From 4b0fcb0c14772afaba7361be7a683e7a2131ef6f Mon Sep 17 00:00:00 2001
From: Andrew Maclean <andrew.amaclean@gmail.com>
Date: Sat, 21 Dec 2024 11:26:43 +1100
Subject: [PATCH] Fixing callbacks and adding Callbacks.md
---
src/PythonicAPI.md | 1 -
src/PythonicAPI/Animation/AnimateActors.py | 3 +-
src/PythonicAPI/Interaction/CallBack.md | 8 +-
src/PythonicAPI/Interaction/CallBack.py | 82 ++++++++++++-------
.../PolyData/PolygonalSurfacePointPlacer.py | 7 +-
src/PythonicAPI/Snippets.md | 2 +-
src/PythonicAPI/Snippets/Callbacks.md | 69 ++++++++++++++++
src/PythonicAPI/Snippets/CameraPosition.md | 37 ++++++---
src/PythonicAPI/Visualization/MovableAxes.py | 8 +-
src/PythonicAPI/Widgets/AffineWidget.py | 7 +-
.../Widgets/ImageTracerWidgetInsideContour.py | 7 +-
11 files changed, 157 insertions(+), 74 deletions(-)
create mode 100644 src/PythonicAPI/Snippets/Callbacks.md
diff --git a/src/PythonicAPI.md b/src/PythonicAPI.md
index c5a32d53307..1e6ee9dbfa4 100644
--- a/src/PythonicAPI.md
+++ b/src/PythonicAPI.md
@@ -730,7 +730,6 @@ See [this tutorial](http://www.vtk.org/Wiki/VTK/Tutorials/3DDataTypes) for a bri
| Example Name | Description | Image |
| -------------- | ------------- | ------- |
-
[AnimateActors](/PythonicAPI/Animation/AnimateActors) | Animate actors.
[AnimateSphere](/PythonicAPI/Animation/AnimateSphere) | Animate a sphere by opening it to an angle of 90°.
[Animation](/PythonicAPI/Utilities/Animation) | Move a sphere across a scene.
diff --git a/src/PythonicAPI/Animation/AnimateActors.py b/src/PythonicAPI/Animation/AnimateActors.py
index 629ad595a12..86822f208cd 100644
--- a/src/PythonicAPI/Animation/AnimateActors.py
+++ b/src/PythonicAPI/Animation/AnimateActors.py
@@ -128,9 +128,8 @@ class AnimationCueObserver:
self.cue.AddObserver('AnimationCueTickEvent', self)
-class ActorAnimator(vtkCallbackCommand):
+class ActorAnimator:
def __init__(self, actor, start_position, end_position):
- super().__init__()
self.actor = actor
self.start_position = start_position
self.end_position = end_position
diff --git a/src/PythonicAPI/Interaction/CallBack.md b/src/PythonicAPI/Interaction/CallBack.md
index 321a0af4fd1..45150bb7743 100644
--- a/src/PythonicAPI/Interaction/CallBack.md
+++ b/src/PythonicAPI/Interaction/CallBack.md
@@ -23,10 +23,10 @@ In the function **PrintCameraOrientation** note how we convert an array to a vec
##### Python
-In Python the approach is even simpler. We simply define a function to use as the callback with this signature: `def MyCallback(obj, ev):`.
-Then, to pass client data to it, we simply do: `MyCallback.myClientData = myClientData`.
-This relies on the fact that Python functions are in fact objects and we are simply adding new attributes such as `myClientData` in this case.
+In Python the approach is even simpler.
-An alternative method is to define a class passsing the needed variables in the `__init__` function and then implement a `_call__` function that does the work.
+We define a function to use as the callback with this signature: `def my_callback(obj, ev):`. Then, to pass client data to it, we simply do: `my_callback.my_client_data = my_client_data`. This relies on the fact that Python functions are in fact objects and we are simply adding new attributes such as `my_client_data` in this case.
+
+An alternative method is to define a class passing the needed variables in the `__init__` function and then implement a `__call__` function that does the work.
