Source code for qpageview.view

# -*- coding: utf-8 -*-
# This file is part of the qpageview package.
# Copyright (c) 2016 - 2019 by Wilbert Berendsen
# 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 2
# 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
# 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 for more information.

The View, deriving from QAbstractScrollArea.

import collections
import contextlib
import weakref

from PyQt5.QtCore import pyqtSignal, QEvent, QPoint, QRect, QSize, Qt
from PyQt5.QtGui import QCursor, QPainter, QPalette, QRegion
from PyQt5.QtWidgets import QGestureEvent, QPinchGesture, QStyle
from PyQt5.QtPrintSupport import QPrinter, QPrintDialog

from . import layout
from . import page
from . import scrollarea
from . import util

from .constants import (

    # rotation:

    # viewModes:

    # orientation:

Position = collections.namedtuple("Position", "pageNumber x y")

[docs]class View(scrollarea.ScrollArea): """View is a generic scrollable widget to display Pages in a layout. Using setPageLayout() you can set a PageLayout to the View, and you can add Pages to the layout using a list-like api. (PageLayout derives from list). A simple PageLayout is set by default. Call updatePageLayout() after every change to the layout (like adding or removing pages). You can also add a Magnifier to magnify parts of a Page, and a Rubberband to enable selecting a rectangular region. View emits the following signals: :attr:`pageCountChanged` (int) emitted when the total amount of pages has changed :attr:`currentPageNumberChanged` (int) emitted when the current page number has changed (starting with 1) :attr:`viewModeChanged` (int) emitted when the ``viewMode`` has changed :attr:`rotationChanged` (int) emitted when the ``rotation`` has changed :attr:`orientationChanged` (int) emitted when the ``orientation`` has changed :attr:`zoomFactorChanged` (float) emitted when the ``zoomFactor`` has changed :attr:`continuousModeChanged` (bool) emitted when the ``continuousMode`` has changed :attr:`pageLayoutModeChanged` (str) emitted when the ``pageLayoutMode`` has changed :attr:`pageLayoutUpdated` () emitted whenever the page layout has been updated (redraw/resize) """ MIN_ZOOM = 0.05 MAX_ZOOM = 64.0 #: whether to enable mouse wheel zooming wheelZoomingEnabled = True #: whether to enable kinetic scrolling while paging (setCurrentPageNumber) kineticPagingEnabled = True #: whether to keep track of current page while scrolling pagingOnScrollEnabled = True #: whether a mouse click in a page makes it the current page clickToSetCurrentPageEnabled = True #: whether PageUp and PageDown call setCurrentPageNumber instead of scroll strictPagingEnabled = False #: can be set to a DocumentPropertyStore object. If set, the object is #: used to store certain View settings on a per-document basis. #: (This happens in the :meth:`clear` and :meth:`setDocument` methods.) documentPropertyStore = None #: (int) emitted when the total amount of pages has changed pageCountChanged = pyqtSignal(int) #: (int) emitted when the current page number has changed (starting with 1) currentPageNumberChanged = pyqtSignal(int) #: (int) emitted when the ``viewMode`` has changed viewModeChanged = pyqtSignal(int) #: (int) emitted when the ``rotation`` has changed rotationChanged = pyqtSignal(int) #: (int) emitted when the ``orientation`` has changed orientationChanged = pyqtSignal(int) #: (float) emitted when the ``zoomFactor`` has changed zoomFactorChanged = pyqtSignal(float) #: (bool) emitted when the ``continuousMode`` has changed continuousModeChanged = pyqtSignal(bool) #: (str) emitted when the ``pageLayoutMode`` has changed pageLayoutModeChanged = pyqtSignal(str) #: emitted whenever the page layout has been updated (redraw/resize) pageLayoutUpdated = pyqtSignal() def __init__(self, parent=None, **kwds): super().__init__(parent, **kwds) self._document = None self._currentPageNumber = 0 self._pageCount = 0 self._scrollingToPage = 0 self._prev_pages_to_paint = set() self._viewMode = FixedScale self._pageLayout = None self._magnifier = None self._rubberband = None self._pinchStartFactor = None self.grabGesture(Qt.PinchGesture) self.viewport().setBackgroundRole(QPalette.Dark) self.verticalScrollBar().setSingleStep(20) self.horizontalScrollBar().setSingleStep(20) self.setMouseTracking(True) self.setMinimumSize(QSize(60, 60)) self.setPageLayout(layout.PageLayout()) props = self._viewMode = props.viewMode self._pageLayout.continuousMode = props.continuousMode self._pageLayout.orientation = props.orientation self._pageLayoutMode = props.pageLayoutMode self.pageLayout().engine = self.pageLayoutModes()[props.pageLayoutMode]()
[docs] def pageCount(self): """Return the number of pages in the view.""" return self._pageCount
[docs] def currentPageNumber(self): """Return the current page number in view (starting with 1).""" return self._currentPageNumber
