PDF4QT/Pdf4QtLibWidgets/sources/pdfdrawspacecontroller.h

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// Copyright (C) 2019-2021 Jakub Melka
//
// This file is part of PDF4QT.
//
// PDF4QT is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// with the written consent of the copyright owner, any later version.
//
// PDF4QT is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with PDF4QT. If not, see <https://www.gnu.org/licenses/>.
#ifndef PDFDRAWSPACECONTROLLER_H
#define PDFDRAWSPACECONTROLLER_H
#include "pdfwidgetsglobal.h"
#include "pdfglobal.h"
#include "pdfdocument.h"
#include "pdfrenderer.h"
#include "pdffont.h"
#include "pdfdocumentdrawinterface.h"
#include "pdfwidgetsnapshot.h"
#include <QRectF>
#include <QObject>
#include <QMarginsF>
class QPainter;
class QScrollBar;
class QTimer;
class BLContext;
namespace pdf
{
class PDFProgress;
class PDFWidget;
class PDFCMSManager;
class PDFTextLayoutGetter;
class PDFWidgetAnnotationManager;
class PDFAsynchronousPageCompiler;
class PDFAsynchronousTextLayoutCompiler;
/// This class controls draw space - page layout. Pages are divided into blocks
/// each block can contain one or multiple pages. Units are in milimeters.
/// Pages are layouted in zoom-independent mode.
class PDFDrawSpaceController : public QObject
{
Q_OBJECT
public:
explicit PDFDrawSpaceController(QObject* parent);
virtual ~PDFDrawSpaceController() override;
/// Sets the document and recalculates the draw space. Document can be nullptr,
/// in that case, draw space is cleared. Optional content activity can be nullptr,
/// in that case, no content is suppressed.
/// \param document Document
void setDocument(const PDFModifiedDocument& document);
/// Sets the page layout. Page layout can be one of the PDF's page layouts.
/// \param pageLayout Page layout
void setPageLayout(PageLayout pageLayout);
/// Returns the page layout
PageLayout getPageLayout() const { return m_pageLayoutMode; }
/// Returns the block count
size_t getBlockCount() const { return m_blockItems.size(); }
/// Return the bounding rectangle of the block. If block doesn't exist,
/// then invalid rectangle is returned (no exception is thrown).
/// \param blockIndex Index of the block
QRectF getBlockBoundingRectangle(size_t blockIndex) const;
/// Represents layouted page. This structure contains index of the block, index of the
/// page and page rectangle, in which the page is contained.
struct LayoutItem
{
constexpr inline explicit LayoutItem() : blockIndex(-1), pageIndex(-1), groupIndex(-1) { }
constexpr inline explicit LayoutItem(PDFInteger blockIndex, PDFInteger pageIndex, PDFInteger groupIndex, const QRectF& pageRectMM) :
blockIndex(blockIndex), pageIndex(pageIndex), groupIndex(groupIndex), pageRectMM(pageRectMM) { }
bool operator ==(const LayoutItem&) const = default;
bool isValid() const { return pageIndex != -1; }
PDFInteger blockIndex;
PDFInteger pageIndex;
PDFInteger groupIndex; ///< Page group index
QRectF pageRectMM;
};
using LayoutItems = std::vector<LayoutItem>;
/// Returns the layout items for desired block. If block doesn't exist,
/// then empty array is returned.
/// \param blockIndex Index of the block
LayoutItems getLayoutItems(size_t blockIndex) const;
/// Returns layout for single page. If page index is invalid,
/// or page layout cannot be found, then invalid layout item is returned.
/// \param pageIndex Page index
LayoutItem getLayoutItemForPage(PDFInteger pageIndex) const;
/// Returns the document
const PDFDocument* getDocument() const { return m_document; }
/// Returns the font cache
const PDFFontCache* getFontCache() const { return &m_fontCache; }
/// Returns the font cache
PDFFontCache* getFontCache() { return &m_fontCache; }
/// Returns optional content activity
const PDFOptionalContentActivity* getOptionalContentActivity() const { return m_optionalContentActivity; }
/// Returns reference bounding box for correct calculation of zoom fit/fit vertical/fit horizontal.
