python3+PyQt5自定义视图详解

Python  /  管理员 发布于 7年前   256

pyqt提供的几个视图类都可以较好工作，包括QLisView，QTableView和QTreeView。但是对于一些难以用现有的方式来呈现数据，这时，可以创建我们自己的视图子类并将其用做模型数据的可视化来解决这一问题。本文通过Python3+pyqt5实现了python Qt GUI 快速编程的16章的例子。

#!/usr/bin/env python3import gzipimport osimport platformimport sysfrom PyQt5.QtCore import (QAbstractTableModel, QDateTime, QModelIndex,    QSize, QTimer, QVariant, Qt,pyqtSignal)from PyQt5.QtGui import ( QColor, QCursor, QFont,    QFontDatabase, QFontMetrics, QPainter, QPalette, QPixmap)from PyQt5.QtWidgets import QApplication,QDialog,QHBoxLayout, QLabel, QMessageBox,QScrollArea, QSplitter, QTableView,QWidget(TIMESTAMP, TEMPERATURE, INLETFLOW, TURBIDITY, CONDUCTIVITY, COAGULATION, RAWPH, FLOCCULATEDPH) = range(8)TIMESTAMPFORMAT = "yyyy-MM-dd hh:mm"class WaterQualityModel(QAbstractTableModel):  def __init__(self, filename):    super(WaterQualityModel, self).__init__()    self.filename = filename    self.results = []  def load(self):    self.beginResetModel()    exception = None    fh = None    try:      if not self.filename:        raise IOError("no filename specified for loading")      self.results = []      line_data = gzip.open(self.filename).read()      for line in line_data.decode("utf8").splitlines():        parts = line.rstrip().split(",")        date = QDateTime.fromString(parts[0] + ":00",          Qt.ISODate)        result = [date]        for part in parts[1:]:          result.append(float(part))        self.results.append(result)    except (IOError, ValueError) as e:      exception = e    finally:      if fh is not None:        fh.close()      self.endResetModel()      if exception is not None:        raise exception  def data(self, index, role=Qt.DisplayRole):    if (not index.isValid() or      not (0 <= index.row() < len(self.results))):      return QVariant()    column = index.column()    result = self.results[index.row()]    if role == Qt.DisplayRole:      item = result[column]      if column == TIMESTAMP:        #item = item.toString(TIMESTAMPFORMAT)        item=item      else:        #item = QString("%1").arg(item, 0, "f", 2)        item = "{0:.2f}".format(item)      return item    elif role == Qt.TextAlignmentRole:      if column != TIMESTAMP:        return QVariant(int(Qt.AlignRight|Qt.AlignVCenter))      return QVariant(int(Qt.AlignLeft|Qt.AlignVCenter))    elif role == Qt.TextColorRole and column == INLETFLOW:      if result[column] < 0:        return QVariant(QColor(Qt.red))    elif (role == Qt.TextColorRole and       column in (RAWPH, FLOCCULATEDPH)):      ph = result[column]      if ph < 7:        return QVariant(QColor(Qt.red))      elif ph >= 8:        return QVariant(QColor(Qt.blue))      else:        return QVariant(QColor(Qt.darkGreen))    return QVariant()  def headerData(self, section, orientation, role=Qt.DisplayRole):    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 == TIMESTAMP:        return "Timestamp"      elif section == TEMPERATURE:        return "\u00B0" +"C"      elif section == INLETFLOW:        return "Inflow"      elif section == TURBIDITY:        return "NTU"      elif section == CONDUCTIVITY:        return "\u03BCS/cm"      elif section == COAGULATION:        return "mg/L"      elif section == RAWPH:        return "Raw Ph"      elif section == FLOCCULATEDPH:        return "Floc Ph"    return int(section + 1)  def rowCount(self, index=QModelIndex()):    return len(self.results)  def columnCount(self, index=QModelIndex()):    return 8class WaterQualityView(QWidget):  clicked = pyqtSignal(QModelIndex)  FLOWCHARS = (chr(0x21DC), chr(0x21DD), chr(0x21C9))  def __init__(self, parent=None):    super(WaterQualityView, self).