src/Mod/Fem/femviewprovider/view_post_histogram.py

# ***************************************************************************
# *   Copyright (c) 2025 Stefan Tröger <stefantroeger@gmx.net>              *
# *                                                                         *
# *   This file is part of the FreeCAD CAx development system.              *
# *                                                                         *
# *   This program is free software; you can redistribute it and/or modify  *
# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
# *   as published by the Free Software Foundation; either version 2 of     *
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# *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
# *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
# *   GNU Library General Public License for more details.                  *
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__title__ = "FreeCAD FEM postprocessing line plot ViewProvider for the document object"
__author__ = "Stefan Tröger"
__url__ = "https://www.freecad.org"

## @package view_post_lineplot
#  \ingroup FEM
#  \brief view provider for post line plot object

import FreeCAD
import FreeCADGui

import Plot
from PySide import QtGui, QtCore
from PySide.QtCore import QT_TRANSLATE_NOOP

import io
import numpy as np
import matplotlib as mpl
from packaging.version import Version

from vtkmodules.numpy_interface.dataset_adapter import VTKArray

from . import view_base_fempostextractors
from . import view_base_fempostvisualization
from femtaskpanels import task_post_histogram

from . import view_base_femobject

_GuiPropHelper = view_base_femobject._GuiPropHelper


class EditViewWidget(QtGui.QWidget):

    def __init__(self, obj, post_dialog):
        super().__init__()

        self._object = obj
        self._post_dialog = post_dialog

        # load the ui and set it up
        self.widget = FreeCADGui.PySideUic.loadUi(
            FreeCAD.getHomePath() + "Mod/Fem/Resources/ui/PostHistogramFieldViewEdit.ui"
        )
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.widget)
        self.setLayout(layout)

        self.__init_widget()

    def __init_widget(self):
        vobj = self._object.ViewObject

        self.widget.Legend.setText(vobj.Legend)
        self._post_dialog._enumPropertyToCombobox(vobj, "Hatch", self.widget.Hatch)
        self._post_dialog._enumPropertyToCombobox(vobj, "LineStyle", self.widget.LineStyle)
        self.widget.LineWidth.setValue(vobj.LineWidth)
        self.widget.HatchDensity.setValue(vobj.HatchDensity)

        # setup the color buttons (don't use FreeCADs color button, as this does not work in popups!)
        self._setup_color_button(self.widget.BarColor, vobj.BarColor, self.barColorChanged)
        self._setup_color_button(self.widget.LineColor, vobj.LineColor, self.lineColorChanged)

        self.widget.Legend.editingFinished.connect(self.legendChanged)
        self.widget.Hatch.activated.connect(self.hatchPatternChanged)
        self.widget.LineStyle.activated.connect(self.lineStyleChanged)
        self.widget.HatchDensity.valueChanged.connect(self.hatchDensityChanged)
        self.widget.LineWidth.valueChanged.connect(self.lineWidthChanged)

        # sometimes weird sizes occur with spinboxes
        self.widget.HatchDensity.setMaximumHeight(self.widget.Hatch.sizeHint().height())
        self.widget.LineWidth.setMaximumHeight(self.widget.LineStyle.sizeHint().height())

    def _setup_color_button(self, button, fcColor, callback):

        barColor = QtGui.QColor(*[v * 255 for v in fcColor])
        icon_size = button.iconSize()
        icon_size.setWidth(icon_size.width() * 2)
        button.setIconSize(icon_size)
        pixmap = QtGui.QPixmap(icon_size)
        pixmap.fill(barColor)
        button.setIcon(pixmap)

        action = QtGui.QWidgetAction(button)
        diag = QtGui.QColorDialog(barColor, parent=button)
        diag.setOption(QtGui.QColorDialog.DontUseNativeDialog, True)
        diag.accepted.connect(action.trigger)
        diag.rejected.connect(action.trigger)
        diag.colorSelected.connect(callback)

        action.setDefaultWidget(diag)
        button.addAction(action)
        button.setPopupMode(QtGui.QToolButton.InstantPopup)