/// If zoom is set in a way to display this bounding box on a screen, then it is assured that
/// any page on the screen will fit this bounding box, regardless of mode (single/two columns, etc.).
QSizeF getReferenceBoundingBox() const;
/// Returns page rotation
PageRotation getPageRotation() const { return m_pageRotation; }
/// Sets page rotation
void setPageRotation(PageRotation pageRotation);
/// Set custom layout. Custom layout provides a way how to define
/// custom page layout, including blocks. Block indices must be properly defined,
/// that means block index must start by zero and must be continuous. If this
/// criteria are not fulfilled, behaviour is undefined.
void setCustomLayout(LayoutItems customLayoutItems);
/// Returns custom layout
const LayoutItems& getCustomLayout() const { return m_customLayoutItems; }
signals:
void drawSpaceChanged();
void repaintNeeded();
void pageImageChanged(bool all, const std::vector<PDFInteger>& pages);
private:
/// Recalculates the draw space. Preserves setted page rotation.
void recalculate();
/// Clears the draw space. Emits signal if desired.
void clear(bool emitSignal);
/// Represents data for the single block. Contains block size in milimeters.
struct LayoutBlock
{
constexpr inline explicit LayoutBlock() = default;
constexpr inline explicit LayoutBlock(const QRectF& blockRectMM) : blockRectMM(blockRectMM) { }
QRectF blockRectMM;
};
using BlockItems = std::vector<LayoutBlock>;
const PDFDocument* m_document;
const PDFOptionalContentActivity* m_optionalContentActivity;
PageLayout m_pageLayoutMode;
LayoutItems m_layoutItems;
BlockItems m_blockItems;
PDFReal m_verticalSpacingMM;
PDFReal m_horizontalSpacingMM;
PageRotation m_pageRotation;
LayoutItems m_customLayoutItems;
/// Font cache
PDFFontCache m_fontCache;
};
/// This is a proxy class to draw space controller using widget. We have two spaces, pixel space
/// (on the controlled widget) and device space (device is draw space controller).
class PDF4QTLIBWIDGETSSHARED_EXPORT PDFDrawWidgetProxy : public QObject
{
Q_OBJECT
public:
explicit PDFDrawWidgetProxy(QObject* parent);
virtual ~PDFDrawWidgetProxy() override;
/// Sets the document and updates the draw space. Document can be nullptr,
/// in that case, draw space is cleared. Optional content activity can be nullptr,
/// in that case, no content is suppressed.
/// \param document Document
void setDocument(const PDFModifiedDocument& document);
void init(PDFWidget* widget);
/// Updates the draw space area
void update();
/// Creates page point to device point matrix for the given rectangle. It creates transformation
/// from page's media box to the target rectangle.
/// \param page Page, for which we want to create matrix
/// \param rectangle Page rectangle, to which is page media box transformed
QTransform createPagePointToDevicePointMatrix(const PDFPage* page, const QRectF& rectangle) const;
/// Draws the actually visible pages on the painter using the rectangle.
/// Rectangle is space in the widget, which is used for painting the PDF.
/// This function is using drawPages function to draw all pages. After that,
/// custom drawing is performed.
/// \sa drawPages
/// \param painter Painter to paint the PDF pages
/// \param rect Rectangle in which the content is painted
void draw(QPainter* painter, QRect rect);
/// Draws the actually visible pages on the context using the rectangle.
/// Rectangle is space in the widget, which is used for painting the PDF.
/// This function is using drawPages function to draw all pages. After that,
/// custom drawing is performed.
/// \sa drawPages
/// \param context Context to paint the PDF pages
/// \param rect Rectangle in which the content is painted
void draw(BLContext& context, QRect rect);
/// Draws the actually visible pages on the painter using the rectangle.
/// Rectangle is space in the widget, which is used for painting the PDF.
/// \param painter Painter to paint the PDF pages
/// \param rect Rectangle in which the content is painted
/// \param features Rendering features
void drawPages(QPainter* painter, QRect rect, PDFRenderer::Features features);
/// Draws the actually visible pages on the painter using the rectangle.
