ENH: Expose image slicing plane positions as traits

itkwidgets/widget_viewer.py

@@ -131,29 +131,37 @@ class Viewer(ViewerParent):
         **itkimage_serialization)
     _rendering_image = CBool(
         default_value=False,
-        help="We are currently volume rendering the image.").tag(
-        sync=True)
+        help="We are currently volume rendering the image.").tag(sync=True)
     interpolation = CBool(
         default_value=True,
-        help="Use linear interpolation in slicing planes.").tag(
-        sync=True)
+        help="Use linear interpolation in slicing planes.").tag(sync=True)
     cmap = Colormap('Viridis (matplotlib)').tag(sync=True)
     _custom_cmap = NDArray(dtype=np.float32, default_value=None, allow_none=True,
                            help="RGB triples from 0.0 to 1.0 that define a custom linear, sequential colormap")\
         .tag(sync=True, **array_serialization)\
         .valid(shape_constraints(None, 3))
     shadow = CBool(
         default_value=True,
-        help="Use shadowing in the volume rendering.").tag(
-        sync=True)
+        help="Use shadowing in the volume rendering.").tag(sync=True)
     slicing_planes = CBool(
         default_value=False,
         help="Display the slicing planes in volume rendering view mode.").tag(
         sync=True)
+    x_slice = CFloat(
+        default_value=None,
+        allow_none=True,
+        help="World-space position of the X slicing plane.").tag(sync=True)
+    y_slice = CFloat(
+        default_value=None,
+        allow_none=True,
+        help="World-space position of the Y slicing plane.").tag(sync=True)
+    z_slice = CFloat(
+        default_value=None,
+        allow_none=True,
+        help="World-space position of the Z slicing plane.").tag(sync=True)
     gradient_opacity = CFloat(
         default_value=0.2,
-        help="Volume rendering gradient opacity, from (0.0, 1.0]").tag(
-        sync=True)
+        help="Volume rendering gradient opacity, from (0.0, 1.0]").tag(sync=True)
     blend = CaselessStrEnum(
         ('composite',
          'max',
@@ -640,15 +648,24 @@ def view(image=None,  # noqa: C901
     select_roi: bool, optional, default: False
         Enable an interactive region of interest widget for the image.
 
+    slicing_planes: bool, optional, default: False
+        Enable slicing planes on the volume rendering.
+
+    x_slice: float, optional, default: None
+        World-space position of the X slicing plane.
+
+    y_slice: float, optional, default: None
+        World-space position of the Y slicing plane.
+
+    z_slice: float, optional, default: None
+        World-space position of the Z slicing plane.
+
     interpolation: bool, optional, default: True
         Linear as opposed to nearest neighbor interpolation for image slices.
 
     gradient_opacity: float, optional, default: 0.22
         Gradient opacity for composite volume rendering, in the range (0.0, 1.0].
 
-    slicing_planes: bool, optional, default: False
-        Enable slicing planes on the volume rendering.
-
     shadow: bool, optional, default: True
         Use shadowing with composite volume rendering.
 

js/lib/viewer.js

@@ -71,6 +71,9 @@ const ViewerModel = widgets.DOMWidgetModel.extend({
       vmax: null,
       shadow: true,
       slicing_planes: false,
+      x_slice: null,
+      y_slice: null,
+      z_slice: null,
       gradient_opacity: 0.2,
       blend: 'composite',
       roi: new Float64Array([0., 0., 0., 0., 0., 0.]),
@@ -494,6 +497,9 @@ const ViewerView = widgets.DOMWidgetView.extend({
       if (rendered_image) {
         this.shadow_changed()
         this.slicing_planes_changed()
+        this.x_slice_changed()
+        this.y_slice_changed()
+        this.z_slice_changed()
         this.gradient_opacity_changed()
         this.blend_changed()
       }
@@ -674,6 +680,40 @@ const ViewerView = widgets.DOMWidgetView.extend({
         }
         this.model.itkVtkViewer.subscribeToggleSlicingPlanes(onSlicingPlanesToggle)
 
