fix(crosshair): adapted for 2D image

bec_widgets/utils/crosshair.py

@@ -1,4 +1,7 @@
+from __future__ import annotations
+
 from collections import defaultdict
+from typing import Any
 
 import numpy as np
 import pyqtgraph as pg
@@ -197,15 +200,18 @@ class Crosshair(QObject):
                 self.marker_2d = pg.ROI(
                     [0, 0], size=[1, 1], pen=pg.mkPen("r", width=2), movable=False
                 )
+                self.marker_2d.skip_auto_range = True
                 self.plot_item.addItem(self.marker_2d)
 
-    def snap_to_data(self, x, y) -> tuple[defaultdict[list], defaultdict[list]]:
+    def snap_to_data(
+        self, x: float, y: float
+    ) -> tuple[None, None] | tuple[defaultdict[Any, list], defaultdict[Any, list]]:
         """
         Finds the nearest data points to the given x and y coordinates.
 
         Args:
-            x: The x-coordinate of the mouse cursor
+            x(float): The x-coordinate of the mouse cursor
-            y: The y-coordinate of the mouse cursor
+            y(float): The y-coordinate of the mouse cursor
 
         Returns:
             tuple: x and y values snapped to the nearest data
@@ -235,7 +241,7 @@ class Crosshair(QObject):
                     y_values[name] = closest_y
                     x_values[name] = closest_x
             elif isinstance(item, pg.ImageItem):  # 2D plot
-                name = item.config.monitor
+                name = item.config.monitor or str(id(item))
                 image_2d = item.image
                 # Clip the x and y values to the image dimensions to avoid out of bounds errors
                 y_values[name] = int(np.clip(y, 0, image_2d.shape[1] - 1))
@@ -320,7 +326,7 @@ class Crosshair(QObject):
                     )
                     self.coordinatesChanged1D.emit(coordinate_to_emit)
                 elif isinstance(item, pg.ImageItem):
-                    name = item.config.monitor
+                    name = item.config.monitor or str(id(item))
                     x, y = x_snap_values[name], y_snap_values[name]
                     if x is None or y is None:
                         continue
@@ -374,7 +380,7 @@ class Crosshair(QObject):
                     )
                     self.coordinatesClicked1D.emit(coordinate_to_emit)
                 elif isinstance(item, pg.ImageItem):
-                    name = item.config.monitor
+                    name = item.config.monitor or str(id(item))
                     x, y = x_snap_values[name], y_snap_values[name]
                     if x is None or y is None:
                         continue
@@ -418,9 +424,17 @@ class Crosshair(QObject):
         """
         x, y = pos
         x_scaled, y_scaled = self.scale_emitted_coordinates(x, y)
-
+        text = f"({x_scaled:.{self.precision}g}, {y_scaled:.{self.precision}g})"
+        for item in self.items:
+            if isinstance(item, pg.ImageItem):
+                image = item.image
+                ix = int(np.clip(x, 0, image.shape[0] - 1))
+                iy = int(np.clip(y, 0, image.shape[1] - 1))
+                intensity = image[ix, iy]
+                text += f"\nIntensity: {intensity:.{self.precision}g}"
+                break
         # Update coordinate label
-        self.coord_label.setText(f"({x_scaled:.{self.precision}g}, {y_scaled:.{self.precision}g})")
+        self.coord_label.setText(text)
         self.coord_label.setPos(x, y)
         self.coord_label.setVisible(True)
 
@@ -436,6 +450,9 @@ class Crosshair(QObject):
         self.clear_markers()
 
     def cleanup(self):
+        if self.marker_2d is not None:
+            self.plot_item.removeItem(self.marker_2d)
+            self.marker_2d = None
         self.plot_item.removeItem(self.v_line)
         self.plot_item.removeItem(self.h_line)
         self.plot_item.removeItem(self.coord_label)

tests/unit_tests/test_crosshair.py

@@ -4,9 +4,6 @@ import pytest
 from qtpy.QtCore import QPointF, Qt
 
 from bec_widgets.utils import Crosshair
-from bec_widgets.widgets.plots.image.image_widget import BECImageWidget
-
-from .client_mocks import mocked_client
 