/// Rectangle is space in the widget, which is used for painting the PDF.
/// \param painter Painter to paint the PDF pages
/// \param rect Rectangle in which the content is painted
/// \param features Rendering features
void drawPages(BLContext& context, QRect rect, PDFRenderer::Features features);
/// Draws thumbnail image of the given size (so larger of the page size
/// width or height equals to pixel size and the latter size is rescaled
/// using the aspect ratio)
/// \param pixelSize Pixel size
QImage drawThumbnailImage(PDFInteger pageIndex, int pixelSize) const;
enum Operation
{
ZoomIn,
ZoomOut,
ZoomFit,
ZoomFitWidth,
ZoomFitHeight,
NavigateDocumentStart,
NavigateDocumentEnd,
NavigateNextPage,
NavigatePreviousPage,
NavigateNextStep,
NavigatePreviousStep,
RotateRight,
RotateLeft
};
/// Performs the desired operation (for example navigation).
/// \param operation Operation to be performed
void performOperation(Operation operation);
/// Scrolls by pixels, if it is possible. If it is not possible to scroll,
/// then nothing happens. Returns pixel offset, by which view camera was moved.
/// \param offset Offset in pixels
QPoint scrollByPixels(QPoint offset);
/// Sets the zoom. Tries to preserve current offsets (so the current visible
/// area will be visible after the zoom).
/// \param zoom New zoom
void zoom(PDFReal zoom);
enum class ZoomHint
{
Fit,
FitWidth,
FitHeight
};
/// Calculates zoom using given hint (i.e. to fill whole space, fill vertical,
/// or fill horizontal).
/// \param hint Zoom hint type
PDFReal getZoomHint(ZoomHint hint) const;
/// Go to the specified page
/// \param pageIndex Page to scroll to
void goToPage(PDFInteger pageIndex);
/// Go to the specified page and ensures point on the page is visible
/// \param pageIndex Page to scroll to
/// \param ensureVisibleRect Rectangle on page, which should be visible
void goToPageAndEnsureVisible(PDFInteger pageIndex, QRectF ensureVisibleRect);
/// Returns current zoom from widget space to device space. So, for example 2.00 corresponds to 200% zoom,
/// and each 1 cm of widget area corresponds to 0.5 cm of the device space area.
PDFReal getZoom() const { return m_zoom; }
/// Sets the page layout. Page layout can be one of the PDF's page layouts.
/// \param pageLayout Page layout
void setPageLayout(PageLayout pageLayout);
/// Sets custom page layout. If this function is used, page layout mode
/// must be set to 'Custom'.
/// \param layoutItems Layout items
void setCustomPageLayout(PDFDrawSpaceController::LayoutItems layoutItems);
/// Returns the page layout
PageLayout getPageLayout() const { return m_controller->getPageLayout(); }
/// Returns pages, which are intersecting rectangle (even partially)
/// \param rect Rectangle to test
std::vector<PDFInteger> getPagesIntersectingRect(QRect rect) const;
/// Returns sorted vector of page indices, which should remain in the cache
std::vector<PDFInteger> getActivePages() const;
/// Returns page, under which is point. If no page is under the point,
/// then -1 is returned. Point is in widget coordinates. If \p pagePoint
/// is not nullptr, then point in page coordinate space is set here.
/// \param point Point
/// \param pagePoint Point in page coordinate system
PDFInteger getPageUnderPoint(QPoint point, QPointF* pagePoint) const;
/// Returns bounding box of pages, which are intersecting rectangle (even partially)
/// \param rect Rectangle to test
QRect getPagesIntersectingRectBoundingBox(QRect rect) const;
/// Returns true, if we are in the block mode (multiple blocks with separate pages),
/// or continuous mode (single block with continuous list of separated pages).
bool isBlockMode() const;
/// Updates renderer (in current implementation, renderer for page thumbnails)
/// using given parameters.
