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// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef PDF_DOCUMENT_LAYOUT_H_
#define PDF_DOCUMENT_LAYOUT_H_
#include <cstddef>
#include <vector>
#include "base/check_op.h"
#include "base/i18n/rtl.h"
#include "base/values.h"
#include "pdf/page_orientation.h"
#include "ui/gfx/geometry/insets.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/size.h"
namespace chrome_pdf {
// Layout of pages within a PDF document. Pages are placed as rectangles
// (possibly rotated) in a non-overlapping vertical sequence.
//
// All layout units are pixels.
//
// The `Options` class controls the behavior of the layout, such as the default
// orientation of pages.
class DocumentLayout final {
public:
// TODO(crbug.com/40155509): Add `kTwoUpEven` page spread support.
enum class PageSpread {
kOneUp = 0, // One page per spread.
kTwoUpOdd = 1, // Two pages per spread, with odd pages first.
};
// Options controlling layout behavior.
class Options final {
public:
Options();
Options(const Options& other);
Options& operator=(const Options& other);
~Options();
friend bool operator==(const Options& lhs, const Options& rhs) {
return lhs.direction() == rhs.direction() &&
lhs.default_page_orientation() == rhs.default_page_orientation() &&
lhs.page_spread() == rhs.page_spread();
}
friend bool operator!=(const Options& lhs, const Options& rhs) {
return !(lhs == rhs);
}
// Serializes layout options to a base::Value::Dict.
base::Value::Dict ToValue() const;
// Deserializes layout options from a base::Value::Dict.
void FromValue(const base::Value::Dict& value);
// Page layout direction. This is tied to the direction of the user's UI,
// rather than the direction of individual pages.
base::i18n::TextDirection direction() const { return direction_; }
void set_direction(base::i18n::TextDirection direction) {
direction_ = direction;
}
PageOrientation default_page_orientation() const {
return default_page_orientation_;
}
// Rotates default page orientation 90 degrees clockwise.
void RotatePagesClockwise();
// Rotates default page orientation 90 degrees counterclockwise.
void RotatePagesCounterclockwise();
PageSpread page_spread() const { return page_spread_; }
// Changes two-up view status.
void set_page_spread(PageSpread spread) { page_spread_ = spread; }
private:
base::i18n::TextDirection direction_ = base::i18n::UNKNOWN_DIRECTION;
PageOrientation default_page_orientation_ = PageOrientation::kOriginal;
PageSpread page_spread_ = PageSpread::kOneUp;
};
static constexpr gfx::Insets kSingleViewInsets =
gfx::Insets::TLBR(/*top=*/3, /*left=*/5, /*bottom=*/7, /*right=*/5);
static constexpr int32_t kBottomSeparator = 4;
static constexpr int32_t kHorizontalSeparator = 1;
DocumentLayout();
DocumentLayout(const DocumentLayout& other) = delete;
DocumentLayout& operator=(const DocumentLayout& other) = delete;
~DocumentLayout();
// Returns the layout options.
const Options& options() const { return options_; }
// Sets the layout options. If certain options with immediate effect change
// (such as the default page orientation), the layout will be marked dirty.
//
// TODO(kmoon): We shouldn't have layout options that take effect immediately.
void SetOptions(const Options& options);
// Returns true if the layout has been modified since the last call to
// clear_dirty(). The initial state is false (clean), which assumes
// appropriate default behavior for an initially empty layout.
bool dirty() const { return dirty_; }
// Clears the dirty() state of the layout. This should be called after any
// layout changes have been applied.
void clear_dirty() { dirty_ = false; }
// Returns the layout's total size.
const gfx::Size& size() const { return size_; }
size_t page_count() const { return page_layouts_.size(); }
// Gets the layout rectangle for a page. Only valid after computing a layout.
const gfx::Rect& page_rect(size_t page_index) const {
DCHECK_LT(page_index, page_count());
return page_layouts_[page_index].outer_rect;
}
// Gets the layout rectangle for a page's bounds (which excludes additional
// regions like page shadows). Only valid after computing a layout.
const gfx::Rect& page_bounds_rect(size_t page_index) const {
DCHECK_LT(page_index, page_count());
return page_layouts_[page_index].inner_rect;
}
// Computes the layout for a given list of `page_sizes` based on `options_`.
void ComputeLayout(const std::vector<gfx::Size>& page_sizes);
private:
// Layout of a single page.
struct PageLayout {
// Bounding rectangle for the page with decorations.
gfx::Rect outer_rect;
// Bounding rectangle for the page without decorations.
gfx::Rect inner_rect;
};
// Helpers for ComputeLayout() handling different page spreads.
void ComputeOneUpLayout(const std::vector<gfx::Size>& page_sizes);
void ComputeTwoUpOddLayout(const std::vector<gfx::Size>& page_sizes);
// Copies `source_rect` to `destination_rect`, setting `dirty_` to true if
// `destination_rect` is modified as a result.
void CopyRectIfModified(const gfx::Rect& source_rect,
gfx::Rect& destination_rect);
Options options_;
// Indicates if the layout has changed in an externally-observable way,
// usually as a result of calling `ComputeLayout()` with different inputs.
//
// Some operations that may trigger layout changes:
// * Changing page sizes
// * Adding or removing pages
// * Changing page orientations
bool dirty_ = false;
// Layout's total size.
gfx::Size size_;
std::vector<PageLayout> page_layouts_;
};
} // namespace chrome_pdf
#endif // PDF_DOCUMENT_LAYOUT_H_