FlatCAM/flatcamGUI/GUIElements.py

# ########################################################## ##
# FlatCAM: 2D Post-processing for Manufacturing            #
# http://flatcam.org                                       #
# Author: Juan Pablo Caram (c)                             #
# Date: 2/5/2014                                           #
# MIT Licence                                              #
# ########################################################## ##

# ########################################################## ##
# File Modified (major mod): Marius Adrian Stanciu         #
# Date: 3/10/2019                                          #
# ########################################################## ##

from PyQt5 import QtGui, QtCore, QtWidgets
from PyQt5.QtCore import Qt, pyqtSignal, pyqtSlot
from PyQt5.QtWidgets import QTextEdit, QCompleter, QAction
from PyQt5.QtGui import QColor, QKeySequence, QPalette, QTextCursor

from copy import copy
import re
import logging
import html

log = logging.getLogger('base')

EDIT_SIZE_HINT = 70


class RadioSet(QtWidgets.QWidget):
    activated_custom = QtCore.pyqtSignal(str)

    def __init__(self, choices, orientation='horizontal', parent=None, stretch=None):
        """
        The choices are specified as a list of dictionaries containing:

        * 'label': Shown in the UI
        * 'value': The value returned is selected

        :param choices: List of choices. See description.
        :param orientation: 'horizontal' (default) of 'vertical'.
        :param parent: Qt parent widget.
        :type choices: list
        """
        super(RadioSet, self).__init__(parent)
        self.choices = copy(choices)
        if orientation == 'horizontal':
            layout = QtWidgets.QHBoxLayout()
        else:
            layout = QtWidgets.QVBoxLayout()

        group = QtWidgets.QButtonGroup(self)

        for choice in self.choices:
            choice['radio'] = QtWidgets.QRadioButton(choice['label'])
            group.addButton(choice['radio'])
            layout.addWidget(choice['radio'], stretch=0)
            choice['radio'].toggled.connect(self.on_toggle)

        layout.setContentsMargins(0, 0, 0, 0)

        if stretch is False:
            pass
        else:
            layout.addStretch()

        self.setLayout(layout)

        self.group_toggle_fn = lambda: None

    def on_toggle(self):
        # log.debug("Radio toggled")
        radio = self.sender()
        if radio.isChecked():
            self.group_toggle_fn()
            ret_val = str(self.get_value())
            self.activated_custom.emit(ret_val)
        return

    def get_value(self):
        for choice in self.choices:
            if choice['radio'].isChecked():
                return choice['value']
        log.error("No button was toggled in RadioSet.")
        return None

    def set_value(self, val):
        for choice in self.choices:
            if choice['value'] == val:
                choice['radio'].setChecked(True)
                return
        log.error("Value given is not part of this RadioSet: %s" % str(val))


# class RadioGroupChoice(QtWidgets.QWidget):
#     def __init__(self, label_1, label_2, to_check, hide_list, show_list, parent=None):
#         """
#         The choices are specified as a list of dictionaries containing:
#
#         * 'label': Shown in the UI
#         * 'value': The value returned is selected
#
#         :param choices: List of choices. See description.
#         :param orientation: 'horizontal' (default) of 'vertical'.
#         :param parent: Qt parent widget.
#         :type choices: list
#         """
#         super().__init__(parent)
#
#         group = QtGui.QButtonGroup(self)
#
#         self.lbl1 = label_1
#         self.lbl2 = label_2
#         self.hide_list = hide_list
#         self.show_list = show_list
#
#         self.btn1 = QtGui.QRadioButton(str(label_1))
#         self.btn2 = QtGui.QRadioButton(str(label_2))
#         group.addButton(self.btn1)
#         group.addButton(self.btn2)
#
#         if to_check == 1:
#             self.btn1.setChecked(True)
#         else:
#             self.btn2.setChecked(True)
#
#         self.btn1.toggled.connect(lambda: self.btn_state(self.btn1))
#         self.btn2.toggled.connect(lambda: self.btn_state(self.btn2))
#
#     def btn_state(self, btn):
#         if btn.text() == self.lbl1:
#             if btn.isChecked() is True:
#                 self.show_widgets(self.show_list)
#                 self.hide_widgets(self.hide_list)
#             else:
#                 self.show_widgets(self.hide_list)
#                 self.hide_widgets(self.show_list)
#
#     def hide_widgets(self, lst):
#         for wgt in lst:
#             wgt.hide()
#
#     def show_widgets(self, lst):
#         for wgt in lst:
#             wgt.show()


class LengthEntry(QtWidgets.QLineEdit):
    def __init__(self, output_units='IN', parent=None):
        super(LengthEntry, self).__init__(parent)

        self.output_units = output_units
        self.format_re = re.compile(r"^([^\s]+)(?:\s([a-zA-Z]+))?$")

        # Unit conversion table OUTPUT-INPUT
        self.scales = {
            'IN': {'IN': 1.0,
                   'MM': 1/25.4},
            'MM': {'IN': 25.4,
                   'MM': 1.0}
        }
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)

    def on_edit_finished(self):
        self.clearFocus()

    def mousePressEvent(self, e, Parent=None):
        super(LengthEntry, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit:
            self.selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        # don't focus out if the user requests an popup menu
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(LengthEntry, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.deselect()
            self.readyToEdit = True

    def returnPressed(self, *args, **kwargs):
        val = self.get_value()
        if val is not None:
            self.set_text(str(val))
        else:
            log.warning("Could not interpret entry: %s" % self.get_text())

    def get_value(self):
        raw = str(self.text()).strip(' ')
        # match = self.format_re.search(raw)

        try:
            units = raw[-2:]
            units = self.scales[self.output_units][units.upper()]
            value = raw[:-2]
            return float(eval(value))*  units
        except IndexError:
            value = raw
            return float(eval(value))
        except KeyError:
            value = raw
            return float(eval(value))
        except:
            log.warning("Could not parse value in entry: %s" % str(raw))
            return None

    def set_value(self, val):
        self.setText(str('%.4f' % val))

    def sizeHint(self):
        default_hint_size = super(LengthEntry, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class FloatEntry(QtWidgets.QLineEdit):
    def __init__(self, parent=None):
        super(FloatEntry, self).__init__(parent)
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)

    def on_edit_finished(self):
        self.clearFocus()

    def mousePressEvent(self, e, Parent=None):
        super(FloatEntry, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit == True:
            self.selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        # don't focus out if the user requests an popup menu
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(FloatEntry, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.deselect()
            self.readyToEdit = True

    def returnPressed(self, *args, **kwargs):
        val = self.get_value()
        if val is not None:
            self.set_text(str(val))
        else:
            log.warning("Could not interpret entry: %s" % self.text())

    def get_value(self):
        raw = str(self.text()).strip(' ')

        try:
            evaled = eval(raw)
            return float(evaled)
        except Exception as e:
            if raw is not '':
                log.error("Could not evaluate val: %s, error: %s" % (str(raw), str(e)))
            return None

    def set_value(self, val):
        if val is not None:
            self.setText("%.4f" % float(val))
        else:
            self.setText("")

    def sizeHint(self):
        default_hint_size = super(FloatEntry, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class FloatEntry2(QtWidgets.QLineEdit):
    def __init__(self, parent=None):
        super(FloatEntry2, self).__init__(parent)
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)

