python3+PyQt5实现柱状图

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：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

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