/// \param rendererEngine Renderer engine
void updateRenderer(RendererEngine rendererEngine);
/// Prefetches (prerenders) pages after page with pageIndex, i.e., prepares
/// for non-flickering scroll operation.
void prefetchPages(PDFInteger pageIndex);
static constexpr PDFReal ZOOM_STEP = 1.2;
const PDFDocument* getDocument() const { return m_controller->getDocument(); }
PDFFontCache* getFontCache() const { return m_controller->getFontCache(); }
const PDFOptionalContentActivity* getOptionalContentActivity() const { return m_controller->getOptionalContentActivity(); }
PDFRenderer::Features getFeatures() const;
const PDFMeshQualitySettings& getMeshQualitySettings() const { return m_meshQualitySettings; }
PDFAsynchronousPageCompiler* getCompiler() const { return m_compiler; }
const PDFCMSManager* getCMSManager() const;
PDFProgress* getProgress() const { return m_progress; }
void setProgress(PDFProgress* progress) { m_progress = progress; }
PDFAsynchronousTextLayoutCompiler* getTextLayoutCompiler() const { return m_textLayoutCompiler; }
PDFWidget* getWidget() const { return m_widget; }
RendererEngine getRendererEngine() const { return m_rendererEngine; }
PageRotation getPageRotation() const { return m_controller->getPageRotation(); }
void setFeatures(PDFRenderer::Features features);
void setPreferredMeshResolutionRatio(PDFReal ratio);
void setMinimalMeshResolutionRatio(PDFReal ratio);
void setColorTolerance(PDFReal colorTolerance);
static constexpr PDFReal getMinZoom() { return MIN_ZOOM; }
static constexpr PDFReal getMaxZoom() { return MAX_ZOOM; }
void registerDrawInterface(IDocumentDrawInterface* drawInterface) { m_drawInterfaces.insert(drawInterface); }
void unregisterDrawInterface(IDocumentDrawInterface* drawInterface) { m_drawInterfaces.erase(drawInterface); }
/// Returns current paper color
QColor getPaperColor();
/// Transforms pixels to device space
/// \param pixel Value in pixels
PDFReal transformPixelToDeviceSpace(PDFReal pixel) const { return pixel * m_pixelToDeviceSpaceUnit; }
/// Transforms value in device space to pixel value
/// \param deviceSpaceValue Value in device space
PDFReal transformDeviceSpaceToPixel(PDFReal deviceSpaceValue) const { return deviceSpaceValue * m_deviceSpaceUnitToPixel; }
/// Returns snapshot of current view area
PDFWidgetSnapshot getSnapshot() const;
/// Sets page group transparency settings. All pages with a given group index
/// will be displayed with this transparency settings.
/// \param groupIndex Group index
/// \param drawPaper Draw background paper
/// \param transparency Page graphics transparency
void setGroupTransparency(PDFInteger groupIndex, bool drawPaper = true, PDFReal transparency = 1.0);
PDFWidgetAnnotationManager* getAnnotationManager() const;
signals:
void drawSpaceChanged();
void pageLayoutChanged();
void renderingError(pdf::PDFInteger pageIndex, const QList<pdf::PDFRenderError>& errors);
void repaintNeeded();
void pageImageChanged(bool all, const std::vector<PDFInteger>& pages);
void textLayoutChanged();
private:
struct LayoutItem
{
constexpr inline explicit LayoutItem() : pageIndex(-1), groupIndex(-1) { }
constexpr inline explicit LayoutItem(PDFInteger pageIndex, PDFInteger groupIndex, const QRect& pageRect) :
pageIndex(pageIndex), groupIndex(groupIndex), pageRect(pageRect) { }
PDFInteger pageIndex;
PDFInteger groupIndex; ///< Used to create group of pages (for transparency and overlay)
QRect pageRect;
};
struct Layout
{
inline void clear()
{
items.clear();
blockRect = QRect();
}
std::vector<LayoutItem> items;
QRect blockRect;
};
struct GroupInfo
{
bool operator==(const GroupInfo&) const = default;
bool drawPaper = true;
PDFReal transparency = 1.0;
};
static constexpr size_t INVALID_BLOCK_INDEX = std::numeric_limits<size_t>::max();
// Minimal/maximal zoom is from 8% to 6400 %, according to the PDF 1.7 Reference,
// Appendix C.
