This article mainly introduces the relevant information of python3 PyQt5 generic delegation to everyone in detail. It has certain reference value. Interested friends can refer to it.
Custom delegation allows us to view the view. Take full control over the appearance and behavior of data items that appear in . If you have a lot of models, you may want to be able to use just one custom delegate for most of the models, but if you can't do that, you will most likely have a lot of duplicate code for those custom delegates. To make maintenance easier, a better approach is not to create a custom delegate for each model, but to use a series of common components that together form a delegate. This article implements the generic delegation example of Chapter 16 of python Qt GUI rapid programming through Python3 pyqt5.
/home/yrd/eric_workspace/chap16/richtextlineedit.py
#!/usr/bin/env python3
import platform
import sys
import html
from PyQt5.QtCore import QSize, Qt,pyqtSignal
from PyQt5.QtGui import QColor, QFont,QFontMetrics, QIcon, QKeySequence, QPixmap,QTextCharFormat
from PyQt5.QtWidgets import QAction,QApplication,QMenu,QTextEdit
class RichTextLineEdit(QTextEdit):
returnPressed=pyqtSignal()
(Bold, Italic, Underline, StrikeOut, Monospaced, Sans, Serif,
NoSuperOrSubscript, Subscript, Superscript) = range(10)
def __init__(self, parent=None):
super(RichTextLineEdit, self).__init__(parent)
self.monofamily = "courier"
self.sansfamily = "helvetica"
self.seriffamily = "times"
self.setLineWrapMode(QTextEdit.NoWrap)
self.setTabChangesFocus(True)
self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
fm = QFontMetrics(self.font())
h = int(fm.height() * (1.4 if platform.system() == "Windows"
else 1.2))
self.setMinimumHeight(h)
self.setMaximumHeight(int(h * 1.2))
self.setToolTip("Press <b>Ctrl+M</b> for the text effects "
"menu and <b>Ctrl+K</b> for the color menu")
def toggleItalic(self):
self.setFontItalic(not self.fontItalic())
def toggleUnderline(self):
self.setFontUnderline(not self.fontUnderline())
def toggleBold(self):
self.setFontWeight(QFont.Normal
if self.fontWeight() > QFont.Normal else QFont.Bold)
def sizeHint(self):
return QSize(self.document().idealWidth() + 5,
self.maximumHeight())
def minimumSizeHint(self):
fm = QFontMetrics(self.font())
return QSize(fm.width("WWWW"), self.minimumHeight())
def contextMenuEvent(self, event):
self.textEffectMenu()
def keyPressEvent(self, event):
if event.modifiers() & Qt.ControlModifier:
handled = False
if event.key() == Qt.Key_B:
self.toggleBold()
handled = True
elif event.key() == Qt.Key_I:
self.toggleItalic()
handled = True
elif event.key() == Qt.Key_K:
self.colorMenu()
handled = True
elif event.key() == Qt.Key_M:
self.textEffectMenu()
handled = True
elif event.key() == Qt.Key_U:
self.toggleUnderline()
handled = True
if handled:
event.accept()
return
if event.key() in (Qt.Key_Enter, Qt.Key_Return):
self.returnPressed.emit()
event.accept()
else:
QTextEdit.keyPressEvent(self, event)
def colorMenu(self):
pixmap = QPixmap(22, 22)
menu = QMenu("Colour")
for text, color in (
("&Black", Qt.black),
("B&lue", Qt.blue),
("Dark Bl&ue", Qt.darkBlue),
("&Cyan", Qt.cyan),
("Dar&k Cyan", Qt.darkCyan),
("&Green", Qt.green),
("Dark Gr&een", Qt.darkGreen),
("M&agenta", Qt.magenta),
("Dark Mage&nta", Qt.darkMagenta),
("&Red", Qt.red),
("&Dark Red", Qt.darkRed)):
color = QColor(color)
pixmap.fill(color)
action = menu.addAction(QIcon(pixmap), text, self.setColor)
action.setData(color)
self.ensureCursorVisible()
menu.exec_(self.viewport().mapToGlobal(
