vibefpmgui.metrics_table

  1"""A sortable table of rows of objects, drawn on demand (Qt asks for the
  2cells on view, not all of them): the Complexity tab's procedures and files.
  3
  4A `QTableWidget` makes an item for each cell: a big project's 9000
  5procedures were 90 000 items, made again at each refill (more than half a
  6second). Here a row is an object (a procedure, a file) and each column says
  7how to show it; tooltips are made when asked for.
  8
  9It has the few `QTableWidget` calls the panel uses (`item`, `rowCount`,
 10`currentRow`, `setCurrentCell`, `cellClicked`, `currentCellChanged`…).
 11"""
 12
 13from __future__ import annotations
 14
 15from collections.abc import Callable
 16from typing import Any, NamedTuple
 17
 18from qtpy.QtCore import QAbstractTableModel, QModelIndex, QRect, Qt, Signal
 19from qtpy.QtGui import QBrush, QColor
 20from qtpy.QtWidgets import QTableView
 21
 22
 23def _role(role) -> int:
 24    return int(getattr(role, "value", role))
 25
 26
 27# The roles as plain numbers: data() is asked for every cell and role, and
 28# comparing a number with one of Qt's enums is ~100 times slower (a Python Enum).
 29DISPLAY, FOREGROUND, FONT, DECORATION, TOOLTIP, USER = (
 30    _role(r) for r in (Qt.DisplayRole, Qt.ForegroundRole, Qt.FontRole, Qt.DecorationRole, Qt.ToolTipRole,
 31                       Qt.UserRole))
 32SAMPLED_ROWS = 200  # rows looked at to size a column to its contents (Qt's default: 1000)
 33
 34
 35class Column(NamedTuple):
 36    title: str
 37    text: Callable[[Any], str]            # a row's text in it
 38    value: Callable[[Any], Any] | None = None  # what it's sorted by (None: its text)
 39    tip: str = ""                         # the title's tooltip
 40
 41
 42class RowStyle(NamedTuple):
 43    """How rows look and what they hold, apart from their text."""
 44    color: Callable[[Any, int], QColor | None] = lambda row, column: None
 45    bold: Callable[[Any, int], bool] = lambda row, column: False
 46    icon: Callable[[Any], Any] | None = None   # the first column's icon (see icon_column)
 47    tip: Callable[[Any], str] | None = None
 48    data: Callable[[Any, int], Any] | None = None  # (row, role) -> a value for that role, or None
 49    icon_column: int = 0
 50
 51
 52class RowModel(QAbstractTableModel):
 53    def __init__(self, columns: list[Column], style: RowStyle, parent=None):
 54        super().__init__(parent)
 55        self.columns = columns
 56        self.style = style
 57        self.rows: list = []
 58        self._sorted: tuple[int, Qt.SortOrder] | None = None
 59        self.bold_font = None  # (set by the table)
 60
 61    def set_rows(self, rows: list):
 62        self.beginResetModel()
 63        self.rows = list(rows)
 64        if self._sorted is not None:
 65            self._sort_rows(*self._sorted)
 66        self.endResetModel()
 67
 68    def rowCount(self, parent=QModelIndex()):  # noqa: B008 - Qt's signature
 69        return 0 if parent.isValid() else len(self.rows)
 70
 71    def columnCount(self, parent=QModelIndex()):  # noqa: B008
 72        return 0 if parent.isValid() else len(self.columns)
 73
 74    def headerData(self, section, orientation, role=DISPLAY):
 75        role = _role(role)
 76        if orientation != Qt.Horizontal or not 0 <= section < len(self.columns):
 77            return None
 78        if role == DISPLAY:
 79            return self.columns[section].title
 80        if role == TOOLTIP:
 81            return self.columns[section].tip or None
 82        return None
 83
 84    def data(self, index, role=DISPLAY):
 85        role = _role(role)
 86        if role not in (DISPLAY, FOREGROUND, FONT, DECORATION, TOOLTIP) and role < USER:
 87            return None  # (alignment, size hints…: Qt's defaults)
 88        if not index.isValid():
 89            return None
 90        row, column = self.rows[index.row()], index.column()
 91        style = self.style
 92        if role == DISPLAY:
 93            return self.columns[column].text(row)
 94        if role == FOREGROUND:
 95            color = style.color(row, column)