Both approaches are demonstrated in the example.
diff --git a/src/PythonicAPI/Interaction/CallBack.py b/src/PythonicAPI/Interaction/CallBack.py
index fd648cdc41f..48d3616b53d 100755
--- a/src/PythonicAPI/Interaction/CallBack.py
+++ b/src/PythonicAPI/Interaction/CallBack.py
@@ -19,6 +19,7 @@ from vtkmodules.vtkRenderingCore import (
vtkActor,
vtkCamera,
vtkPolyDataMapper,
+ vtkProperty,
vtkRenderWindow,
vtkRenderWindowInteractor,
vtkRenderer
@@ -51,48 +52,42 @@ def main():
iren = vtkRenderWindowInteractor()
iren.render_window = ren_win
- # Use a cone as a source with the golden ratio for the height. Because we can!
+ # Use a cone as a source with the golden ratio (φ) for the height. Because we can!
+ # If the short side is one then φ = 2 × sin(54°) or φ = 1/2 + √5 / 2
source = vtkConeSource(center=(0, 0, 0), radius=1, height=1.6180339887498948482, resolution=128)
# Pipeline
mapper = vtkPolyDataMapper()
source >> mapper
- actor = vtkActor(mapper=mapper)
- actor.property.color = colors.GetColor3d('Peacock')
- # Lighting
- actor.property.ambient = 0.6
- actor.property.diffuse = 0.2
- actor.property.specular = 1.0
- actor.property.specular_power = 20.0
+ # Color and surface properties.
+ actor_property = vtkProperty(color=colors.GetColor3d('Peacock'),
+ ambient=0.6, diffuse=0.2,
+ specular=1.0, specular_power=20.0)
+ actor = vtkActor(mapper=mapper, property=actor_property)
# Get an outline of the data set for context.
+ outline_property = vtkProperty(color=colors.GetColor3d('Black'), line_width=2)
outline = vtkOutlineFilter()
outline_mapper = vtkPolyDataMapper()
source >> outline >> outline_mapper
- outline_actor = vtkActor(mapper=outline_mapper)
- outline_actor.property.color = colors.GetColor3d('Black')
- outline_actor.property.line_width = 2
+ outline_actor = vtkActor(mapper=outline_mapper, property=outline_property)
# Add the actors to the renderer.
ren.AddActor(actor)
ren.AddActor(outline_actor)
# Set up a nice camera position.
- camera = vtkCamera()
- camera.position = (4.6, -2.0, 3.8)
- camera.focal_point = (0.0, 0.0, 0.0)
- camera.clipping_range = (3.2, 10.2)
- camera.view_up = (0.3, 1.0, 0.13)
+ camera = vtkCamera(position=(4.6, -2.0, 3.8), focal_point=(0.0, 0.0, 0.0),
+ clipping_range=(3.2, 10.2), view_up=(0.3, 1.0, 0.13))
ren.active_camera = camera
ren_win.Render()
- rgb = [0.0] * 4
- colors.GetColor("Carrot", rgb)
- rgb = tuple(rgb[:3])
+ rgb = tuple(colors.GetColor3d('Carrot'))
widget = vtkOrientationMarkerWidget(orientation_marker=make_axes_actor(),
interactor=iren, default_renderer=ren,
- outline_color=rgb, viewport=(0.0, 0.0, 0.2, 0.2), zoom=1.5, enabled=True,
+ outline_color=rgb, viewport=(0.0, 0.0, 0.2, 0.2),
+ zoom=1.5, enabled=True,
interactive=True)
# Set up the callback.
@@ -107,7 +102,6 @@ def main():
# Or:
# observer = OrientationObserver(ren.active_camera)
# iren.AddObserver('EndInteractionEvent', observer)
-
iren.Initialize()
iren.Start()
@@ -117,14 +111,17 @@ def get_orientation(caller, ev):
Print out the orientation.
We must do this before we register the callback in the calling function.
- GetOrientation.cam = ren.active_camera
+ Add the active camera as an attribute.
+ get_orientation.cam = ren.active_camera
:param caller: The caller.
:param ev: The event.
:return:
"""
# Just do this to demonstrate who called callback and the event that triggered it.
- print(caller.class_name, 'Event Id:', ev)
+ print(f'Caller: {caller.class_name}, Event Id: {ev}')
+ # Verify that we have a camera in this case.
+ print(f'Camera: {get_orientation.cam.class_name}')
# Now print the camera orientation.
camera_orientation(get_orientation.cam)
@@ -135,19 +132,42 @@ class OrientationObserver:
def __call__(self, caller, ev):
# Just do this to demonstrate who called callback and the event that triggered it.
- print(caller.class_name, 'Event Id:', ev)
+ print(f'Caller: {caller.class_name}, Event Id: {ev}')
+ # Verify that we have a camera in this case.