    def on_edit_finished(self):
        self.clearFocus()

    def mousePressEvent(self, e, Parent=None):
        super(FloatEntry2, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit:
            self.selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        # don't focus out if the user requests an popup menu
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(FloatEntry2, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.deselect()
            self.readyToEdit = True

    def get_value(self):
        raw = str(self.text()).strip(' ')

        try:
            evaled = eval(raw)
            return float(evaled)
        except Exception as e:
            if raw is not '':
                log.error("Could not evaluate val: %s, error: %s" % (str(raw), str(e)))
            return None

    def set_value(self, val):
        self.setText("%.4f" % val)

    def sizeHint(self):
        default_hint_size = super(FloatEntry2, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class IntEntry(QtWidgets.QLineEdit):

    def __init__(self, parent=None, allow_empty=False, empty_val=None):
        super(IntEntry, self).__init__(parent)
        self.allow_empty = allow_empty
        self.empty_val = empty_val
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)

    def on_edit_finished(self):
        self.clearFocus()

    def mousePressEvent(self, e, Parent=None):
        super(IntEntry, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit:
            self.selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        # don't focus out if the user requests an popup menu
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(IntEntry, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.deselect()
            self.readyToEdit = True

    def get_value(self):

        if self.allow_empty:
            if str(self.text()) == "":
                return self.empty_val
        # make the text() first a float and then int because if text is a float type,
        # the int() can't convert directly a "text float" into a int type.
        ret_val = float(self.text())
        ret_val = int(ret_val)
        return ret_val

    def set_value(self, val):

        if val == self.empty_val and self.allow_empty:
            self.setText("")
            return

        self.setText(str(val))

    def sizeHint(self):
        default_hint_size = super(IntEntry, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class FCEntry(QtWidgets.QLineEdit):
    def __init__(self, parent=None):
        super(FCEntry, self).__init__(parent)
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)

    def on_edit_finished(self):
        self.clearFocus()

    def mousePressEvent(self, e, parent=None):
        super(FCEntry, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit:
            self.selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(FCEntry, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.deselect()
            self.readyToEdit = True

    def get_value(self):
        return str(self.text())

    def set_value(self, val):
        if type(val) is float:
            self.setText('%.4f' % val)
        else:
            self.setText(str(val))

    def sizeHint(self):
        default_hint_size = super(FCEntry, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class FCEntry2(FCEntry):
    def __init__(self, parent=None):
        super(FCEntry2, self).__init__(parent)

    def set_value(self, val, decimals=4):
        try:
            fval = float(val)
        except ValueError:
            return
        self.setText('%.*f' % (decimals, fval))


class FCEntry3(FCEntry):
    def __init__(self, parent=None):
        super(FCEntry3, self).__init__(parent)

    def set_value(self, val, decimals=4):
        try:
            fval = float(val)
        except ValueError:
            return
        self.setText('%.*f' % (decimals, fval))

    def get_value(self):
        value = str(self.text()).strip(' ')

        try:
            return float(eval(value))
        except Exception as e:
            log.warning("Could not parse value in entry: %s" % str(e))
            return None


class EvalEntry(QtWidgets.QLineEdit):
    def __init__(self, parent=None):
        super(EvalEntry, self).__init__(parent)
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)

    def on_edit_finished(self):
        self.clearFocus()

    def mousePressEvent(self, e, parent=None):
        super(EvalEntry, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit:
            self.selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(EvalEntry, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.deselect()
            self.readyToEdit = True

    def returnPressed(self, *args, **kwargs):
        val = self.get_value()
        if val is not None:
            self.setText(str(val))
        else:
            log.warning("Could not interpret entry: %s" % self.get_text())

    def get_value(self):
        raw = str(self.text()).strip(' ')
        evaled = 0.0
        try:
            evaled = eval(raw)
        except Exception as e:
            if raw is not '':
                log.error("Could not evaluate val: %s, error: %s" % (str(raw), str(e)))
            return None
        return evaled

    def set_value(self, val):
        self.setText(str(val))

    def sizeHint(self):
        default_hint_size = super(EvalEntry, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class EvalEntry2(QtWidgets.QLineEdit):
    def __init__(self, parent=None):
        super(EvalEntry2, self).__init__(parent)
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)

    def on_edit_finished(self):
        self.clearFocus()

    def mousePressEvent(self, e, parent=None):
        super(EvalEntry2, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit:
            self.selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(EvalEntry2, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.deselect()
            self.readyToEdit = True

    def get_value(self):
        raw = str(self.text()).strip(' ')
        evaled = 0.0
        try:
            evaled = eval(raw)
        except Exception as e:
            if raw is not '':
                log.error("Could not evaluate val: %s, error: %s" % (str(raw), str(e)))
            return None
        return evaled

    def set_value(self, val):
        self.setText(str(val))

    def sizeHint(self):
        default_hint_size = super(EvalEntry2, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class FCSpinner(QtWidgets.QSpinBox):
    def __init__(self, parent=None):
        super(FCSpinner, self).__init__(parent)
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)
        self.lineEdit().installEventFilter(self)

    def eventFilter(self, object, event):
        if event.type() == QtCore.QEvent.MouseButtonPress:
            if self.readyToEdit:
                self.lineEdit().selectAll()
                self.readyToEdit = False
            else:
                self.lineEdit().deselect()
            return True
        return False

    def wheelEvent(self, *args, **kwargs):
        # should work only there is a focus in the lineedit of the SpinBox
        if self.readyToEdit is False:
            super().wheelEvent(*args, **kwargs)

    def on_edit_finished(self):
        self.clearFocus()

    # def mousePressEvent(self, e, parent=None):
    #     super(FCSpinner, self).mousePressEvent(e)  # required to deselect on 2e click
    #     if self.readyToEdit:
    #         self.lineEdit().selectAll()
    #         self.readyToEdit = False

    def focusOutEvent(self, e):
        # don't focus out if the user requests an popup menu
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(FCSpinner, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.lineEdit().deselect()
            self.readyToEdit = True

    def get_value(self):
        return int(self.value())

    def set_value(self, val):
        try:
            k = int(val)
        except Exception as e:
            log.debug(str(e))
            return
        self.setValue(k)

    def set_range(self, min_val, max_val):
        self.setRange(min_val, max_val)

    # def sizeHint(self):
    #     default_hint_size = super(FCSpinner, self).sizeHint()
    #     return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class FCDoubleSpinner(QtWidgets.QDoubleSpinBox):
    def __init__(self, parent=None):
        super(FCDoubleSpinner, self).__init__(parent)
        self.readyToEdit = True
        self.editingFinished.connect(self.on_edit_finished)
        self.lineEdit().installEventFilter(self)

    def eventFilter(self, object, event):
        if event.type() == QtCore.QEvent.MouseButtonPress:
            if self.readyToEdit:
                self.lineEdit().selectAll()
                self.readyToEdit = False
            else:
                self.lineEdit().deselect()
            return True
        return False

    def on_edit_finished(self):
        self.clearFocus()

    def wheelEvent(self, *args, **kwargs):
        # should work only there is a focus in the lineedit of the SpinBox
        if self.readyToEdit is False:
            super().wheelEvent(*args, **kwargs)