 96            return QBrush(color) if color is not None else None
 97        if role == FONT:
 98            return self.bold_font if style.bold(row, column) else None
 99        if role == DECORATION:
100            return style.icon(row) if style.icon is not None and column == style.icon_column else None
101        if role == TOOLTIP:
102            return style.tip(row) if style.tip is not None else None
103        if style.data is not None:
104            return style.data(row, role)
105        return None
106
107    def sort(self, column, order=Qt.AscendingOrder):
108        self._sorted = (column, order)
109        self.layoutAboutToBeChanged.emit()
110        old = self.persistentIndexList()  # (the current row, the selection: they follow their rows)
111        old_rows = [self.rows[i.row()] for i in old]
112        self._sort_rows(column, order)
113        place = {id(row): n for n, row in enumerate(self.rows)}
114        self.changePersistentIndexList(old, [self.index(place[id(row)], i.column()) for row, i in zip(old_rows, old,
115                                                                                                    strict=True)])
116        self.layoutChanged.emit()
117
118    def _sort_rows(self, column: int, order):
119        spec = self.columns[column]
120        key = spec.value or spec.text
121        self.rows.sort(key=key, reverse=order == Qt.DescendingOrder)  # (stable: ties keep their order)
122
123
124class Cell:
125    """A cell, as `QTableWidget.item` gives it (what the panel and its tests ask of one)."""
126
127    def __init__(self, model: RowModel, index):
128        self.model, self.index = model, index
129
130    def text(self) -> str:
131        return self.model.data(self.index, DISPLAY) or ""
132
133    def data(self, role):
134        return self.model.data(self.index, role)
135
136    def foreground(self) -> QBrush:
137        return self.model.data(self.index, FOREGROUND) or QBrush()
138
139    def toolTip(self) -> str:
140        return self.model.data(self.index, TOOLTIP) or ""
141
142
143class _Title:
144    def __init__(self, text: str):
145        self._text = text
146
147    def text(self) -> str:
148        return self._text
149
150
151class MetricsTable(QTableView):
152    """A `QTableView` of a `RowModel`, with `QTableWidget`'s cell signals."""
153
154    cellClicked = Signal(int, int)
155    currentCellChanged = Signal(int, int, int, int)  # row, column, previous row, previous column
156
157    def __init__(self, columns: list[Column], style: RowStyle, parent=None):
158        super().__init__(parent)
159        self.row_model = RowModel(columns, style, self)
160        self.setModel(self.row_model)
161        self.verticalHeader().setResizeContentsPrecision(SAMPLED_ROWS)
162        self.horizontalHeader().setResizeContentsPrecision(SAMPLED_ROWS)
163        font = self.font()
164        font.setBold(True)
165        self.row_model.bold_font = font
166        self.clicked.connect(lambda index: self.cellClicked.emit(index.row(), index.column()))
167        self.selectionModel().currentChanged.connect(
168            lambda now, before: self.currentCellChanged.emit(now.row(), now.column(), before.row(), before.column()))
169
170    def set_rows(self, rows: list):
171        self.row_model.set_rows(rows)
172
173    def rows(self) -> list:
174        """The rows, in the order shown."""
175        return self.row_model.rows
176
177    def rowCount(self) -> int:
178        return len(self.row_model.rows)
179
180    def item(self, row: int, column: int) -> Cell | None:
181        index = self.row_model.index(row, column)
182        return Cell(self.row_model, index) if index.isValid() else None
183
184    def currentRow(self) -> int:
185        return self.currentIndex().row()
186
187    def setCurrentCell(self, row: int, column: int):
188        self.setCurrentIndex(self.row_model.index(row, column) if row >= 0 else QModelIndex())
189
190    def horizontalHeaderItem(self, column: int) -> _Title:
191        return _Title(self.row_model.columns[column].title)
192
193    def visualItemRect(self, cell: Cell) -> QRect:
194        return self.visualRect(cell.index)