Add Instance.set_snapshot_size to rips Python client

Wraps the new setSnapshotSize gRPC command so callers can do

    ri.set_snapshot_size(1600, 1000)
    for plot in ri.project.plots():
        plot.export_snapshot(export_folder=...)

and get 1600x1000 PNGs back. Mirrors the existing
Instance.set_plot_window_size wrapper shape. The headless_plot_export
example is updated to demonstrate the call between plot creation and
the export_snapshot loop.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hakonhagland

GrpcInterface/Python/rips/PythonExamples/export_and_plotting/headless_plot_export.py

@@ -26,6 +26,12 @@
     summary_cases=[summary_case], address="WOPR:A*;WOPR:B*"
 )
 
+# Resize the plot sub-windows so the exported PNGs come out at the
+# requested resolution. Without this, the offscreen layout engine picks
+# its own (typically small) geometry and snapshots ignore the --size
+# launch parameter.
+resinsight.set_snapshot_size(1200, 1000)
+
 plots = resinsight.project.plots()
 for plot in plots:
     plot.export_snapshot()

GrpcInterface/Python/rips/instance.py

@@ -561,6 +561,44 @@ def set_plot_window_size(self, width: int, height: int):
             )
         )
 
+    def set_snapshot_size(self, width: int, height: int):
+        """
+        Set the size used for snapshot export of plots and 3D views.
+
+        Affects subsequent calls to ``export_snapshot`` /
+        ``export_snapshots``. Equivalent to the ``--snapshotsize`` CLI
+        flag. Must be called after at least one plot window has been
+        created (otherwise there is nothing to resize).
+
+        Unlike :meth:`set_plot_window_size`, which only resizes the
+        outer plot main window, this method un-maximizes and resizes
+        each MDI sub-window so the actual plot widget is rendered at
+        the requested dimensions.
+
+        Recommended call order for a filled snapshot:
+
+        1. :meth:`set_plot_window_size` *before* creating plots, so the
+           plots are realized inside MDI sub-windows.
+        2. Create the plot(s).
+        3. ``project.plots()`` to fetch the plot to export. This can
+           re-tile the MDI sub-windows back to their defaults, so call
+           ``set_snapshot_size`` *after* it, not before.
+        4. ``set_snapshot_size(width, height)``.
+        5. ``plot.export_snapshot(...)``.
+
+        **Parameters**::
+
+            Parameter | Description      | Type
+            --------- | ---------------- | -----
+            width     | Width in pixels  | Integer
+            height    | Height in pixels | Integer
+        """
+        return self.__execute_command(
+            setSnapshotSize=Commands_pb2.SetWindowSizeParams(
+                width=width, height=height
+            )
+        )
+
     def major_version(self) -> int:
         """Get an integer with the major version number"""
         return int(self.__version_message().major_version)