# Phase 2 Sidebar Fixes - Complete Implementation

**Date:** 2025-11-27  
**Status:** ✅ Complete  
**Build Status:** ✅ Compiles successfully (editor library verified)

## Overview

Fixed critical sidebar UX issues based on user feedback:
- Sidebar state persistence
- Fixed expand button positioning
- Category enabled/disabled states
- Enhanced visual feedback and tooltips
- Improved emulator layout handling
- Fixed sidebar stuck issues with right panel interaction

## Changes Implemented

### 1. Sidebar State Persistence

**Files:** `user_settings.h`, `user_settings.cc`, `editor_manager.cc`

**Added to UserSettings::Preferences:**
```cpp
bool sidebar_collapsed = false;      // Start expanded
bool sidebar_tree_view_mode = true;  // Start in tree view
std::string sidebar_active_category; // Last active category
```

**Flow:**
1. Settings loaded → Applied to card_registry on startup
2. User toggles sidebar → Callback saves state immediately
3. Next launch → Sidebar restores exact state

**Implementation:**
- `EditorManager::Initialize()` applies saved state (lines 503-508)
- Callbacks registered (lines 529-541):
  - `SetSidebarStateChangedCallback` - Auto-saves on toggle
  - `SetCategoryChangedCallback` - Auto-saves on category switch

### 2. Fixed Expand Button Position

**File:** `editor_card_registry.cc`

**Problem:** Expand button was in menu bar, collapse button in sidebar (inconsistent UX)

**Solution:** Added collapsed sidebar strip UI (lines 580-625, 1064-1114)
- When collapsed: Draw 16px thin strip at sidebar edge
- Expand button positioned at same location as collapse button would be
- Click strip button to expand
- Menu bar toggle still works as secondary method

**User Experience:**
- ✅ Collapse sidebar → Button appears in same spot
- ✅ Click to expand → Sidebar opens smoothly
- ✅ No hunting for expand button in menu bar

### 3. Fixed Layout Offset Calculation

**File:** `editor_manager.h`

**Problem:** Collapsed sidebar returned 0.0f offset, causing dockspace to overlap

**Solution:** Return `GetCollapsedSidebarWidth()` (16px) when collapsed (lines 95-113)

**Fixed:**
- ✅ Sidebar strip always reserves 16px
- ✅ Dockspace doesn't overlap collapsed sidebar
- ✅ Right panel interaction no longer causes sidebar to disappear

### 4. Category Enabled/Disabled States

**Files:** `editor_card_registry.h`, `editor_card_registry.cc`, `editor_manager.cc`

**Added:**
- `has_rom` callback parameter to DrawSidebar / DrawTreeSidebar
- Enabled check: `rom_loaded || category == "Emulator"`
- Visual: 40% opacity + disabled hover for categories requiring ROM

**Icon View (DrawSidebar):**
- Disabled categories: Grayed out, very subtle hover
- Tooltip shows: "🟡 Overworld Editor | ─── | 📁 Open a ROM first"
- Click does nothing when disabled

**Tree View (DrawTreeSidebar):**
- Disabled categories: 40% opacity
- Enhanced tooltip with instructions: "Open a ROM first | Use File > Open ROM to load a ROM file"
- Tree node not selectable/clickable when disabled

### 5. Enhanced Visual Feedback

**File:** `editor_card_registry.cc`

**Category Buttons:**
- Active indicator bar: 4px width (was 2px), no rounding for crisp edge
- Active button: 90% accent opacity, 100% on hover
- Inactive button: 50% opacity, 130% brightness on hover
- Disabled button: 30% opacity, minimal hover

**Tooltips (Rich Formatting):**
```
Icon View Category:
  🗺 Overworld Editor
  ─────────────────
  Click to switch to Overworld view
  ✓ Currently Active

Disabled Category:
  🟡 Overworld Editor
  ─────────────────
  📁 Open a ROM first

Icon View Card:
  🗺 Overworld Canvas
  ─────────────────
  Ctrl+Shift+O
  👁 Visible
```

### 6. Fixed Emulator Layout Handling

**File:** `editor_manager.cc`

**Reset Workspace Layout (lines 126-146):**
- Now uses `RebuildLayout()` instead of `InitializeEditorLayout()`
- Checks `IsEmulatorVisible()` before `current_editor_`
- Validates ImGui frame scope before rebuilding
- Falls back to deferred rebuild if not in frame

**Switch to Emulator (lines 1908-1930):**
- Validates ImGui context before initializing layout
- Checks `IsLayoutInitialized()` before initializing
- Logs confirmation of layout initialization

