Source code for qpageview.highlight

# -*- coding: utf-8 -*-
# This file is part of the qpageview package.
# Copyright (c) 2010 - 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.

Highlight rectangular areas inside a View.

import collections
import weakref

from PyQt5.QtCore import QRect, QRectF, QTimer
from PyQt5.QtGui import QPainter, QPen
from PyQt5.QtWidgets import QApplication

[docs]class Highlighter: """A Highlighter can draw rectangles to highlight e.g. links in a View. An instance represents a certain type of highlighting, e.g. of a particular style. The paintRects() method is called with a list of rectangles that need to be drawn. To implement different highlighting behaviour just inherit paintRects(). The default implementation of paintRects() uses the `color` attribute to get the color to use and the `lineWidth` (default: 2) and `radius` (default: 3) attributes. `lineWidth` specifies the thickness in pixels of the border drawn, `radius` specifies the distance in pixels the border is drawn (by default with rounded corners) around the area to be highlighted. `color` is set to None by default, causing the paintRects method to choose the application's palette highlight color. """ lineWidth = 2 radius = 3 color = None
[docs] def paintRects(self, painter, rects): """Override this method to implement different drawing behaviour.""" color = self.color if self.color is not None else QApplication.palette().highlight().color() pen = QPen(color) pen.setWidth(self.lineWidth) painter.setPen(pen) painter.setRenderHint(QPainter.Antialiasing, True) rad = self.radius for r in rects: r.adjust(-rad, -rad, rad, rad) painter.drawRoundedRect(r, rad, rad)
[docs]class HighlightViewMixin: """Mixin methods vor view.View for highlighting areas. This mixin allows for highlighting rectangular areas on pages. You can highlight different sets of areas independently, using different Highlighter instances. Highlighting can be set to stay on forever or to disappear after a certain amount of microseconds. If desired, the View can be scrolled to show the highlighted areas. How the highlighting is drawn is determined by the paintRects() method of Highlighter. """ def __init__(self, parent=None, **kwds): self._highlights = weakref.WeakKeyDictionary() self._defaultHighlighter = None super().__init__(parent, **kwds)
[docs] def defaultHighlighter(self): """Return a default highlighter, creating it if necessary.""" if self._defaultHighlighter is None: self._defaultHighlighter = Highlighter() return self._defaultHighlighter
[docs] def setDefaultHighlighter(self, highlighter): """Set a Highlighter to use as the default highlighter.""" self._defaultHighlighter = highlighter
[docs] def highlightRect(self, areas): """Return the bounding rect of the areas.""" boundingRect = QRect() for page, rects in areas.items(): f = page.mapToPage(1, 1).rect pbound = QRect() for r in rects: pbound |= f(r) boundingRect |= pbound.translated(page.pos()) return boundingRect
[docs] def highlight(self, areas, highlighter=None, msec=0, scroll=False, margins=None, allowKinetic=True): """Highlight the areas dict using the given or default highlighter. The areas dict maps Page objects to lists of rectangles, where the rectangle is a QRectF() inside (0, 0, 1, 1) like the area attribute of a Link. If the highlighter is not specified, the default highlighter will be used. If msec > 0, the highlighting will vanish after that many microseconds. If scroll is True, the View will be scrolled to show the areas to highlight if needed, using View.ensureVisible(highlightRect(areas), margins, allowKinetic). """ if highlighter is None: highlighter = self.defaultHighlighter() if scroll: self.ensureVisible(self.highlightRect(areas), margins, allowKinetic) if msec: msec += self.remainingScrollTime() d = weakref.WeakKeyDictionary(areas) if msec: selfref = weakref.ref(self) def clear(): self = selfref() if self: self.clearHighlight(highlighter) t = QTimer(singleShot = True, timeout = clear) t.start(msec) else: t = None self.clearHighlight(highlighter) self._highlights[highlighter] = (d, t) self.viewport().update()
[docs] def clearHighlight(self, highlighter=None): """Removes the highlighted areas of the given or default highlighter.""" if highlighter is None: highlighter = self.defaultHighlighter() try: (d, t) = self._highlights[highlighter] except KeyError: return if t is not None: t.stop() del self._highlights[highlighter] self.viewport().update()
[docs] def isHighlighting(self, highlighter=None): """Return True if the given or default highlighter is active.""" if highlighter is None: highlighter = self.defaultHighlighter() return highlighter in self._highlights
[docs] def highlightUrls(self, urls, highlighter=None, msec=0, scroll=False, margins=None, allowKinetic=True): """Convenience method highlighting the specified urls in the Document. The urls argument is a list of urls (str); the other arguments are used for calling highlight() on the areas returned by getUrlHighlightAreas(urls). """ areas = self.getUrlHighlightAreas(urls) if areas: self.highlight(areas, highlighter, msec, scroll, margins, allowKinetic)
[docs] def getUrlHighlightAreas(self, urls): """Return the areas to highlight all occurrences of the specified URLs. The areas are found in the dictionary returned by document().urls(). URLs that are not in that dictionary are silently skipped. If there is no document set this method returns nothing. """ doc = self.document() if doc: u = doc.urls() if u: pages = doc.pages() areas = collections.defaultdict(list) for url in urls: d = u.get(url) if d: for n, linkareas in d.items(): rects = [] for a in linkareas: r = QRectF() r.setCoords(*a) rects.append(r) areas[pages[n]].extend(rects) return areas
[docs] def paintEvent(self, ev): """Paint the highlighted areas in the viewport.""" super().paintEvent(ev) # first paint the contents painter = QPainter(self.viewport()) for highlighter, (d, t) in self._highlights.items(): for page, rect in self.pagesToPaint(ev.rect(), painter): try: areas = d[page] except KeyError: continue rectarea = page.mapFromPage(1, 1).rect(rect) f = page.mapToPage(1, 1).rect rects = [f(area) for area in areas if area & rectarea] highlighter.paintRects(painter, rects)