Merge pull request #29 from Kitware/fix_unwanted_vtk_import

fix(utils): do not import vtk unnecessarily

Author: Justineantoine

examples/00_vanilla/vanilla_example.py

@@ -4,7 +4,6 @@
 from trame.app.testing import enable_testing
 from trame.decorators import TrameApp, change
 from trame_rca.widgets import rca
-from trame_rca.utils import AbstractWindow
 from trame.app import get_server
 from trame.ui.vuetify3 import SinglePageLayout
 from trame.widgets import vuetify3 as v3
@@ -14,7 +13,7 @@
 DEFAULT_ROTATION_STEP = 45
 
 
-class RotatableImageWindow(AbstractWindow):
+class RotatableImageWindow:
     def __init__(self, path):
         self._image = Image.open(path).convert("RGB")
         self._image_angle = 0

examples/02_doom/doom.wad

@@ -1,7 +1,49 @@
+from typing import Protocol, runtime_checkable
+from numpy.typing import NDArray
 from wslink import register as exportRpc
 from wslink.websocket import LinkProtocol
 
 
+@runtime_checkable
+class AbstractWindow(Protocol):
+    """
+    Protocol defining the interface for interacting with a remote window through RCA.
+
+    Any class matching this interface can be used as a remote window, regardless of inheritance.
+    Implementing classes must define the required methods and properties to enable window interaction.
+    """
+
+    @property
+    def img_cols_rows(self) -> tuple[NDArray, int, int]:
+        """
+        Returns a tuple containing:
+        - the window content as a NumPy array,
+        - the number of columns,
+        - and the number of rows.
+
+        Called by the scheduler to render the current window view.
+        """
+        pass
+
+    def process_resize_event(self, width: int, height: int) -> None:
+        """
+        Handle a resize event for the RCA (RenderWindowInteractor).
+
+        This method is triggered by the adapter whenever the window is resized.
+        """
+        pass
+
+    def process_interaction_event(self, event: dict) -> None:
+        """
+        Handle an interaction event from the RCA (RenderWindowInteractor).
+
+        This method is invoked by the adapter whenever an interaction event occurs.
+        Refer to the event types defined in:
+        https://github.com/Kitware/vtk-js/blob/master/Sources/Rendering/Core/RenderWindowInteractor/index.js
+        """
+        pass
+
+
 class AreaAdapter:
     def __init__(self, name):
         self.area_name = name

trame_rca/protocol.py

@@ -3,23 +3,25 @@
 import os
 import asyncio
 import time
-from abc import ABC, abstractmethod
 from asyncio import Queue
 from concurrent.futures.thread import ThreadPoolExecutor
 from concurrent.futures import Executor
 from enum import Enum
-from packaging.version import Version
-from typing import Callable, Optional
+from typing import Callable, Optional, TYPE_CHECKING
 
 from numpy.typing import NDArray
 from trame.app import asynchronous
-from vtkmodules.util.numpy_support import vtk_to_numpy
-from vtkmodules.vtkRenderingCore import vtkRenderWindow, vtkWindowToImageFilter
-import json
 from trame_rca.encoders.pil import encode as encode_pil
 
-from vtkmodules.vtkCommonCore import vtkCommand, vtkVersion
-from vtkmodules.vtkWebCore import vtkRemoteInteractionAdapter
+if TYPE_CHECKING:
+    from vtkmodules.vtkRenderingCore import vtkRenderWindow
+
+from trame_rca.protocol import AbstractWindow
+
+try:
+    from trame_rca.vtk_utils import VtkWindow
+except ModuleNotFoundError as e:
+    print(e.msg)
 
 try:
     from trame_rca.encoders.turbo_jpeg import encode as encode_turbo
@@ -32,6 +34,14 @@
 
 ENCODING_POOL = ThreadPoolExecutor(max(4, os.cpu_count()))
 
+__all__ = [
+    "AbstractWindow",
+    "RcaEncoder",
+    "RcaViewAdapter",
+    "RcaRenderScheduler",
+    "VtkWindow",
+]
+
 
 def time_now_ms() -> int:
     return int(time.time_ns() / 1000000)
@@ -40,8 +50,12 @@ def time_now_ms() -> int:
 def window_wrapper(window: AbstractWindow | vtkRenderWindow) -> AbstractWindow:
     if isinstance(window, AbstractWindow):
         return window
+
+    from vtkmodules.vtkRenderingCore import vtkRenderWindow
+
     if isinstance(window, vtkRenderWindow):
         return VtkWindow(window)
+
     raise RuntimeError(
         "Invalid window object provided: expected an instance of AbstractWindow"
     )
@@ -73,89 +87,6 @@ def encode(
         return self._impl(np_image, self.value, cols, rows, quality, now_ms)
 