[docs] def setCurrentPageNumber(self, num): """Scrolls to the specified page number (starting with 1). If the page is already in view, the view is not scrolled, otherwise the view is scrolled to center the page. (If the page is larger than the view, the top-left corner is positioned top-left in the view.) """ self.updateCurrentPageNumber(num) page = self.currentPage() if page: margins = self._pageLayout.margins() + self._pageLayout.pageMargins() with self.pagingOnScrollDisabled(): self.ensureVisible(page.geometry(), margins, self.kineticPagingEnabled) if self.isScrolling(): self._scrollingToPage = True
[docs] def updateCurrentPageNumber(self, num): """Set the current page number without scrolling the view.""" count = self.pageCount() n = max(min(count, num), 1 if count else 0) if n == num and n != self._currentPageNumber: self._currentPageNumber = num self.currentPageNumberChanged.emit(num)
[docs] def gotoNextPage(self): """Convenience method to go to the next page.""" num = self.currentPageNumber() if num < self.pageCount(): self.setCurrentPageNumber(num + 1)
[docs] def gotoPreviousPage(self): """Convenience method to go to the previous page.""" num = self.currentPageNumber() if num > 1: self.setCurrentPageNumber(num - 1)
[docs] def currentPage(self): """Return the page pointed to by currentPageNumber().""" if self._pageCount: return self._pageLayout[self._currentPageNumber-1]
[docs] def page(self, num): """Return the page at the specified number (starting at 1).""" if 0 < num <= self._pageCount: return self._pageLayout[num-1]
[docs] def pages(self): """Return a list of all Pages in the page layout.""" return list(self._pageLayout)
[docs] def position(self): """Return a three-tuple Position(pageNumber, x, y). The Position describes where the center of the viewport is on the layout. The page is the page number (starting with 1) and x and y the position on the page, in a 0..1 range. This way a position can be remembered even if the zoom or orientation of the layout changes. """ pos = self.viewport().rect().center() i, x, y = self._pageLayout.pos2offset(pos - self.layoutPosition()) return Position(i + 1, x, y)
[docs] def setPosition(self, position, allowKinetic=True): """Centers the view on the spot stored in the specified Position. If allowKinetic is False, immediately jumps to the position, otherwise scrolls smoothly (if kinetic scrolling is enabled). """ i, x, y = position rect = self.viewport().rect() rect.moveCenter(self._pageLayout.offset2pos((i - 1, x, y))) self.ensureVisible(rect, allowKinetic=allowKinetic)
[docs] def setPageLayout(self, layout): """Set our current PageLayout instance. The dpiX and dpiY attributes of the layout are set to the physical resolution of the widget, which should result in a natural size of 100% at zoom factor 1.0. """ if self._pageLayout: self._unschedulePages(self._pageLayout) layout.dpiX = self.physicalDpiX() layout.dpiY = self.physicalDpiY() self._pageLayout = layout self.updatePageLayout()
[docs] def pageLayout(self): """Return our current PageLayout instance.""" return self._pageLayout
[docs] def pageLayoutModes(self): """Return a dictionary mapping names to callables. The callable returns a configured LayoutEngine that is set to the page layout. You can reimplement this method to returns more layout modes, but it is required that the name "single" exists. """ def single(): return layout.LayoutEngine() def raster(): return layout.RasterLayoutEngine() def double_left(): engine = layout.RowLayoutEngine() engine.pagesPerRow = 2 engine.pagesFirstRow = 0 return engine def double_right(): engine = double_left() engine.pagesFirstRow = 1 return engine return locals()
[docs] def pageLayoutMode(self): """Return the currently set page layout mode.""" return self._pageLayoutMode
[docs] def setPageLayoutMode(self, mode): """Set the page layout mode. The mode is one of the names returned by pageLayoutModes(). The mode name "single" is guaranteed to exist. """ if mode != self._pageLayoutMode: # get a suitable LayoutEngine try: engine = self.pageLayoutModes()[mode]() except KeyError: return self._pageLayout.engine = engine # keep the current page in view page = self.currentPage() self.updatePageLayout() if page: margins = self._pageLayout.margins() + self._pageLayout.pageMargins() with self.pagingOnScrollDisabled(): self.ensureVisible(page.geometry(), margins, False) self._pageLayoutMode = mode self.pageLayoutModeChanged.emit(mode) if self.viewMode(): with self.keepCentered(): self.fitPageLayout()
[docs] def updatePageLayout(self, lazy=False): """Update layout, adjust scrollbars, keep track of page count. If lazy is set to True, calls lazyUpdate() to update the view. """ self._pageLayout.update() # keep track of page count count = self._pageLayout.count() if count != self._pageCount: self._pageCount = count self.pageCountChanged.emit(count) n = max(min(count, self._currentPageNumber), 1 if count else 0) self.updateCurrentPageNumber(n) self.setAreaSize(self._pageLayout.size()) self.pageLayoutUpdated.emit() self.lazyUpdate() if lazy else self.viewport().update()
