If I search for letter x forward (button Next), everything works as it should, but as soon as I change direction (button Previous), this happens:
QsciScintilla.findFirst() doesn't move selection. I.e., first press of button Previous doesn't do anything;QsciScintilla.findNext() moves in steps of 2, thus skipping one character.ATM I'm considering translating logic for find operations from C++ to Python, thus potentially fixing the issue, but it'd be nice to know that I made some novice mistake, thus avoiding all the extra work...
Here's the code:
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.Qsci import *
import sys
class FindAndReplace(QWidget):
def __init__(self, *arg, **kwarg):
super(self.__class__, self).__init__(*arg, **kwarg)
rows = QVBoxLayout()
self.editor = QsciScintilla()
self.editor.setText(f'{"x"*40}\n{"y"*40}\n{"z"*40}\n')
rows.addWidget(self.editor)
self.text_to_find = ''
self.state_ = tuple()
self.find = QLineEdit()
self.find_previous = QPushButton('&Previous')
self.find_next = QPushButton('&Next')
self.find_lbl = QLabel('&Find')
self.find_lbl.setBuddy(self.find)
row = QHBoxLayout()
for w in (self.find_lbl, self.find, self.find_previous, self.find_next):
row.addWidget(w)
rows.addLayout(row)
self.re = QCheckBox('&Regular expressions')
self.cs = QCheckBox('&Case sensitive')
self.wo = QCheckBox('Whole &words')
self.wrap = QCheckBox('Wrap aroun&d')
self.show_ = QCheckBox('&Unfold folded text')
self.posix = QCheckBox('POSI&X-compatible RE')
row = QHBoxLayout()
for w in (self.re, self.cs, self.wo, self.wrap, self.show_, self.posix):
row.addWidget(w)
rows.addLayout(row)
self.setLayout(rows)
self.find_previous.clicked.connect(lambda: self.findText(forward = False))
self.find_next.clicked.connect(lambda: self.findText(forward = True))
def findText(self, forward):
text_to_find = self.find.text()
state_ = ( \
self.re.isChecked(), self.cs.isChecked(),
self.wo.isChecked(), self.wrap.isChecked(),
forward, -1, -1,
self.show_.isChecked(), self.posix.isChecked(),
)
if text_to_find != self.text_to_find or state_ != self.state_:
self.text_to_find = text_to_find
self.state_ = state_
# search with new conditions.
self.editor.findFirst(text_to_find, *state_)
else:
# search with previously set conditions.
self.editor.findNext()
if __name__ == '__main__':
app = QApplication(sys.argv)
FindAndReplace().show()
sys.exit(app.exec_())
The findNext function looks buggy to me. If I use getSelection to explicitly enter line and index in findFirst, and avoid using findNext altogether, everything works as expected:
def findText(self, forward):
text_to_find = self.find.text()
if forward:
line, index = self.editor.getSelection()[2:]
else:
line, index = self.editor.getSelection()[:2]
state_ = (
self.re.isChecked(), self.cs.isChecked(),
self.wo.isChecked(), self.wrap.isChecked(),
forward, line, index,
self.show_.isChecked(), self.posix.isChecked(),
)
self.text_to_find = text_to_find
self.state_ = state_
self.editor.findFirst(text_to_find, *state_)
Looking at the latest source code (qsciscintilla.cpp, line 1853) I see this:
// Finally adjust the start position so that we don't find the same one again.
if (findState.forward)
findState.startpos = targend;
else if ((findState.startpos = targstart - 1) < 0)
findState.startpos = 0;
I may be misunderstanding the intention of the code, but why does it subtract one here? AFAICS, this will create an off-by-one error when searching backwards.