While searching for a solution to tabbing through QTableWidgets in PyQt, I found this old question on StackOverflow that needed help creating the code necessary to allow a QTextEdit to capture Shift-tab to deindent code.
Below is the thoroughly commented code that explains how all this works:
import sys
from PyQt4 import QtCore, QtGui
class TabPlainTextEdit(QtGui.QTextEdit):
def __init__(self,parent):
QtGui.QTextEdit.__init__(self, parent)
def keyPressEvent(self, event):
# Shift + Tab is not the same as trying to catch a Shift modifier and a tab Key.
# Shift + Tab is a Backtab!!
if event.key() == QtCore.Qt.Key_Backtab:
cur = self.textCursor()
# Copy the current selection
pos = cur.position() # Where a selection ends
anchor = cur.anchor() # Where a selection starts (can be the same as above)
# Can put QtGui.QTextCursor.MoveAnchor as the 2nd arg, but this is the default
cur.setPosition(pos)
# Move the position back one, selection the character prior to the original position
cur.setPosition(pos-1,QtGui.QTextCursor.KeepAnchor)
if str(cur.selectedText()) == "\t":
# The prior character is a tab, so delete the selection
cur.removeSelectedText()
# Reposition the cursor with the one character offset
cur.setPosition(anchor-1)
cur.setPosition(pos-1,QtGui.QTextCursor.KeepAnchor)
else:
# Try all of the above, looking before the anchor (This helps if the achor is before a tab)
cur.setPosition(anchor)
cur.setPosition(anchor-1,QtGui.QTextCursor.KeepAnchor)
if str(cur.selectedText()) == "\t":
cur.removeSelectedText()
cur.setPosition(anchor-1)
cur.setPosition(pos-1,QtGui.QTextCursor.KeepAnchor)
else:
# Its not a tab, so reset the selection to what it was
cur.setPosition(anchor)
cur.setPosition(pos,QtGui.QTextCursor.KeepAnchor)
else:
return QtGui.QTextEdit.keyPressEvent(self, event)
def main():
app = QtGui.QApplication(sys.argv)
w = TabPlainTextEdit(None)
w.show()
sys.exit(app.exec_())
if __name__ == "__main__":
main()