Formula Dialog

FormulaDialog(parent)

Bases: QDialog

A QDialog that provides a user-friendly interface for creating mathematical formulas using existing curves as variables. It includes a calculator-style button layout and a table showing available curve variables.

Parameters:

Name	Type	Description	Default
parent	QObject	The parent object	required

Source code in trace/widgets/formula_dialog.py

def __init__(self, parent: QObject):
    """Initialize the formula dialog.

    Parameters
    ----------
    parent : QObject
        The parent object
    """
    super().__init__(parent)
    self.setWindowTitle("Formula Input")

    layout = QVBoxLayout(self)

    layout.addSpacerItem(QSpacerItem(0, 0, QSizePolicy.Minimum, QSizePolicy.Expanding))

    self.field = QLineEdit(self)
    self.curve_model = CurveModel(parent)

    self.pv_list = QTableView(self)
    self.pv_list.setModel(self.curve_model)
    self.pv_list.setEditTriggers(QAbstractItemView.EditTriggers(0))
    self.pv_list.setMaximumWidth(1000)
    self.pv_list.setMaximumHeight(1000)

    # Hide all columns unused. Leave one to add a button to
    header = self.pv_list.horizontalHeader()
    header.setSectionResizeMode(0, QHeaderView.ResizeToContents)
    header.setStretchLastSection(True)

    layout.addWidget(self.pv_list)
    layout.addWidget(self.field)

    self.pv_list.doubleClicked.connect(self.insert_pv_key)

    # Define the list of calculator buttons.
    # It's a bunch of preset buttons, but users can type other functions under math.
    # fmt: off
    buttons = [
        "7",   "8",      "9",      "+",       "(",      ")",
        "4",   "5",      "6",      "-",       "^2",     "sqrt()",
        "1",   "2",      "3",      "*",       "^-1",    "ln()",
        "0",   "e",      "pi",     "/",       "sin()",  "asin()",
        ".",   "abs()",  "min()",  "^",       "cos()",  "acos()",
        "PV",  "Clear",  "max()",  "mean()",  "tan()",  "atan()",
    ]
    # fmt: on

    # Create the calculator buttons and connect them to the input field
    grid_layout = QGridLayout()
    for i, button_text in enumerate(buttons):
        button = QPushButton(button_text, self)
        row = i // 6
        col = i % 6
        grid_layout.addWidget(button, row, col)
        # Connect the button clicked signal to the appropriate action
        # PV currently does nothing, this is a remnant
        # From when we would have the pv_list open in a new window
        if button_text == "PV":
            self.PVButton = button
            self.PVButton.setCheckable(True)
            self.PVButton.setChecked(True)
            self.PVButton.clicked.connect(self.showPVList)
        elif button_text == "Clear":
            button.clicked.connect(lambda _: self.field.clear())
        else:
            button.clicked.connect(lambda _, text=button_text: self.field.insert(text))
    layout.addLayout(grid_layout)

    # Add an "OK" button to accept the formula and close the dialog
    ok_button = QPushButton("Add Formula Curve", self)
    ok_button.clicked.connect(self.accept_formula)
    layout.addWidget(ok_button)

keyPressEvent(e)

Handle key press events for formula submission.

Parameters:

Name	Type	Description	Default
e	QKeyEvent	The key press event	required

Source code in trace/widgets/formula_dialog.py

def keyPressEvent(self, e: QKeyEvent) -> None:
    """Handle key press events for formula submission.

    Parameters
    ----------
    e : QKeyEvent
        The key press event
    """
    if e.key() == Qt.Key_Return or e.key() == Qt.Key_Enter:
        self.accept_formula()
    return super().keyPressEvent(e)

showPVList()

Hide or show the PV list on PVButton click.

Source code in trace/widgets/formula_dialog.py

@Slot()
def showPVList(self):
    """Hide or show the PV list on PVButton click."""
    show = self.PVButton.isChecked()
    if show:
        self.pv_list.show()
    else:
        self.pv_list.hide()

accept_formula()

Accept the entered formula and emit the formula_accepted signal.

Source code in trace/widgets/formula_dialog.py

@Slot()
def accept_formula(self) -> None:
    """Accept the entered formula and emit the formula_accepted signal."""
    formula = "f://" + self.field.text()
    formula = re.sub(r"\s+", "", formula)

    self.formula_accepted.emit(formula)
    self.field.setText("")
    self.accept()

insert_pv_key(index)

Insert the variable name into the formula field when a row is double-clicked.

Parameters:

Name	Type	Description	Default
index	QModelIndex	The index of the double-clicked row	required

Source code in trace/widgets/formula_dialog.py

@Slot(QModelIndex)
def insert_pv_key(self, index: QModelIndex) -> None:
    """Insert the variable name into the formula field when a row is double-clicked.

