ladybird/Libraries/LibWeb/HTML/Canvas/CanvasTextDrawingStyles.h
Andreas Kling e85c3c97fb LibWeb: Add mode flag to CSSStyleValue::to_string()
This will be used to differentiate between serialization for resolved
style (i.e window.getComputedStyle()) and serialization for all other
purposes.
2024-12-07 08:31:03 +00:00

85 lines
4.5 KiB
C++

/*
* Copyright (c) 2023, Bastiaan van der Plaat <bastiaan.v.d.plaat@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibWeb/CSS/Parser/Parser.h>
#include <LibWeb/CSS/StyleComputer.h>
#include <LibWeb/CSS/StyleValues/ShorthandStyleValue.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/HTML/Canvas/CanvasState.h>
namespace Web::HTML {
// https://html.spec.whatwg.org/multipage/canvas.html#canvastextdrawingstyles
template<typename IncludingClass>
class CanvasTextDrawingStyles {
public:
~CanvasTextDrawingStyles() = default;
ByteString font() const
{
// When font style value is empty return default string
if (!my_drawing_state().font_style_value) {
return "10px sans-serif";
}
// On getting, the font attribute must return the serialized form of the current font of the context (with no 'line-height' component).
auto const& font_style_value = my_drawing_state().font_style_value->as_shorthand();
auto font_style = font_style_value.longhand(CSS::PropertyID::FontStyle);
auto font_weight = font_style_value.longhand(CSS::PropertyID::FontWeight);
auto font_size = font_style_value.longhand(CSS::PropertyID::FontSize);
auto font_family = font_style_value.longhand(CSS::PropertyID::FontFamily);
return ByteString::formatted("{} {} {} {}",
font_style->to_string(CSS::CSSStyleValue::SerializationMode::Normal),
font_weight->to_string(CSS::CSSStyleValue::SerializationMode::Normal),
font_size->to_string(CSS::CSSStyleValue::SerializationMode::Normal),
font_family->to_string(CSS::CSSStyleValue::SerializationMode::Normal));
}
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'),
// and the resulting font must be assigned to the context, with the 'line-height' component forced to 'normal', with the 'font-size' component converted to CSS pixels,
// and with system fonts being computed to explicit values.
// FIXME: with the 'line-height' component forced to 'normal'
// FIXME: with the 'font-size' component converted to CSS pixels
auto font_style_value_result = parse_css_value(CSS::Parser::ParsingContext {}, font, CSS::PropertyID::Font);
// If the new value is syntactically incorrect (including using property-independent style sheet syntax like 'inherit' or 'initial'), then it must be ignored, without assigning a new font value.
// NOTE: ShorthandStyleValue should be the only valid option here. We implicitly VERIFY this below.
if (!font_style_value_result || !font_style_value_result->is_shorthand()) {
return;
}
my_drawing_state().font_style_value = font_style_value_result.release_nonnull();
// 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 = font_list->first();
}
Bindings::CanvasTextAlign text_align() const { return my_drawing_state().text_align; }
void set_text_align(Bindings::CanvasTextAlign text_align) { my_drawing_state().text_align = text_align; }
Bindings::CanvasTextBaseline text_baseline() const { return my_drawing_state().text_baseline; }
void set_text_baseline(Bindings::CanvasTextBaseline text_baseline) { my_drawing_state().text_baseline = text_baseline; }
protected:
CanvasTextDrawingStyles() = default;
private:
CanvasState::DrawingState& my_drawing_state() { return reinterpret_cast<IncludingClass&>(*this).drawing_state(); }
CanvasState::DrawingState const& my_drawing_state() const { return reinterpret_cast<IncludingClass const&>(*this).drawing_state(); }
};
}