    # def keyPressEvent(self, in_event):  # 46 = dot; 44 = comma:
    #     if in_event.key() == 44:
    #         print(in_event, "ahaaa")
    #         event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress, 46, Qt.NoModifier, 0, 0, 0)
    #         QtWidgets.QApplication.sendEvent(self.parent(), event)
    #     else:
    #         super().keyPressEvent(in_event)

    def focusOutEvent(self, e):
        # don't focus out if the user requests an popup menu
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(FCDoubleSpinner, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.lineEdit().deselect()
            self.readyToEdit = True

    def get_value(self):
        return float(self.value())

    def set_value(self, val):
        try:
            k = float(val)
        except Exception as e:
            log.debug(str(e))
            return
        self.setValue(k)

    def set_precision(self, val):
        self.setDecimals(val)

    def set_range(self, min_val, max_val):
        self.setRange(min_val, max_val)


class FCCheckBox(QtWidgets.QCheckBox):
    def __init__(self, label='', parent=None):
        super(FCCheckBox, self).__init__(str(label), parent)

    def get_value(self):
        return self.isChecked()

    def set_value(self, val):
        self.setChecked(val)

    def toggle(self):
        self.set_value(not self.get_value())


class FCTextArea(QtWidgets.QPlainTextEdit):
    def __init__(self, parent=None):
        super(FCTextArea, self).__init__(parent)

    def set_value(self, val):
        self.setPlainText(val)

    def get_value(self):
        return str(self.toPlainText())

    def sizeHint(self, custom_sizehint=None):
        default_hint_size = super(FCTextArea, self).sizeHint()

        if custom_sizehint is None:
            return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())
        else:
            return QtCore.QSize(custom_sizehint, default_hint_size.height())


class FCTextAreaRich(QtWidgets.QTextEdit):
    def __init__(self, parent=None):
        super(FCTextAreaRich, self).__init__(parent)

    def set_value(self, val):
        self.setText(val)

    def get_value(self):
        return str(self.toPlainText())

    def sizeHint(self):
        default_hint_size = super(FCTextAreaRich, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())


class FCTextAreaExtended(QtWidgets.QTextEdit):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.completer = MyCompleter()

        self.model = QtCore.QStringListModel()
        self.completer.setModel(self.model)
        self.set_model_data(keyword_list=[])
        self.completer.insertText.connect(self.insertCompletion)

        self.completer_enable = False

    def set_model_data(self, keyword_list):
        self.model.setStringList(keyword_list)

    def insertCompletion(self, completion):
        tc = self.textCursor()
        extra = (len(completion) - len(self.completer.completionPrefix()))

        # don't insert if the word is finished but add a space instead
        if extra == 0:
            tc.insertText(' ')
            self.completer.popup().hide()
            return

        tc.movePosition(QTextCursor.Left)
        tc.movePosition(QTextCursor.EndOfWord)
        tc.insertText(completion[-extra:])
        # add a space after inserting the word
        tc.insertText(' ')
        self.setTextCursor(tc)
        self.completer.popup().hide()

    def focusInEvent(self, event):
        if self.completer:
            self.completer.setWidget(self)
        QTextEdit.focusInEvent(self, event)

    def set_value(self, val):
        self.setText(val)

    def get_value(self):
        self.toPlainText()

    def insertFromMimeData(self, data):
        """
        Reimplemented such that when SHIFT is pressed and doing click Paste in the contextual menu, the '\' symbol
        is replaced with the '/' symbol. That's because of the difference in path separators in Windows and TCL
        :param data:
        :return:
        """
        modifier = QtWidgets.QApplication.keyboardModifiers()
        if modifier == Qt.ShiftModifier:
            text = data.text()
            text = text.replace('\\', '/')
            self.insertPlainText(text)
        else:
            self.insertPlainText(data.text())

    def keyPressEvent(self, event):
        """
        Reimplemented so the CTRL + SHIFT + V shortcut key combo will paste the text but replacing '\' with '/'
        :param event:
        :return:
        """
        key = event.key()
        modifier = QtWidgets.QApplication.keyboardModifiers()

        if modifier & Qt.ControlModifier and modifier & Qt.ShiftModifier:
            if key == QtCore.Qt.Key_V:
                clipboard = QtWidgets.QApplication.clipboard()
                clip_text = clipboard.text()
                clip_text = clip_text.replace('\\', '/')
                self.insertPlainText(clip_text)

        if modifier & Qt.ControlModifier and key == Qt.Key_Slash:
            self.comment()

        tc = self.textCursor()
        if (key == Qt.Key_Tab or key == Qt.Key_Enter or key == Qt.Key_Return) and self.completer.popup().isVisible():
            self.completer.insertText.emit(self.completer.getSelected())
            self.completer.setCompletionMode(QCompleter.PopupCompletion)
            return
        elif key == Qt.Key_BraceLeft:
            tc.insertText('{}')
            self.moveCursor(QtGui.QTextCursor.Left)
        elif key == Qt.Key_BracketLeft:
            tc.insertText('[]')
            self.moveCursor(QtGui.QTextCursor.Left)
        elif key == Qt.Key_ParenLeft:
            tc.insertText('()')
            self.moveCursor(QtGui.QTextCursor.Left)

        elif key == Qt.Key_BraceRight:
            tc.select(QtGui.QTextCursor.WordUnderCursor)
            if tc.selectedText() == '}':
                tc.movePosition(QTextCursor.Right)
                self.setTextCursor(tc)
            else:
                tc.clearSelection()
                self.textCursor().insertText('}')
        elif key == Qt.Key_BracketRight:
            tc.select(QtGui.QTextCursor.WordUnderCursor)
            if tc.selectedText() == ']':
                tc.movePosition(QTextCursor.Right)
                self.setTextCursor(tc)
            else:
                tc.clearSelection()
                self.textCursor().insertText(']')
        elif key == Qt.Key_ParenRight:
            tc.select(QtGui.QTextCursor.WordUnderCursor)
            if tc.selectedText() == ')':
                tc.movePosition(QTextCursor.Right)
                self.setTextCursor(tc)
            else:
                tc.clearSelection()
                self.textCursor().insertText(')')
        else:
            super(FCTextAreaExtended, self).keyPressEvent(event)

        if self.completer_enable:
            tc.select(QTextCursor.WordUnderCursor)
            cr = self.cursorRect()

            if len(tc.selectedText()) > 0:
                self.completer.setCompletionPrefix(tc.selectedText())
                popup = self.completer.popup()
                popup.setCurrentIndex(self.completer.completionModel().index(0, 0))

                cr.setWidth(self.completer.popup().sizeHintForColumn(0)
                            + self.completer.popup().verticalScrollBar().sizeHint().width())
                self.completer.complete(cr)
            else:
                self.completer.popup().hide()

    def comment(self):
        """
        Got it from here:
        https://stackoverflow.com/questions/49898820/how-to-get-text-next-to-cursor-in-qtextedit-in-pyqt4
        :return:
        """
        pos = self.textCursor().position()
        self.moveCursor(QtGui.QTextCursor.StartOfLine)
        line_text = self.textCursor().block().text()
        if self.textCursor().block().text().startswith(" "):
            # skip the white space
            self.moveCursor(QtGui.QTextCursor.NextWord)
        self.moveCursor(QtGui.QTextCursor.NextCharacter,QtGui.QTextCursor.KeepAnchor)
        character = self.textCursor().selectedText()
        if character == "#":
            # delete #
            self.textCursor().deletePreviousChar()
            # delete white space 
            self.moveCursor(QtGui.QTextCursor.NextWord,QtGui.QTextCursor.KeepAnchor)
            self.textCursor().removeSelectedText()
        else:
            self.moveCursor(QtGui.QTextCursor.PreviousCharacter,QtGui.QTextCursor.KeepAnchor)
            self.textCursor().insertText("# ")
        cursor = QtGui.QTextCursor(self.textCursor())
        cursor.setPosition(pos)
        self.setTextCursor(cursor)


class FCComboBox(QtWidgets.QComboBox):

    def __init__(self, parent=None, callback=None):
        super(FCComboBox, self).__init__(parent)
        self.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.view = self.view()
        self.view.viewport().installEventFilter(self)
        self.view.setContextMenuPolicy(Qt.CustomContextMenu)