__init__(parent)    self.scrollarea = None    self.model = None    self.setFocusPolicy(Qt.StrongFocus)    self.selectedRow = -1    self.flowfont = self.font()    size = self.font().pointSize()    if platform.system() == "Windows":      fontDb = QFontDatabase()      for face in [face.toLower() for face in fontDb.families()]:        if face.contains("unicode"):          self.flowfont = QFont(face, size)          break      else:        self.flowfont = QFont("symbol", size)        WaterQualityView.FLOWCHARS = (chr(0xAC), chr(0xAE),           chr(0xDE))  def setModel(self, model):    self.model = model    #self.connect(self.model,    #    SIGNAL("dataChanged(QModelIndex,QModelIndex)"),    #    self.setNewSize)    self.model.dataChanged.connect(self.setNewSize)    #self.connect(self.model, SIGNAL("modelReset()"), self.setNewSize)    self.model.modelReset.connect(self.setNewSize)    self.setNewSize()  def setNewSize(self):    self.resize(self.sizeHint())    self.update()    self.updateGeometry()  def minimumSizeHint(self):    size = self.sizeHint()    fm = QFontMetrics(self.font())    size.setHeight(fm.height() * 3)    return size  def sizeHint(self):    fm = QFontMetrics(self.font())    size = fm.height()    return QSize(fm.width("9999-99-99 99:99 ") + (size * 4),           (size / 4) + (size * self.model.rowCount()))  def paintEvent(self, event):    if self.model is None:      return    fm = QFontMetrics(self.font())    timestampWidth = fm.width("9999-99-99 99:99 ")    size = fm.height()    indicatorSize = int(size * 0.8)    offset = int(1.5 * (size - indicatorSize))    minY = event.rect().y()    maxY = minY + event.rect().height() + size    minY -= size    painter = QPainter(self)    painter.setRenderHint(QPainter.Antialiasing)    painter.setRenderHint(QPainter.TextAntialiasing)    y = 0    for row in range(self.model.rowCount()):      x = 0      if minY <= y <= maxY:        painter.save()        painter.setPen(self.palette().color(QPalette.Text))        if row == self.selectedRow:          painter.fillRect(x, y + (offset * 0.8),  self.width(), size, self.palette().highlight())          painter.setPen(self.palette().color(  QPalette.HighlightedText))        #timestamp = self.model.data(#self.model.index(row, TIMESTAMP)).toDateTime()        timestamp = self.model.data(self.model.index(row, TIMESTAMP))painter.drawText(x, y + size,timestamp.toString(TIMESTAMPFORMAT))        #print(timestamp.toString(TIMESTAMPFORMAT))        x += timestampWidth        temperature = self.model.data(self.model.index(row, TEMPERATURE))        #temperature = temperature.toDouble()[0]        temperature = float(temperature)        if temperature < 20:          color = QColor(0, 0,  int(255 * (20 - temperature) / 20))        elif temperature > 25:          color = QColor(int(255 * temperature / 100), 0, 0)        else:          color = QColor(0, int(255 * temperature / 100), 0)        painter.setPen(Qt.NoPen)        painter.setBrush(color)        painter.drawEllipse(x, y + offset, indicatorSize,      indicatorSize)        x += size        rawPh = self.model.data(self.model.index(row, RAWPH))        #rawPh = rawPh.toDouble()[0]        rawPh = float(rawPh)        if rawPh < 7:          color = QColor(int(255 * rawPh / 10), 0, 0)        elif rawPh >= 8:          color = QColor(0, 0, int(255 * rawPh / 10))        else:          color = QColor(0, int(255 * rawPh / 10), 0)        painter.setBrush(color)        painter.drawEllipse(x, y + offset, indicatorSize,      indicatorSize)        x += size        flocPh = self.model.data(self.model.index(row, FLOCCULATEDPH))        #flocPh = flocPh.toDouble()[0]        flocPh = float(flocPh)        if flocPh < 7:          color = QColor(int(255 * flocPh / 10), 0, 0)        elif flocPh >= 8:          color = QColor(0, 0, int(255 * flocPh / 10))        else:          color = QColor(0, int(255 * flocPh / 10), 0)        painter.setBrush(color)        painter.drawEllipse(x, y + offset, indicatorSize,      indicatorSize)        painter.restore()        painter.save()        x += size        flow = self.model.data(self.model.index(row, INLETFLOW))        #flow = flow.toDouble()[0]        flow = float(flow)        char = None        if flow <= 0:          char = WaterQualityView.FLOWCHARS[0]        elif flow < 3.6:          char = WaterQualityView.FLOWCHARS[1]        elif flow > 4.7:          char = WaterQualityView.FLOWCHARS[2]        if char is not None:          painter.setFont(self.flowfont)          painter.drawText(x, y + size, char)        painter.restore()      y += size      if y > maxY:        break  def mousePressEvent(self, event):    fm = QFontMetrics(self.font())    self.selectedRow = event.y() // fm.height()    self.update()    #self.emit(SIGNAL("clicked(QModelIndex)"),    #     self.model.index(self.selectedRow, 0))    self.clicked.emit(self.model.index(self.selectedRow, 0))  def keyPressEvent(self, event):    if self.model is None:      return    row = -1    if event.key() == Qt.Key_Up:      row = max(0, self.selectedRow - 1)    elif event.key() == Qt.Key_Down:      row = min(self.selectedRow + 1, self.model.rowCount() - 1)    if row != -1 and row != self.selectedRow:      self.selectedRow = row      if self.scrollarea is not None:        fm = QFontMetrics(self.font())        y = fm.height() * self.selectedRow        print(y)        self.scrollarea.ensureVisible(0, y)      self.update()      #self.emit(SIGNAL("clicked(QModelIndex)"),      #     self.model.index(self.selectedRow, 0))      self.clicked.emit(self.model.index(self.selectedRow, 0))    else:      QWidget.keyPressEvent(self, event)class MainForm(QDialog):  def __init__(self, parent=None):    super(MainForm, self).__init__(parent)    self.model = WaterQualityModel(os.path.join(        os.path.dirname(__file__), "waterdata.csv.gz"))    self.tableView = QTableView()    self.tableView.setAlternatingRowColors(True)    self.tableView.setModel(self.model)    self.waterView = WaterQualityView()    self.waterView.setModel(self.model)    scrollArea = QScrollArea()    scrollArea.setBackgroundRole(QPalette.Light)    scrollArea.setWidget(self.waterView)    self.waterView.scrollarea = scrollArea    splitter = QSplitter(Qt.Horizontal)    splitter.addWidget(self.tableView)    splitter.addWidget(scrollArea)    splitter.setSizes([600, 250])    layout = QHBoxLayout()    layout.addWidget(splitter)    self.setLayout(layout)    self.setWindowTitle("Water Quality Data")    QTimer.singleShot(0, self.initialLoad)  def initialLoad(self):    QApplication.setOverrideCursor(QCursor(Qt.WaitCursor))    splash = QLabel(self)    pixmap = QPixmap(os.path.join(os.path.dirname(__file__),        "iss013-e-14802.jpg"))    #print(os.path.join(os.path.dirname(__file__),    #    "iss013-e-14802.jpg"))    splash.setPixmap(pixmap)    splash.setWindowFlags(Qt.SplashScreen)    splash.move(self.x() + ((self.width() - pixmap.width()) / 2),          self.y() + ((self.height() - pixmap.height()) / 2))    splash.show()    QApplication.processEvents()    try:      self.model.load()    except IOError as e:      QMessageBox.warning(self, "Water Quality - Error", e)    else:      self.tableView.resizeColumnsToContents()    splash.close()    QApplication.processEvents()    QApplication.restoreOverrideCursor()app = QApplication(sys.argv)form = MainForm()form.resize(850, 620)form.show()app.exec_()

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