[docs] @contextlib.contextmanager def modifyPages(self): """Return the list of pages and enter a context to make modifications. Note that the first page is at index 0. On exit of the context the page layout is updated. """ pages = list(self._pageLayout) if self.rubberband(): selectedpages = set(p for p, r in self.rubberband().selectedPages()) else: selectedpages = set() lazy = bool(pages) try: yield pages finally: lazy &= bool(pages) removedpages = set(self._pageLayout) - set(pages) if selectedpages & removedpages: self.rubberband().clearSelection() # rubberband'll always be there self._unschedulePages(removedpages) self._pageLayout[:] = pages if self._viewMode: zoomFactor = self._pageLayout.zoomFactor self.fitPageLayout() if zoomFactor != self._pageLayout.zoomFactor: lazy = False self.updatePageLayout(lazy)
[docs] @contextlib.contextmanager def modifyPage(self, num): """Return the page (numbers start with 1) and enter a context. On exit of the context, the page layout is updated. """ page = yield page if page: self._unschedulePages((page,)) self.updatePageLayout(True)
[docs] def clear(self): """Convenience method to clear the current layout.""" self.setPages([])
[docs] def setPages(self, pages): """Load the iterable of pages into the View. Existing pages are removed, and the document is set to None. """ if self.documentPropertyStore and self._document: self.documentPropertyStore.set(self._document, self._document = None with self.modifyPages() as pgs: pgs[:] = pages
[docs] def setDocument(self, document): """Set the Document to display (see document.Document).""" store = self._document is not document and self.documentPropertyStore if store and self._document: store.set(self._document, self._document = document with self.modifyPages() as pages: pages[:] = document.pages() if store: (store.get(document) or store.default or
[docs] def document(self): """Return the Document currently displayed (see document.Document).""" return self._document
[docs] def reload(self): """If a Document was set, invalidate()s it and then reloads it.""" if self._document: self._document.invalidate() with self.modifyPages() as pages: pages[:] = self._document.pages()
[docs] def loadPdf(self, filename, renderer=None): """Convenience method to load the specified PDF file. The filename can also be a QByteArray or an already loaded popplerqt5.Poppler.Document instance. """ from . import poppler self.setDocument(poppler.PopplerDocument(filename, renderer))
[docs] def loadSvgs(self, filenames, renderer=None): """Convenience method to load the specified list of SVG files. Each SVG file is loaded in one Page. A filename can also be a QByteArray. """ from . import svg self.setDocument(svg.SvgDocument(filenames, renderer))
[docs] def loadImages(self, filenames, renderer=None): """Convenience method to load images from the specified list of files. Each image is loaded in one Page. A filename can also be a QByteArray or a QImage. """ from . import image self.setDocument(image.ImageDocument(filenames, renderer))
[docs] def print(self, printer=None, pageNumbers=None, showDialog=True): """Print all, or speficied pages to QPrinter printer. If given the pageNumbers should be a list containing page numbers starting with 1. If showDialog is True, a print dialog is shown, and printing is canceled when the user cancels the dialog. If the QPrinter to use is not specified, a default one is created. The print job is started and returned (a printing.PrintJob instance), so signals for monitoring the progress could be connected to. (If the user cancels the dialog, no print job is returned.) """ if printer is None: printer = QPrinter() printer.setResolution(300) if showDialog: dlg = QPrintDialog(printer, self) dlg.setMinMax(1, self.pageCount()) if not dlg.exec_(): return # cancelled if not pageNumbers: if printer.printRange() == QPrinter.CurrentPage: pageNumbers = [self.currentPageNumber()] else: if printer.printRange() == QPrinter.PageRange: first = printer.toPage() or 1 last = printer.fromPage() or self.pageCount() else: first, last = 1, self.pageCount() pageNumbers = list(range(first, last + 1)) if printer.pageOrder() == QPrinter.LastPageFirst: pageNumbers.reverse() # add the page objects pageList = [(n, for n in pageNumbers] from . import printing job = printing.PrintJob(printer, pageList) job.start() return job
[docs] @staticmethod def properties(): """Return an uninitialized ViewProperties object.""" return ViewProperties()
[docs] def readProperties(self, settings): """Read View settings from the QSettings object. If a documentPropertyStore is set, the settings are also set as default for the DocumentPropertyStore. """ props = props.position = None # storing the position makes no sense props.set(self) if self.documentPropertyStore: self.documentPropertyStore.default = props
[docs] def writeProperties(self, settings): """Write the current View settings to the QSettings object. If a documentPropertyStore is set, the settings are also set as default for the DocumentPropertyStore. """ props = props.position = None # storing the position makes no sense if self.documentPropertyStore: self.documentPropertyStore.default = props