self.cursorRect().center()))
def setColor(self):
action = self.sender()
if action is not None and isinstance(action, QAction):
color = QColor(action.data())
if color.isValid():
self.setTextColor(color)
def textEffectMenu(self):
format = self.currentCharFormat()
menu = QMenu("Text Effect")
for text, shortcut, data, checked in (
("&Bold", "Ctrl+B", RichTextLineEdit.Bold,
self.fontWeight() > QFont.Normal),
("&Italic", "Ctrl+I", RichTextLineEdit.Italic,
self.fontItalic()),
("Strike &out", None, RichTextLineEdit.StrikeOut,
format.fontStrikeOut()),
("&Underline", "Ctrl+U", RichTextLineEdit.Underline,
self.fontUnderline()),
("&Monospaced", None, RichTextLineEdit.Monospaced,
format.fontFamily() == self.monofamily),
("&Serifed", None, RichTextLineEdit.Serif,
format.fontFamily() == self.seriffamily),
("S&ans Serif", None, RichTextLineEdit.Sans,
format.fontFamily() == self.sansfamily),
("&No super or subscript", None,
RichTextLineEdit.NoSuperOrSubscript,
format.verticalAlignment() ==
QTextCharFormat.AlignNormal),
("Su&perscript", None, RichTextLineEdit.Superscript,
format.verticalAlignment() ==
QTextCharFormat.AlignSuperScript),
("Subs&cript", None, RichTextLineEdit.Subscript,
format.verticalAlignment() ==
QTextCharFormat.AlignSubScript)):
action = menu.addAction(text, self.setTextEffect)
if shortcut is not None:
action.setShortcut(QKeySequence(shortcut))
action.setData(data)
action.setCheckable(True)
action.setChecked(checked)
self.ensureCursorVisible()
menu.exec_(self.viewport().mapToGlobal(
self.cursorRect().center()))
def setTextEffect(self):
action = self.sender()
if action is not None and isinstance(action, QAction):
what = action.data()
if what == RichTextLineEdit.Bold:
self.toggleBold()
return
if what == RichTextLineEdit.Italic:
self.toggleItalic()
return
if what == RichTextLineEdit.Underline:
self.toggleUnderline()
return
format = self.currentCharFormat()
if what == RichTextLineEdit.Monospaced:
format.setFontFamily(self.monofamily)
elif what == RichTextLineEdit.Serif:
format.setFontFamily(self.seriffamily)
elif what == RichTextLineEdit.Sans:
format.setFontFamily(self.sansfamily)
if what == RichTextLineEdit.StrikeOut:
format.setFontStrikeOut(not format.fontStrikeOut())
if what == RichTextLineEdit.NoSuperOrSubscript:
format.setVerticalAlignment(
QTextCharFormat.AlignNormal)
elif what == RichTextLineEdit.Superscript:
format.setVerticalAlignment(
QTextCharFormat.AlignSuperScript)
elif what == RichTextLineEdit.Subscript:
format.setVerticalAlignment(
QTextCharFormat.AlignSubScript)
self.mergeCurrentCharFormat(format)
def toSimpleHtml(self):
htmltext = ""
black = QColor(Qt.black)
block = self.document().begin()
while block.isValid():
iterator = block.begin()
while iterator != block.end():
fragment = iterator.fragment()
if fragment.isValid():
format = fragment.charFormat()
family = format.fontFamily()
color = format.foreground().color()
text=html.escape(fragment.text())
if (format.verticalAlignment() ==
QTextCharFormat.AlignSubScript):
text = "<sub>{0}</sub>".format(text)
elif (format.verticalAlignment() ==
QTextCharFormat.AlignSuperScript):
text = "<sup>{0}</sup>".format(text)
if format.fontUnderline():
text = "<u>{0}</u>".format(text)
if format.fontItalic():
text = "<i>{0}</i>".format(text)
if format.fontWeight() > QFont.Normal:
text = "<b>{0}</b>".format(text)
if format.fontStrikeOut():
text = "<s>{0}</s>".format(text)
if color != black or family:
attribs = ""
if color != black:
attribs += ' color="{0}"'.format(color.name())
if family:
