"""PyQt5 widgets to render wave generator systems.
"""

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# Written in 2019 by Garth Zeglin <garthz@cmu.edu>

# To the extent possible under law, the author has dedicated all copyright
# and related and neighboring rights to this software to the public domain
# worldwide. This software is distributed without any warranty.

# You should have received a copy of the CC0 Public Domain Dedication along with this software.
# If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.

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import math, logging
import numpy as np

# for documentation on the PyQt5 API, see http://pyqt.sourceforge.net/Docs/PyQt5/index.html
from PyQt5 import QtCore, QtGui, QtWidgets

# set up logger for module
log = logging.getLogger('QtConcentricLoops')

# filter out most logging; the default is NOTSET which passes along everything
# log.setLevel(logging.WARNING)

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[docs]class QtWaves1D(QtWidgets.QWidget):
    """Custom widget representing a 1D wave system generator."""

    def __init__(self, channels=1):
        super().__init__()
        self.setMinimumSize(QtCore.QSize(100, 100))
        self.setAutoFillBackground(True)

        # graphical state variables
        self.W = channels              # the number of waves to show superimposed

        # q is a (W, N) matrix representing W waves of N sample points
        # the values are vertical position ranging over [-1,1]
        N = 20
        self.q = np.zeros((self.W, N))

        # finish initialization
        self.show()
        return

[docs]    def update_positions(self, positions):
        """Update the wave display with a (W, N) numpy matrix of position values."""
        self.q = positions
        self.repaint()

    # === element drawing methods ============================================================

    # === Qt API methods ============================================================
[docs]    def paintEvent(self, e):
        """Subclass implementation of parent QWidget class callback to repaint the graphics."""
        geometry = self.geometry()
        view_width = geometry.width()
        view_height = geometry.height()

        # clear the background
        qp = QtGui.QPainter()
        qp.begin(self)
        qp.fillRect(QtCore.QRectF(0, 0, view_width, view_height), QtCore.Qt.white)
        # qp.setRenderHint(QtGui.QPainter.Antialiasing)

        # Set up a coordinate system centered in the visible area.
        scene_width   = 22         # define minimum visible area
        scene_height  = 2
        scene_aspect  = scene_width / scene_height
        view_aspect = view_width / view_height
        if scene_aspect > view_aspect:
            scaling = view_width / scene_width
        else:
            scaling = view_height/scene_height

        qp.save()
        qp.translate(QtCore.QPointF(view_width/2, view_height/2))
        qp.scale(scaling, scaling)

        # draw the wave as a set of circular masses
        pen = QtGui.QPen(QtCore.Qt.black)
        pen.setWidthF(0.01)
        qp.setPen(pen)

        W = len(self.q)
        for i, wave in enumerate(self.q[:]):
            color = QtGui.QColor()
            hue = i / W
            color.setHsvF(hue, 1.0, 1.0, 1.0)
            brush = QtGui.QBrush(color)
            qp.setBrush(brush)

            N = len(wave)
            x_delta = 21 / N
            for i, pos in enumerate(wave):
                x = -10 + i*x_delta
                qp.drawEllipse(QtCore.QPointF(x, -pos), 0.2, 0.2)

        # restore the initial unscaled coordinates
        qp.restore()
        qp.end()

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