ladybird/Userland/Applications/PDFViewer/PDFViewer.cpp
sin-ack 3f3f45580a Everywhere: Add sv suffix to strings relying on StringView(char const*)
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).

No functional changes.
2022-07-12 23:11:35 +02:00

373 lines
11 KiB
C++

/*
* Copyright (c) 2021-2022, Matthew Olsson <mattco@serenityos.org>
* Copyright (c) 2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "PDFViewer.h"
#include <AK/Array.h>
#include <AK/BinarySearch.h>
#include <LibConfig/Client.h>
#include <LibGUI/Action.h>
#include <LibGUI/MessageBox.h>
#include <LibGUI/Painter.h>
#include <LibPDF/Renderer.h>
static constexpr int PAGE_PADDING = 10;
static constexpr Array zoom_levels = {
17,
21,
26,
33,
41,
51,
64,
80,
100,
120,
144,
173,
207,
249,
299,
358,
430
};
PDFViewer::PDFViewer()
{
set_should_hide_unnecessary_scrollbars(true);
set_focus_policy(GUI::FocusPolicy::StrongFocus);
set_scrollbars_enabled(true);
start_timer(30'000);
m_page_view_mode = static_cast<PageViewMode>(Config::read_i32("PDFViewer"sv, "Display"sv, "PageMode"sv, 0));
}
PDF::PDFErrorOr<void> PDFViewer::set_document(RefPtr<PDF::Document> document)
{
m_document = document;
m_current_page_index = document->get_first_page_index();
m_zoom_level = initial_zoom_level;
m_rendered_page_list.clear();
m_rendered_page_list.ensure_capacity(document->get_page_count());
for (u32 i = 0; i < document->get_page_count(); i++)
m_rendered_page_list.unchecked_append(HashMap<u32, RenderedPage>());
TRY(cache_page_dimensions(true));
update();
return {};
}
PDF::PDFErrorOr<NonnullRefPtr<Gfx::Bitmap>> PDFViewer::get_rendered_page(u32 index)
{
auto& rendered_page_map = m_rendered_page_list[index];
auto existing_rendered_page = rendered_page_map.get(m_zoom_level);
if (existing_rendered_page.has_value() && existing_rendered_page.value().rotation == m_rotations)
return existing_rendered_page.value().bitmap;
auto rendered_page = TRY(render_page(index));
rendered_page_map.set(m_zoom_level, { rendered_page, m_rotations });
return rendered_page;
}
void PDFViewer::paint_event(GUI::PaintEvent& event)
{
GUI::Frame::paint_event(event);
GUI::Painter painter(*this);
painter.add_clip_rect(widget_inner_rect());
painter.add_clip_rect(event.rect());
painter.fill_rect(event.rect(), Color(0x80, 0x80, 0x80));
if (!m_document)
return;
auto handle_error = [&]<typename T>(PDF::PDFErrorOr<T> maybe_error) {
if (maybe_error.is_error()) {
auto error = maybe_error.release_error();
GUI::MessageBox::show_error(nullptr, String::formatted("Error rendering page:\n{}", error.message()));
return true;
}
return false;
};
if (m_page_view_mode == PageViewMode::Single) {
auto maybe_page = get_rendered_page(m_current_page_index);
if (handle_error(maybe_page))
return;
auto page = maybe_page.release_value();
set_content_size(page->size());
painter.translate(frame_thickness(), frame_thickness());
painter.translate(-horizontal_scrollbar().value(), -vertical_scrollbar().value());
int x = max(0, (width() - page->width()) / 2);
int y = max(0, (height() - page->height()) / 2);
painter.blit({ x, y }, *page, page->rect());
return;
}
set_content_size({ m_page_dimension_cache.max_width, m_page_dimension_cache.total_height });
size_t first_page_index = 0;
size_t last_page_index = 0;
binary_search(m_page_dimension_cache.render_info, vertical_scrollbar().value(), &first_page_index, [](int height, PageDimensionCache::RenderInfo const& render_info) {
return height - render_info.total_height_before_this_page;
});
binary_search(m_page_dimension_cache.render_info, vertical_scrollbar().value() + height(), &last_page_index, [](int height, PageDimensionCache::RenderInfo const& render_info) {
return height - render_info.total_height_before_this_page;
});
auto initial_offset = m_page_dimension_cache.render_info[first_page_index].total_height_before_this_page - vertical_scrollbar().value();
painter.translate(frame_thickness(), frame_thickness());
painter.translate(-horizontal_scrollbar().value(), initial_offset);
auto middle = height() / 2;
auto y_offset = initial_offset;
for (size_t page_index = first_page_index; page_index <= last_page_index; page_index++) {
auto maybe_page = get_rendered_page(page_index);
if (handle_error(maybe_page))
return;
auto page = maybe_page.release_value();
auto x = max(0, (width() - page->width()) / 2);
painter.blit({ x, PAGE_PADDING }, *page, page->rect());
auto diff_y = page->height() + PAGE_PADDING * 2;
painter.translate(0, diff_y);
if (y_offset < middle && y_offset + diff_y >= middle)
change_page(page_index);
y_offset += diff_y;
}
}
void PDFViewer::set_current_page(u32 current_page)
{
m_current_page_index = current_page;
vertical_scrollbar().set_value(m_page_dimension_cache.render_info[current_page].total_height_before_this_page);
update();
}
void PDFViewer::resize_event(GUI::ResizeEvent&)
{
for (auto& map : m_rendered_page_list)
map.clear();
if (m_document)
