ladybird/Userland/Applications/PDFViewer/PDFViewer.h
Matthew Olsson c3c2121b57 PDFViewer: Allow zooming in and out + scrolling
When holding ctrl and scrolling, the page will be zoomed in an out.
When zoomed in on a page, scrolling with move vertically up and down
the page (or horizontally if shift is being held).

In order to speed up zooming, zoomed bitmaps are cached per-page at
each distinct zoom level. This cache is cleared every 30 seconds to
prevent OOM problems.
2021-05-18 16:35:23 +02:00

66 lines
1.3 KiB
C++

/*
* Copyright (c) 2021, Matthew Olsson <mattco@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/HashMap.h>
#include <LibGUI/AbstractScrollableWidget.h>
#include <LibGfx/Bitmap.h>
#include <LibPDF/Document.h>
static constexpr u16 zoom_levels[] = {
17,
21,
26,
33,
41,
51,
64,
80,
100,
120,
144,
173,
207,
249,
299,
358,
430
};
static constexpr size_t number_of_zoom_levels = sizeof(zoom_levels) / sizeof(zoom_levels[0]);
static constexpr size_t initial_zoom_level = 8;
class PDFViewer : public GUI::AbstractScrollableWidget {
C_OBJECT(PDFViewer)
public:
virtual ~PDFViewer() override = default;
void set_document(RefPtr<PDF::Document>);
protected:
PDFViewer();
virtual void paint_event(GUI::PaintEvent&) override;
virtual void mousewheel_event(GUI::MouseEvent&) override;
virtual void timer_event(Core::TimerEvent&) override;
private:
RefPtr<Gfx::Bitmap> get_rendered_page(u32 index);
RefPtr<Gfx::Bitmap> render_page(const PDF::Page&);
void zoom_in();
void zoom_out();
RefPtr<PDF::Document> m_document;
u32 m_current_page_index { 0 };
Vector<HashMap<u32, RefPtr<Gfx::Bitmap>>> m_rendered_page_list;
u8 m_zoom_level { initial_zoom_level };
};