Fix RectangularROIModel docstring

Author: gselzer

src/ndv/models/_roi_model.py

@@ -13,11 +13,11 @@
 class RectangularROIModel(NDVModel):
     """Representation of an axis-aligned rectangular Region of Interest (ROI).
 
-    Parameters
+    Attributes
     ----------
     visible : bool
         Whether to display this roi.
-    bounding_box: tuple[tuple[float, float], tuple[float, float]]
+    bounding_box : tuple[tuple[float, float], tuple[float, float]]
         The minimum (2D) point and the maximum (2D) point contained within the
         region. Using these two points, an axis-aligned bounding box can be
         constructed.

src/ndv/views/_vispy/_array_canvas.py

@@ -141,13 +141,14 @@ def __init__(self, parent: Any) -> None:
         self._handles.order = 100
         self._handles.interactive = True
 
-        self._tform = self._rect.transforms.get_transform("canvas", "scene")
-
         self.set_fill(_cmap.Color("transparent"))
         self.set_border(_cmap.Color("yellow"))
         self.set_handles(_cmap.Color("white"))
         self.set_visible(False)
 
+    def _tform(self) -> scene.transforms.BaseTransform:
+        return self._rect.transforms.get_transform("canvas", "scene")
+
     def can_select(self) -> bool:
         return True
 
@@ -206,7 +207,7 @@ def set_bounding_box(
     def on_mouse_move(self, event: MouseMoveEvent) -> bool:
         # Convert canvas -> world
         canvas_pos = (event.x, event.y)
-        world_pos = self._tform.map(canvas_pos)[:2]
+        world_pos = self._tform().map(canvas_pos)[:2]
         # moving a handle
         if self._move_mode == ROIMoveMode.HANDLE:
             # The anchor is set to the opposite handle, which never moves.
@@ -229,7 +230,7 @@ def on_mouse_press(self, event: MousePressEvent) -> bool:
         self.set_selected(True)
         # Convert canvas -> world
         canvas_pos = (event.x, event.y)
-        world_pos = self._tform.map(canvas_pos)[:2]
+        world_pos = self._tform().map(canvas_pos)[:2]
         drag_idx = self._handle_under(world_pos)
         # If a marker is pressed
         if drag_idx is not None:
@@ -247,7 +248,7 @@ def on_mouse_release(self, event: MouseReleaseEvent) -> bool:
 
     def get_cursor(self, mme: MouseMoveEvent) -> CursorType | None:
         canvas_pos = (mme.x, mme.y)
-        pos = self._tform.map(canvas_pos)[:2]
+        pos = self._tform().map(canvas_pos)[:2]
         if self._handle_under(pos) is not None:
             center = self._rect.center
             if pos[0] < center[0] and pos[1] < center[1]:

tests/test_controller.py

@@ -9,7 +9,13 @@
 import numpy as np
 import pytest
 
-from ndv._types import MouseButton, MouseMoveEvent, MousePressEvent, MouseReleaseEvent
+from ndv._types import (
+    CursorType,
+    MouseButton,
+    MouseMoveEvent,
+    MousePressEvent,
+    MouseReleaseEvent,
+)
 from ndv.controllers import ArrayViewer
 from ndv.controllers._channel_controller import ChannelController
 from ndv.models._array_display_model import ArrayDisplayModel, ChannelMode
@@ -309,18 +315,25 @@ def test_roi_interaction() -> None:
         return
 
     ctrl = ArrayViewer()
+    roi = RectangularROIModel()
+    ctrl.roi = roi
+    roi_view = ctrl._roi_view
+    assert roi_view is not None
 
-    canvas_roi_start = (0, 0)
+    # FIXME: We need a large world space on the canvas, but
+    # VispyArrayCanvas.set_range is not implemented yet. This workaround
+    # sets the range to the extent of the data i.e. the extent of the ROI
+    roi.bounding_box = ((0, 0), (500, 500))
+    ctrl._canvas.set_range()
+    # Note that these positions are far apart to satisfy sufficient distance
+    # in world space
+    canvas_roi_start = (200, 200)
     world_roi_start = tuple(ctrl._canvas.canvas_to_world(canvas_roi_start)[:2])
-    canvas_new_start = (-100, -100)
+    canvas_new_start = (100, 100)
     world_new_start = tuple(ctrl._canvas.canvas_to_world(canvas_new_start)[:2])
-    canvas_roi_end = (100, 100)
+    canvas_roi_end = (300, 300)
     world_roi_end = tuple(ctrl._canvas.canvas_to_world(canvas_roi_end)[:2])
-
-    roi = RectangularROIModel(bounding_box=(world_roi_start, world_roi_end))
-    ctrl.roi = roi
-    roi_view = ctrl._roi_view
-    assert roi_view is not None
+    roi.bounding_box = (world_roi_start, world_roi_end)
 
     # Note - avoid diving into rendering logic here - just identify view
     with patch.object(ctrl._canvas, "elements_at", return_value=[ctrl._roi_view]):
@@ -339,3 +352,42 @@ def test_roi_interaction() -> None:
             canvas_new_start[0], canvas_new_start[1], MouseButton.LEFT
         )
         ctrl._canvas.on_mouse_release(mre)
+
+        # Test translation
+        roi.bounding_box = (world_roi_start, world_roi_end)
+        mpe = MousePressEvent(
+            (canvas_roi_start[0] + canvas_roi_end[0] / 2),
+            (canvas_roi_start[1] + canvas_roi_end[1] / 2),
+            MouseButton.LEFT,
+        )
+        ctrl._canvas.on_mouse_press(mpe)
+        assert roi_view.selected()
+        mme = MouseMoveEvent(
+            (canvas_roi_start[0] + canvas_new_start[0] / 2),
+            (canvas_roi_start[1] + canvas_new_start[1] / 2),
+            MouseButton.LEFT,
+        )
+        ctrl._canvas.on_mouse_move(mme)
+        assert roi.bounding_box[0] == pytest.approx(world_new_start, 1e-6)
+        assert roi.bounding_box[1] == pytest.approx(world_roi_start, 1e-6)
+        mre = MouseReleaseEvent(
+            (canvas_roi_start[0] + canvas_new_start[0] / 2),
+            (canvas_roi_start[1] + canvas_new_start[1] / 2),
+            MouseButton.LEFT,
+        )
+        ctrl._canvas.on_mouse_release(mre)
+
+    # Test cursors
+    roi.bounding_box = (world_roi_start, world_roi_end)
+    # Top-Left corner
+    mme = MouseMoveEvent(canvas_roi_start[0], canvas_roi_start[1])
+    assert roi_view.get_cursor(mme) == CursorType.FDIAG_ARROW
+    # Top-Right corner
+    mme = MouseMoveEvent(canvas_roi_start[0], canvas_roi_end[1])
+    assert roi_view.get_cursor(mme) == CursorType.BDIAG_ARROW
+    # Middle
+    mme = MouseMoveEvent(
+        (canvas_roi_start[0] + canvas_roi_end[0]) / 2,
+        (canvas_roi_start[1] + canvas_roi_end[1]) / 2,
+    )
+    assert roi_view.get_cursor(mme) == CursorType.ALL_ARROW