Merge pull request #32053 from mantidproject/scd238_sliceviewer_fix

Sliceviewer cursor tracking fix for MDHistograms ornl-next

docs/source/release/v6.2.0/framework.rst

@@ -55,5 +55,6 @@ Improvements
 
 Bugfixes
 ########
+- Fix cursor tracking from getting stuck and displaying incorrect signals when viewing MDHistogram workspaces in :ref:`sliceviewer`.
 
 :ref:`Release 6.2.0 <v6.2.0>`
\ No newline at end of file

qt/python/mantidqt/widgets/sliceviewer/imageinfowidget.py

@@ -13,6 +13,7 @@ import numpy as np
 from mantidqt.utils.qt import import_qt
 from matplotlib.collections import QuadMesh
 from matplotlib.image import AxesImage
+from matplotlib.transforms import Bbox
 
 from .lineplots import CursorTracker, cursor_info
 from .transform import NonOrthogonalTransform
@@ -25,18 +26,25 @@ ImageInfoWidget = import_qt('.._common', 'mantidqt.widgets', 'ImageInfoWidget')
 
 class ImageInfoTracker(CursorTracker):
     def __init__(self, image: Union[AxesImage, QuadMesh], transform: NonOrthogonalTransform,
-                 do_transform: bool, widget: ImageInfoWidget):
+                 do_transform: bool, widget: ImageInfoWidget, cursor_transform: tuple = None):
         """
         Update the image that the widget refers too.
         :param: An AxesImage or Mesh instance to track
         :param: transpose_xy: If true the cursor position should be transposed
                 before sending to the table update
+        :param do_transform: Flag to perform transform for QuadMesh images
+        :param widget: ImageInfoWidget instance
+        :param cursor_transform: Full axes limits to use for mouse coord transform to use instead of image extents
         """
         super().__init__(image_axes=image.axes, autoconnect=False)
         self._image = image
         self.transform = transform
         self.do_transform = do_transform
         self._widget = widget
+        self._cursor_transform = None
+        if cursor_transform is not None:
+            self._cursor_transform = Bbox([[cursor_transform[1][0], cursor_transform[0][0]],
+                                           [cursor_transform[1][1], cursor_transform[0][1]]])
 
         if hasattr(image, 'get_extent'):
             self.on_cursor_at = self._on_cursor_at_axesimage
@@ -59,7 +67,7 @@ class ImageInfoTracker(CursorTracker):
         if self._image is None:
             return
 
-        cinfo = cursor_info(self._image, xdata, ydata)
+        cinfo = cursor_info(self._image, xdata, ydata, full_bbox=self._cursor_transform)
         if cinfo is not None:
             arr, _, (i, j) = cinfo
             if (0 <= i < arr.shape[0]) and (0 <= j < arr.shape[1]) and not np.ma.is_masked(arr[i, j]):

qt/python/mantidqt/widgets/sliceviewer/lineplots.py

@@ -397,12 +397,13 @@ CursorInfo = namedtuple("CursorInfo", ("array", "extent", "point"))
 
 
 @lru_cache(maxsize=32)
-def cursor_info(image: AxesImage, xdata: float, ydata: float) -> Optional[CursorInfo]:
+def cursor_info(image: AxesImage, xdata: float, ydata: float, full_bbox: Bbox = None) -> Optional[CursorInfo]:
     """Return information on the image for the given position in
     data coordinates.
     :param image: An instance of an image type
     :param xdata: X data coordinate of cursor
     :param xdata: Y data coordinate of cursor
+    :param full_bbox: Bbox of full workspace dimension to use for transforming mouse position
     :return: None if point is not valid on the image else return CursorInfo type
     """
     extent = image.get_extent()
@@ -410,7 +411,14 @@ def cursor_info(image: AxesImage, xdata: float, ydata: float) -> Optional[Cursor
     arr = image.get_array()
     data_extent = Bbox([[ymin, xmin], [ymax, xmax]])
     array_extent = Bbox([[0, 0], arr.shape[:2]])
-    trans = BboxTransform(boxin=data_extent, boxout=array_extent)
+    if full_bbox is None:
+        trans = BboxTransform(boxin=data_extent, boxout=array_extent)
+    else:
+        # If the view is zoomed in and the slice is changed, then the image extents
+        # and data extents change. This causes the cursor to be transformed to the
+        # wrong point for certain MDH workspaces (since it cannot be dynamically rebinned).
+        # This will use the full WS data dimensions to do the transformation
+        trans = BboxTransform(boxin=full_bbox, boxout=array_extent)
     point = trans.transform_point([ydata, xdata])
     if any(np.isnan(point)):
         return None

qt/python/mantidqt/widgets/sliceviewer/view.py

@@ -65,6 +65,7 @@ class SliceViewerDataView(QWidget):
         self._line_plots = None
         self._image_info_tracker = None
         self._region_selection_on = False
+        self._orig_lims = None
 
         # Dimension widget
         self.dimensions_layout = QGridLayout()
@@ -253,8 +254,6 @@ class SliceViewerDataView(QWidget):
                                     transpose=self.dimensions.transpose,
                                     norm=self.colorbar.get_norm(),
                                     **kwargs)
-        self.on_track_cursor_state_change(self.track_cursor_checked())
-
         # ensure the axes data limits are updated to match the
         # image. For example if the axes were zoomed and the
         # swap dimensions was clicked we need to restore the
@@ -262,6 +261,11 @@ class SliceViewerDataView(QWidget):
         extent = self.image.get_extent()
         self.ax.set_xlim(extent[0], extent[1])
         self.ax.set_ylim(extent[2], extent[3])
+        # Set the original data limits which get passed to the ImageInfoWidget so that
+        # the mouse projection to data space is correct for MDH workspaces when zoomed/changing slices
+        self._orig_lims = self.get_axes_limits()
+
+        self.on_track_cursor_state_change(self.track_cursor_checked())
 
         self.draw_plot()
 
@@ -384,7 +388,8 @@ class SliceViewerDataView(QWidget):
         self._image_info_tracker = ImageInfoTracker(image=self.image,
                                                     transform=self.nonortho_transform,
                                                     do_transform=self.nonorthogonal_mode,
-                                                    widget=self.image_info_widget)
+                                                    widget=self.image_info_widget,
+                                                    cursor_transform=self._orig_lims)
 
         if state:
             self._image_info_tracker.connect()
@@ -463,7 +468,6 @@ class SliceViewerDataView(QWidget):
         else:
             return None
 
-
     def set_axes_limits(self, xlim, ylim):
         """
         Set the view limits on the image axes to the given extents. Assume the