MUST(cache_page_dimensions());
update();
}
void PDFViewer::mousewheel_event(GUI::MouseEvent& event)
{
if (!m_document)
return;
bool scrolled_down = event.wheel_delta_y() > 0;
if (event.ctrl()) {
if (scrolled_down) {
zoom_out();
} else {
zoom_in();
}
return;
}
auto& scrollbar = event.shift() ? horizontal_scrollbar() : vertical_scrollbar();
if (m_page_view_mode == PageViewMode::Multiple) {
if (scrolled_down) {
if (scrollbar.value() != scrollbar.max())
scrollbar.increase_slider_by(20);
} else {
if (scrollbar.value() > 0)
scrollbar.decrease_slider_by(20);
}
} else {
if (scrolled_down) {
if (scrollbar.value() == scrollbar.max()) {
if (m_current_page_index < m_document->get_page_count() - 1) {
change_page(m_current_page_index + 1);
scrollbar.set_value(0);
}
} else {
scrollbar.increase_slider_by(20);
}
} else {
if (scrollbar.value() == 0) {
if (m_current_page_index > 0) {
change_page(m_current_page_index - 1);
scrollbar.set_value(scrollbar.max());
}
} else {
scrollbar.decrease_slider_by(20);
}
}
}
update();
}
void PDFViewer::mousedown_event(GUI::MouseEvent& event)
{
if (event.button() == GUI::MouseButton::Middle) {
m_pan_starting_position = to_content_position(event.position());
set_override_cursor(Gfx::StandardCursor::Drag);
}
}
void PDFViewer::mouseup_event(GUI::MouseEvent&)
{
set_override_cursor(Gfx::StandardCursor::None);
}
void PDFViewer::mousemove_event(GUI::MouseEvent& event)
{
if (event.buttons() & GUI::MouseButton::Middle) {
auto delta = to_content_position(event.position()) - m_pan_starting_position;
horizontal_scrollbar().decrease_slider_by(delta.x());
vertical_scrollbar().decrease_slider_by(delta.y());
update();
}
}
void PDFViewer::timer_event(Core::TimerEvent&)
{
// Clear the bitmap vector of all pages except the current page
for (size_t i = 0; i < m_rendered_page_list.size(); i++) {
if (i != m_current_page_index)
m_rendered_page_list[i].clear();
}
}
void PDFViewer::zoom_in()
{
if (m_zoom_level < zoom_levels.size() - 1) {
m_zoom_level++;
MUST(cache_page_dimensions());
update();
}
}
void PDFViewer::zoom_out()
{
if (m_zoom_level > 0) {
m_zoom_level--;
MUST(cache_page_dimensions());
update();
}
}
void PDFViewer::reset_zoom()
{
m_zoom_level = initial_zoom_level;
MUST(cache_page_dimensions());
update();
}
void PDFViewer::rotate(int degrees)
{
m_rotations = (m_rotations + degrees + 360) % 360;
MUST(cache_page_dimensions());
update();
}
void PDFViewer::set_page_view_mode(PageViewMode mode)
{
m_page_view_mode = mode;
Config::write_i32("PDFViewer"sv, "Display"sv, "PageMode"sv, static_cast<i32>(mode));
update();
}
PDF::PDFErrorOr<NonnullRefPtr<Gfx::Bitmap>> PDFViewer::render_page(u32 page_index)
{
auto page = TRY(m_document->get_page(page_index));
auto& page_size = m_page_dimension_cache.render_info[page_index].size;
auto bitmap = TRY(Gfx::Bitmap::try_create(Gfx::BitmapFormat::BGRA8888, page_size.to_type<int>()));
TRY(PDF::Renderer::render(*m_document, page, bitmap));
if (page.rotate + m_rotations != 0) {
int rotation_count = ((page.rotate + m_rotations) / 90) % 4;
if (rotation_count == 3) {
bitmap = TRY(bitmap->rotated(Gfx::RotationDirection::CounterClockwise));
} else {
for (int i = 0; i < rotation_count; i++)
bitmap = TRY(bitmap->rotated(Gfx::RotationDirection::Clockwise));
}
}
return bitmap;
}
PDF::PDFErrorOr<void> PDFViewer::cache_page_dimensions(bool recalculate_fixed_info)
{
if (recalculate_fixed_info)
m_page_dimension_cache.page_info.clear_with_capacity();
if (m_page_dimension_cache.page_info.is_empty()) {
m_page_dimension_cache.page_info.ensure_capacity(m_document->get_page_count());
for (size_t i = 0; i < m_document->get_page_count(); i++) {
auto page = TRY(m_document->get_page(i));
auto box = page.media_box;
m_page_dimension_cache.page_info.unchecked_append(PageDimensionCache::PageInfo {
{ box.width(), box.height() },
page.rotate,
});
}
}
auto zoom_scale_factor = static_cast<float>(zoom_levels[m_zoom_level]) / 100.0f;
m_page_dimension_cache.render_info.clear_with_capacity();
m_page_dimension_cache.render_info.ensure_capacity(m_page_dimension_cache.page_info.size());
float max_width = 0;
float total_height = 0;
for (size_t i = 0; i < m_page_dimension_cache.page_info.size(); i++) {
auto& [size, rotation] = m_page_dimension_cache.page_info[i];
rotation += m_rotations;
auto page_scale_factor = size.height() / size.width();
auto height = static_cast<float>(this->height() - 2 * frame_thickness()) * zoom_scale_factor - PAGE_PADDING * 2;
auto width = height / page_scale_factor;
if (rotation % 2)
swap(width, height);
max_width = max(max_width, width);
m_page_dimension_cache.render_info.append({
{ width, height },
total_height,
});
total_height += height;
}
m_page_dimension_cache.max_width = max_width;
m_page_dimension_cache.total_height = total_height;
return {};
}
void PDFViewer::change_page(u32 new_page)
{
m_current_page_index = new_page;
if (on_page_change)
on_page_change(m_current_page_index);
}