+ print(f'Camera: {self.cam.class_name}')
# Now print the camera orientation.
camera_orientation(self.cam)
def camera_orientation(cam):
- flt_fmt = '9.6g'
- fmt = '{:' + flt_fmt + '}'
- print(f'{"Position:":>15s},{" ".join(map(fmt.format, cam.position))}')
- print(f'{"Focal point:":>15s},{" ".join(map(fmt.format, cam.focal_point))}')
- print(f'{"Clipping range:":>15s},{" ".join(map(fmt.format, cam.clipping_range))}')
- print(f'{"View up:":>15s},{" ".join(map(fmt.format, cam.view_up))}')
- print(f'{"Distance:":>15s},{cam.distance:{flt_fmt}}')
+ flt_fmt = '0.6g'
+ # print(caller.class_name, "modified")
+ # Print the interesting stuff.
+ res = list()
+ res.append(f'Camera orientation:')
+ res.append(f'{"position":>15s} = ({fmt_floats(cam.position)})')
+ res.append(f'{"focal_point":>15s} = ({fmt_floats(cam.focal_point)})')
+ res.append(f'{"view_up":>15s} = ({fmt_floats(cam.view_up)})')
+ res.append(f'{"distance":>15s} = {cam.distance:{flt_fmt}}')
+ res.append(f'{"clipping_range":>15s} = ({fmt_floats(cam.clipping_range)})')
+ print(' \n'.join(res))
+ print()
+
+
+def fmt_floats(v, w=0, d=6, pt='g'):
+ """
+ Pretty print a list or tuple of floats.
+
+ :param v: The list or tuple of floats.
+ :param w: Total width of the field.
+ :param d: The number of decimal places.
+ :param pt: The presentation type, 'f', 'g' or 'e'.
+ :return: A string.
+ """
+ pt = pt.lower()
+ if pt not in ['f', 'g', 'e']:
+ pt = 'f'
+ return ', '.join([f'{element:{w}.{d}{pt}}' for element in v])
def make_axes_actor():
diff --git a/src/PythonicAPI/PolyData/PolygonalSurfacePointPlacer.py b/src/PythonicAPI/PolyData/PolygonalSurfacePointPlacer.py
index eab4f7306c0..6bceccf4d1d 100755
--- a/src/PythonicAPI/PolyData/PolygonalSurfacePointPlacer.py
+++ b/src/PythonicAPI/PolyData/PolygonalSurfacePointPlacer.py
@@ -66,16 +66,11 @@ def main():
interactor.Start()
-class MyCallback(vtkCallbackCommand):
+class MyCallback:
def __init__(self, representation):
- super().__init__()
-
self.representation = representation
def __call__(self, caller, ev):
- self.Execute(self, id, ev)
-
- def Execute(self, caller, id, event):
print('There are ', self.representation.GetNumberOfNodes(), ' nodes.')
diff --git a/src/PythonicAPI/Snippets.md b/src/PythonicAPI/Snippets.md
index 65e6bae2eed..d69abba4665 100644
--- a/src/PythonicAPI/Snippets.md
+++ b/src/PythonicAPI/Snippets.md
@@ -2,11 +2,11 @@
Snippets are chunks of code that can be cut (*snipped*) and pasted into examples. We want each example to be stand-alone, so we do not keep the snippet code in a library.
-
### Available snippets
| Snippet | Description | |
| -------------- | ------------- | ------- |
+[Callbacks](/PythonicAPI/Snippets/Callbacks.md) | Implementing callbacks.
[CameraPosition](/PythonicAPI/Snippets/CameraPosition.md) | Get the camera position and focal point.
[CheckVTKVersion](/PythonicAPI/Snippets/CheckVTKVersion.md) | Check the VTK version returning `True` if the requested VTK version is >= the current version.
[DrawViewportBorder](/PythonicAPI/Snippets/DrawViewportBorder.md) | Draw a border around a renderer's viewport.
diff --git a/src/PythonicAPI/Snippets/Callbacks.md b/src/PythonicAPI/Snippets/Callbacks.md
new file mode 100644
index 00000000000..4be961f92ad
--- /dev/null
+++ b/src/PythonicAPI/Snippets/Callbacks.md
@@ -0,0 +1,69 @@
+### Description
+
+If a function is passed to another function as an argument, it is known as a callback.