attribs += ' face="{0}"'.format(family)
text = "<font{0}>{1}</font>".format(attribs,text)
htmltext += text
iterator += 1
block = block.next()
return htmltext
if __name__ == "__main__":
def printout(lineedit):
print(str(lineedit.toHtml()))
print(str(lineedit.toPlainText()))
print(str(lineedit.toSimpleHtml()))
app = QApplication(sys.argv)
lineedit = RichTextLineEdit()
lineedit.returnPressed.connect(lambda:printout(lineedit))
lineedit.show()
lineedit.setWindowTitle("RichTextEdit")
app.exec_()/home/yrd/eric_workspace/chap16/genericdelegates .py
#!/usr/bin/env python3
from PyQt5.QtCore import (QDate, QSize, Qt)
from PyQt5.QtWidgets import (QApplication, QDateEdit, QLineEdit,
QSpinBox, QStyledItemDelegate,QStyle)
from PyQt5.QtGui import QColor,QTextDocument
import richtextlineedit
class GenericDelegate(QStyledItemDelegate):
def __init__(self, parent=None):
super(GenericDelegate, self).__init__(parent)
self.delegates = {}
def insertColumnDelegate(self, column, delegate):
delegate.setParent(self)
self.delegates[column] = delegate
def removeColumnDelegate(self, column):
if column in self.delegates:
del self.delegates[column]
def paint(self, painter, option, index):
delegate = self.delegates.get(index.column())
if delegate is not None:
delegate.paint(painter, option, index)
else:
QStyledItemDelegate.paint(self, painter, option, index)
def createEditor(self, parent, option, index):
delegate = self.delegates.get(index.column())
if delegate is not None:
return delegate.createEditor(parent, option, index)
else:
return QStyledItemDelegate.createEditor(self, parent, option,
index)
def setEditorData(self, editor, index):
delegate = self.delegates.get(index.column())
if delegate is not None:
delegate.setEditorData(editor, index)
else:
QStyledItemDelegate.setEditorData(self, editor, index)
def setModelData(self, editor, model, index):
delegate = self.delegates.get(index.column())
if delegate is not None:
delegate.setModelData(editor, model, index)
else:
QStyledItemDelegate.setModelData(self, editor, model, index)
class IntegerColumnDelegate(QStyledItemDelegate):
def __init__(self, minimum=0, maximum=100, parent=None):
super(IntegerColumnDelegate, self).__init__(parent)
self.minimum = minimum
self.maximum = maximum
def createEditor(self, parent, option, index):
spinbox = QSpinBox(parent)
spinbox.setRange(self.minimum, self.maximum)
spinbox.setAlignment(Qt.AlignRight|Qt.AlignVCenter)
return spinbox
def setEditorData(self, editor, index):
value = index.model().data(index, Qt.DisplayRole)
editor.setValue(value)
def setModelData(self, editor, model, index):
editor.interpretText()
model.setData(index, editor.value())
class DateColumnDelegate(QStyledItemDelegate):
def __init__(self, minimum=QDate(),
maximum=QDate.currentDate(),
format="yyyy-MM-dd", parent=None):
super(DateColumnDelegate, self).__init__(parent)
self.minimum = minimum
self.maximum = maximum
self.format = format
def createEditor(self, parent, option, index):
dateedit = QDateEdit(parent)
#dateedit=QDateTimeEdit(parent)
dateedit.setDateRange(self.minimum, self.maximum)
dateedit.setAlignment(Qt.AlignRight|Qt.AlignVCenter)
dateedit.setDisplayFormat(self.format)
dateedit.setCalendarPopup(True)
return dateedit
def setEditorData(self, editor, index):
value = index.model().data(index, Qt.DisplayRole)
#if value.isNull:
editor.setDate(value)
#editor.setDisplayFormat(self.format)
def setModelData(self, editor, model, index):
model.setData(index, editor.date())
def paint(self, painter, option, index):
text = index.model().data(index, Qt.DisplayRole).toString(self.format)
