ENH: Add units trait for scale bar units

Author: thewtex

itkwidgets/widget_viewer.py

@@ -143,6 +143,8 @@ class Viewer(ViewerParent):
             help="We are downsampling the image to meet the size limits.").tag(sync=True)
     _reset_crop_requested = CBool(default_value=False,
             help="The user requested a reset of the roi.").tag(sync=True)
+    units = Unicode('', help="Units to display in the scale bar.").tag(sync=True)
+    point_set_representations = List(trait=Unicode(), default_value=[], help="Point set representation").tag(sync=True)
     point_sets = PointSetList(default_value=None, allow_none=True, help="Point sets to visualize").tag(sync=True, **polydata_list_serialization)
     point_set_colors = NDArray(dtype=np.float32, default_value=np.zeros((0, 3), dtype=np.float32),
                     help="RGB colors for the points sets")\
@@ -574,6 +576,9 @@ def view(image=None,
     Other Parameters
     ----------------
 
+    units: string, optional, default: ''
+        Units to display in the scale bar.
+
     actors: vtkActor, vtkAssembly, vtkVolume, optional, default: None
         List of standard vtk objects, colors are extracted from their properties
 

js/lib/viewer.js

@@ -77,6 +77,7 @@ const ViewerModel = widgets.DOMWidgetModel.extend({
       select_roi: false,
       _reset_crop_requested: false,
       _scale_factors: new Uint8Array([1, 1, 1]),
+      units: '',
       point_sets: null,
       point_set_colors: new Float32Array([0., 0., 0.]),
       point_set_opacities: new Float32Array([1.0]),
@@ -667,6 +668,8 @@ const ViewerView = widgets.DOMWidgetView.extend({
         this.geometry_opacities_changed()
       }
       this.mode_changed()
+
+      this.units_changed()
   },
 
   render: function() {
@@ -691,6 +694,7 @@ const ViewerView = widgets.DOMWidgetView.extend({
     this.model.on('change:rotate', this.rotate_changed, this)
     this.model.on('change:annotations', this.annotations_changed, this)
     this.model.on('change:mode', this.mode_changed, this)
+    this.model.on('change:units', this.units_changed, this)
     this.model.on('change:camera', this.camera_changed, this)
 
     let toDecompress = []
@@ -924,6 +928,15 @@ const ViewerView = widgets.DOMWidgetView.extend({
     }
   },
 
+  units_changed: function() {
+    const units = this.model.get('units')
+    if (this.model.hasOwnProperty('itkVtkViewer')) {
+      console.log(`Units: ${units}`)
+      const viewProxy = this.model.itkVtkViewer.getViewProxy()
+      viewProxy.setUnits(units)
+    }
+  },
+
   camera_changed: function() {
     const camera = this.model.get('camera')
     if (this.model.hasOwnProperty('itkVtkViewer')) {