+
+We define a function to use as the callback with this signature: `def my_callback(obj, ev):`. Then, to pass client data to it, we simply do: `my_callback.my_client_data = my_client_data`. This relies on the fact that Python functions are in fact objects and we are simply adding new attributes such as `my_client_data` in this case.
+
+An alternative method is to define a class passing the needed variables in the `__init__` function and then implement a `__call__` function that does the work.
+
+The simplest implementation of a callback is [CameraPosition](../CameraPosition) where we do not even pass client data to it.
+
+An implementation passing client data for both a function and a class is [CallBack](../../Interaction/CallBack), the skeleton code of this is outlined here.
+
+To use the snippet, click the *Copy to clipboard* at the upper right of the code blocks.
+
+### Implementation
+
+``` Python
+
+def get_orientation(caller, ev):
+ """
+ Print out the orientation.
+
+ We must do this before we register the callback in the calling function.
+ Add the active camera as an attribute:
+ get_orientation.cam = ren.active_camera
+
+ :param caller: The caller.
+ :param ev: The event.
+ :return:
+ """
+ # Just do this to demonstrate who called callback and the event that triggered it.
+ print(f'Caller: {caller.class_name}, Event Id: {ev}')
+ # Verify that we have a camera in this case.
+ print(f'Camera: {get_orientation.cam.class_name}')
+ # Now print the camera orientation.
+ # camera_orientation(get_orientation.cam)
+
+
+class OrientationObserver:
+ def __init__(self, cam):
+ self.cam = cam
+
+ def __call__(self, caller, ev):
+ # Just do this to demonstrate who called callback and the event that triggered it.
+ print(f'Caller: {caller.class_name}, Event Id: {ev}')
+ # Verify that we have a camera in this case.
+ print(f'Camera: {self.cam.class_name}')
+ # Now print the camera orientation.
+ # camera_orientation(self.cam)
+
+```
+
+### Usage
+
+``` Python
+ # Set up the callback.
+ if use_function_callback:
+ # We are going to output the camera position when the event
+ # is triggered, so we add the active camera as an attribute.
+ get_orientation.cam = ren.active_camera
+ # Register the callback with the object that is observing.
+ iren.AddObserver('EndInteractionEvent', get_orientation)
+ else:
+ iren.AddObserver('EndInteractionEvent', OrientationObserver(ren.active_camera))
+ # Or:
+ # observer = OrientationObserver(ren.active_camera)
+ # iren.AddObserver('EndInteractionEvent', observer)
+
+```
diff --git a/src/PythonicAPI/Snippets/CameraPosition.md b/src/PythonicAPI/Snippets/CameraPosition.md
index 48908834e49..35c2f248ab7 100644
--- a/src/PythonicAPI/Snippets/CameraPosition.md
+++ b/src/PythonicAPI/Snippets/CameraPosition.md
@@ -7,7 +7,6 @@ To use the snippet, click the *Copy to clipboard* at the upper right of the code
### Implementation
``` Python
-
def camera_modified_callback(caller, event):
"""
Used to estimate positions similar to the book illustrations.
@@ -15,16 +14,34 @@ def camera_modified_callback(caller, event):
:param event:
:return:
"""
- print(caller.class_name, "modified")
+ flt_fmt = '0.6g'
+ # print(caller.class_name, "modified")
# Print the interesting stuff.
- res = f'\tcamera = ren.active_camera\n'
- res += f'\tcamera.position = ({", ".join(map("{0:0.6f}".format, caller.position))})\n'
- res += f'\tcamera.focal_point = ({", ".join(map("{0:0.6f}".format, caller.focal_point))})\n'
- res += f'\tcamera.view_up = ({", ".join(map("{0:0.6f}".format, caller.view_up))})\n'
- res += f'\tcamera.distance = {"{0:0.6f}".format(caller.GetDistance())}\n'
- res += f'\tcamera.clipping_range = ({", ".join(map("{0:0.6f}".format, caller.clipping_range))})\n'
- print(res)
+ res = list()
+ res.append(f' camera = ren.active_camera')
+ res.append(f' camera.position = ({fmt_floats(caller.position)})')
+ res.append(f' camera.focal_point = ({fmt_floats(caller.focal_point)})')
+ res.append(f' camera.view_up = ({fmt_floats(caller.view_up)})')
+ res.append(f' camera.distance = {caller.distance:{flt_fmt}}')
+ res.append(f' camera.clipping_range = ({fmt_floats(caller.clipping_range)})')
+ print(' \n'.join(res))
+ print()
+
+
+def fmt_floats(v, w=0, d=6, pt='g'):
+ """
+ Pretty print a list or tuple of floats.
