#!/usr/bin/env python3 # -*- coding: utf-8 -*- """ Line measurement tool. Interaction: - Toggle ON → click once to place the start point. - Move mouse → live preview of the line (start → cursor). - Click again → finalize the end point; line is drawn. - Drag center → move the whole line. - Drag endpoint → reposition that endpoint (live update). - Toggle OFF → line is erased. Physical length is computed using the pixel sizes stored in the two scale bars (scale_bar_1 for X, scale_bar_2 for Y). """ import logging from typing import Optional import numpy as np import pyqtgraph as pg from PyQt5 import QtWidgets, QtCore, QtGui _HANDLE_HIT_PX = 12 _HANDLE_SIZE_PX = 10 def _line_pen(): p = pg.mkPen('y', width=2) p.setCosmetic(True) return p def _handle_pen(): p = pg.mkPen('c', width=1) p.setCosmetic(True) return p def _handle_brush(): return QtGui.QBrush(QtGui.QColor(0, 200, 255, 200)) class LineProfileManager: _IDLE = 'idle' # waiting for first click _PLACING = 'placing' # start set, tracking mouse for end _PLACED = 'placed' # line finalised _MOVING = 'moving' # dragging center handle _DRAG_ENDPOINT = 'drag_endpoint' # dragging one of the two endpoint handles def __init__(self, image_view: pg.ImageView, stats_label: QtWidgets.QLabel, logger: Optional[logging.Logger] = None): self.image_view = image_view self.stats_label = stats_label self.logger = logger self.scalebar_manager = None self._gv = image_view.ui.graphicsView self._item: Optional[QtWidgets.QGraphicsLineItem] = None self._handle_c: Optional[QtWidgets.QGraphicsRectItem] = None # center self._handle_p1: Optional[QtWidgets.QGraphicsRectItem] = None # start self._handle_p2: Optional[QtWidgets.QGraphicsRectItem] = None # end self._x1 = self._y1 = self._x2 = self._y2 = 0.0 self._state = self._IDLE self._enabled = False self._last_image: Optional[np.ndarray] = None self._drag_start_sp = None self._drag_start_geom = None # (x1,y1,x2,y2) snapshot for move self._drag_endpoint_idx = None # 1 or 2 self._shift = False self._vp_filter = _LineVpFilter(self) self._key_filter = _LineKeyFilter(self) self._gv.viewport().installEventFilter(self._vp_filter) app = QtWidgets.QApplication.instance() if app: app.installEventFilter(self._key_filter) # ── public API ──────────────────────────────────────────────────────── def set_scalebar_manager(self, scalebar_manager): self.scalebar_manager = scalebar_manager def toggle(self, state): from PyQt5.QtCore import Qt if state == Qt.Checked: self._enabled = True self._state = self._IDLE self._gv.viewport().setCursor(QtCore.Qt.CrossCursor) self.stats_label.setText("Line: click to set start point") else: self._enabled = False self._remove_graphics() self._state = self._IDLE self._gv.viewport().setCursor(QtCore.Qt.ArrowCursor) self.stats_label.setText("No line") def update_stats(self, image: np.ndarray): self._last_image = image if self._state == self._PLACED: self._refresh_stats() def reset(self): self._remove_graphics() if self._enabled: self._state = self._IDLE self._gv.viewport().setCursor(QtCore.Qt.CrossCursor) self.stats_label.setText("Line: click to set start point") def cleanup(self): self._remove_graphics() try: self._gv.viewport().removeEventFilter(self._vp_filter) except Exception: pass try: app = QtWidgets.QApplication.instance() if app: app.removeEventFilter(self._key_filter) except Exception: pass # ── helpers ─────────────────────────────────────────────────────────── def _sc(self): return self._gv.scene() def _to_scene(self, vp_pos) -> QtCore.QPointF: return self._gv.mapToScene(vp_pos) def _pixel_sizes(self): if self.scalebar_manager is None: return 1.0, 1.0 return (self.scalebar_manager.scale_bar_1.pixel_size, self.scalebar_manager.scale_bar_2.pixel_size) # ── graphics ────────────────────────────────────────────────────────── def _remove_graphics(self): sc = self._sc() for attr in ('_item', '_handle_c', '_handle_p1', '_handle_p2'): item = getattr(self, attr) if item is not None: if sc: sc.removeItem(item) setattr(self, attr, None) def _make_handle(self) -> QtWidgets.QGraphicsRectItem: s = _HANDLE_SIZE_PX / 2.0 h = QtWidgets.QGraphicsRectItem(-s, -s, 2*s, 2*s) h.setPen(_handle_pen()) h.setBrush(_handle_brush()) h.setFlag(QtWidgets.QGraphicsItem.ItemIgnoresTransformations) h.setZValue(1001) return h def _create_graphics(self): self._remove_graphics() sc = self._sc() if sc is None: return self._item = QtWidgets.QGraphicsLineItem( self._x1, self._y1, self._x2, self._y2) self._item.setPen(_line_pen()) self._item.setZValue(1000) sc.addItem(self._item) self._handle_c = self._make_handle() self._handle_p1 = self._make_handle() self._handle_p2 = self._make_handle() sc.addItem(self._handle_c) sc.addItem(self._handle_p1) sc.addItem(self._handle_p2) self._place_handles() def _place_handles(self): if self._handle_c is not None: self._handle_c.setPos((self._x1 + self._x2) / 2.0, (self._y1 + self._y2) / 2.0) if self._handle_p1 is not None: self._handle_p1.setPos(self._x1, self._y1) if self._handle_p2 is not None: self._handle_p2.setPos(self._x2, self._y2) def _apply_geom(self): if self._item is not None: self._item.setLine(self._x1, self._y1, self._x2, self._y2) self._place_handles() def _hit(self, handle, vp_pos) -> bool: if handle is None: return False h_vp = self._gv.mapFromScene(handle.pos()) return (np.hypot(vp_pos.x() - h_vp.x(), vp_pos.y() - h_vp.y()) <= _HANDLE_HIT_PX) # ── constraint ──────────────────────────────────────────────────────── def _constrain(self, ax, ay, fx, fy): if not self._shift: return fx, fy if abs(fx - ax) >= abs(fy - ay): return fx, ay # horizontal return ax, fy # vertical # ── mouse events ────────────────────────────────────────────────────── def _on_press(self, vp_pos) -> bool: if not self._enabled: return False sp = self._to_scene(vp_pos) if self._state == self._IDLE: self._x1 = self._x2 = sp.x() self._y1 = self._y2 = sp.y() self._create_graphics() self._state = self._PLACING self.stats_label.setText("Line: drag to end, release to place") return True if self._state == self._PLACED: if self._hit(self._handle_p1, vp_pos): self._state = self._DRAG_ENDPOINT self._drag_endpoint_idx = 1 self._gv.viewport().setCursor(QtCore.Qt.CrossCursor) return True if self._hit(self._handle_p2, vp_pos): self._state = self._DRAG_ENDPOINT self._drag_endpoint_idx = 2 self._gv.viewport().setCursor(QtCore.Qt.CrossCursor) return True if self._hit(self._handle_c, vp_pos): self._state = self._MOVING self._drag_start_sp = sp self._drag_start_geom = (self._x1, self._y1, self._x2, self._y2) self._gv.viewport().setCursor(QtCore.Qt.SizeAllCursor) return True return False def _on_move(self, vp_pos) -> bool: sp = self._to_scene(vp_pos) if self._state == self._PLACING: x, y = self._constrain(self._x1, self._y1, sp.x(), sp.y()) self._x2, self._y2 = x, y self._apply_geom() self._refresh_stats() return True if self._state == self._DRAG_ENDPOINT: if self._drag_endpoint_idx == 1: x, y = self._constrain(self._x2, self._y2, sp.x(), sp.y()) self._x1, self._y1 = x, y else: x, y = self._constrain(self._x1, self._y1, sp.x(), sp.y()) self._x2, self._y2 = x, y self._apply_geom() self._refresh_stats() return True if self._state == self._MOVING: dx = sp.x() - self._drag_start_sp.x() dy = sp.y() - self._drag_start_sp.y() x1, y1, x2, y2 = self._drag_start_geom self._x1, self._y1 = x1 + dx, y1 + dy self._x2, self._y2 = x2 + dx, y2 + dy self._apply_geom() return True return False def _on_release(self, vp_pos) -> bool: if self._state == self._PLACING: sp = self._to_scene(vp_pos) x, y = self._constrain(self._x1, self._y1, sp.x(), sp.y()) self._x2, self._y2 = x, y self._apply_geom() self._state = self._PLACED self._gv.viewport().setCursor(QtCore.Qt.ArrowCursor) self._refresh_stats() return True if self._state in (self._MOVING, self._DRAG_ENDPOINT): self._state = self._PLACED self._drag_endpoint_idx = None self._refresh_stats() self._gv.viewport().setCursor(QtCore.Qt.ArrowCursor) return True return False # ── stats ───────────────────────────────────────────────────────────── def _refresh_stats(self): img_item = self.image_view.getImageItem() if img_item is None: return p1 = img_item.mapFromScene(QtCore.QPointF(self._x1, self._y1)) p2 = img_item.mapFromScene(QtCore.QPointF(self._x2, self._y2)) ix1, iy1 = p1.x(), p1.y() ix2, iy2 = p2.x(), p2.y() dx_px = ix2 - ix1 dy_px = iy2 - iy1 length_px = float(np.hypot(dx_px, dy_px)) px_x, px_y = self._pixel_sizes() length_um = float(np.hypot(dx_px * px_x, dy_px * px_y)) length_mm = length_um / 1000.0 angle = float(np.degrees(np.arctan2(dy_px, dx_px))) if self._state in (self._PLACING, self._DRAG_ENDPOINT): self.stats_label.setText( f"Line: {length_px:.0f} px | {length_um:.2f} µm") return self.stats_label.setText( f"Line\n" f"Length: {length_px:.1f} px\n" f" {length_um:.2f} µm ({length_mm:.4f} mm)\n" f"ΔX: {abs(dx_px):.1f} px = {abs(dx_px)*px_x:.2f} µm\n" f"ΔY: {abs(dy_px):.1f} px = {abs(dy_px)*px_y:.2f} µm\n" f"Angle: {angle:.1f}°\n" f"Start: ({ix1:.1f}, {iy1:.1f})\n" f"End: ({ix2:.1f}, {iy2:.1f})") class _LineKeyFilter(QtCore.QObject): def __init__(self, mgr): super().__init__() self.mgr = mgr def eventFilter(self, _obj, event): t = event.type() if t == QtCore.QEvent.KeyPress and event.key() == QtCore.Qt.Key_Shift: self.mgr._shift = True elif t == QtCore.QEvent.KeyRelease and event.key() == QtCore.Qt.Key_Shift: self.mgr._shift = False return False class _LineVpFilter(QtCore.QObject): def __init__(self, mgr: LineProfileManager): super().__init__() self.mgr = mgr def eventFilter(self, _obj, event): t = event.type() if t == QtCore.QEvent.MouseButtonPress: if event.button() == QtCore.Qt.LeftButton: return self.mgr._on_press(event.pos()) elif t == QtCore.QEvent.MouseMove: return self.mgr._on_move(event.pos()) elif t == QtCore.QEvent.MouseButtonRelease: if event.button() == QtCore.Qt.LeftButton: return self.mgr._on_release(event.pos()) return False