Minor updates to the documentation and a new image

src/PythonicAPI/Snippets/Slider2D.md

@@ -2,6 +2,10 @@
 
 Implement a 2D slider widget.
 
+A vtkSliderRepresentation2D has a large number of properties. Most of these properties are defined in the dataclass: `Slider2DProperties`. It is best to create a function `def make_slider_properties():` that will be used to set up the slider with your preferred values for the parameters. If there are multiple sliders in your application then it is easy to modify the slider properties returned from this function as needed.
+
+This is the approach adopted in [Slider2D](../../Widgets/Slider2D) and [KochanekSplineDemo](../../PolyData/KochanekSplineDemo).
+
 To use the snippet, click the *Copy to clipboard* at the upper right of the code blocks.
 
 ### Implementation
@@ -165,16 +169,3 @@ class SliderCallback:
 ### Usage
 
 For examples showing the usage of this snippet and changing most of the default parameters, please see: [Slider2D](../../Widgets/Slider2D) and [KochanekSplineDemo](../../PolyData/KochanekSplineDemo).
-
-``` Python
-    ...
-    sp = Slider2DProperties()
-    sp.title_text = 'Sphere Resolution'
-    sp.Range.value = 5
-    ...
-    widget = make_2d_slider_widget(sp, render_window_interactor)
-    cb = SliderCallback(sphere_source)
-    widget.AddObserver(vtkCommand.InteractionEvent, cb)
-    ...
-
-```

src/PythonicAPI/Snippets/Slider3D.md

@@ -2,6 +2,10 @@
 
 Implement a 3D slider widget.
 
+A vtkSliderRepresentation3D has a large number of properties. Most of these properties are defined in the dataclass: `Slider3DProperties`. It is best to create a function `def make_slider_properties():` that will be used to set up the slider with your preferred values for the parameters. If there are multiple sliders in your application then it is easy to modify the slider properties returned from this function as needed.
+
+This is the approach adopted in [Slider3D](../../Widgets/Slider3D).
+
 To use the snippet, click the *Copy to clipboard* at the upper right of the code blocks.
 
 ### Implementation
@@ -126,16 +130,3 @@ class SliderCallback:
 ### Usage
 
 For an example showing the usage of this snippet and changing most of the default parameters, please see: [Slider3D](../../Widgets/Slider3D).
-
-``` Python
-    ...
-    sp = Slider2DProperties()
-    sp.title_text = 'Sphere Resolution'
-    sp.Range.value = 8
-    ...
-    widget = make_3d_slider_widget(sp, render_window_interactor)
-    cb = SliderCallback(sphere_source)
-    widget.AddObserver(vtkCommand.InteractionEvent, cb)
-    ...
-
-```

src/PythonicAPI/Widgets/Slider2D.py

@@ -10,6 +10,7 @@ import vtkmodules.vtkRenderingOpenGL2
 from vtkmodules.vtkCommonColor import vtkNamedColors
 from vtkmodules.vtkCommonCore import vtkCommand
 from vtkmodules.vtkFiltersSources import vtkSphereSource
+from vtkmodules.vtkInteractionStyle import vtkInteractorStyleTrackballCamera
 from vtkmodules.vtkInteractionWidgets import (
     vtkSliderRepresentation2D,
     vtkSliderWidget
@@ -46,6 +47,8 @@ def main():
     # An interactor.
     render_window_interactor = vtkRenderWindowInteractor()
     render_window_interactor.render_window = render_window
+    style = vtkInteractorStyleTrackballCamera()
+    render_window_interactor.interactor_style = style
 
     # Add the actors to the scene.
     renderer.AddActor(actor)

src/PythonicAPI/Widgets/Slider3D.py

@@ -10,6 +10,7 @@ import vtkmodules.vtkRenderingOpenGL2
 from vtkmodules.vtkCommonColor import vtkNamedColors
 from vtkmodules.vtkCommonCore import vtkCommand
 from vtkmodules.vtkFiltersSources import vtkSphereSource
+from vtkmodules.vtkInteractionStyle import vtkInteractorStyleTrackballCamera
 from vtkmodules.vtkInteractionWidgets import (
     vtkSliderRepresentation3D,
     vtkSliderWidget
@@ -49,6 +50,8 @@ def main():
     # An interactor.
     render_window_interactor = vtkRenderWindowInteractor()
     render_window_interactor.render_window = render_window
+    style = vtkInteractorStyleTrackballCamera()
+    render_window_interactor.interactor_style = style
 
     # Add the actors to the scene.
     renderer.AddActor(actor)
@@ -57,7 +60,7 @@ def main():
     render_window.Render()
 
     sp = make_slider_properties()
-    
+
     sp.Range.value = sphere_source.theta_resolution
     sp.Text.title = 'Sphere Resolution'