图例示例链接到本标题
此示例展示了如何将图例从图表中分离出来，以及如何将其重新附加。
默认情况下，图表在同一个视图中绘制图例。在某些情况下，用户可能希望将图例绘制到其他位置。为了实现这一点，可以单独绘制图例。分离意味着图表不绘制图例或尝试更改其布局。分离的图例可以绘制到用户希望的位置，例如，在另一个图形场景中。图例的行为可以通过运行图例示例进行检查。在示例中，我们使用柱状系列，其中添加或删除柱状集。图例反映了系列的变化。图例可以分离或重新附加到图表上，其对齐方式可以修改。当图例分离时，它可以自由地调整大小和位置。
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
"""PySide6 port of the Legend example from Qt v5.x"""
import sys
from PySide6.QtCore import Qt, QRectF, Slot
from PySide6.QtGui import QBrush, QColor, QPainter, QPen
from PySide6.QtWidgets import (QApplication, QDoubleSpinBox,
QFormLayout, QGridLayout, QGroupBox,
QPushButton, QWidget)
from PySide6.QtCharts import QBarSeries, QBarSet, QChart, QChartView
class MainWidget(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self.chart = QChart()
self.series = QBarSeries()
self.main_layout = QGridLayout()
self.button_layout = QGridLayout()
self.font_layout = QFormLayout()
self.font_size = QDoubleSpinBox()
self.legend_posx = QDoubleSpinBox()
self.legend_posy = QDoubleSpinBox()
self.legend_width = QDoubleSpinBox()
self.legend_height = QDoubleSpinBox()
self.detach_legend_button = QPushButton("Toggle attached")
self.detach_legend_button.clicked.connect(self.toggle_attached)
self.button_layout.addWidget(self.detach_legend_button, 0, 0)
self.add_set_button = QPushButton("add barset")
self.add_set_button.clicked.connect(self.add_barset)
self.button_layout.addWidget(self.add_set_button, 2, 0)
self.remove_barset_button = QPushButton("remove barset")
self.remove_barset_button.clicked.connect(self.remove_barset)
self.button_layout.addWidget(self.remove_barset_button, 3, 0)
self.align_button = QPushButton("Align (Bottom)")
self.align_button.clicked.connect(self.set_legend_alignment)
self.button_layout.addWidget(self.align_button, 4, 0)
self.bold_button = QPushButton("Toggle bold")
self.bold_button.clicked.connect(self.toggle_bold)
self.button_layout.addWidget(self.bold_button, 8, 0)
self.italic_button = QPushButton("Toggle italic")
self.italic_button.clicked.connect(self.toggle_italic)
self.button_layout.addWidget(self.italic_button, 9, 0)
self.legend_posx.valueChanged.connect(self.update_legend_layout)
self.legend_posy.valueChanged.connect(self.update_legend_layout)
self.legend_width.valueChanged.connect(self.update_legend_layout)
self.legend_height.valueChanged.connect(self.update_legend_layout)
legend_layout = QFormLayout()
legend_layout.addRow("HPos", self.legend_posx)
legend_layout.addRow("VPos", self.legend_posy)
legend_layout.addRow("Width", self.legend_width)
legend_layout.addRow("Height", self.legend_height)
self.legend_settings = QGroupBox("Detached legend")
self.legend_settings.setLayout(legend_layout)
self.button_layout.addWidget(self.legend_settings)
self.legend_settings.setVisible(False)
# Create chart view with the chart
self.chart_view = QChartView(self.chart, self)
# Create spinbox to modify font size
self.font_size.setValue(self.chart.legend().font().pointSizeF())
self.font_size.valueChanged.connect(self.font_size_changed)
self.font_layout.addRow("Legend font size", self.font_size)
# Create layout for grid and detached legend
self.main_layout.addLayout(self.button_layout, 0, 0)
self.main_layout.addLayout(self.font_layout, 1, 0)
self.main_layout.addWidget(self.chart_view, 0, 1, 3, 1)