 
-class AbstractWindow(ABC):
-    """
-    Abstract base class for interacting with a remote window through the RCA.
-
-    Subclasses must implement the abstract methods defined in this class
-    to enable interaction with the window.
-    """
-
-    @property
-    @abstractmethod
-    def img_cols_rows(self) -> tuple[NDArray, int, int]:
-        """
-        Returns a tuple containing:
-        - the window content as a NumPy array,
-        - the number of columns,
-        - and the number of rows.
-
-        Called by the scheduler to render the current window view.
-        """
-        pass
-
-    @abstractmethod
-    def process_resize_event(self, width: int, height: int) -> None:
-        """
-        Handle a resize event for the RCA (RenderWindowInteractor).
-
-        This method is triggered by the adapter whenever the window is resized.
-        """
-        pass
-
-    @abstractmethod
-    def process_interaction_event(self, event: dict) -> None:
-        """
-        Handle an interaction event from the RCA (RenderWindowInteractor).
-
-        This method is invoked by the adapter whenever an interaction event occurs.
-        Refer to the event types defined in:
-        https://github.com/Kitware/vtk-js/blob/master/Sources/Rendering/Core/RenderWindowInteractor/index.js
-        """
-        pass
-
-
-class VtkWindow(AbstractWindow):
-    def __init__(self, vtk_render_window: vtkRenderWindow):
-        self._vtk_render_window = vtk_render_window
-        self._window_to_image = vtkWindowToImageFilter()
-        self._window_to_image.SetInput(vtk_render_window)
-        self._window_to_image.SetScale(1)
-        self._window_to_image.ReadFrontBufferOff()
-        self._window_to_image.ShouldRerenderOff()
-        self._window_to_image.FixBoundaryOn()
-        self._iren = self._vtk_render_window.GetInteractor()
-        self._iren.EnableRenderOff()
-        self._vtk_render_window.ShowWindowOff()
-
-    @property
-    def img_cols_rows(self):
-        self._vtk_render_window.Render()
-        self._window_to_image.Modified()
-        self._window_to_image.Update()
-
-        image_data = self._window_to_image.GetOutput()
-        rows, cols, _ = image_data.GetDimensions()
-        scalars = image_data.GetPointData().GetScalars()
-        np_image = vtk_to_numpy(scalars)
-        np_image = np_image.reshape((cols, rows, -1))
-        np_image[:] = np_image[::-1, :, :]
-        return np_image, cols, rows
-
-    def process_resize_event(self, width, height):
-        self._iren.UpdateSize(width, height)
-
-        if Version(vtkVersion().vtk_version) < Version("9.5"):
-            self._iren.InvokeEvent(vtkCommand.WindowResizeEvent)
-
-    def process_interaction_event(self, event):
-        event_type = event["type"]
-        if event_type in ["StartInteractionEvent", "EndInteractionEvent"]:
-            return
-
-        vtkRemoteInteractionAdapter.ProcessEvent(self._iren, json.dumps(event))
-
-
 class RcaRenderScheduler:
     """
     Render scheduler which renders images and pushing the encoded output to a given callback function.

trame_rca/utils.py

@@ -0,0 +1,47 @@
+import json
+from packaging.version import Version
+import vtkmodules.vtkRenderingOpenGL2  # noqa
+from vtkmodules.util.numpy_support import vtk_to_numpy
+from vtkmodules.vtkCommonCore import vtkCommand, vtkVersion
+from vtkmodules.vtkRenderingCore import vtkRenderWindow, vtkWindowToImageFilter
+from vtkmodules.vtkWebCore import vtkRemoteInteractionAdapter
+
+
+class VtkWindow:
+    def __init__(self, vtk_render_window: vtkRenderWindow):
+        self._vtk_render_window = vtk_render_window
+        self._window_to_image = vtkWindowToImageFilter()
+        self._window_to_image.SetInput(vtk_render_window)
+        self._window_to_image.SetScale(1)
+        self._window_to_image.ReadFrontBufferOff()
+        self._window_to_image.ShouldRerenderOff()
+        self._window_to_image.FixBoundaryOn()
+        self._iren = self._vtk_render_window.GetInteractor()
+        self._iren.EnableRenderOff()
+        self._vtk_render_window.ShowWindowOff()
+
+    @property
+    def img_cols_rows(self):
+        self._vtk_render_window.Render()
+        self._window_to_image.Modified()
+        self._window_to_image.Update()
+
+        image_data = self._window_to_image.GetOutput()
+        rows, cols, _ = image_data.GetDimensions()
+        scalars = image_data.GetPointData().GetScalars()
+        np_image = vtk_to_numpy(scalars)
+        np_image = np_image.reshape((cols, rows, -1))
+        np_image[:] = np_image[::-1, :, :]
+        return np_image, cols, rows
+
+    def process_resize_event(self, width, height):
+        self._iren.UpdateSize(width, height)
+        if Version(vtkVersion().vtk_version) < Version("9.5"):
+            self._iren.InvokeEvent(vtkCommand.WindowResizeEvent)
+
+    def process_interaction_event(self, event):
+        event_type = event["type"]
+        if event_type in ["StartInteractionEvent", "EndInteractionEvent"]:
+            return
+
+        vtkRemoteInteractionAdapter.ProcessEvent(self._iren, json.dumps(event))