python3+PyQt5 使用自定义委托控制数据项的展示和 编辑

委托可以纯粹用来控制外观或者提供自定义编辑器用来完成控制编辑操作，又或者用于这两方面。本文用python3+pyQt5改写实现了python Qt Gui快速编程这本书的14章的例子。通过委托，实现了owner和country域和组合框组合在一起，TEU与微调框组合在一起。还增添了一个export按钮，用于将数据导出来成指定的txt格式的文本。

/home/yrd/eric_workspace/chap14/ships_delegate_ans/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/chap14/ships_delegate_ans/ships_ans.py

#!/usr/bin/env python3

import platform
import re
from PyQt5.QtCore import (QAbstractTableModel, QDataStream, QFile,
                          QIODevice, QModelIndex,QRegExp, QSize,QVariant, Qt,pyqtSignal)
from PyQt5.QtGui import QColor,QTextDocument
from PyQt5.QtWidgets import QApplication, QWidget,QComboBox, QLineEdit,QSpinBox, QStyle,QStyledItemDelegate, QTextEdit
import richtextlineedit

NAME, OWNER, COUNTRY, DESCRIPTION, TEU = range(5)

MAGIC_NUMBER = 0x570C4
FILE_VERSION = 1


class Ship(object):

    def __init__(self, name, owner, country, teu=0, description=""):
        self.name = name
        self.owner = owner
        self.country = cou