMLCanvasElement>) {
return document->style_computer().compute_font_for_style_values(&canvas_element, {}, font_family, font_size, font_style, font_weight, font_width);
} else {
return document->style_computer().compute_font_for_style_values(nullptr, {}, font_family, font_size, font_style, font_weight, font_width);
}
},
[](HTML::WorkerGlobalScope*) -> RefPtr<Gfx::FontCascadeList const> {
// FIXME: implement computing the font for HTML::WorkerGlobalScope
return {};
});
if (!font_list)
return;
if (font_list->is_empty())
return;
my_drawing_state().current_font_cascade_list = font_list->first();
}
Bindings::CanvasTextAlign text_align() const { return my_drawing_state().text_align; }