 # pylint: disable = redefined-outer-name
 
@@ -25,14 +22,20 @@ def plot_widget_with_crosshair(qtbot):
 
 
 @pytest.fixture
-def image_widget_with_crosshair(qtbot, mocked_client):
+def image_widget_with_crosshair(qtbot):
-    widget = BECImageWidget(client=mocked_client())
+    widget = pg.PlotWidget()
-    widget._image.add_custom_image(name="test", data=np.random.random((100, 200)))
-    widget._image.hook_crosshair()
     qtbot.addWidget(widget)
     qtbot.waitExposed(widget)
 
-    yield widget._image.crosshair, widget._image.plot_item
+    image_item = pg.ImageItem()
+    image_item.setImage(np.random.rand(100, 100))
+    image_item.config = type("obj", (object,), {"monitor": "test"})
+
+    widget.addItem(image_item)
+    plot_item = widget.getPlotItem()
+    crosshair = Crosshair(plot_item=plot_item, precision=3)
+
+    yield crosshair, plot_item
 
 
 def test_mouse_moved_lines(plot_widget_with_crosshair):
@@ -104,13 +107,13 @@ def test_mouse_moved_signals_2D(image_widget_with_crosshair):
 
     crosshair.coordinatesChanged2D.connect(slot)
 
-    pos_in_view = QPointF(22.0, 55.0)
+    pos_in_view = QPointF(21.0, 55.0)
     pos_in_scene = plot_item.vb.mapViewToScene(pos_in_view)
     event_mock = [pos_in_scene]
 
     crosshair.mouse_moved(event_mock)
 
-    assert emitted_values_2D == [("test", 22.0, 55.0)]
+    assert emitted_values_2D == [("test", 21, 55)]
 
 
 def test_mouse_moved_signals_2D_outside(image_widget_with_crosshair):
@@ -226,3 +229,41 @@ def test_crosshair_clicked_signal(qtbot, plot_widget_with_crosshair):
 
     assert np.isclose(round(x, 1), 2)
     assert np.isclose(round(y, 1), 5)
+
+
+def test_update_coord_label_1D(plot_widget_with_crosshair):
+    crosshair, _ = plot_widget_with_crosshair
+    # Provide a test position
+    pos = (10, 20)
+    crosshair.update_coord_label(pos)
+    expected_text = f"({10:.3g}, {20:.3g})"
+    # Verify that the coordinate label shows only the 1D coordinates (no intensity line)
+    assert crosshair.coord_label.toPlainText() == expected_text
+    label_pos = crosshair.coord_label.pos()
+    assert np.isclose(label_pos.x(), 10)
+    assert np.isclose(label_pos.y(), 20)
+    assert crosshair.coord_label.isVisible()
+
+
+def test_update_coord_label_2D(image_widget_with_crosshair):
+    crosshair, plot_item = image_widget_with_crosshair
+
+    known_image = np.array([[10, 20], [30, 40]], dtype=float)
+
+    for item in plot_item.items:
+        if isinstance(item, pg.ImageItem):
+            item.setImage(known_image)
+
+    pos = (0.5, 1.2)
+    crosshair.update_coord_label(pos)
+
+    ix = int(np.clip(0.5, 0, known_image.shape[0] - 1))  # 0
+    iy = int(np.clip(1.2, 0, known_image.shape[1] - 1))  # 1
+    intensity = known_image[ix, iy]  # Expected: 20
+    expected_text = f"({0.5:.3g}, {1.2:.3g})\nIntensity: {intensity:.3g}"
+
+    assert crosshair.coord_label.toPlainText() == expected_text
+    label_pos = crosshair.coord_label.pos()
+    assert np.isclose(label_pos.x(), 0.5)
+    assert np.isclose(label_pos.y(), 1.2)
+    assert crosshair.coord_label.isVisible()