# -*- coding: utf-8 -*-
#
# This file is part of the qpageview package.
#
# Copyright (c) 2016 - 2019 by Wilbert Berendsen
# Copyright (c) 2024 by Benjamin Johnson
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 3
# of the License, or (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
# See http://www.gnu.org/licenses/ for more information.
"""
PDF rendering backend using QtPdf.
"""
import platform
from PyQt6.QtCore import Qt, QByteArray, QModelIndex, QRect, QRectF, QSize, QUrl
from PyQt6.QtGui import QPainter, QTransform
from PyQt6.QtPdf import QPdfDocument, QPdfDocumentRenderOptions
# Check for PDF link support (added in Qt 6.6)
# As of 2026, some Linux distros still ship older Qt versions without it.
# We will attempt to run with point-and-click disabled on such systems.
try:
from PyQt6.QtPdf import QPdfLinkModel
except ImportError:
QPdfLinkModel = None
import sys
print("qpageview: "
"PDF links are disabled because QPdfLinkModel is unavailable.",
file=sys.stderr)
from . import document
from . import page
from . import link
from . import locking
from . import render
from . import util
[docs]
class Link(link.Link):
"""A link that encapsulates QPdfLinkModel data."""
def __init__(self, linkobj, index, pointSize):
self._targetPage = linkobj.data(index, QPdfLinkModel.Role.Page.value)
self._url = linkobj.data(index,
QPdfLinkModel.Role.Url.value).toString()
# Convert to relative coordinates between 0.0 and 1.0 as expected
# by link.Link, which uses them for compatibility with Poppler
rect = linkobj.data(index, QPdfLinkModel.Role.Rectangle.value)
x1, y1, x2, y2 = rect.normalized().getCoords()
self.area = (x1 / pointSize.width(), y1 / pointSize.height(),
x2 / pointSize.width(), y2 / pointSize.height())
@property
def fileName(self):
"""The file name if this is an external link."""
return QUrl(self.url).fileName() if self.isExternal else ""
@property
def isExternal(self):
"""Indicates whether this is an external link."""
return (self.url and "://" in self.url)
@property
def targetPage(self):
"""If this is an internal link, the page number to which the
link should jump; otherwise -1."""
# QtPdf pages are 0-indexed, but our View is 1-indexed
return -1 if self._targetPage == -1 else self._targetPage + 1
@property
def url(self):
"""The URL the link points to."""
url = self._url
if platform.system() == "Windows":
# Fix weird things QUrl does to local paths
for proto in ("file", "textedit"):
scheme = "{0}://".format(proto)
pos = len(scheme) + 1 # the colon should be here
if (url.startswith(scheme)
and url[pos - 1].isalpha() and not url[pos].isalpha()):
# Capitalize the drive letter because that is the standard
# format, and some path-matching functions (incorrectly)
# assume case sensitivity
driveLetter = url[pos - 1].upper()
# Make sure there is a colon after the drive letter
if url[pos] != ":":
driveLetter = "{0}:".format(driveLetter)
path = url[pos:]
url = "".join((scheme, driveLetter, path))
return url
[docs]
class PdfPage(page.AbstractRenderedPage):
"""A Page capable of displaying one page of a QPdfDocument instance.
It has two additional instance attributes:
`document`: the QPdfDocument instance
`pageNumber`: the page number to render
"""
def __init__(self, document, pageNumber, renderer=None):
super().__init__(renderer)
self.document = document
self.pageNumber = pageNumber
self.setPageSize(document.pagePointSize(pageNumber))
[docs]
@classmethod
def loadDocument(cls, document, renderer=None, pageSlice=None):
"""Convenience class method yielding instances of this class.
The Page instances are created from the document, in page number order.
The specified Renderer is used, or else the global QtPdf renderer.
If pageSlice is given, it should be a slice object and only those pages
are then loaded.
"""
it = range(document.pageCount())
if pageSlice is not None:
it = it[pageSlice]
for num in it:
yield cls(document, num, renderer)
[docs]
@classmethod
def load(cls, filename, renderer=None):
"""Load a PDF document, and yield of instances of this class.
The filename can also be a QByteArray or a QPdfDocument instance.
The specified Renderer is used, or else the global PDF renderer.
"""
doc = load(filename)
return cls.loadDocument(doc, renderer) if doc else ()
[docs]
def mutex(self):
"""No two pages of the same document are rendered at the same time."""
return self.document
[docs]
def group(self):
"""Reimplemented to return the document our page is displayed from."""
return self.document
[docs]
def ident(self):
"""Reimplemented to return the page number of this page."""
return self.pageNumber
[docs]
def text(self, rect):
"""Returns text inside rectangle."""
rectf = self.mapFromPage().rect(rect)
with locking.lock(self.document):
return self.document.getSelection(
self.pageNumber, rectf.topLeft(), rectf.bottomRight()).text()
[docs]
def links(self):
"""Return links inside the document."""