[docs] def setViewMode(self, mode): """Sets the current ViewMode.""" if mode == self._viewMode: return self._viewMode = mode if mode: with self.keepCentered(): self.fitPageLayout() else: # call layout once to tell FixedScale is active self.pageLayout().fit(QSize(), mode) self.viewModeChanged.emit(mode)
[docs] def viewMode(self): """Returns the current ViewMode.""" return self._viewMode
[docs] def setRotation(self, rotation): """Set the current rotation.""" layout = self._pageLayout if rotation != layout.rotation: with self.keepCentered(): layout.rotation = rotation self.fitPageLayout() self.rotationChanged.emit(rotation)
[docs] def rotation(self): """Return the current rotation.""" return self._pageLayout.rotation
[docs] def rotateLeft(self): """Rotate the pages 270 degrees.""" self.setRotation((self.rotation() - 1) & 3)
[docs] def rotateRight(self): """Rotate the pages 90 degrees.""" self.setRotation((self.rotation() + 1) & 3)
[docs] def setOrientation(self, orientation): """Set the orientation (Horizontal or Vertical).""" layout = self._pageLayout if orientation != layout.orientation: with self.keepCentered(): layout.orientation = orientation self.fitPageLayout() self.orientationChanged.emit(orientation)
[docs] def orientation(self): """Return the current orientation (Horizontal or Vertical).""" return self._pageLayout.orientation
[docs] def setContinuousMode(self, continuous): """Sets whether the layout should display all pages. If True, the layout shows all pages. If False, only the page set containing the current page is displayed. If the pageLayout() does not support the PageSetLayoutMixin methods, this method does nothing. """ layout = self._pageLayout oldcontinuous = layout.continuousMode if continuous: if not oldcontinuous: with self.pagingOnScrollDisabled(), self.keepCentered(): layout.continuousMode = True self.fitPageLayout() self.continuousModeChanged.emit(True) elif oldcontinuous: p = self.currentPage() index = layout.index(p) if p else 0 with self.pagingOnScrollDisabled(), self.keepCentered(): layout.continuousMode = False layout.currentPageSet = layout.pageSet(index) self.fitPageLayout() self.continuousModeChanged.emit(False)
[docs] def continuousMode(self): """Return True if the layout displays all pages.""" return self._pageLayout.continuousMode
[docs] def displayPageSet(self, what): """Try to display a page set (if the layout is not in continuous mode). `what` can be: "next": go to the next page set "previous": go to the previous page set "first": go to the first page set "last": go to the last page set integer: go to the specified page set """ layout = self._pageLayout if layout.continuousMode: return sb = None # where to move the scrollbar after fitlayout if what == "first": what = 0 sb = "up" # move to the start elif what == "last": what = layout.pageSetCount() - 1 sb = "down" # move to the end elif what == "previous": what = layout.currentPageSet - 1 if what < 0: return sb = "down" elif what == "next": what = layout.currentPageSet + 1 if what >= layout.pageSetCount(): return sb = "up" elif not 0 <= what < layout.pageSetCount(): return layout.currentPageSet = what self.fitPageLayout() self.updatePageLayout() if sb: self.verticalScrollBar().setValue(0 if sb == "up" else self.verticalScrollBar().maximum()) if self.pagingOnScrollEnabled and not self._scrollingToPage: s = layout.currentPageSetSlice() num = s.stop - 1 if sb == "down" else s.start self.updateCurrentPageNumber(num + 1)
[docs] def setMagnifier(self, magnifier): """Sets the Magnifier to use (or None to disable the magnifier). The viewport takes ownership of the Magnifier. """ if self._magnifier: self.viewport().removeEventFilter(self._magnifier) self._magnifier.setParent(None) self._magnifier = magnifier if magnifier: magnifier.setParent(self.viewport()) self.viewport().installEventFilter(magnifier)
[docs] def magnifier(self): """Returns the currently set magnifier.""" return self._magnifier
[docs] def setRubberband(self, rubberband): """Sets the Rubberband to use for selections (or None to not use one).""" if self._rubberband: self.viewport().removeEventFilter(self._rubberband) self.zoomFactorChanged.disconnect(self._rubberband.slotZoomChanged) self.rotationChanged.disconnect(self._rubberband.clearSelection) self._rubberband.setParent(None) self._rubberband = rubberband if rubberband: rubberband.setParent(self.viewport()) rubberband.clearSelection() self.viewport().installEventFilter(rubberband) self.zoomFactorChanged.connect(rubberband.slotZoomChanged) self.rotationChanged.connect(rubberband.clearSelection)
[docs] def rubberband(self): """Return the currently set rubberband.""" return self._rubberband
[docs] @contextlib.contextmanager def pagingOnScrollDisabled(self): """During this context a scroll is not tracked to update the current page number.""" old, self._scrollingToPage = self._scrollingToPage, True try: yield finally: self._scrollingToPage = old