    @QtCore.Slot(QtGui.QColor)
    def lineColorChanged(self, color):

        pixmap = QtGui.QPixmap(self.widget.LineColor.iconSize())
        pixmap.fill(color)
        self.widget.LineColor.setIcon(pixmap)

        self._object.ViewObject.LineColor = color.getRgb()

    @QtCore.Slot(QtGui.QColor)
    def barColorChanged(self, color):

        pixmap = QtGui.QPixmap(self.widget.BarColor.iconSize())
        pixmap.fill(color)
        self.widget.BarColor.setIcon(pixmap)

        self._object.ViewObject.BarColor = color.getRgb()

    @QtCore.Slot(float)
    def lineWidthChanged(self, value):
        self._object.ViewObject.LineWidth = value

    @QtCore.Slot(float)
    def hatchDensityChanged(self, value):
        self._object.ViewObject.HatchDensity = value

    @QtCore.Slot(int)
    def hatchPatternChanged(self, index):
        self._object.ViewObject.Hatch = index

    @QtCore.Slot(int)
    def lineStyleChanged(self, index):
        self._object.ViewObject.LineStyle = index

    @QtCore.Slot()
    def legendChanged(self):
        self._object.ViewObject.Legend = self.widget.Legend.text()


class EditFieldAppWidget(QtGui.QWidget):

    def __init__(self, obj, post_dialog):
        super().__init__()

        self._object = obj
        self._post_dialog = post_dialog

        # load the ui and set it up
        self.widget = FreeCADGui.PySideUic.loadUi(
            FreeCAD.getHomePath() + "Mod/Fem/Resources/ui/PostHistogramFieldAppEdit.ui"
        )
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.widget)
        self.setLayout(layout)

        self.__init_widget()

    def __init_widget(self):
        # set the other properties

        self._post_dialog._enumPropertyToCombobox(self._object, "XField", self.widget.Field)
        self._post_dialog._enumPropertyToCombobox(self._object, "XComponent", self.widget.Component)
        self.widget.Extract.setChecked(self._object.ExtractFrames)

        self.widget.Field.activated.connect(self.fieldChanged)
        self.widget.Component.activated.connect(self.componentChanged)
        self.widget.Extract.toggled.connect(self.extractionChanged)

    @QtCore.Slot(int)
    def fieldChanged(self, index):
        self._object.XField = index
        self._post_dialog._enumPropertyToCombobox(self._object, "XComponent", self.widget.Component)
        self._post_dialog._recompute()

    @QtCore.Slot(int)
    def componentChanged(self, index):
        self._object.XComponent = index
        self._post_dialog._recompute()

    @QtCore.Slot(bool)
    def extractionChanged(self, extract):
        self._object.ExtractFrames = extract
        self._post_dialog._recompute()


class EditIndexAppWidget(QtGui.QWidget):

    def __init__(self, obj, post_dialog):
        super().__init__()

        self._object = obj
        self._post_dialog = post_dialog

        # load the ui and set it up
        self.widget = FreeCADGui.PySideUic.loadUi(
            FreeCAD.getHomePath() + "Mod/Fem/Resources/ui/PostHistogramIndexAppEdit.ui"
        )
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.widget)
        self.setLayout(layout)

        self.__init_widget()

    def __init_widget(self):
        # set the other properties

        self.widget.Index.setValue(self._object.Index)
        self._post_dialog._enumPropertyToCombobox(self._object, "XField", self.widget.Field)
        self._post_dialog._enumPropertyToCombobox(self._object, "XComponent", self.widget.Component)

        self.widget.Index.valueChanged.connect(self.indexChanged)
        self.widget.Field.activated.connect(self.fieldChanged)
        self.widget.Component.activated.connect(self.componentChanged)

        # sometimes weird sizes occur with spinboxes
        self.widget.Index.setMaximumHeight(self.widget.Field.sizeHint().height())

