refactor: Allow leaving the filename empty for saving a screenshot, i…

…t will now default to a timestamped filename

examples/scopes/tekscope/save_screenshot.py

@@ -4,14 +4,19 @@
 from tm_devices.drivers import MSO6B
 
 with DeviceManager(verbose=True) as dm:
-    # Get a scope
+    # Add a scope
     scope: MSO6B = dm.add_scope("192.168.0.1")
 
     # Send some commands
     scope.add_new_math("MATH1", "CH1")  # add MATH1 to CH1
     scope.turn_channel_on("CH2")  # turn on channel 2
     scope.set_and_check(":HORIZONTAL:SCALE", 100e-9)  # adjust horizontal scale
 
+    # Save a screenshot as a timestamped file, will create a screenshot on the device,
+    # copy it to the current working directory on the local machine,
+    # and then delete the screenshot file from the device.
+    scope.save_screenshot()
+
     # Save a screenshot as example.png, will create a screenshot on the device,
     # copy it to the current working directory on the local machine,
     # and then delete the screenshot file from the device.

src/tm_devices/driver_mixins/abstract_device_functionality/screen_capture_mixin.py

@@ -3,9 +3,12 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
+from datetime import datetime
 from pathlib import Path
 from typing import final, Optional, Tuple, TYPE_CHECKING, Union
 
+from dateutil.tz import tzlocal
+
 if TYPE_CHECKING:
     import os
 
@@ -28,7 +31,7 @@ def valid_image_extensions(self) -> Tuple[str, ...]:
     @final
     def save_screenshot(
         self,
-        filename: Union[str, os.PathLike[str]],
+        filename: Optional[Union[str, os.PathLike[str]]] = None,
         *,
         colors: Optional[str] = None,
         view_type: Optional[str] = None,
@@ -39,15 +42,23 @@ def save_screenshot(
         """Capture a screenshot from the device and save it locally.
 
         Args:
-            filename: The name of the file to save the screenshot as.
+            filename: The name of the file to save the screenshot as. Defaults to a timestamped
+                name using the first valid image extension.
             colors: The color scheme to use for the screenshot. (Not used by all devices)
             view_type: The type of view to capture. (Not used by all devices)
             local_folder: The local folder to save the screenshot in. Defaults to "./".
             device_folder: The folder on the device to save the screenshot in. Defaults to "./".
             keep_device_file: Whether to keep the file on the device after downloading it.
                 Defaults to False.
         """
-        filename_path = Path(filename)
+        if not filename:
+            filename_path = Path(
+                datetime.now(tz=tzlocal()).strftime(
+                    f"%Y%m%d_%H%M%S{self.valid_image_extensions[0]}"
+                )
+            )
+        else:
+            filename_path = Path(filename)
         if filename_path.suffix.lower() not in self.valid_image_extensions:
             msg = (
                 f"Invalid image extension: {filename_path.suffix!r}, "

tests/test_scopes.py

@@ -6,12 +6,14 @@
 import subprocess
 import sys
 
+from datetime import datetime
 from typing import cast, TYPE_CHECKING
 from unittest import mock
 
 import pytest
 import pyvisa as visa
 
+from dateutil.tz import tzlocal
 from packaging.version import Version
 
 from tm_devices import DeviceManager, register_additional_usbtmc_mapping
@@ -503,25 +505,36 @@ def test_tekscopepc(
     ):
         scope.save_screenshot("temp.png", device_folder="filename.txt")
 
-    filename = pathlib.Path("temp.png")
-    local_file = tmp_path / filename
     with mock.patch(
         "pyvisa.resources.messagebased.MessageBasedResource.read_raw",
         mock.MagicMock(return_value=b"1234"),
+    ), mock.patch(
+        "pyvisa.resources.messagebased.MessageBasedResource.write",
+        mock.MagicMock(return_value=None),
+    ), mock.patch(
+        "pyvisa.resources.messagebased.MessageBasedResource.read",
+        mock.MagicMock(return_value="1"),  # this mocks the *OPC? query return value
     ):
-        scope.save_screenshot(filename, local_folder=tmp_path)
+        scope.enable_verification = False
+        filename = pathlib.Path(
+            datetime.now(tz=tzlocal()).strftime(f"%Y%m%d_%H%M%S{scope.valid_image_extensions[0]}")
+        )
+        local_file = tmp_path / filename
+        scope.save_screenshot(local_folder=tmp_path)
         assert local_file.read_bytes() == b"1234"
         stdout = capsys.readouterr().out
         assert "SAVE:IMAGE:COMPOSITION NORMAL" in stdout
         assert f'SAVE:IMAGE "./{filename.as_posix()}"' in stdout
         assert f'FILESYSTEM:READFILE "./{filename.as_posix()}"' in stdout
         assert f'FILESYSTEM:DELETE "./{filename.as_posix()}"' in stdout
 
-    local_file = tmp_path / "folder" / filename
     with mock.patch(
         "pyvisa.resources.messagebased.MessageBasedResource.read_raw",
         mock.MagicMock(return_value=b"5678"),
     ):
+        scope.enable_verification = True
+        filename = pathlib.Path("temp.png")
+        local_file = tmp_path / "folder" / filename
         scope.save_screenshot(
             filename,
             local_folder=local_file.parent,