self.setLayout(self.main_layout)
self.create_series()
def create_series(self):
self.add_barset()
self.add_barset()
self.add_barset()
self.add_barset()
self.chart.addSeries(self.series)
self.chart.setTitle("Legend detach example")
self.chart.createDefaultAxes()
self.chart.legend().setVisible(True)
self.chart.legend().setAlignment(Qt.AlignBottom)
self.chart_view.setRenderHint(QPainter.Antialiasing)
def show_legend_spinbox(self):
self.legend_settings.setVisible(True)
chart_viewrect = self.chart_view.rect()
self.legend_posx.setMinimum(0)
self.legend_posx.setMaximum(chart_viewrect.width())
self.legend_posx.setValue(150)
self.legend_posy.setMinimum(0)
self.legend_posy.setMaximum(chart_viewrect.height())
self.legend_posy.setValue(150)
self.legend_width.setMinimum(0)
self.legend_width.setMaximum(chart_viewrect.width())
self.legend_width.setValue(150)
self.legend_height.setMinimum(0)
self.legend_height.setMaximum(chart_viewrect.height())
self.legend_height.setValue(75)
def hide_legend_spinbox(self):
self.legend_settings.setVisible(False)
@Slot()
def toggle_attached(self):
legend = self.chart.legend()
if legend.isAttachedToChart():
legend.detachFromChart()
legend.setBackgroundVisible(True)
legend.setBrush(QBrush(QColor(128, 128, 128, 128)))
legend.setPen(QPen(QColor(192, 192, 192, 192)))
self.show_legend_spinbox()
self.update_legend_layout()
else:
legend.attachToChart()
legend.setBackgroundVisible(False)
self.hide_legend_spinbox()
self.update()
@Slot()
def add_barset(self):
series_count = self.series.count()
bar_set = QBarSet(f"set {series_count}")
delta = series_count * 0.1
bar_set.append([1 + delta, 2 + delta, 3 + delta, 4 + delta])
self.series.append(bar_set)
@Slot()
def remove_barset(self):
sets = self.series.barSets()
len_sets = len(sets)
if len_sets > 0:
self.series.remove(sets[len_sets - 1])
@Slot()
def set_legend_alignment(self):
button = self.sender()
legend = self.chart.legend()
alignment = legend.alignment()
if alignment == Qt.AlignTop:
legend.setAlignment(Qt.AlignLeft)
if button:
button.setText("Align (Left)")
elif alignment == Qt.AlignLeft:
legend.setAlignment(Qt.AlignBottom)
if button:
button.setText("Align (Bottom)")
elif alignment == Qt.AlignBottom:
legend.setAlignment(Qt.AlignRight)
if button:
button.setText("Align (Right)")
else:
if button:
button.setText("Align (Top)")
legend.setAlignment(Qt.AlignTop)
@Slot()
def toggle_bold(self):
legend = self.chart.legend()
font = legend.font()
font.setBold(not font.bold())
legend.setFont(font)
@Slot()
def toggle_italic(self):
legend = self.chart.legend()
font = legend.font()
font.setItalic(not font.italic())
legend.setFont(font)
@Slot()
def font_size_changed(self):
legend = self.chart.legend()
font = legend.font()
font_size = self.font_size.value()
if font_size < 1:
font_size = 1
font.setPointSizeF(font_size)
legend.setFont(font)
@Slot()
def update_legend_layout(self):
legend = self.chart.legend()
rect = QRectF(self.legend_posx.value(), self.legend_posy.value(),
self.legend_width.value(), self.legend_height.value())
legend.setGeometry(rect)
legend.update()
if __name__ == "__main__":
app = QApplication(sys.argv)
w = MainWidget()
available_geometry = w.screen().availableGeometry()
size = available_geometry.height() * 0.75
w.setFixedSize(size, size)
w.show()
sys.exit(app.exec())