[docs] def scrollContentsBy(self, dx, dy): """Reimplemented to move the rubberband and adjust the mouse cursor.""" if self._rubberband: self._rubberband.scrollBy(QPoint(dx, dy)) if not self.isScrolling() and not self.isDragging(): # don't adjust the cursor during a kinetic scroll pos = self.viewport().mapFromGlobal(QCursor.pos()) if pos in self.viewport().rect() and not self.viewport().childAt(pos): self.adjustCursor(pos) self.viewport().update() # keep track of current page. If the scroll wasn't initiated by the # setCurrentPage() call, check # whether the current page number needs # to be updated if self.pagingOnScrollEnabled and not self._scrollingToPage and self.pageCount() > 0: # do nothing if current page is still fully in view if self.currentPage().geometry() not in self.visibleRect(): # find the page in the center of the view layout = self._pageLayout pos = self.visibleRect().center() p = layout.pageAt(pos) or layout.nearestPageAt(pos) if p: num = layout.index(p) + 1 self.updateCurrentPageNumber(num)
[docs] def stopScrolling(self): """Reimplemented to adjust the mouse cursor on scroll stop.""" super().stopScrolling() self._scrollingToPage = False pos = self.viewport().mapFromGlobal(QCursor.pos()) if pos in self.viewport().rect() and not self.viewport().childAt(pos): self.adjustCursor(pos)
[docs] def fitPageLayout(self): """Fit the layout according to the view mode. Does nothing in FixedScale mode. Prevents scrollbar/resize loops by precalculating which scrollbars will appear. """ mode = self.viewMode() if mode == FixedScale: return maxsize = self.maximumViewportSize() # can vertical or horizontal scrollbars appear? vcan = self.verticalScrollBarPolicy() == Qt.ScrollBarAsNeeded hcan = self.horizontalScrollBarPolicy() == Qt.ScrollBarAsNeeded # width a scrollbar takes off the viewport size framewidth = 0 if, None, self): framewidth = * 2 scrollbarextent =, None, self) + framewidth # remember old factor zoom_factor = self.zoomFactor() # first try to fit full size layout = self._pageLayout, mode) layout.update() # minimal values minwidth = maxsize.width() minheight = maxsize.height() if vcan: minwidth -= scrollbarextent if hcan: minheight -= scrollbarextent # do width and/or height fit? fitw = layout.width <= maxsize.width() fith = layout.height <= maxsize.height() if not fitw and not fith: if vcan or hcan:, minheight), mode) elif mode & FitWidth and fitw and not fith and vcan: # a vertical scrollbar will appear w = minwidth, maxsize.height()), mode) layout.update() if layout.height <= maxsize.height(): # now the vert. scrollbar would disappear! # enlarge it as long as the vertical scrollbar would not be needed while True: w += 1, maxsize.height()), mode) layout.update() if layout.height > maxsize.height(): - 1, maxsize.height()), mode) break elif mode & FitHeight and fith and not fitw and hcan: # a horizontal scrollbar will appear h = minheight, h), mode) layout.update() if layout.width <= maxsize.width(): # now the horizontal scrollbar would disappear! # enlarge it as long as the horizontal scrollbar would not be needed while True: h += 1, h), mode) layout.update() if layout.width > maxsize.width():, h - 1), mode) break if zoom_factor != self.zoomFactor(): self.zoomFactorChanged.emit(self.zoomFactor()) self._unschedulePages(layout)
[docs] @contextlib.contextmanager def keepCentered(self, pos=None): """Context manager to keep the same spot centered while changing the layout. If pos is not given, the viewport's center is used. After yielding, updatePageLayout() is called. """ if pos is None: pos = self.viewport().rect().center() # find the spot on the page layout = self._pageLayout layout_pos = self.layoutPosition() pos_on_layout = pos - layout_pos offset = layout.pos2offset(pos_on_layout) pos_on_layout -= layout.pos() # pos() of the layout might change yield self.updatePageLayout() new_pos_on_layout = layout.offset2pos(offset) - layout.pos() diff = new_pos_on_layout - pos self.verticalScrollBar().setValue(diff.y()) self.horizontalScrollBar().setValue(diff.x())
[docs] def setZoomFactor(self, factor, pos=None): """Set the zoom factor (1.0 by default). If pos is given, that position (in viewport coordinates) is kept in the center if possible. If None, zooming centers around the viewport center. """ factor = max(self.MIN_ZOOM, min(self.MAX_ZOOM, factor)) if factor != self._pageLayout.zoomFactor: with self.keepCentered(pos): self._pageLayout.zoomFactor = factor if self._pageLayout.zoomsToFit(): self.setViewMode(FixedScale) self.zoomFactorChanged.emit(factor) self._unschedulePages(self._pageLayout)
[docs] def zoomFactor(self): """Return the page layout's zoom factor.""" return self._pageLayout.zoomFactor
[docs] def zoomIn(self, pos=None, factor=1.1): """Zoom in. If pos is given, it is the position in the viewport to keep centered. Otherwise zooming centers around the viewport center. """ self.setZoomFactor(self.zoomFactor() * factor, pos)