palette = QApplication.palette()
document = QTextDocument()
document.setDefaultFont(option.font)
if option.state & QStyle.State_Selected:
document.setHtml("<font color={0}>{1}</font>".format(palette.highlightedText().color().name(),text))
else:
document.setHtml(text)
painter.save()
color = (palette.highlight().color()
if option.state & QStyle.State_Selected
else QColor(index.model().data(index,
Qt.BackgroundColorRole)))
painter.fillRect(option.rect, color)
painter.translate(option.rect.x(), option.rect.y())
document.drawContents(painter)
painter.restore()
class PlainTextColumnDelegate(QStyledItemDelegate):
def __init__(self, parent=None):
super(PlainTextColumnDelegate, self).__init__(parent)
def createEditor(self, parent, option, index):
lineedit = QLineEdit(parent)
return lineedit
def setEditorData(self, editor, index):
value = index.model().data(index, Qt.DisplayRole)
editor.setText(value)
def setModelData(self, editor, model, index):
model.setData(index, editor.text())
class RichTextColumnDelegate(QStyledItemDelegate):
def __init__(self, parent=None):
super(RichTextColumnDelegate, self).__init__(parent)
def paint(self, painter, option, index):
text = index.model().data(index, Qt.DisplayRole)
palette = QApplication.palette()
document = QTextDocument()
document.setDefaultFont(option.font)
if option.state & QStyle.State_Selected:
document.setHtml("<font color={0}>{1}</font>".format(palette.highlightedText().color().name(),text))
else:
document.setHtml(text)
painter.save()
color = (palette.highlight().color()
if option.state & QStyle.State_Selected
else QColor(index.model().data(index,
Qt.BackgroundColorRole)))
painter.fillRect(option.rect, color)
painter.translate(option.rect.x(), option.rect.y())
document.drawContents(painter)
painter.restore()
def sizeHint(self, option, index):
text = index.model().data(index).toString()
document = QTextDocument()
document.setDefaultFont(option.font)
document.setHtml(text)
return QSize(document.idealWidth() + 5,
option.fontMetrics.height())
def createEditor(self, parent, option, index):
lineedit = richtextlineedit.RichTextLineEdit(parent)
return lineedit
def setEditorData(self, editor, index):
value = index.model().data(index, Qt.DisplayRole)
editor.setHtml(value)
def setModelData(self, editor, model, index):
model.setData(index, editor.toSimpleHtml())/home/yrd/eric_workspace/chap16/carhirelog.pyw
#!/usr/bin/env python3
import bisect
import os
import platform
import sys
from PyQt5.QtCore import (QAbstractTableModel, QDate, QModelIndex,
QVariant, Qt,pyqtSignal)
from PyQt5.QtWidgets import (QApplication, QMainWindow,
QShortcut, QTableView)
from PyQt5.QtGui import QKeySequence
import genericdelegates
(LICENSE, CUSTOMER, HIRED, MILEAGEOUT, RETURNED, MILEAGEBACK,
NOTES, MILEAGE, DAYS) = range(9)
class CarHireLog(object):
def __init__(self, license, customer, hired, mileageout,
returned=QDate(), mileageback=0, notes=""):
self.license = license # plain text
self.customer = customer # plain text
self.hired = hired # QDate
self.mileageout = mileageout # int
self.returned = returned # QDate
self.mileageback = mileageback # int
self.notes = notes # HTML
def field(self, column):
if column == LICENSE:
return self.license
elif column == CUSTOMER:
return self.customer
elif column == HIRED:
return self.hired
elif column == MILEAGEOUT:
return self.mileageout
elif column == RETURNED:
return self.returned
elif column == MILEAGEBACK:
return self.mileageback
elif column == NOTES:
return self.notes
elif column == MILEAGE:
return self.mileage()
elif column == DAYS:
return self.days()
assert False
def mileage(self):
return (0 if self.mileageback == 0
else self.mileageback - self.mileageout)
def days(self):
return (0 if not self.returned.isValid()
else self.hired.daysTo(self.returned))
def __hash__(self):
return super(CarHireLog, self).__hash__()
def __eq__(self, other):
if self.hired != other.hired:
return False
if self.customer != other.customer:
return False
if self.license != other.license:
return False
return id(self) == id(other)
def __lt__(self, other):
if self.hired < other.hired:
return True
if self.customer < other.customer:
return True
if self.license < other.license:
return True
return id(self) < id(other)
class CarHireModel(QAbstractTableModel):
dataChanged = pyqtSignal(QModelIndex,QModelIndex)
def __init__(self, parent=None):
super(CarHireModel, self).__init__(parent)
self.logs = []
# Generate fake data
import gzip
import random
import string
surname_data = gzip.open(os.path.join(
os.path.dirname(__file__), "surnames.txt.gz")).read()
surnames = surname_data.decode("utf8").splitlines()
years = ("06 ", "56 ", "07 ", "57 ", "08 ", "58 ")
titles = ("Ms ", "Mr ", "Ms ", "Mr ", "Ms ", "Mr ", "Dr ")
notetexts = ("Returned <font color=red><b>damaged</b></font>",
"Returned with <i>empty fuel tank</i>",
"Customer <b>complained</b> about the <u>engine</u>",
"Customer <b>complained</b> about the <u>gears</u>",
"Customer <b>complained</b> about the <u>clutch</u>",
"Returned <font color=darkred><b>dirty</b></font>",)
today = QDate.currentDate()
for i in range(250):
license = []
for c in range(5):
license.append(random.choice(string.ascii_uppercase))
license = ("".join(license[:2]) + random.choice(years) +
"".join(license[2:]))
customer = random.choice(titles) + random.choice(surnames)
hired = today.addDays(-random.randint(0, 365))
mileageout = random.randint(10000, 30000)
notes = ""
if random.random() >= 0.2:
days = random.randint(1, 21)
returned = hired.addDays(days)
mileageback = (mileageout +
(days * random.randint(30, 300)))
if random.random() > 0.75:
notes = random.choice(notetexts)
else:
returned = QDate()
mileageback = 0
log = CarHireLog(license, customer, hired, mileageout,
returned, mileageback, notes)
bisect.insort(self.logs, log)
def rowCount(self, index=QModelIndex()):
return len(self.logs)
def columnCount(self, index=QModelIndex()):
return 9
def data(self, index, role):
if not index.isValid():
return QVariant()
if role == Qt.DisplayRole:
log = self.logs[index.row()]
value = log.field(index.column())
if (index.column() in (MILEAGEBACK, MILEAGE, DAYS) and
value == 0):
return 0
return value
if (role == Qt.TextAlignmentRole and
index.column() not in (LICENSE, CUSTOMER, NOTES)):
return QVariant(int(Qt.AlignRight|Qt.AlignVCenter))
if role == Qt.BackgroundColorRole:
palette = QApplication.palette()
if index.column() in (LICENSE, MILEAGE, DAYS):
return QVariant(palette.alternateBase())
else:
return QVariant(palette.base())
return QVariant()
def setData(self, index, value, role=Qt.EditRole):
if (index.isValid() and role == Qt.EditRole and
index.column() not in (LICENSE, MILEAGE, DAYS)):
log = self.logs[index.row()]
column = index.column()
if column == CUSTOMER:
log.customer = value
elif column == HIRED:
#log.hired = value.toDate()
log.hired = value
elif column == MILEAGEOUT:
log.mileageout = value
elif column == RETURNED:
#log.returned = value.toDate()
log.returned = value
elif column == MILEAGEBACK:
log.mileageback = value
elif column == NOTES:
log.notes = value