+        const onXSliceChanged = (position) => {
+          if (position !== this.model.get('x_slice')) {
+            this.model.set('x_slice', position)
+            this.model.save_changes()
+          }
+        }
+        this.model.itkVtkViewer.subscribeXSliceChanged(onXSliceChanged)
+        if (this.model.get('x_slice') === null) {
+          this.model.set('x_slice', this.model.itkVtkViewer.getXSlice())
+          this.model.save_changes()
+        }
+        const onYSliceChanged = (position) => {
+          if (position !== this.model.get('y_slice')) {
+            this.model.set('y_slice', position)
+            this.model.save_changes()
+          }
+        }
+        this.model.itkVtkViewer.subscribeYSliceChanged(onYSliceChanged)
+        if (this.model.get('y_slice') === null) {
+          this.model.set('y_slice', this.model.itkVtkViewer.getYSlice())
+          this.model.save_changes()
+        }
+        const onZSliceChanged = (position) => {
+          if (position !== this.model.get('z_slice')) {
+            this.model.set('z_slice', position)
+            this.model.save_changes()
+          }
+        }
+        this.model.itkVtkViewer.subscribeZSliceChanged(onZSliceChanged)
+        if (this.model.get('z_slice') === null) {
+          this.model.set('z_slice', this.model.itkVtkViewer.getZSlice())
+          this.model.save_changes()
+        }
+
         const onGradientOpacityChange = (opacity) => {
           if (opacity !== this.model.get('gradient_opacity')) {
             this.model.set('gradient_opacity', opacity)
@@ -706,6 +746,9 @@ const ViewerView = widgets.DOMWidgetView.extend({
     this.model.on('change:vmax', this.vmax_changed, this)
     this.model.on('change:shadow', this.shadow_changed, this)
     this.model.on('change:slicing_planes', this.slicing_planes_changed, this)
+    this.model.on('change:x_slice', this.x_slice_changed, this)
+    this.model.on('change:y_slice', this.y_slice_changed, this)
+    this.model.on('change:z_slice', this.z_slice_changed, this)
     this.model.on('change:gradient_opacity', this.gradient_opacity_changed, this)
     this.model.on('change:blend', this.blend_changed, this)
     this.model.on('change:select_roi', this.select_roi_changed, this)
@@ -1040,6 +1083,27 @@ const ViewerView = widgets.DOMWidgetView.extend({
     }
   },
 
+  x_slice_changed: function() {
+    const position = this.model.get('x_slice')
+    if (this.model.hasOwnProperty('itkVtkViewer') && !this.model.use2D && position !== null) {
+      this.model.itkVtkViewer.setXSlice(position)
+    }
+  },
+
+  y_slice_changed: function() {
+    const position = this.model.get('y_slice')
+    if (this.model.hasOwnProperty('itkVtkViewer') && !this.model.use2D && position !== null) {
+      this.model.itkVtkViewer.setYSlice(position)
+    }
+  },
+
+  z_slice_changed: function() {
+    const position = this.model.get('z_slice')
+    if (this.model.hasOwnProperty('itkVtkViewer') && !this.model.use2D && position !== null) {
+      this.model.itkVtkViewer.setZSlice(position)
+    }
+  },
+
   gradient_opacity_changed: function() {
     const gradient_opacity = this.model.get('gradient_opacity')
     if (this.model.hasOwnProperty('itkVtkViewer') && !this.model.use2D) {

js/package.json

@@ -61,7 +61,7 @@
     "copy-webpack-plugin": "^4.5.1",
     "css-element-queries": "^1.0.2",
     "itk": "^10.2.0",
-    "itk-vtk-viewer": "^9.10.4",
+    "itk-vtk-viewer": "^9.11.0",
     "jupyter-dataserializers": "^2.1.0",
     "mobx": "^5.13.0",
     "vtk.js": "^13.0.0"