[docs] def zoomOut(self, pos=None, factor=1.1): """Zoom out. If pos is given, it is the position in the viewport to keep centered. Otherwise zooming centers around the viewport center. """ self.setZoomFactor(self.zoomFactor() / factor, pos)
[docs] def zoomNaturalSize(self, pos=None): """Zoom to the natural pixel size of the current page. The natural pixel size zoom factor can be different than 1.0, if the screen's DPI differs from the current page's DPI. """ p = self.currentPage() factor = p.dpi / self.physicalDpiX() if p else 1.0 self.setZoomFactor(factor, pos)
[docs] def layoutPosition(self): """Return the position of the PageLayout relative to the viewport. This is the top-left position of the layout, relative to the top-left position of the viewport. If the layout is smaller than the viewport it is centered by default. (See ScrollArea.alignment.) """ return self.areaPos() - self._pageLayout.pos()
[docs] def visibleRect(self): """Return the QRect of the page layout that is currently visible in the viewport.""" return self.visibleArea().translated(self._pageLayout.pos())
[docs] def visiblePages(self, rect=None): """Yield the Page instances that are currently visible. If rect is not given, the visibleRect() is used. The pages are sorted so that the pages with the largest visible part come first. """ if rect is None: rect = self.visibleRect() def key(page): overlayrect = rect & page.geometry() return overlayrect.width() * overlayrect.height() return sorted(self._pageLayout.pagesAt(rect), key=key, reverse=True)
[docs] def ensureVisible(self, rect, margins=None, allowKinetic=True): """Ensure rect is visible, switching page set if necessary.""" if not any(self.pageLayout().pagesAt(rect)): if self.continuousMode(): return # we might need to switch page set # find the rect for p in layout.PageRects(self.pageLayout()).intersecting(*rect.getCoords()): num = self.pageLayout().index(p) self.displayPageSet(self.pageLayout().pageSet(num)) break else: return rect = rect.translated(-self._pageLayout.pos()) super().ensureVisible(rect, margins, allowKinetic)
[docs] def adjustCursor(self, pos): """Sets the correct mouse cursor for the position on the page.""" pass
[docs] def repaintPage(self, page): """Call this when you want to redraw the specified page.""" rect = page.geometry().translated(self.layoutPosition()) self.viewport().update(rect)
[docs] def lazyUpdate(self, page=None): """Lazily repaint page (if visible) or all visible pages. Defers updating the viewport for a page until all rendering tasks for that page have finished. This reduces flicker. """ viewport = self.viewport() full = True updates = [] for p in self.visiblePages(): rect = self.visibleRect() & p.geometry() if rect and p.renderer: imgs, missing, key, *rest =, viewport, rect.translated(-p.pos())) if missing: full = False if page is p or page is None: p.renderer.schedule(p, key, missing, self.lazyUpdate) elif page is p or page is None: updates.append(rect.translated(self.layoutPosition())) if full: viewport.update() elif updates: viewport.update(sum(updates, QRegion()))
[docs] def rerender(self, page=None): """Schedule the specified page or all pages for rerendering. Call this when you have changed render options or page contents. Repaints the page or visible pages lazily, reducing flicker. """ renderers = collections.defaultdict(list) pages = (page,) if page else self._pageLayout for p in pages: if p.renderer: renderers[p.renderer].append(p) for renderer, pages in renderers.items(): renderer.invalidate(pages) self.lazyUpdate(page)
def _unschedulePages(self, pages): """(Internal.) Unschedule rendering of pages that are pending but not needed anymore. Called inside paintEvent, on zoomFactor change and some other places. This prevents rendering jobs hogging the cpu for pages that are deleted or out of view. """ unschedule = collections.defaultdict(set) for page in pages: if page.renderer: unschedule[page.renderer].add(page) for renderer, pages in unschedule.items(): renderer.unschedule(pages, self.repaintPage)
[docs] def pagesToPaint(self, rect, painter): """Yield (page, rect) to paint in the specified rectangle. The specified rect is in viewport coordinates, as in the paint event. The returned rect describes the part of the page actually to draw, in page coordinates. (The full rect can be found in page.rect().) Translates the painter to the top left of each page. The pages are sorted with largest area last. """ layout_pos = self.layoutPosition() ev_rect = rect.translated(-layout_pos) for p in self.visiblePages(ev_rect): r = (p.geometry() & ev_rect).translated(-p.pos()) painter.translate(layout_pos + p.pos()) yield p, r painter.restore()
[docs] def event(self, ev): """Reimplemented to get Gesture events.""" if isinstance(ev, QGestureEvent) and self.handleGestureEvent(ev): ev.accept() # Accepts all gestures in the event return True return super().event(ev)
[docs] def handleGestureEvent(self, event): """Gesture event handler. Return False if event is not accepted. Currently only cares about PinchGesture. Could also handle Swipe and Pan gestures. """ ## originally contributed by David Rydh, 2017 pinch = event.gesture(Qt.PinchGesture) if pinch: return self.pinchGesture(pinch) return False