self.dataChanged[QModelIndex,QModelIndex].emit(index,index)
return True
return False
def headerData(self, section, orientation, role):
if role == Qt.TextAlignmentRole:
if orientation == Qt.Horizontal:
return QVariant(int(Qt.AlignCenter))
return QVariant(int(Qt.AlignRight|Qt.AlignVCenter))
if role != Qt.DisplayRole:
return QVariant()
if orientation == Qt.Horizontal:
if section == LICENSE:
return "License"
elif section == CUSTOMER:
return "Customer"
elif section == HIRED:
return "Hired"
elif section == MILEAGEOUT:
return "Mileage #1"
elif section == RETURNED:
return "Returned"
elif section == MILEAGEBACK:
return "Mileage #2"
elif section == DAYS:
return "Days"
elif section == MILEAGE:
return "Miles"
elif section == NOTES:
return "Notes"
return section + 1
def flags(self, index):
flag = QAbstractTableModel.flags(self, index)
if index.column() not in (LICENSE, MILEAGE, DAYS):
flag |= Qt.ItemIsEditable
return flag
class HireDateColumnDelegate(genericdelegates.DateColumnDelegate):
def createEditor(self, parent, option, index):
i = index.sibling(index.row(), RETURNED)
self.maximum = i.model().data(i, Qt.DisplayRole).addDays(-1)
return genericdelegates.DateColumnDelegate.createEditor(
self, parent, option, index)
class ReturnDateColumnDelegate(genericdelegates.DateColumnDelegate):
def createEditor(self, parent, option, index):
i = index.sibling(index.row(), HIRED)
self.minimum = i.model().data(i, Qt.DisplayRole).addDays(1)
return genericdelegates.DateColumnDelegate.createEditor(
self, parent, option, index)
class MileageOutColumnDelegate(genericdelegates.IntegerColumnDelegate):
def createEditor(self, parent, option, index):
i = index.sibling(index.row(), MILEAGEBACK)
maximum = i.model().data(i, Qt.DisplayRole)
self.maximum = 1000000 if maximum == 0 else maximum - 1
return genericdelegates.IntegerColumnDelegate.createEditor(
self, parent, option, index)
class MileageBackColumnDelegate(genericdelegates.IntegerColumnDelegate):
def createEditor(self, parent, option, index):
i = index.sibling(index.row(), MILEAGEOUT)
self.minimum = i.model().data(i, Qt.DisplayRole) + 1
return genericdelegates.IntegerColumnDelegate.createEditor(
self, parent, option, index)
class MainForm(QMainWindow):
def __init__(self, parent=None):
super(MainForm, self).__init__(parent)
model = CarHireModel(self)
self.view = QTableView()
self.view.setModel(model)
self.view.resizeColumnsToContents()
delegate = genericdelegates.GenericDelegate(self)
delegate.insertColumnDelegate(CUSTOMER,
genericdelegates.PlainTextColumnDelegate())
earliest = QDate.currentDate().addYears(-3)
delegate.insertColumnDelegate(HIRED,
HireDateColumnDelegate(earliest))
delegate.insertColumnDelegate(MILEAGEOUT,
MileageOutColumnDelegate(0, 1000000))
delegate.insertColumnDelegate(RETURNED,
ReturnDateColumnDelegate(earliest))
delegate.insertColumnDelegate(MILEAGEBACK,
MileageBackColumnDelegate(0, 1000000))
delegate.insertColumnDelegate(NOTES,
genericdelegates.RichTextColumnDelegate())
self.view.setItemDelegate(delegate)
self.setCentralWidget(self.view)
QShortcut(QKeySequence("Escape"), self, self.close)
QShortcut(QKeySequence("Ctrl+Q"), self, self.close)
self.setWindowTitle("Car Hire Logs")
app = QApplication(sys.argv)
form = MainForm()
rect = QApplication.desktop().availableGeometry()
form.resize(int(rect.width() * 0.7), int(rect.height() * 0.8))
form.move(0, 0)
form.show()
app.exec_()Running results:
python3 PyQt5 implements a page indexer application that supports multi-threading
##
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