Add legend example

Task-number: PYSIDE-738
Change-Id: I68614a1a0e417f8318adc4f008d452bc280abcb3
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 252 insertions, 0 deletions

diff --git a/examples/charts/legend.py b/examples/charts/legend.py
new file mode 100644
index 000000000..47099e729
--- /dev/null
+++ b/examples/charts/legend.py
@@ -0,0 +1,252 @@
+#############################################################################
+##
+## Copyright (C) 2018 The Qt Company Ltd.
+## Contact: http://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python examples of the Qt Toolkit.
+##
+## $QT_BEGIN_LICENSE:BSD$
+## You may use this file under the terms of the BSD license as follows:
+##
+## "Redistribution and use in source and binary forms, with or without
+## modification, are permitted provided that the following conditions are
+## met:
+##   * Redistributions of source code must retain the above copyright
+##     notice, this list of conditions and the following disclaimer.
+##   * Redistributions in binary form must reproduce the above copyright
+##     notice, this list of conditions and the following disclaimer in
+##     the documentation and/or other materials provided with the
+##     distribution.
+##   * Neither the name of The Qt Company Ltd nor the names of its
+##     contributors may be used to endorse or promote products derived
+##     from this software without specific prior written permission.
+##
+##
+## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+"""PySide2 port of the Legend example from Qt v5.x"""
+
+import sys
+from PySide2.QtCore import Qt, QRectF
+from PySide2.QtGui import QBrush, QColor, QPainter, QPen
+from PySide2.QtWidgets import (QApplication, QDoubleSpinBox,
+    QFormLayout, QGridLayout, QGroupBox, QPushButton, QWidget)
+from PySide2.QtCharts import QtCharts
+
+class MainWidget(QWidget):
+    def __init__(self, parent=None):
+        super(MainWidget, self).__init__(parent)
+        self.chart = QtCharts.QChart()
+        self.series = QtCharts.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 = QtCharts.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 hideLegendSpinbox(self):
+        self.legend_settings.setVisible(False)
+
+    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.hideLegendSpinbox()
+        self.update()
+
+    def add_barset(self):
+        series_count = self.series.count()
+        bar_set = QtCharts.QBarSet("set {}".format(series_count))
+        delta = series_count * 0.1
+        bar_set.append([1 + delta, 2 + delta, 3 + delta, 4 + delta])
+        self.series.append(bar_set)
+
+    def remove_barset(self):
+        sets = self.series.barSets()
+        len_sets = len(sets)
+        if len_sets > 0:
+            self.series.remove(sets[len_sets - 1])
+
+    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)
+
+    def toggle_bold(self):
+        legend = self.chart.legend()
+        font = legend.font()
+        font.setBold(not font.bold())
+        legend.setFont(font)
+
+    def toggle_italic(self):
+        legend = self.chart.legend()
+        font = legend.font()
+        font.setItalic(not font.italic())
+        legend.setFont(font)
+
+    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)
+
+    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 = app.desktop().availableGeometry(w)
+    size = available_geometry.height() * 0.75
+    w.setFixedSize(size, size)
+    w.show()
+    sys.exit(app.exec_())