        # the callback() will be called on customcontextmenu event and will be be passed 2 parameters:
        # pos = mouse right click click position
        # self = is the combobox object itself
        if callback:
            self.view.customContextMenuRequested.connect(lambda pos: callback(pos, self))

    def eventFilter(self, obj, event):
        if event.type() == QtCore.QEvent.MouseButtonRelease:
            if event.button() == Qt.RightButton:
                return True
        return False

    def wheelEvent(self, *args, **kwargs):
        pass

    def get_value(self):
        return str(self.currentText())

    def set_value(self, val):
        self.setCurrentIndex(self.findText(str(val)))


class FCInputDialog(QtWidgets.QInputDialog):
    def __init__(self, parent=None, ok=False, val=None, title=None, text=None, min=None, max=None, decimals=None,
                 init_val=None):
        super(FCInputDialog, self).__init__(parent)
        self.allow_empty = ok
        self.empty_val = val

        self.val = 0.0
        self.ok = ''

        self.init_value = init_val if init_val else 0.0

        if title is None:
            self.title = 'title'
        else:
            self.title = title
        if text is None:
            self.text = 'text'
        else:
            self.text = text
        if min is None:
            self.min = 0
        else:
            self.min = min
        if max is None:
            self.max = 0
        else:
            self.max = max
        if decimals is None:
            self.decimals = 6
        else:
            self.decimals = decimals

    def get_value(self):
        self.val, self.ok = self.getDouble(self, self.title, self.text, min=self.min,
                                           max=self.max, decimals=self.decimals, value=self.init_value)
        return [self.val, self.ok]

    # "Transform", "Enter the Angle value:"
    def set_value(self, val):
        pass


class FCButton(QtWidgets.QPushButton):
    def __init__(self, parent=None):
        super(FCButton, self).__init__(parent)

    def get_value(self):
        return self.isChecked()

    def set_value(self, val):
        self.setText(str(val))


class FCMenu(QtWidgets.QMenu):
    def __init__(self):
        super().__init__()
        self.mouse_is_panning = False

    def popup(self, pos, action=None):
        self.mouse_is_panning = False
        super().popup(pos)


class FCTab(QtWidgets.QTabWidget):
    def __init__(self, parent=None):
        super(FCTab, self).__init__(parent)
        self.setTabsClosable(True)
        self.tabCloseRequested.connect(self.closeTab)

    def deleteTab(self, currentIndex):
        widget = self.widget(currentIndex)
        if widget is not None:
            widget.deleteLater()
        self.removeTab(currentIndex)

    def closeTab(self, currentIndex):
        self.removeTab(currentIndex)

    def protectTab(self, currentIndex):
        self.tabBar().setTabButton(currentIndex, QtWidgets.QTabBar.RightSide, None)


# class FCTabBar(QtWidgets.QTabBar):
#     def tabSizeHint(self, index):
#         size =QtWidgets.QTabBar.tabSizeHint(self, index)
#         w = int(self.width()/self.count())
#         return QtCore.QSize(w, size.height())


class FCDetachableTab(QtWidgets.QTabWidget):
    """
    From here:
    https://stackoverflow.com/questions/47267195/in-pyqt4-is-it-possible-to-detach-tabs-from-a-qtabwidget
    """

    def __init__(self, protect=None, protect_by_name=None, parent=None):
        super().__init__()

        self.tabBar = self.FCTabBar(self)
        self.tabBar.onMoveTabSignal.connect(self.moveTab)
        self.tabBar.detachedTabDropSignal.connect(self.detachedTabDrop)
        self.set_detachable(val=True)

        self.setTabBar(self.tabBar)

        # Used to keep a reference to detached tabs since their QMainWindow
        # does not have a parent
        self.detachedTabs = {}

        # a way to make sure that tabs can't be closed after they attach to the parent tab
        self.protect_tab = True if protect is not None and protect is True else False

        self.protect_by_name = protect_by_name if isinstance(protect_by_name, list) else None

        # Close all detached tabs if the application is closed explicitly
        QtWidgets.qApp.aboutToQuit.connect(self.closeDetachedTabs) # @UndefinedVariable

        # used by the property self.useOldIndex(param)
        self.use_old_index = None
        self.old_index = None

        self.setTabsClosable(True)
        self.tabCloseRequested.connect(self.closeTab)

    def set_rmb_callback(self, callback):
        """

        :param callback: Function to call on right mouse click on tab
        :type callback: func
        :return: None
        """

        self.tabBar.right_click.connect(callback)

    def set_detachable(self, val=True):
        try:
            self.tabBar.onDetachTabSignal.disconnect()
        except TypeError:
            pass

        if val is True:
            self.tabBar.onDetachTabSignal.connect(self.detachTab)
            # the tab can be moved around
            self.tabBar.can_be_dragged = True
        else:
            # the detached tab can't be moved
            self.tabBar.can_be_dragged = False

        return val

    def setupContextMenu(self):
        self.setContextMenuPolicy(QtCore.Qt.ActionsContextMenu)

    def addContextMenu(self, entry, call_function, icon=None, initial_checked=False):
        action_name = str(entry)
        action = QtWidgets.QAction(self)
        action.setCheckable(True)
        action.setText(action_name)
        if icon:
            assert isinstance(icon, QtGui.QIcon), \
                "Expected the argument to be QtGui.QIcon. Instead it is %s" % type(icon)
            action.setIcon(icon)
        action.setChecked(initial_checked)
        self.addAction(action)
        action.triggered.connect(call_function)

    def useOldIndex(self, param):
        if param:
            self.use_old_index = True
        else:
            self.use_old_index = False

    def deleteTab(self, currentIndex):
        widget = self.widget(currentIndex)
        if widget is not None:
            widget.deleteLater()
        self.removeTab(currentIndex)

    def closeTab(self, currentIndex):
        """
        Slot connected to the tabCloseRequested signal

        :param currentIndex:
        :return:
        """

        self.removeTab(currentIndex)

    def protectTab(self, currentIndex):
        # self.FCTabBar().setTabButton(currentIndex, QtWidgets.QTabBar.RightSide, None)
        self.tabBar.setTabButton(currentIndex, QtWidgets.QTabBar.RightSide, None)

    def setMovable(self, movable):
        """
        The default movable functionality of QTabWidget must remain disabled
        so as not to conflict with the added features

        :param movable:
        :return:
        """
        pass

    @pyqtSlot(int, int)
    def moveTab(self, fromIndex, toIndex):
        """
        Move a tab from one position (index) to another