document, pageNumber = self.document, self.pageNumber
try:
return self._linksCache
except AttributeError:
if QPdfLinkModel is None:
# Link support is unavailable; return an empty cache
self._linksCache = link.Links()
return self._linksCache
with locking.lock(document):
lm = QPdfLinkModel(document=document, page=pageNumber)
parentIndex = QModelIndex()
links = []
for row in range(lm.rowCount(parentIndex)):
index = lm.index(row, 0, parentIndex)
links.append(Link(lm, index,
document.pagePointSize(pageNumber)))
self._linksCache = link.Links(links)
return self._linksCache
[docs]
class PdfDocument(document.SingleSourceDocument):
"""A lazily loaded PDF document."""
pageClass = PdfPage
def __init__(self, source=None, renderer=None):
super().__init__(source, renderer)
self._document = None
[docs]
def invalidate(self):
"""Reimplemented to clear the Document reference."""
super().invalidate()
self._document = None
[docs]
def createPages(self):
doc = self.document()
if doc:
return self.pageClass.loadDocument(doc, self.renderer)
return ()
[docs]
def document(self):
"""Return the QPdfDocument object.
Returns None if no source was yet set, and False if loading failed.
"""
if self._document is None:
source = self.source()
if source:
self._document = load(source) or False
return self._document
[docs]
class PdfRenderer(render.AbstractRenderer):
[docs]
def tiles(self, width, height):
"""Yield four-tuples Tile(x, y, w, h) describing the tiles to render.
For the QtPdf backend, this always returns a single tile covering
the entire page because QtPdf does not support selectively rendering
a smaller area.
"""
yield render.Tile(0, 0, width, height)
[docs]
def render(self, page, key, tile, paperColor=None):
"""Generate a QImage for tile of the Page."""
if key.rotation:
# this is only doable by drawing on a second QImage
return super().render(page, key, tile, paperColor)
else:
# reuse the QImage returned by QPdfDocument.render() to save memory
image = self._render(page, key, tile)
if paperColor:
painter = QPainter(image)
painter.setCompositionMode(
QPainter.CompositionMode.CompositionMode_DestinationOver)
painter.fillRect(image.rect(), paperColor)
return image
[docs]
def draw(self, page, painter, key, tile, paperColor=None):
"""Draw a tile on the painter.
The painter is already at the right position and rotation.
"""
matrix = painter.deviceTransform()
painter.drawImage(0, 0, self._render(page, key, tile, matrix))
def _render(self, page, key, tile, matrix=None):
"""The actual rendering logic shared by render() and draw()."""
pageSize = page.pageSize() # in points
# key and tile coordinates scale with device resolution and zoom level
source = QRectF(0, 0, key.width, key.height)
target = QRectF(0, 0, tile.w, tile.h)
if key.rotation & 1:
pageSize.transpose()
target.setSize(target.size().transposed())
doc = page.document
num = page.pageNumber
# We use this to scale from key/tile to device coordinates
if matrix is None:
matrix = QTransform()
# When we are displaying an image on screen, our painter coordinates
# are "actual size" and scaling is our responsibility. When printing,
# the painter coordinates are scaled to the device's resolution and
# scaling is the device's responsibility.
# Note: m11 and m22 are our horizontal and vertical scaling factors.
actualSize = (matrix.m11() == matrix.m22() == 1)
# Oversampling produces more readable output at lower resolutions
# when painting at "actual size"
multiplier = util.oversampleFactor(key, pageSize) if actualSize else 1
# Set rendering options
RenderFlag = QPdfDocumentRenderOptions.RenderFlag
renderOptions = QPdfDocumentRenderOptions()
# This ridiculous back-and-forth conversion is necessary because
# PyQt6's enum types don't implement bitwise OR
renderFlags = 0
if not self.antialiasing:
renderFlags |= RenderFlag.TextAliased.value
renderFlags |= RenderFlag.ImageAliased.value
renderFlags |= RenderFlag.PathAliased.value
renderOptions.setRenderFlags(RenderFlag(renderFlags))
# Render the image at the output device's resolution (or double
# that if we are oversampling)
s = matrix.scale(multiplier, multiplier).mapRect(source)
renderSize = QSize(int(s.width()), int(s.height()))
with locking.lock(doc):
image = doc.render(num, renderSize, renderOptions)
if tile != (0, 0, key.width, key.height):
# Crop the image to the tile boundaries
image = image.copy(matrix.mapRect(QRect(*map(int, tile))))
if actualSize and QRectF(image.rect()) != target:
# Scale the image to our requested resolution
image = image.scaled(int(target.width()), int(target.height()),
Qt.AspectRatioMode.IgnoreAspectRatio,
Qt.TransformationMode.SmoothTransformation)
return image
[docs]
def load(source):
"""Load a PDF document.
Source may be:
- a QPdfDocument, which is then simply returned :-)
- a filename
- a QByteArray instance.
Returns None if the document could not be loaded.
"""
if isinstance(source, QPdfDocument):
return source
elif isinstance(source, str) or isinstance(source, QByteArray):
# We need to create the QPdfDocument without a parent QObject so
# Python can garbage-collect it properly when it goes out of scope
document = QPdfDocument(None) # parent has no default value
document.load(source)
return document
# Install a default renderer so PdfPage can be used directly
PdfPage.renderer = PdfRenderer()