**Update Loop (lines 653-675):**
- Checks `IsRebuildRequested()` flag
- Determines correct editor type (Emulator takes priority)
- Executes rebuild and clears flag

## Behavioral Changes

### Sidebar Lifecycle

**Before:**
```
Start: Always collapsed, tree mode
Toggle: No persistence
Restart: Always collapsed again
```

**After:**
```
Start: Reads from settings (default: expanded, tree mode)
Toggle: Auto-saves immediately
Restart: Restores exact previous state
```

### Category Switching

**Before:**
```
Multiple editors open → Sidebar auto-switches → User confused
No visual feedback → Unclear which category is active
```

**After:**
```
User explicitly selects category → Stays on that category
4px accent indicator bar → Clear active state
Enhanced tooltips → Explains what each category does
Disabled categories → Grayed out with helpful "Open ROM first" message
```

### Emulator Integration

**Before:**
```
Open emulator → Layout not initialized → Cards floating
Reset layout → Doesn't affect emulator properly
```

**After:**
```
Open emulator → Layout initializes with proper docking
Reset layout → Correctly rebuilds emulator layout
Emulator category → Shows in sidebar when emulator visible
```

## User Workflow Improvements

### Opening Editor Without ROM

**Before:**
```
1. Start app (no ROM)
2. Sidebar shows placeholder with single "Open ROM" button
3. Categories not visible
```

**After:**
```
1. Start app (no ROM)
2. Sidebar shows all categories (grayed out except Emulator)
3. Hover category → "📁 Open a ROM first"
4. Clear visual hierarchy of what's available vs requires ROM
```

### Collapsing Sidebar

**Before:**
```
1. Click collapse button in sidebar
2. Sidebar disappears
3. Hunt for expand icon in menu bar
4. Click menu icon to expand
5. Button moved - have to find collapse button again
```

**After:**
```
1. Click collapse button (bottom of sidebar)
2. Sidebar shrinks to 16px strip
3. Expand button appears in same spot
4. Click to expand
5. Collapse button right where expand button was
```

### Switching Between Editors

**Before:**
```
Open Overworld → Category switches to "Overworld"
Open Dungeon → Category auto-switches to "Dungeon"
Want to see Overworld cards while Dungeon is active? Can't.
```

**After:**
```
Open Overworld → Category stays on user's selection
Open Dungeon → Category stays on user's selection
Want to see Overworld cards? Click Overworld category button
Clear visual feedback: Active category has 4px accent bar
```

## Technical Implementation

### Callback Architecture

```
User Action → UI Component → Callback → Save Settings

Examples:
- Click collapse → ToggleSidebarCollapsed() → on_sidebar_state_changed_() → Save()
- Switch category → SetActiveCategory() → on_category_changed_() → Save()
- Toggle tree mode → ToggleTreeViewMode() → on_sidebar_state_changed_() → Save()
```

### Layout Offset Calculation

```cpp
GetLeftLayoutOffset() {
  if (!sidebar_visible) return 0.0f;
  
  if (collapsed) return 16.0f;  // Strip width
  
  return tree_mode ? 200.0f : 48.0f;  // Full width
}
```

**Impact:**
- Dockspace properly reserves space for sidebar strip
- Right panel interaction doesn't cause overlap
- Smooth resizing when toggling modes

### Emulator as Category

**Registration:** Lines 298-364 in `editor_manager.cc`
- Emulator cards registered with category="Emulator"
- Cards: CPU Debugger, PPU Viewer, Memory, etc.

**Sidebar Integration:** Lines 748-752 in `editor_manager.cc`
- When `IsEmulatorVisible()` → Add "Emulator" to active_categories
- Emulator doesn't require ROM (always enabled)
- Layout initializes on first switch to emulator

## Verification

✅ **Compilation:** Editor library builds successfully  
✅ **State Persistence:** Settings save/load correctly  
✅ **Visual Feedback:** Enhanced tooltips with color coordination  
✅ **Category Enabled States:** ROM-requiring categories properly disabled  
✅ **Layout System:** Emulator layout initializes and resets correctly  
✅ **Offset Calculation:** Sidebar strip reserves proper space

## Summary

All Phase 2 fixes complete:
- ✅ Sidebar state persists across sessions
- ✅ Expand button at fixed position (not in menu bar)
- ✅ Categories show enabled/disabled state
- ✅ Enhanced tooltips with rich formatting
- ✅ Improved category switching visual feedback
- ✅ Emulator layout properly initializes and resets
- ✅ Sidebar doesn't get stuck with right panel interaction

**Result:** VSCode-like sidebar experience with professional UX and persistent state.