        :param fromIndex:   the original index location of the tab
        :param toIndex:     the new index location of the tab
        :return:
        """

        widget = self.widget(fromIndex)
        icon = self.tabIcon(fromIndex)
        text = self.tabText(fromIndex)

        self.removeTab(fromIndex)
        self.insertTab(toIndex, widget, icon, text)
        self.setCurrentIndex(toIndex)

    @pyqtSlot(int, QtCore.QPoint)
    def detachTab(self, index, point):
        """
        Detach the tab by removing it's contents and placing them in
        a DetachedTab window

        :param index:   the index location of the tab to be detached
        :param point:   the screen position for creating the new DetachedTab window
        :return:
        """
        self.old_index = index

        # Get the tab content and add name FlatCAM to the tab so we know on which app is this tab linked
        name = "FlatCAM " + self.tabText(index)
        icon = self.tabIcon(index)
        if icon.isNull():
            icon = self.window().windowIcon()
        contentWidget = self.widget(index)

        try:
            contentWidgetRect = contentWidget.frameGeometry()
        except AttributeError:
            return

        # Create a new detached tab window
        detachedTab = self.FCDetachedTab(name, contentWidget)
        detachedTab.setWindowModality(QtCore.Qt.NonModal)
        detachedTab.setWindowIcon(icon)
        detachedTab.setGeometry(contentWidgetRect)
        detachedTab.onCloseSignal.connect(self.attachTab)
        detachedTab.onDropSignal.connect(self.tabBar.detachedTabDrop)
        detachedTab.move(point)
        detachedTab.show()

        # Create a reference to maintain access to the detached tab
        self.detachedTabs[name] = detachedTab

    def attachTab(self, contentWidget, name, icon, insertAt=None):
        """
        Re-attach the tab by removing the content from the DetachedTab window,
        closing it, and placing the content back into the DetachableTabWidget

        :param contentWidget:   the content widget from the DetachedTab window
        :param name:            the name of the detached tab
        :param icon:            the window icon for the detached tab
        :param insertAt:        insert the re-attached tab at the given index
        :return:
        """

        # Make the content widget a child of this widget
        contentWidget.setParent(self)

        # Remove the reference
        del self.detachedTabs[name]
        # make sure that we strip the 'FlatCAM' part of the detached name otherwise the tab name will be too long
        name = name.partition(' ')[2]

        # helps in restoring the tab to the same index that it was before was detached
        insert_index = self.old_index if self.use_old_index is True else insertAt

        # Create an image from the given icon (for comparison)
        if not icon.isNull():
            try:
                tabIconPixmap = icon.pixmap(icon.availableSizes()[0])
                tabIconImage = tabIconPixmap.toImage()
            except IndexError:
                tabIconImage = None
        else:
            tabIconImage = None

        # Create an image of the main window icon (for comparison)
        if not icon.isNull():
            try:
                windowIconPixmap = self.window().windowIcon().pixmap(icon.availableSizes()[0])
                windowIconImage = windowIconPixmap.toImage()
            except IndexError:
                windowIconImage = None
        else:
            windowIconImage = None

        # Determine if the given image and the main window icon are the same.
        # If they are, then do not add the icon to the tab
        if tabIconImage == windowIconImage:
            if insert_index is None:
                index = self.addTab(contentWidget, name)
            else:
                index = self.insertTab(insert_index, contentWidget, name)
        else:
            if insert_index is None:
                index = self.addTab(contentWidget, icon, name)
            else:
                index = self.insertTab(insert_index, contentWidget, icon, name)

        # on reattaching the tab if protect is true then the closure button is not added
        if self.protect_tab is True:
            self.protectTab(index)

        # on reattaching the tab disable the closure button for the tabs with the name in the self.protect_by_name list
        if self.protect_by_name is not None:
            for tab_name in self.protect_by_name:
                for index in range(self.count()):
                    if str(tab_name) == str(self.tabText(index)):
                        self.protectTab(index)

        # Make this tab the current tab
            if index > -1:
                self.setCurrentIndex(insert_index) if self.use_old_index else self.setCurrentIndex(index)

    def removeTabByName(self, name):
        """
        Remove the tab with the given name, even if it is detached

        :param name: the name of the tab to be removed
        :return:
        """

        # Remove the tab if it is attached
        attached = False
        for index in range(self.count()):
            if str(name) == str(self.tabText(index)):
                self.removeTab(index)
                attached = True
                break


        # If the tab is not attached, close it's window and
        # remove the reference to it
        if not attached:
            for key in self.detachedTabs:
                if str(name) == str(key):
                    self.detachedTabs[key].onCloseSignal.disconnect()
                    self.detachedTabs[key].close()
                    del self.detachedTabs[key]
                    break

    @QtCore.pyqtSlot(str, int, QtCore.QPoint)
    def detachedTabDrop(self, name, index, dropPos):
        """
        Handle dropping of a detached tab inside the DetachableTabWidget

        :param name:        the name of the detached tab
        :param index:       the index of an existing tab (if the tab bar
    #                       determined that the drop occurred on an
    #                       existing tab)
        :param dropPos:     the mouse cursor position when the drop occurred
        :return:
        """

        # If the drop occurred on an existing tab, insert the detached
        # tab at the existing tab's location
        if index > -1:

            # Create references to the detached tab's content and icon
            contentWidget = self.detachedTabs[name].contentWidget
            icon = self.detachedTabs[name].windowIcon()

            # Disconnect the detached tab's onCloseSignal so that it
            # does not try to re-attach automatically
            self.detachedTabs[name].onCloseSignal.disconnect()

            # Close the detached
            self.detachedTabs[name].close()

            # Re-attach the tab at the given index
            self.attachTab(contentWidget, name, icon, index)

        # If the drop did not occur on an existing tab, determine if the drop
        # occurred in the tab bar area (the area to the side of the QTabBar)
        else:

            # Find the drop position relative to the DetachableTabWidget
            tabDropPos = self.mapFromGlobal(dropPos)

            # If the drop position is inside the DetachableTabWidget...
            if self.rect().contains(tabDropPos):

                # If the drop position is inside the tab bar area (the
                # area to the side of the QTabBar) or there are not tabs
                # currently attached...
                if tabDropPos.y() < self.tabBar.height() or self.count() == 0:

                    # Close the detached tab and allow it to re-attach
                    # automatically
                    self.detachedTabs[name].close()

    def closeDetachedTabs(self):
        """
        Close all tabs that are currently detached.