    @QtCore.Slot(int)
    def fieldChanged(self, index):
        self._object.XField = index
        self._post_dialog._enumPropertyToCombobox(self._object, "XComponent", self.widget.Component)
        self._post_dialog._recompute()

    @QtCore.Slot(int)
    def componentChanged(self, index):
        self._object.XComponent = index
        self._post_dialog._recompute()

    @QtCore.Slot(int)
    def indexChanged(self, value):
        self._object.Index = value
        self._post_dialog._recompute()


class VPPostHistogramFieldData(view_base_fempostextractors.VPPostExtractor):
    """
    A View Provider for extraction of 1D field data specially for histograms
    """

    def __init__(self, vobj):
        super().__init__(vobj)
        vobj.Proxy = self

    def _get_properties(self):

        prop = [
            _GuiPropHelper(
                type="App::PropertyString",
                name="Legend",
                group="HistogramPlot",
                doc=QT_TRANSLATE_NOOP("FEM", "The name used in the plots legend"),
                value="",
            ),
            _GuiPropHelper(
                type="App::PropertyColor",
                name="BarColor",
                group="HistogramBar",
                doc=QT_TRANSLATE_NOOP("FEM", "The color the data bin area is drawn with"),
                value=(0, 85, 255, 255),
            ),
            _GuiPropHelper(
                type="App::PropertyEnumeration",
                name="Hatch",
                group="HistogramBar",
                doc=QT_TRANSLATE_NOOP("FEM", "The hatch pattern drawn in the bar"),
                value=["None", "/", "\\", "|", "-", "+", "x", "o", "O", ".", "*"],
            ),
            _GuiPropHelper(
                type="App::PropertyIntegerConstraint",
                name="HatchDensity",
                group="HistogramBar",
                doc=QT_TRANSLATE_NOOP("FEM", "The line width of the hatch)"),
                value=(1, 1, 99, 1),
            ),
            _GuiPropHelper(
                type="App::PropertyColor",
                name="LineColor",
                group="HistogramLine",
                doc=QT_TRANSLATE_NOOP("FEM", "The color the data bin area is drawn with"),
                value=(0, 0, 0, 1),  # black
            ),
            _GuiPropHelper(
                type="App::PropertyFloatConstraint",
                name="LineWidth",
                group="HistogramLine",
                doc=QT_TRANSLATE_NOOP(
                    "FEM", "The width of the bar, between 0 and 1 (1 being without gaps)"
                ),
                value=(1, 0, 99, 0.1),
            ),
            _GuiPropHelper(
                type="App::PropertyEnumeration",
                name="LineStyle",
                group="HistogramLine",
                doc=QT_TRANSLATE_NOOP("FEM", "The style the line is drawn in"),
                value=["None", "-", "--", "-.", ":"],
            ),
        ]
        return super()._get_properties() + prop

    def attach(self, vobj):
        self.Object = vobj.Object
        self.ViewObject = vobj

    def getIcon(self):
        return ":/icons/FEM_PostField.svg"

    def get_app_edit_widget(self, post_dialog):
        return EditFieldAppWidget(self.Object, post_dialog)

    def get_view_edit_widget(self, post_dialog):
        return EditViewWidget(self.Object, post_dialog)

    def get_preview(self):

        fig = mpl.pyplot.figure(figsize=(0.4, 0.2), dpi=500)
        ax = mpl.pyplot.Axes(fig, [0.0, 0.0, 2, 1])
        ax.set_axis_off()
        fig.add_axes(ax)

        kwargs = self.get_kw_args()
        patch = mpl.patches.Rectangle(xy=(0, 0), width=2, height=1, **kwargs)
        ax.add_patch(patch)

        data = io.BytesIO()
        mpl.pyplot.savefig(data, bbox_inches=0, transparent=True)
        mpl.pyplot.close()

        pixmap = QtGui.QPixmap()
        pixmap.loadFromData(data.getvalue())

        return (pixmap, self.ViewObject.Legend)

    def get_kw_args(self):
        # builds kw args from the properties
        kwargs = {}

