Here is a start. In the code below, the clickable phrases in the text are translated to a ordered list of text cursors. When the mouse is moved (i.e. when a mouseMove event occurs) the position in the text under the mouse pointer is compared to this list of text cursors. If this position falls within the bounds of a cursor in the list, the corresponding phrase is highlighted by setting the extra selections of the browser. When a mouse button is clicked and the mouse is over a clickable phrase, a signal is emitted containing a text cursor corresponding to the selected phrase in the text. This signal can then be connected to a slot of another widget for further actions (like opening a message box like in the example below).
from PyQt5.QtCore import pyqtSignal, Qt
from PyQt5.QtWidgets import QTextBrowser, QApplication, QMessageBox
from PyQt5.QtGui import QFont, QSyntaxHighlighter, QTextCharFormat, QTextCursor
import bisect, re
class MyHighlighter(QSyntaxHighlighter):
def __init__(self, keywords, parent):
super().__init__(parent)
self.keywords = keywords
def highlightBlock(self, block):
if not self.keywords:
return
charFormat = QTextCharFormat()
charFormat.setFontWeight(QFont.Bold)
charFormat.setForeground(Qt.darkMagenta)
regex = re.compile('|'.join(self.keywords), re.IGNORECASE)
result = regex.search(block, 0)
while result:
self.setFormat(result.start(),result.end()-result.start(), charFormat)
result = regex.search(block, result.end())
class MyBrowser(QTextBrowser):
text_clicked = pyqtSignal("QTextCursor")
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.setMouseTracking(True)
self.setTextInteractionFlags(Qt.NoTextInteraction)
# self.phrases contains all phrases that should be clickable.
self.phrases = set()
self.cursors = []
# ExtraSelection object for highlighting phrases under the mouse cursor
self.selection = QTextBrowser.ExtraSelection()
self.selection.format.setBackground(Qt.blue)
self.selection.format.setForeground(Qt.white)
self.selected_cursor = None
# custom highlighter for highlighting all phrases
self.highlighter = MyHighlighter(self.phrases, self)
self.document().contentsChange.connect(self.text_has_changed)
@property
def selected_cursor(self):
return None if self.selection.cursor == QTextCursor() else self.selection.cursor
@selected_cursor.setter
def selected_cursor(self, cursor):
if cursor is None:
cursor = QTextCursor()
if self.selection.cursor != cursor:
self.selection.cursor = cursor
self.setExtraSelections([self.selection])
def mouseMoveEvent(self, event):
''' Update currently selected cursor '''
cursor = self.cursorForPosition(event.pos())
self.selected_cursor = self.find_selected_cursor(cursor)
def mouseReleaseEvent(self, event):
''' Emit self.selected_cursor signal when currently hovering over selectable phrase'''
if self.selected_cursor:
self.text_clicked.emit(self.selected_cursor)
self.selected_cursor = None
def add_phrase(self, phrase):
''' Add phrase to set of phrases and update list of text cursors'''
if phrase not in self.phrases:
self.phrases.add(phrase)
self.find_cursors(phrase)
self.highlighter.rehighlight()
def find_cursors(self, phrase):
''' Find all occurrences of phrase in the current document and add corresponding text cursor
to self.cursors '''
if not phrase:
return
self.moveCursor(self.textCursor().Start)
while self.find(phrase):
cursor = self.textCursor()
bisect.insort(self.cursors, cursor)
self.moveCursor(self.textCursor().Start)
def find_selected_cursor(self, cursor):
''' return text cursor corresponding to current mouse position or None if mouse not currently
over selectable phrase'''
position = cursor.position()
index = bisect.bisect(self.cursors, cursor)
if index < len(self.cursors) and self.cursors[index].anchor() <= position:
return self.cursors[index]
return None
def text_has_changed(self):
self.cursors.clear()
self.selected_cursor = None
for phrase in self.phrases:
self.find_cursors(phrase)
self.highlighter.rehighlight()
def text_message(widget):
def inner(cursor):
text = cursor.selectedText()
pos = cursor.selectionStart()
QMessageBox.information(widget, 'Information',
f'You have clicked on the phrase <b>{text}</b><br>'
f'which starts at position {pos} in the text')
return inner
if __name__=="__main__":
app = QApplication([])
window = MyBrowser()
window.resize(400,300)
information = text_message(window)
text = '''
<h1>Title</h1>
<p>This is a random text with. The following words are highlighted</p>
<ul>
<li>keyword1</li>
<li>keyword2</li>
</ul>
<p>Click on either keyword1 or keyword2 to get more info.
'''
window.add_phrase('keyword1')
window.add_phrase('keyword2')
window.setText(text)
window.text_clicked.connect(information)
window.show()
app.exec()
