ladybird/Userland/Libraries/LibWeb/HTML/TextMetrics.h
sin-ack 9121cc7cae LibWeb: Implement CanvasRenderingContext2D.measureText
This requires an implementation of the "text preparation algorithm" as
specified here:

html.spec.whatwg.org/multipage/canvas.html#text-preparation-algorithm

However, we're missing a lot of things such as the
CanvasTextDrawingStyles interface, so most of the algorithm was not
implemented. Additionally, we also are not able to use a LineBox like
the algorithm suggests, because our layouting infra is not up to the
task yet. The prepare_text function does nothing other than figuring out
the width of the given text and return glyphs with offsets at the
moment.
2022-01-04 22:41:07 +00:00

66 lines
2.8 KiB
C++

/*
* Copyright (c) 2021, sin-ack <sin-ack@protonmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibJS/Heap/Handle.h>
#include <LibWeb/Bindings/Wrappable.h>
namespace Web::HTML {
class TextMetrics
: public RefCounted<TextMetrics>
, public Bindings::Wrappable {
public:
using WrapperType = Bindings::TextMetricsWrapper;
static RefPtr<TextMetrics> create();
double width() const { return m_width; }
double actual_bounding_box_left() const { return m_actual_bounding_box_left; }
double actual_bounding_box_right() const { return m_actual_bounding_box_right; }
double font_bounding_box_ascent() const { return m_font_bounding_box_ascent; }
double font_bounding_box_descent() const { return m_font_bounding_box_descent; }
double actual_bounding_box_ascent() const { return m_actual_bounding_box_ascent; }
double actual_bounding_box_descent() const { return m_actual_bounding_box_descent; }
double em_height_ascent() const { return m_em_height_ascent; }
double em_height_descent() const { return m_em_height_descent; }
double hanging_baseline() const { return m_hanging_baseline; }
double alphabetic_baseline() const { return m_alphabetic_baseline; }
double ideographic_baseline() const { return m_ideographic_baseline; }
void set_width(double width) { m_width = width; }
void set_actual_bounding_box_left(double left) { m_actual_bounding_box_left = left; }
void set_actual_bounding_box_right(double right) { m_actual_bounding_box_right = right; }
void set_font_bounding_box_ascent(double ascent) { m_font_bounding_box_ascent = ascent; }
void set_font_bounding_box_descent(double descent) { m_font_bounding_box_descent = descent; }
void set_actual_bounding_box_ascent(double ascent) { m_actual_bounding_box_ascent = ascent; }
void set_actual_bounding_box_descent(double descent) { m_actual_bounding_box_descent = descent; }
void set_em_height_ascent(double ascent) { m_em_height_ascent = ascent; }
void set_em_height_descent(double descent) { m_em_height_descent = descent; }
void set_hanging_baseline(double baseline) { m_hanging_baseline = baseline; }
void set_alphabetic_baseline(double baseline) { m_alphabetic_baseline = baseline; }
void set_ideographic_baseline(double baseline) { m_ideographic_baseline = baseline; }
private:
explicit TextMetrics() { }
double m_width { 0 };
double m_actual_bounding_box_left { 0 };
double m_actual_bounding_box_right { 0 };
double m_font_bounding_box_ascent { 0 };
double m_font_bounding_box_descent { 0 };
double m_actual_bounding_box_ascent { 0 };
double m_actual_bounding_box_descent { 0 };
double m_em_height_ascent { 0 };
double m_em_height_descent { 0 };
double m_hanging_baseline { 0 };
double m_alphabetic_baseline { 0 };
double m_ideographic_baseline { 0 };
};
}