        :return:
        """
        listOfDetachedTabs = []

        for key in self.detachedTabs:
            listOfDetachedTabs.append(self.detachedTabs[key])

        for detachedTab in listOfDetachedTabs:
            detachedTab.close()

    class FCDetachedTab(QtWidgets.QMainWindow):
        """
        When a tab is detached, the contents are placed into this QMainWindow.  The tab
        can be re-attached by closing the dialog or by dragging the window into the tab bar
        """

        onCloseSignal = pyqtSignal(QtWidgets.QWidget, str, QtGui.QIcon)
        onDropSignal = pyqtSignal(str, QtCore.QPoint)

        def __init__(self, name, contentWidget):
            QtWidgets.QMainWindow.__init__(self, None)

            self.setObjectName(name)
            self.setWindowTitle(name)

            self.contentWidget = contentWidget
            self.setCentralWidget(self.contentWidget)
            self.contentWidget.show()

            self.windowDropFilter = self.WindowDropFilter()
            self.installEventFilter(self.windowDropFilter)
            self.windowDropFilter.onDropSignal.connect(self.windowDropSlot)

        @QtCore.pyqtSlot(QtCore.QPoint)
        def windowDropSlot(self, dropPos):
            """
            Handle a window drop event

            :param dropPos:     the mouse cursor position of the drop
            :return:
            """
            self.onDropSignal.emit(self.objectName(), dropPos)

        def closeEvent(self, event):
            """
            If the window is closed, emit the onCloseSignal and give the
            content widget back to the DetachableTabWidget

            :param event:    a close event
            :return:
            """
            self.onCloseSignal.emit(self.contentWidget, self.objectName(), self.windowIcon())

        class WindowDropFilter(QtCore.QObject):
            """
            An event filter class to detect a QMainWindow drop event
            """

            onDropSignal = pyqtSignal(QtCore.QPoint)

            def __init__(self):
                QtCore.QObject.__init__(self)
                self.lastEvent = None

            def eventFilter(self, obj, event):
                """
                Detect a QMainWindow drop event by looking for a NonClientAreaMouseMove (173)
                event that immediately follows a Move event

                :param obj:     the object that generated the event
                :param event:   the current event
                :return:
                """

                # If a NonClientAreaMouseMove (173) event immediately follows a Move event...
                if self.lastEvent == QtCore.QEvent.Move and event.type() == 173:

                    # Determine the position of the mouse cursor and emit it with the
                    # onDropSignal
                    mouseCursor = QtGui.QCursor()
                    dropPos = mouseCursor.pos()
                    self.onDropSignal.emit(dropPos)
                    self.lastEvent = event.type()
                    return True

                else:
                    self.lastEvent = event.type()
                    return False

    class FCTabBar(QtWidgets.QTabBar):
        onDetachTabSignal = pyqtSignal(int, QtCore.QPoint)
        onMoveTabSignal = pyqtSignal(int, int)
        detachedTabDropSignal = pyqtSignal(str, int, QtCore.QPoint)

        right_click = pyqtSignal(int)

        def __init__(self, parent=None):
            QtWidgets.QTabBar.__init__(self, parent)

            self.setAcceptDrops(True)
            self.setElideMode(QtCore.Qt.ElideRight)
            self.setSelectionBehaviorOnRemove(QtWidgets.QTabBar.SelectLeftTab)

            self.prev_index = -1

            self.dragStartPos = QtCore.QPoint()
            self.dragDropedPos = QtCore.QPoint()
            self.mouseCursor = QtGui.QCursor()
            self.dragInitiated = False

            # set this to False and the tab will no longer be displayed as detached
            self.can_be_dragged = True

        def mouseDoubleClickEvent(self, event):
            """
            Send the onDetachTabSignal when a tab is double clicked

            :param event:   a mouse double click event
            :return:
            """

            event.accept()
            self.onDetachTabSignal.emit(self.tabAt(event.pos()), self.mouseCursor.pos())

        def mousePressEvent(self, event):
            """
            Set the starting position for a drag event when the left mouse button is pressed.
            Start detection of a right mouse click.

            :param event:   a mouse press event
            :return:
            """
            if event.button() == QtCore.Qt.LeftButton:
                self.dragStartPos = event.pos()
            elif event.button() == QtCore.Qt.RightButton:
                self.prev_index = self.tabAt(event.pos())

            self.dragDropedPos.setX(0)
            self.dragDropedPos.setY(0)
            self.dragInitiated = False

            QtWidgets.QTabBar.mousePressEvent(self, event)

        def mouseReleaseEvent(self, event):
            """
            Finish the detection of the right mouse click on the tab


            :param event:   a mouse press event
            :return:
            """
            if event.button() == QtCore.Qt.RightButton and self.prev_index == self.tabAt(event.pos()):
                self.right_click.emit(self.prev_index)
            self.prev_index = -1

            QtWidgets.QTabBar.mouseReleaseEvent(self, event)

        def mouseMoveEvent(self, event):
            """
            Determine if the current movement is a drag.  If it is, convert it into a QDrag.  If the
            drag ends inside the tab bar, emit an onMoveTabSignal.  If the drag ends outside the tab
            bar, emit an onDetachTabSignal.

            :param event:   a mouse move event
            :return:
            """
            # Determine if the current movement is detected as a drag
            if not self.dragStartPos.isNull() and \
                    ((event.pos() - self.dragStartPos).manhattanLength() < QtWidgets.QApplication.startDragDistance()):
                self.dragInitiated = True

            # If the current movement is a drag initiated by the left button
            if (((event.buttons() & QtCore.Qt.LeftButton)) and self.dragInitiated and self.can_be_dragged):

                # Stop the move event
                finishMoveEvent = QtGui.QMouseEvent(
                    QtCore.QEvent.MouseMove, event.pos(), QtCore.Qt.NoButton, QtCore.Qt.NoButton, QtCore.Qt.NoModifier
                )
                QtWidgets.QTabBar.mouseMoveEvent(self, finishMoveEvent)

                # Convert the move event into a drag
                drag = QtGui.QDrag(self)
                mimeData = QtCore.QMimeData()
                # mimeData.setData('action', 'application/tab-detach')
                drag.setMimeData(mimeData)
                # screen = QScreen(self.parentWidget().currentWidget().winId())
                # Create the appearance of dragging the tab content
                try:
                    pixmap = self.parent().widget(self.tabAt(self.dragStartPos)).grab()
                except Exception as e:
                    log.debug("GUIElements.FCDetachable. FCTabBar.mouseMoveEvent() --> %s" % str(e))
                    return

                targetPixmap = QtGui.QPixmap(pixmap.size())
                targetPixmap.fill(QtCore.Qt.transparent)
                painter = QtGui.QPainter(targetPixmap)
                painter.setOpacity(0.85)
                painter.drawPixmap(0, 0, pixmap)
                painter.end()
                drag.setPixmap(targetPixmap)

                # Initiate the drag
                dropAction = drag.exec_(QtCore.Qt.MoveAction | QtCore.Qt.CopyAction)

                # For Linux:  Here, drag.exec_() will not return MoveAction on Linux.  So it
                #             must be set manually
                if self.dragDropedPos.x() != 0 and self.dragDropedPos.y() != 0:
                    dropAction = QtCore.Qt.MoveAction

                # If the drag completed outside of the tab bar, detach the tab and move
                # the content to the current cursor position
                if dropAction == QtCore.Qt.IgnoreAction:
                    event.accept()
                    self.onDetachTabSignal.emit(self.tabAt(self.dragStartPos), self.mouseCursor.pos())

                # Else if the drag completed inside the tab bar, move the selected tab to the new position
                elif dropAction == QtCore.Qt.MoveAction:
                    if not self.dragDropedPos.isNull():
                        event.accept()
                        self.onMoveTabSignal.emit(self.tabAt(self.dragStartPos), self.tabAt(self.dragDropedPos))
            else:
                QtWidgets.QTabBar.mouseMoveEvent(self, event)

        def dragEnterEvent(self, event):
            """
            Determine if the drag has entered a tab position from another tab position