    Parameters
    ----------
    index : QModelIndex
        The index of the double-clicked row
    """
    if index.isValid():
        key = self.curve_model.row_to_key(index.row())
        if key:
            current_text = self.field.text()
            cursor_pos = self.field.cursorPosition()
            # Add the variable with curly braces
            new_text = current_text[:cursor_pos] + "{" + key + "}" + current_text[cursor_pos:]
            self.field.setText(new_text)
            # Move cursor after the inserted variable (key length + 2 characters for braces)
            self.field.setCursorPosition(cursor_pos + len(key) + 2)

CurveModel(control_panel)

Bases: QAbstractTableModel

Table model for displaying available curves in the formula dialog. It provides a two-column view of available curves with their variable names and curve names for use in formula creation.

Parameters:

Name	Type	Description	Default
control_panel	ControlPanel	The control panel containing the curve dictionary	required

Source code in trace/widgets/formula_dialog.py

def __init__(self, control_panel):
    """Initialize the curve model.

    Parameters
    ----------
    control_panel : ControlPanel
        The control panel containing the curve dictionary
    """
    super().__init__()
    self.control_panel = control_panel
    self._headers = ["Variable Name", "Curve Name"]

rowCount(parent=QModelIndex())

Return the number of rows in the model.

Source code in trace/widgets/formula_dialog.py

def rowCount(self, parent=QModelIndex()) -> int:
    """Return the number of rows in the model."""
    if hasattr(self.control_panel, "curve_dict"):
        return len(self.control_panel.curve_dict)
    return 0

columnCount(parent=QModelIndex())

Return the number of columns in the model.

Source code in trace/widgets/formula_dialog.py

def columnCount(self, parent=QModelIndex()) -> int:
    """Return the number of columns in the model."""
    return len(self._headers)

data(index, role=Qt.DisplayRole)

Return the data for the given index and role.

Parameters:

Name	Type	Description	Default
index	QModelIndex	The model index	required
role	int	The data role	DisplayRole

Returns:

Type	Description
Any	The data for the given index and role

Source code in trace/widgets/formula_dialog.py

def data(self, index, role=Qt.DisplayRole) -> Any:
    """Return the data for the given index and role.

    Parameters
    ----------
    index : QModelIndex
        The model index
    role : int
        The data role

    Returns
    -------
    Any
        The data for the given index and role
    """
    if not index.isValid():
        return None

    if not hasattr(self.control_panel, "curve_dict"):
        return None

    curve_dict = self.control_panel.curve_dict
    if len(curve_dict) == 0:
        return None

    # Get the key at this row
    keys = list(curve_dict.keys())
    if index.row() >= len(keys):
        return None

    key = keys[index.row()]
    curve = curve_dict[key]

    if role == Qt.DisplayRole:
        if index.column() == 0:
            return key
        elif index.column() == 1:
            if hasattr(curve, "name") and callable(curve.name):
                return curve.name()
            elif hasattr(curve, "name"):
                return curve.name
            elif hasattr(curve, "address"):
                return curve.address
            return str(curve)
    return None

headerData(section, orientation, role=Qt.DisplayRole)

Return the header data for the given section.

Parameters:

Name	Type	Description	Default
section	int	The section index	required
orientation	Orientation	The orientation (horizontal or vertical)	required
role	int	The data role	DisplayRole

Returns:

Type	Description
Any	The header data

Source code in trace/widgets/formula_dialog.py

def headerData(self, section, orientation, role=Qt.DisplayRole) -> Any:
    """Return the header data for the given section.

    Parameters
    ----------
    section : int
        The section index
    orientation : Qt.Orientation
        The orientation (horizontal or vertical)
    role : int
        The data role

    Returns
    -------
    Any
        The header data
    """
    if orientation == Qt.Horizontal and role == Qt.DisplayRole:
        return self._headers[section]
    return None

row_to_key(row)

Get the variable key for the given row index.

Parameters:

Name	Type	Description	Default
row	int	Row index for the requested key.	required

Returns:

Type	Description
str or None	The variable key for the row, or None if invalid

Source code in trace/widgets/formula_dialog.py

def row_to_key(self, row: int) -> str:
    """Get the variable key for the given row index.

    Parameters
    ----------
    row : int
        Row index for the requested key.

    Returns
    -------
    str or None
        The variable key for the row, or None if invalid
    """
    if not (0 <= row < self.rowCount()):
        return None

    curve_dict = self.control_panel.curve_dict
    keys = list(curve_dict.keys())
    return keys[row]

refresh()

Force a refresh of the model data.

Source code in trace/widgets/formula_dialog.py

def refresh(self) -> None:
    """Force a refresh of the model data."""
    self.beginResetModel()
    self.endResetModel()