[docs] def pinchGesture(self, gesture): """Pinch gesture event handler. Return False if event is not accepted. Currently only cares about ScaleFactorChanged and not RotationAngleChanged. """ ## originally contributed by David Rydh, 2017 # Gesture start? Reset _pinchStartFactor in case we didn't # catch the finish event if gesture.state() == Qt.GestureStarted: self._pinchStartFactor = None changeFlags = gesture.changeFlags() if changeFlags & QPinchGesture.ScaleFactorChanged: factor ="totalScaleFactor") if not self._pinchStartFactor: # Gesture start? self._pinchStartFactor = self.zoomFactor() self.setZoomFactor(self._pinchStartFactor * factor, self.mapFromGlobal(gesture.hotSpot().toPoint())) # Gesture finished? if gesture.state() in (Qt.GestureFinished, Qt.GestureCanceled): self._pinchStartFactor = None return True
[docs] def paintEvent(self, ev): """Paint the contents of the viewport.""" painter = QPainter(self.viewport()) pages_to_paint = set() for p, r in self.pagesToPaint(ev.rect(), painter): p.paint(painter, r, self.repaintPage) pages_to_paint.add(p) # remove pending render jobs for pages that were visible, but are not # visible now rect = self.visibleRect() pages = set(page for page in self._prev_pages_to_paint - pages_to_paint if not rect.intersects(page.geometry())) self._unschedulePages(pages) self._prev_pages_to_paint = pages_to_paint
[docs] def resizeEvent(self, ev): """Reimplemented to scale the view if needed and update the scrollbars.""" if self._viewMode and not self._pageLayout.empty(): with self.pagingOnScrollDisabled(): # sensible repositioning vbar = self.verticalScrollBar() hbar = self.horizontalScrollBar() x, xm = hbar.value(), hbar.maximum() y, ym = vbar.value(), vbar.maximum() self.fitPageLayout() self.updatePageLayout() if xm: hbar.setValue(round(x * hbar.maximum() / xm)) if ym: vbar.setValue(round(y * vbar.maximum() / ym)) super().resizeEvent(ev)
[docs] def wheelEvent(self, ev): """Reimplemented to support wheel zooming and paging through page sets.""" if self.wheelZoomingEnabled and ev.angleDelta().y() and ev.modifiers() & Qt.CTRL: factor = 1.1 ** util.sign(ev.angleDelta().y()) self.setZoomFactor(self.zoomFactor() * factor, ev.pos()) elif not ev.modifiers(): # if scrolling is not possible, try going to next or previous pageset. sb = self.verticalScrollBar() sp = self.strictPagingEnabled if ev.angleDelta().y() > 0 and sb.value() == 0: self.gotoPreviousPage() if sp else self.displayPageSet("previous") elif ev.angleDelta().y() < 0 and sb.value() == sb.maximum(): self.gotoNextPage() if sp else self.displayPageSet("next") else: super().wheelEvent(ev) else: super().wheelEvent(ev)
[docs] def mousePressEvent(self, ev): """Implemented to set the clicked page as current, without moving it.""" if self.clickToSetCurrentPageEnabled: page = self._pageLayout.pageAt(ev.pos() - self.layoutPosition()) if page: num = self._pageLayout.index(page) + 1 self.updateCurrentPageNumber(num) super().mousePressEvent(ev)
[docs] def mouseMoveEvent(self, ev): """Implemented to adjust the mouse cursor depending on the page contents.""" # no cursor updates when dragging the background is busy, see if not self.isDragging(): self.adjustCursor(ev.pos()) super().mouseMoveEvent(ev)
[docs] def keyPressEvent(self, ev): """Reimplemented to go to next or previous page set if possible.""" # ESC clears the selection, if any. if (ev.key() == Qt.Key_Escape and not ev.modifiers() and self.rubberband() and self.rubberband().hasSelection()): self.rubberband().clearSelection() return # Paging through page sets? sb = self.verticalScrollBar() sp = self.strictPagingEnabled if ev.key() == Qt.Key_PageUp: if sp: self.gotoPreviousPage() elif sb.value() == 0: self.displayPageSet("previous") else: super().keyPressEvent(ev) elif ev.key() == Qt.Key_PageDown: if sp: self.gotoNextPage() elif sb.value() == sb.maximum(): self.displayPageSet("next") else: super().keyPressEvent(ev) elif ev.key() == Qt.Key_Home and ev.modifiers() == Qt.ControlModifier: self.setCurrentPageNumber(1) if sp else self.displayPageSet("first") elif ev.key() == Qt.Key_End and ev.modifiers() == Qt.ControlModifier: self.setCurrentPageNumber(self.pageCount()) if sp else self.displayPageSet("last") else: super().keyPressEvent(ev)
[docs]class ViewProperties: """Simple helper class encapsulating certain settings of a View. The settings can be set to and got from a View, and saved to or loaded from a QSettings group. Class attributes serve as default values, None means: no change. All methods return self, so operations can easily be chained. If you inherit from a View and add more settings, you can also add properties to this class by inheriting from it. Reimplement to return an instance of your new ViewProperties subclass. """ position = None rotation = Rotate_0 zoomFactor = 1.0 viewMode = FixedScale orientation = None continuousMode = None pageLayoutMode = None