static constexpr PDFReal MIN_ZOOM = 8.0 / 100.0;
static constexpr PDFReal MAX_ZOOM = 6400.0 / 100.0;
static constexpr qint64 CACHE_CLEAR_TIMEOUT = 5000;
static constexpr qint64 CACHE_PAGE_EXPIRATION_TIMEOUT = 30000;
/// Converts rectangle from device space to the pixel space
QRectF fromDeviceSpace(const QRectF& rect) const;
void performPageCacheClear();
void onTextLayoutChanged();
void onOptionalContentGroupStateChanged();
void onColorManagementSystemChanged();
void onHorizontalScrollbarValueChanged(int value);
void onVerticalScrollbarValueChanged(int value);
void setHorizontalOffset(int value);
void setVerticalOffset(int value);
void setBlockIndex(int index);
void updateHorizontalScrollbarFromOffset();
void updateVerticalScrollbarFromOffset();
GroupInfo getGroupInfo(int groupIndex) const;
template<typename T>
struct Range
{
constexpr inline Range() : min(T()), max(T()) { }
constexpr inline Range(T value) : min(value), max(value) { }
constexpr inline Range(T min, T max) : min(min), max(max) { }
T min;
T max;
constexpr inline T bound(T value) { return qBound(min, value, max); }
};
/// Flag, disables the update
bool m_updateDisabled;
/// Current block (in the draw space controller)
size_t m_currentBlock;
/// Number of pixels (fractional) per milimeter (unit is pixel/mm) of the screen,
/// so, size of the area in milimeters can be computed as pixelCount * m_pixelPerMM [mm].
PDFReal m_pixelPerMM;
/// Zoom from widget space to device space. So, for example 2.00 corresponds to 200% zoom,
/// and each 1 cm of widget area corresponds to 0.5 cm of the device space area.
PDFReal m_zoom;
/// Converts pixel to device space units (mm) using zoom
PDFReal m_pixelToDeviceSpaceUnit;
/// Converts device space units (mm) to real pixels using zoom
PDFReal m_deviceSpaceUnitToPixel;
/// Actual vertical offset of the draw space area in the widget (so block will be drawn
/// with this vertical offset)
PDFInteger m_verticalOffset;
/// Range of vertical offset
Range<PDFInteger> m_verticalOffsetRange;
/// Actual horizontal offset of the draw space area in the widget (so block will be drawn
/// with this horizontal offset)
PDFInteger m_horizontalOffset;
/// Range for horizontal offset
Range<PDFInteger> m_horizontalOffsetRange;
/// Draw space controller
PDFDrawSpaceController* m_controller;
/// Controlled draw widget (proxy is for this widget)
PDFWidget* m_widget;
/// Vertical scrollbar
QScrollBar* m_verticalScrollbar;
/// Horizontal scrollbar
QScrollBar* m_horizontalScrollbar;
/// Current page layout
Layout m_layout;
/// Renderer features
PDFRenderer::Features m_features;
/// Mesh quality settings
PDFMeshQualitySettings m_meshQualitySettings;
/// Page compiler
PDFAsynchronousPageCompiler* m_compiler;
/// Text layout compiler
PDFAsynchronousTextLayoutCompiler* m_textLayoutCompiler;
/// Page image rasterizer for thumbnails
PDFRasterizer* m_rasterizer;
/// Progress
PDFProgress* m_progress;
/// Cache clear timer
QTimer* m_cacheClearTimer;
/// Additional drawing interfaces
std::set<IDocumentDrawInterface*> m_drawInterfaces;
/// Renderer engine
RendererEngine m_rendererEngine;
/// Page group info for rendering. Group of pages
/// can be rendered with transparency or without paper
/// as overlay.
std::map<PDFInteger, GroupInfo> m_groupInfos;
};
} // namespace pdf
#endif // PDFDRAWSPACECONTROLLER_H