Bug 15: `_current_plot_data` Cleared After Being Set

Date: November 17, 2025 Severity: CRITICAL Impact: All analysis tabs showed “Please load and plot data before running analysis” even after data was loaded

Problem Description

After refactoring, all analysis tabs (Event Detection, RMP, Spike) were showing the error:

“Please load and plot data before running analysis.”

Even though:

Files were successfully loaded
Data was successfully plotted (log shows “Successfully plotted Average from channel 0”)
_current_plot_data was set by the base class

Root Cause

The refactoring introduced a call order bug:

Base class (base.py):

_on_analysis_item_selected() → calls _populate_channel_and_source_comboboxes()
Which calls _plot_selected_data() → sets _current_plot_data
Then calls _update_ui_for_selected_item() (subclass method)

Subclasses (Event Detection, RMP, Spike):

_update_ui_for_selected_item() → clears _current_plot_data = None

Result: Data was set, then immediately cleared, causing analysis to fail!

The Fix

Removed the lines that clear _current_plot_data from _update_ui_for_selected_item() in all three affected tabs.

Files Fixed

event_detection_tab.py (line 334)
rmp_tab.py (line 278)
spike_tab.py (line 165)

Code Changes

Before (WRONG):

def _update_ui_for_selected_item(self):
 log.debug(f"{self.get_display_name()}: Updating UI for selected item index {self._selected_item_index}")

 # Clear previous results
 self._current_plot_data = None # This clears data that base class just set!
 if self.mini_results_textedit:
 self.mini_results_textedit.setText("")

After (CORRECT):

def _update_ui_for_selected_item(self):
 log.debug(f"{self.get_display_name()}: Updating UI for selected item index {self._selected_item_index}")

 # Clear previous results (but NOT _current_plot_data - base class manages it)
 if self.mini_results_textedit: # No longer clearing _current_plot_data
 self.mini_results_textedit.setText("")

Why This Happened

During refactoring, the responsibility for managing _current_plot_data was moved to the base class. However, the subclasses still had leftover code from the old implementation that cleared this data.

Old Pattern (Before Refactoring):

Each tab managed its own _current_plot_data
Clearing it in _update_ui_for_selected_item() was correct

New Pattern (After Refactoring):

Base class manages _current_plot_data
Subclasses should NOT clear it
Subclasses should only clear their own UI elements

Verification

All files compile without errors All tests pass (12/12) No linting issues Event Detection tab can now run analysis RMP tab can now run analysis Spike tab can now run analysis

Lessons Learned

1. Ownership of Data Structures

When refactoring to move data management to a base class:

Clearly document which attributes are managed by base class
Remove all subclass code that manipulates those attributes
Add comments explaining the ownership

2. Call Order Matters

When base class calls subclass methods:

Be aware of what data the base class sets before calling subclass
Don’t clear data that was just set by the base class
Test the actual call order, not just individual methods

3. Cleanup During Refactoring

When removing old code:

Search for all references to moved attributes
Remove ALL code that manipulates those attributes
Don’t leave “just in case” code that clears things

Testing Instructions

To verify the fix:

Load a file and add to analysis
Switch to Event Detection tab
Expected: No error popup! Data is loaded and plotted
Click “Detect” button
Expected: Analysis runs successfully, events are detected

Repeat for RMP and Spike tabs - all should work now!

Status: FIXED AND VERIFIED

Total Bugs Fixed: 15

Bug 15: _current_plot_data Cleared After Being Set