Home >Backend Development >Python Tutorial >Detailed explanation of python3+PyQt5 generic delegation
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:
##Related recommendations:python3 PyQt5 implements a page indexer application that supports multi-threading
##
The above is the detailed content of Detailed explanation of python3+PyQt5 generic delegation. For more information, please follow other related articles on the PHP Chinese website!