            :param event:   a drag enter event
            :return:
            """
            mimeData = event.mimeData()
            # formats = mcd imeData.formats()

            # if formats.contains('action') and mimeData.data('action') == 'application/tab-detach':
            # event.acceptProposedAction()

            QtWidgets.QTabBar.dragMoveEvent(self, event)

        def dropEvent(self, event):
            """
            Get the position of the end of the drag

            :param event:    a drop event
            :return:
            """
            self.dragDropedPos = event.pos()
            QtWidgets.QTabBar.dropEvent(self, event)

        def detachedTabDrop(self, name, dropPos):
            """
            Determine if the detached tab drop event occurred on an existing tab,
            then send the event to the DetachableTabWidget

            :param name:
            :param dropPos:
            :return:
            """
            tabDropPos = self.mapFromGlobal(dropPos)

            index = self.tabAt(tabDropPos)

            self.detachedTabDropSignal.emit(name, index, dropPos)


class FCDetachableTab2(FCDetachableTab):
    tab_closed_signal = pyqtSignal(object)

    def __init__(self, protect=None, protect_by_name=None, parent=None):
        super(FCDetachableTab2, self).__init__(protect=protect, protect_by_name=protect_by_name, parent=parent)

    def closeTab(self, currentIndex):
        """
        Slot connected to the tabCloseRequested signal

        :param currentIndex:
        :return:
        """
        idx = self.currentIndex()

        self.tab_closed_signal.emit(self.tabText(idx))

        self.removeTab(currentIndex)


class VerticalScrollArea(QtWidgets.QScrollArea):
    """
    This widget extends QtGui.QScrollArea to make a vertical-only
    scroll area that also expands horizontally to accomodate
    its contents.
    """
    def __init__(self, parent=None):
        QtWidgets.QScrollArea.__init__(self, parent=parent)
        self.setWidgetResizable(True)
        self.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
        self.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAsNeeded)

    def eventFilter(self, source, event):
        """
        The event filter gets automatically installed when setWidget()
        is called.

        :param source:
        :param event:
        :return:
        """
        if event.type() == QtCore.QEvent.Resize and source == self.widget():
            # log.debug("VerticalScrollArea: Widget resized:")
            # log.debug(" minimumSizeHint().width() = %d" % self.widget().minimumSizeHint().width())
            # log.debug(" verticalScrollBar().width() = %d" % self.verticalScrollBar().width())

            self.setMinimumWidth(self.widget().sizeHint().width() +
                                 self.verticalScrollBar().sizeHint().width())

            # if self.verticalScrollBar().isVisible():
            #     log.debug(" Scroll bar visible")
            #     self.setMinimumWidth(self.widget().minimumSizeHint().width() +
            #                          self.verticalScrollBar().width())
            # else:
            #     log.debug(" Scroll bar hidden")
            #     self.setMinimumWidth(self.widget().minimumSizeHint().width())
        return QtWidgets.QWidget.eventFilter(self, source, event)


class OptionalInputSection:

    def __init__(self, cb, optinputs, logic=True):
        """
        Associates the a checkbox with a set of inputs.

        :param cb: Checkbox that enables the optional inputs.
        :param optinputs: List of widgets that are optional.
        :param logic: When True the logic is normal, when False the logic is in reverse
        It means that for logic=True, when the checkbox is checked the widgets are Enabled, and
        for logic=False, when the checkbox is checked the widgets are Disabled
        :return:
        """
        assert isinstance(cb, FCCheckBox), \
            "Expected an FCCheckBox, got %s" % type(cb)

        self.cb = cb
        self.optinputs = optinputs
        self.logic = logic

        self.on_cb_change()
        self.cb.stateChanged.connect(self.on_cb_change)

    def on_cb_change(self):

        if self.cb.checkState():
            for widget in self.optinputs:
                if self.logic is True:
                    widget.setEnabled(True)
                else:
                    widget.setEnabled(False)
        else:
            for widget in self.optinputs:
                if self.logic is True:
                    widget.setEnabled(False)
                else:
                    widget.setEnabled(True)


class OptionalHideInputSection:

    def __init__(self, cb, optinputs, logic=True):
        """
        Associates the a checkbox with a set of inputs.

        :param cb: Checkbox that enables the optional inputs.
        :param optinputs: List of widgets that are optional.
        :param logic: When True the logic is normal, when False the logic is in reverse
        It means that for logic=True, when the checkbox is checked the widgets are Enabled, and
        for logic=False, when the checkbox is checked the widgets are Disabled
        :return:
        """
        assert isinstance(cb, FCCheckBox), \
            "Expected an FCCheckBox, got %s" % type(cb)

        self.cb = cb
        self.optinputs = optinputs
        self.logic = logic

        self.on_cb_change()
        self.cb.stateChanged.connect(self.on_cb_change)

    def on_cb_change(self):

        if self.cb.checkState():
            for widget in self.optinputs:
                if self.logic is True:
                    widget.show()
                else:
                    widget.hide()
        else:
            for widget in self.optinputs:
                if self.logic is True:
                    widget.hide()
                else:
                    widget.show()


class FCTable(QtWidgets.QTableWidget):
    def __init__(self, parent=None):
        super(FCTable, self).__init__(parent)

    def sizeHint(self):
        default_hint_size = super(FCTable, self).sizeHint()
        return QtCore.QSize(EDIT_SIZE_HINT, default_hint_size.height())

    def getHeight(self):
        height = self.horizontalHeader().height()
        for i in range(self.rowCount()):
            height += self.rowHeight(i)
        return height

    def getWidth(self):
        width = self.verticalHeader().width()
        for i in range(self.columnCount()):
            width += self.columnWidth(i)
        return width

    # color is in format QtGui.Qcolor(r, g, b, alpha) with or without alpfa
    def setColortoRow(self, rowIndex, color):
        for j in range(self.columnCount()):
            self.item(rowIndex, j).setBackground(color)

    # if user is clicking an blank area inside the QTableWidget it will deselect currently selected rows
    def mousePressEvent(self, event):
        if self.itemAt(event.pos()) is None:
            self.clearSelection()
        else:
            QtWidgets.QTableWidget.mousePressEvent(self, event)

    def setupContextMenu(self):
        self.setContextMenuPolicy(QtCore.Qt.ActionsContextMenu)

    def addContextMenu(self, entry, call_function, icon=None):
        action_name = str(entry)
        action = QtWidgets.QAction(self)
        action.setText(action_name)
        if icon:
            assert isinstance(icon, QtGui.QIcon), \
                "Expected the argument to be QtGui.QIcon. Instead it is %s" % type(icon)
            action.setIcon(icon)
        self.addAction(action)
        action.triggered.connect(call_function)


class SpinBoxDelegate(QtWidgets.QItemDelegate):

    def __init__(self, units):
        super(SpinBoxDelegate, self).__init__()
        self.units = units
        self.current_value = None

    def createEditor(self, parent, option, index):
        editor = QtWidgets.QDoubleSpinBox(parent)
        editor.setMinimum(-999.9999)
        editor.setMaximum(999.9999)

        if self.units == 'MM':
            editor.setDecimals(2)
        else:
            editor.setDecimals(3)

        return editor

    def setEditorData(self, spinBox, index):
        try:
            value = float(index.model().data(index, Qt.EditRole))
        except ValueError:
            value = self.current_value
            # return

        spinBox.setValue(value)

    def setModelData(self, spinBox, model, index):
        spinBox.interpretText()
        value = spinBox.value()
        self.current_value = value

        model.setData(index, value, Qt.EditRole)

    def updateEditorGeometry(self, editor, option, index):
        editor.setGeometry(option.rect)

    def setDecimals(self, spinbox, digits):
        spinbox.setDecimals(digits)


class Dialog_box(QtWidgets.QWidget):
    def __init__(self, title=None, label=None, icon=None, initial_text=None):
        """