        # colors need a workaround, some error occurs with rgba tuple
        kwargs["edgecolor"] = self.ViewObject.LineColor
        kwargs["facecolor"] = self.ViewObject.BarColor
        kwargs["linestyle"] = self.ViewObject.LineStyle
        kwargs["linewidth"] = self.ViewObject.LineWidth
        if self.ViewObject.Hatch != "None":
            kwargs["hatch"] = self.ViewObject.Hatch * self.ViewObject.HatchDensity

        return kwargs

    def get_default_color_property(self):
        return "BarColor"


class VPPostHistogramIndexOverFrames(VPPostHistogramFieldData):
    """
    A View Provider for extraction of 1D index over frames data
    """

    def __init__(self, vobj):
        super().__init__(vobj)

    def getIcon(self):
        return ":/icons/FEM_PostIndex.svg"

    def get_app_edit_widget(self, post_dialog):
        return EditIndexAppWidget(self.Object, post_dialog)


class VPPostHistogram(view_base_fempostvisualization.VPPostVisualization):
    """
    A View Provider for Histogram plots
    """

    def __init__(self, vobj):
        super().__init__(vobj)

    def _get_properties(self):

        prop = [
            _GuiPropHelper(
                type="App::PropertyBool",
                name="Cumulative",
                group="Histogram",
                doc=QT_TRANSLATE_NOOP(
                    "FEM", "If the bars should show the cumulative sum left to right"
                ),
                value=False,
            ),
            _GuiPropHelper(
                type="App::PropertyEnumeration",
                name="Type",
                group="Histogram",
                doc=QT_TRANSLATE_NOOP("FEM", "The type of histogram plotted"),
                value=["bar", "barstacked", "step", "stepfilled"],
            ),
            _GuiPropHelper(
                type="App::PropertyFloatConstraint",
                name="BarWidth",
                group="Histogram",
                doc=QT_TRANSLATE_NOOP(
                    "FEM", "The width of the bar, between 0 and 1 (1 being without gaps)"
                ),
                value=(0.9, 0, 1, 0.05),
            ),
            _GuiPropHelper(
                type="App::PropertyFloatConstraint",
                name="HatchLineWidth",
                group="Histogram",
                doc=QT_TRANSLATE_NOOP("FEM", "The line width of all drawn hatch patterns"),
                value=(1, 0, 99, 0.1),
            ),
            _GuiPropHelper(
                type="App::PropertyInteger",
                name="Bins",
                group="Histogram",
                doc=QT_TRANSLATE_NOOP("FEM", "The number of bins the data is split into"),
                value=10,
            ),
            _GuiPropHelper(
                type="App::PropertyString",
                name="Title",
                group="Plot",
                doc=QT_TRANSLATE_NOOP("FEM", "The histogram plot title"),
                value="",
            ),
            _GuiPropHelper(
                type="App::PropertyString",
                name="XLabel",
                group="Plot",
                doc=QT_TRANSLATE_NOOP("FEM", "The label shown for the histogram X axis"),
                value="",
            ),
            _GuiPropHelper(
                type="App::PropertyString",
                name="YLabel",
                group="Plot",
                doc=QT_TRANSLATE_NOOP("FEM", "The label shown for the histogram Y axis"),
                value="",
            ),
            _GuiPropHelper(
                type="App::PropertyBool",
                name="Legend",
                group="Plot",
                doc=QT_TRANSLATE_NOOP("FEM", "Determines if the legend is plotted"),
                value=True,
            ),
            _GuiPropHelper(
                type="App::PropertyEnumeration",
                name="LegendLocation",
                group="Plot",
                doc=QT_TRANSLATE_NOOP("FEM", "Determines if the legend is plotted"),
                value=[
                    "best",
                    "upper right",
                    "upper left",
                    "lower left",
                    "lower right",
                    "right",
                    "center left",
                    "center right",
                    "lower center",
                    "upper center",
                    "center",
                ],
            ),
        ]
        return prop

    def getIcon(self):
        return ":/icons/FEM_PostHistogram.svg"

    def setEdit(self, vobj, mode):