[docs] def setdefaults(self): """Set all properties to default values. Also used by View on init.""" self.orientation = Vertical self.continuousMode = True self.pageLayoutMode = "single" return self
[docs] def copy(self): """Return a copy or ourselves.""" cls = type(self) props = cls.__new__(cls) props.__dict__.update(self.__dict__) return props
[docs] def names(self): """Return a tuple with all the property names we support.""" return ( 'position', 'rotation', 'zoomFactor', 'viewMode', 'orientation', 'continuousMode', 'pageLayoutMode', )
[docs] def mask(self, names): """Set properties not listed in names to None.""" for name in self.names(): if name not in names and getattr(self, name) is not None: setattr(self, name, None) return self
[docs] def get(self, view): """Get the properties of a View.""" self.position = view.position() self.rotation = view.rotation() self.orientation = view.orientation() self.viewMode = view.viewMode() self.zoomFactor = view.zoomFactor() self.continuousMode = view.continuousMode() self.pageLayoutMode = view.pageLayoutMode() return self
[docs] def set(self, view): """Set all our properties that are not None to a View.""" if self.pageLayoutMode is not None: view.setPageLayoutMode(self.pageLayoutMode) if self.rotation is not None: view.setRotation(self.rotation) if self.orientation is not None: view.setOrientation(self.orientation) if self.continuousMode is not None: view.setContinuousMode(self.continuousMode) if self.viewMode is not None: view.setViewMode(self.viewMode) if self.zoomFactor is not None: if self.viewMode is FixedScale or not view.pageLayout().zoomsToFit(): view.setZoomFactor(self.zoomFactor) if self.position is not None: view.setPosition(self.position, False) return self
[docs] def save(self, settings): """Save the properties that are not None to a QSettings group.""" if self.pageLayoutMode is not None: settings.setValue("pageLayoutMode", self.pageLayoutMode) else: settings.remove("pageLayoutMode") if self.rotation is not None: settings.setValue("rotation", self.rotation) else: settings.remove("rotation") if self.orientation is not None: settings.setValue("orientation", self.orientation) else: settings.remove("orientation") if self.continuousMode is not None: settings.setValue("continuousMode", self.continuousMode) else: settings.remove("continuousMode") if self.viewMode is not None: settings.setValue("viewMode", self.viewMode) else: settings.remove("viewMode") if self.zoomFactor is not None: settings.setValue("zoomFactor", self.zoomFactor) else: settings.remove("zoomFactor") if self.position is not None: settings.setValue("position/pageNumber", self.position.pageNumber) settings.setValue("position/x", self.position.x) settings.setValue("position/y", self.position.y) else: settings.remove("position") return self
[docs] def load(self, settings): """Load the properties from a QSettings group.""" if settings.contains("pageLayoutMode"): v = settings.value("pageLayoutMode", "", str) if v: self.pageLayoutMode = v if settings.contains("rotation"): v = settings.value("rotation", -1, int) if v in (Rotate_0, Rotate_90, Rotate_180, Rotate_270): self.rotation = v if settings.contains("orientation"): v = settings.value("orientation", 0, int) if v in (Horizontal, Vertical): self.orientation = v if settings.contains("continuousMode"): v = settings.value("continuousMode", True, bool) self.continuousMode = v if settings.contains("viewMode"): v = settings.value("viewMode", -1, int) if v in (FixedScale, FitHeight, FitWidth, FitBoth): self.viewMode = v if settings.contains("zoomFactor"): v = settings.value("zoomFactor", 0, float) if v: self.zoomFactor = v if settings.contains("position/pageNumber"): pageNumber = settings.value("position/pageNumber", -1, int) if pageNumber != -1: x = settings.value("position/x", 0.0, float) y = settings.value("position/y", 0.0, float) self.position = Position(pageNumber, x, y) return self
[docs]class DocumentPropertyStore: """Store ViewProperties (settings) on a per-Document basis. If you create a DocumentPropertyStore and install it in the documentPropertyStore attribute of a View, the View will automatically remember its settings for earlier displayed Document instances. """ default = None mask = None def __init__(self): self._properties = weakref.WeakKeyDictionary()
[docs] def get(self, document): """Get the View properties stored for the document, if available. If a ViewProperties instance is stored in the `default` attribute, it is returned when no properties were available. Otherwise, None is returned. """ props = self._properties.get(document) if props is None: if self.default: props = self.default if self.mask: props = props.copy().mask(self.mask) return props
[docs] def set(self, document, properties): """Store the View properties for the document. If the `mask` attribute is set to a list or tuple of names, only the listed properties are remembered. """ if self.mask: properties.mask(self.mask) self._properties[document] = properties