python3+PyQt5 柱状图

本文通过Python3+pyqt5实现了python Qt GUI 快速编程的16章的excise例子。

#!/usr/bin/env python3

import random
import sys
from PyQt5.QtCore import (QAbstractListModel, QAbstractTableModel,
        QModelIndex, QSize, QTimer, QVariant, Qt,pyqtSignal)
from PyQt5.QtWidgets import (QApplication, QDialog, QHBoxLayout,
        QListView, QSpinBox, QStyledItemDelegate,QStyleOptionViewItem, QWidget)
from PyQt5.QtGui import QColor,QPainter,QPixmap

class BarGraphModel(QAbstractListModel):
    dataChanged=pyqtSignal(QModelIndex,QModelIndex)
    def __init__(self):
        super(BarGraphModel, self).__init__()
        self.__data = []
        self.__colors = {}
        self.minValue = 0
        self.maxValue = 0


    def rowCount(self, index=QModelIndex()):
        return len(self.__data)


    def insertRows(self, row, count):
        extra = row + count
        if extra >= len(self.__data):
            self.beginInsertRows(QModelIndex(), row, row + count - 1)
            self.__data.extend([0] * (extra - len(self.__data) + 1))
            self.endInsertRows()
            return True
        return False


    def flags(self, index):
        #return (QAbstractTableModel.flags(self, index)|Qt.ItemIsEditable)
        return (QAbstractListModel.flags(self, index)|Qt.ItemIsEditable)

    def setData(self, index, value, role=Qt.DisplayRole):
        row = index.row()
        if not index.isValid() or 0 > row >= len(self.__data):
            return False
        changed = False
        if role == Qt.DisplayRole:
            value = value
            self.__data[row] = value
            if self.minValue > value:
                self.minValue = value
            if self.maxValue < value:
                self.maxValue = value
            changed = True
        elif role == Qt.UserRole:
            self.__colors[row] = value
            #self.emit(SIGNAL("dataChanged(QModelIndex,QModelIndex)"),
            #          index, index)
            self.dataChanged[QModelIndex,QModelIndex].emit(index, index)
            changed = True
        if changed:
            #self.emit(SIGNAL("dataChanged(QModelIndex,QModelIndex)"),
             #         index, index)
            self.dataChanged[QModelIndex,QModelIndex].emit(index, index)
        return changed


    def data(self, index, role=Qt.DisplayRole):
        row = index.row()
        if not index.isValid() or 0 > row >= len(self.__data):
            return QVariant()
        if role == Qt.DisplayRole:
            return self.__data[row]
        if role == Qt.UserRole:
            return QVariant(self.__colors.get(row,
                    QColor(Qt.red)))
        if role == Qt.DecorationRole:
            color = QColor(self.__colors.get(row,
                    QColor(Qt.red)))
            pixmap = QPixmap(20, 20)
            pixmap.fill(color)
            return QVariant(pixmap)
        return QVariant()


class BarGraphDelegate(QStyledItemDelegate):

    def __init__(self, minimum=0, maximum=100, parent=None):
        super(BarGraphDelegate, self).__init__(parent)
        self.minimum = minimum
        self.maximum = maximum


    def paint(self, painter, option, index):
        myoption = QStyleOptionViewItem(option)
        myoption.displayAlignment |= (Qt.AlignRight|Qt.AlignVCenter)
        QStyledItemDelegate.paint(self, painter, myoption, index)


    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 BarGraphView(QWidget):

    WIDTH = 20

    def __init__(self, parent=None):
        super(BarGraphView, self).__init__(parent)
        self.model = None


    def setModel(self, model):
        self.model = model
        #self.connect(self.model,
        #        SIGNAL("dataChanged(QModelIndex,QModelIndex)"),
        #        self.update)
        self.model.dataChanged[QModelIndex,QModelIndex].connect(self.update)
        #self.connect(self.model, SIGNAL("modelReset()"), self.update)
        self.model.modelReset.connect(self.update)


    def sizeHint(self):
        return self.minimumSizeHint()


    def minimumSizeHint(self):
        if self.model is None:
            return QSize(BarGraphView.WIDTH * 10, 100)
        return QSize(BarGraphView.WIDTH * self.model.rowCount(), 100)


    def paintEvent(self, event):
        if self.model is None:
            return
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        span = self.model.maxValue - self.model.minValue
        painter.setWindow(0, 0, BarGraphView.WIDTH * self.model.rowCount(),
                          span)
        for row in range(self.model.rowCount()):
            x = row * BarGraphView.WIDTH
            index = self.model.index(row)
            color = QColor(self.model.data(index, Qt.UserRole))
            y = self.model.data(index)
            painter.fillRect(x, span - y, BarGraphView.WIDTH, y, color)


class MainForm(QDialog):

    def __init__(self, parent=None):
        super(MainForm, self).__init__(parent)

        self.model = BarGraphModel()
        self.barGraphView = BarGraphView()
        self.barGraphView.setModel(self.model)
        self.listView = QListView()
        self.listView.setModel(self.model)
        self.listView.setItemDelegate(BarGraphDelegate(0, 1000, self))
        self.listView.setMaximumWidth(100)
        self.listView.setEditTriggers(QListView.DoubleClicked|
                                      QListView.EditKeyPressed)
        layout = QHBoxLayout()
        layout.addWidget(self.listView)
        layout.addWidget(self.barGraphView, 1)
        self.setLayout(layout)

        self.setWindowTitle("Bar Grapher")
        QTimer.singleShot(0, self.initialLoad)


    def initialLoad(self):
        # Generate fake data
        count = 20
        self.model.insertRows(0, count - 1)
        for row in range(count):
            value = random.randint(1, 150)
            color = QColor(random.randint(0, 255), random.randint(0, 255),
                           random.randint(0, 255))
            index = self.model.index(row)
            self.model.setData(index, value)
            self.model.setData(index, QVariant(color), Qt.UserRole)


app = QApplication(sys.argv)
form = MainForm()
form.resize(600, 400)
form.show()
app.exec_()

运行结果：