        # build up the task panel
        taskd = task_post_histogram._TaskPanel(vobj)

        # show it
        FreeCADGui.Control.showDialog(taskd)

        return True

    def show_visualization(self):

        if not hasattr(self, "_plot") or not self._plot:
            main = FreeCADGui.getMainWindow()
            self._plot = Plot.Plot()
            self._plot.setWindowTitle(self.Object.Label)
            self._plot.setParent(main)
            self._plot.setWindowFlags(QtGui.Qt.Dialog)
            self._plot.resize(main.size().height() / 2, main.size().height() / 3)  # keep it square
            self.update_visualization()

        self._plot.show()

    def get_kw_args(self, obj):
        view = obj.ViewObject
        if not view or not hasattr(view, "Proxy"):
            return {}
        if not hasattr(view.Proxy, "get_kw_args"):
            return {}
        return view.Proxy.get_kw_args()

    def update_visualization(self):

        if not hasattr(self, "_plot") or not self._plot:
            return

        self._plot.axes.clear()
        bins = self.ViewObject.Bins

        # we do not iterate the table, but iterate the children. This makes it possible
        # to attribute the correct styles
        full_args = []
        full_data = []
        labels = []
        for child in self.Object.Group:

            table = child.Table
            kwargs = self.get_kw_args(child)

            # iterate over the table and plot all
            color_factor = np.linspace(1, 0.5, table.GetNumberOfColumns())
            legend_multiframe = table.GetNumberOfColumns() > 1
            for i in range(table.GetNumberOfColumns()):

                # add the kw args, with some slide change over color for multiple frames
                args = kwargs.copy()
                for key in kwargs:

                    if "color" in key:
                        value = np.array(kwargs[key]) * color_factor[i]
                        args[key] = mpl.colors.to_hex(value)

                full_args.append(args)

                data = VTKArray(table.GetColumn(i))
                full_data.append(data)

                # legend labels
                if child.ViewObject.Legend:
                    if not legend_multiframe:
                        labels.append(child.ViewObject.Legend)
                    else:
                        postfix = table.GetColumnName(i).split("-")[-1]
                        labels.append(child.ViewObject.Legend + " - " + postfix)
                else:
                    legend_prefix = ""
                    if len(self.Object.Group) > 1:
                        legend_prefix = child.Source.Label + ": "
                    labels.append(legend_prefix + table.GetColumnName(i))

        args = {}
        args["rwidth"] = self.ViewObject.BarWidth
        args["cumulative"] = self.ViewObject.Cumulative
        args["histtype"] = self.ViewObject.Type
        args["label"] = labels
        if Version(mpl.__version__) >= Version("3.10.0"):
            args["hatch_linewidth"] = self.ViewObject.HatchLineWidth

        n, b, patches = self._plot.axes.hist(full_data, bins, **args)

        # set the patches view properties.
        if len(full_args) == 1:
            for patch in patches:
                patch.set(**full_args[0])
        elif len(full_args) > 1:
            for i, args in enumerate(full_args):
                for patch in patches[i]:
                    patch.set(**full_args[i])

        # axes decoration
        if self.ViewObject.Title:
            self._plot.axes.set_title(self.ViewObject.Title)
        if self.ViewObject.XLabel:
            self._plot.axes.set_xlabel(self.ViewObject.XLabel)
        if self.ViewObject.YLabel:
            self._plot.axes.set_ylabel(self.ViewObject.YLabel)

        if self.ViewObject.Legend and labels:
            self._plot.axes.legend(loc=self.ViewObject.LegendLocation)

        self._plot.update()

    def get_next_default_color(self):
        # we use the next color in order. We do not check (yet) if this
        # color is already taken
        i = len(self.Object.Group)
        cmap = mpl.pyplot.get_cmap("tab10")
        return cmap(i)