+ :param v: The list or tuple of floats.
+ :param w: Total width of the field.
+ :param d: The number of decimal places.
+ :param pt: The presentation type, 'f', 'g' or 'e'.
+ :return: A string.
+ """
+ pt = pt.lower()
+ if pt not in ['f', 'g', 'e']:
+ pt = 'f'
+ return ', '.join([f'{element:{w}.{d}{pt}}' for element in v])
```
### Usage
@@ -34,4 +51,4 @@ def camera_modified_callback(caller, event):
ren.active_camera.AddObserver('ModifiedEvent', camera_modified_callback)
```
-Once you have the output, replace the `ren.GetActiveCamera().AddObserver...` line with the output data.
+Once you have the output, replace the `ren.active_camera.AddObserver(...)` line with the output data.
diff --git a/src/PythonicAPI/Visualization/MovableAxes.py b/src/PythonicAPI/Visualization/MovableAxes.py
index 9dcad6abe97..c56076cee5b 100755
--- a/src/PythonicAPI/Visualization/MovableAxes.py
+++ b/src/PythonicAPI/Visualization/MovableAxes.py
@@ -3,7 +3,6 @@ import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
-from vtkmodules.vtkCommonCore import vtkCallbackCommand
from vtkmodules.vtkFiltersSources import (
vtkConeSource
)
@@ -102,10 +101,8 @@ def main():
render_window_interactor.Start()
-class PositionCallback(vtkCallbackCommand):
+class PositionCallback:
def __init__(self, x_label, y_label, z_label, axes):
- super().__init__()
-
self.x_label = x_label
self.y_label = y_label
self.z_label = z_label
@@ -113,9 +110,6 @@ class PositionCallback(vtkCallbackCommand):
self.followers = [self.x_label, self.y_label, self.z_label]
def __call__(self, caller, ev):
- self.Execute(caller, ev)
-
- def Execute(self, caller, eid, call_data=None):
self.axes.InitPathTraversal()
count = 0
diff --git a/src/PythonicAPI/Widgets/AffineWidget.py b/src/PythonicAPI/Widgets/AffineWidget.py
index 423b8195e88..1a1a5d5a81a 100755
--- a/src/PythonicAPI/Widgets/AffineWidget.py
+++ b/src/PythonicAPI/Widgets/AffineWidget.py
@@ -78,18 +78,13 @@ def main():
iren.Start()
-class AffineCallback(vtkCallbackCommand):
+class AffineCallback:
def __init__(self, actor, affine_representation):
- super().__init__()
-
self.actor = actor
self.affine_rep = affine_representation
self.transform = vtkTransform()
def __call__(self, caller, ev):
- self.Execute(self, id, ev)
-
- def Execute(self, caller, id, event):
self.affine_rep.GetTransform(self.transform)
self.actor.SetUserTransform(self.transform)
diff --git a/src/PythonicAPI/Widgets/ImageTracerWidgetInsideContour.py b/src/PythonicAPI/Widgets/ImageTracerWidgetInsideContour.py
index de595390fed..23467643e59 100755
--- a/src/PythonicAPI/Widgets/ImageTracerWidgetInsideContour.py
+++ b/src/PythonicAPI/Widgets/ImageTracerWidgetInsideContour.py
@@ -57,17 +57,12 @@ def main():
interactor.Start()
-class AffineCallback(vtkCallbackCommand):
+class AffineCallback:
def __init__(self, image, tracer_widget):
- super().__init__()
-
self.image = image
self.tracer_widget = tracer_widget
def __call__(self, caller, ev):
- self.Execute(self, id, ev)
-
- def Execute(self, caller, identifier, event):
path = vtkPolyData()
if not self.tracer_widget.IsClosed():
--
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