        :param title: string with the window title
        :param label: string with the message inside the dialog box
        """
        super(Dialog_box, self).__init__()
        if initial_text is None:
            self.location = str((0, 0))
        else:
            self.location = initial_text

        self.ok = False

        self.dialog_box = QtWidgets.QInputDialog()
        self.dialog_box.setMinimumWidth(290)
        self.setWindowIcon(icon)

        self.location, self.ok = self.dialog_box.getText(self, title, label,
                                                         text=str(self.location).replace('(', '').replace(')', ''))
        self.readyToEdit = True

    def mousePressEvent(self, e, parent=None):
        super(Dialog_box, self).mousePressEvent(e)  # required to deselect on 2e click
        if self.readyToEdit:
            self.lineEdit().selectAll()
            self.readyToEdit = False

    def focusOutEvent(self, e):
        # don't focus out if the user requests an popup menu
        if e.reason() != QtCore.Qt.PopupFocusReason:
            super(Dialog_box, self).focusOutEvent(e)  # required to remove cursor on focusOut
            self.lineEdit().deselect()
            self.readyToEdit = True


class _BrowserTextEdit(QTextEdit):

    def __init__(self, version):
        QTextEdit.__init__(self)
        self.menu = None
        self.version = version

    def contextMenuEvent(self, event):
        self.menu = self.createStandardContextMenu(event.pos())
        clear_action = QAction("Clear", self)
        clear_action.setShortcut(QKeySequence(Qt.Key_Delete))   # it's not working, the shortcut
        self.menu.addAction(clear_action)
        clear_action.triggered.connect(self.clear)
        self.menu.exec_(event.globalPos())

    def clear(self):
        QTextEdit.clear(self)
        text = "FlatCAM %s - Type >help< to get started\n\n" % self.version
        text = html.escape(text)
        text = text.replace('\n', '<br/>')
        self.moveCursor(QTextCursor.End)
        self.insertHtml(text)


class _ExpandableTextEdit(QTextEdit):
    """
    Class implements edit line, which expands themselves automatically
    """

    historyNext = pyqtSignal()
    historyPrev = pyqtSignal()

    def __init__(self, termwidget, *args):
        QTextEdit.__init__(self, *args)
        self.setStyleSheet("font: 9pt \"Courier\";")
        self._fittedHeight = 1
        self.textChanged.connect(self._fit_to_document)
        self._fit_to_document()
        self._termWidget = termwidget

        self.completer = MyCompleter()

        self.model = QtCore.QStringListModel()
        self.completer.setModel(self.model)
        self.set_model_data(keyword_list=[])
        self.completer.insertText.connect(self.insertCompletion)

    def set_model_data(self, keyword_list):
        self.model.setStringList(keyword_list)

    def insertCompletion(self, completion):
        tc = self.textCursor()
        extra = (len(completion) - len(self.completer.completionPrefix()))

        # don't insert if the word is finished but add a space instead
        if extra == 0:
            tc.insertText(' ')
            self.completer.popup().hide()
            return

        tc.movePosition(QTextCursor.Left)
        tc.movePosition(QTextCursor.EndOfWord)
        tc.insertText(completion[-extra:])
        # add a space after inserting the word
        tc.insertText(' ')
        self.setTextCursor(tc)
        self.completer.popup().hide()

    def focusInEvent(self, event):
        if self.completer:
            self.completer.setWidget(self)
        QTextEdit.focusInEvent(self, event)

    def keyPressEvent(self, event):
        """
        Catch keyboard events. Process Enter, Up, Down
        """

        key = event.key()
        if (key == Qt.Key_Tab or key == Qt.Key_Return or key == Qt.Key_Enter) and self.completer.popup().isVisible():
            self.completer.insertText.emit(self.completer.getSelected())
            self.completer.setCompletionMode(QCompleter.PopupCompletion)
            return

        if event.matches(QKeySequence.InsertParagraphSeparator):
            text = self.toPlainText()
            if self._termWidget.is_command_complete(text):
                self._termWidget.exec_current_command()
                return
        elif event.matches(QKeySequence.MoveToNextLine):
            text = self.toPlainText()
            cursor_pos = self.textCursor().position()
            textBeforeEnd = text[cursor_pos:]

            if len(textBeforeEnd.split('\n')) <= 1:
                self.historyNext.emit()
                return
        elif event.matches(QKeySequence.MoveToPreviousLine):
            text = self.toPlainText()
            cursor_pos = self.textCursor().position()
            text_before_start = text[:cursor_pos]
            # lineCount = len(textBeforeStart.splitlines())
            line_count = len(text_before_start.split('\n'))
            if len(text_before_start) > 0 and \
                    (text_before_start[-1] == '\n' or text_before_start[-1] == '\r'):
                line_count += 1
            if line_count <= 1:
                self.historyPrev.emit()
                return
        elif event.matches(QKeySequence.MoveToNextPage) or \
                event.matches(QKeySequence.MoveToPreviousPage):
            return self._termWidget.browser().keyPressEvent(event)

        tc = self.textCursor()

        QTextEdit.keyPressEvent(self, event)
        tc.select(QTextCursor.WordUnderCursor)
        cr = self.cursorRect()

        if len(tc.selectedText()) > 0:
            self.completer.setCompletionPrefix(tc.selectedText())
            popup = self.completer.popup()
            popup.setCurrentIndex(self.completer.completionModel().index(0, 0))

            cr.setWidth(self.completer.popup().sizeHintForColumn(0)
                        + self.completer.popup().verticalScrollBar().sizeHint().width())
            self.completer.complete(cr)
        else:
            self.completer.popup().hide()

    def sizeHint(self):
        """
        QWidget sizeHint impelemtation
        """
        hint = QTextEdit.sizeHint(self)
        hint.setHeight(self._fittedHeight)
        return hint

    def _fit_to_document(self):
        """
        Update widget height to fit all text
        """
        documentsize = self.document().size().toSize()
        self._fittedHeight = documentsize.height() + (self.height() - self.viewport().height())
        self.setMaximumHeight(self._fittedHeight)
        self.updateGeometry()

    def insertFromMimeData(self, mime_data):
        # Paste only plain text.
        self.insertPlainText(mime_data.text())


class MyCompleter(QCompleter):
    insertText = pyqtSignal(str)

    def __init__(self, parent=None):
        QCompleter.__init__(self)
        self.setCompletionMode(QCompleter.PopupCompletion)
        self.highlighted.connect(self.setHighlighted)
        # self.popup().installEventFilter(self)

    # def eventFilter(self, obj, event):
    #     if event.type() == QtCore.QEvent.Wheel and obj is self.popup():
    #         pass
    #     return False

    def setHighlighted(self, text):
        self.lastSelected = text

    def getSelected(self):
        return self.lastSelected