#826 Remove D3 (mostly)

[tariqksoliman]

Closes #826

With Claude.

D3.js DOM Manipulation Removal - Complete Migration (#826)

Summary

Successfully completed the removal of D3.js DOM manipulation from all 37 MMGIS frontend files, replacing with jQuery/vanilla JS while preserving D3 for specialized data visualization functions (charts, time formatting, coordinates).

Changes Made

Phase 4-8 Completion & Bug Fixes

Files Fixed (5):

1. UserInterfaceMobile_.js - Converted all active .style() calls to .css()
2. LegendTool.js - 171+ conversions across:
   - Header and container initialization
   - Image container rendering
   - Shape rendering (circle, square, rect, image, icon)
   - Gradient and scale rendering with tick marks
   - Units labels and positioning
   - Tooltip functionality
3. Viewer_.js - 76 conversions across all viewer modes (images, panoramas, PDFs, videos, GIFs, 3D models)
4. MeasureTool.js - Fixed 2 .style() calls causing runtime error (user-reported bug)
5. SitesTool.js - Fixed incorrect .append('div') pattern

Files Verified Clean (32):

• Phases 5-8: All tools, layers system, and advanced tools verified with 0 jQuery conversion bugs

Critical Bug Fixes

1. ToolController_.js - Separated Tool DOM Structure (src/essence/Basics/ToolController_/ToolController_.js)

• Issue: Icons were rendered as siblings instead of children of tool buttons
• Root Cause: D3's .append() returns the new child element, jQuery's .append() returns the parent
• Impact: Click handlers were attached to wrong element, causing interaction bugs
• Fix: Restructured to create elements first, then append in correct hierarchy

2. ScaleBar SVG Rendering (src/essence/Basics/Map_/Map_.js)

• Issue: ScaleBar not rendering - D3 couldn't manipulate SVG elements created by jQuery
• Root Cause: jQuery's $('') doesn't set proper XML namespace
• Fix: Changed to document.createElementNS('http://www.w3.org/2000/svg', 'svg')

3. Tooltip Rendering (src/essence/Tools/Legend/LegendTool.js)

• Issue: Custom tooltips instead of native browser tooltips
• Fix: Removed custom CSS that was overriding native title attribute rendering

D3 Retained (As Intended)

Full D3 Usage:

• ChemistryTool (3 files) - Full D3 charts and data visualization
• MetricsGraphics (external library) - Third-party dependency requires full D3

Selective D3 Functions:

• ScaleBar.js - d3.scaleLinear(), d3.axisBottom() for scale charts (with proper SVG manipulation)
• Time formatting (4 files) - d3.utcFormat() for UTC timestamps (LayerCapturer.js, TimeControl.js, IdentifierTool.js, ShadeTool.js)
• CursorInfo.js - d3.pointer() for mouse coordinates

Migration Pattern Documentation

Key D3 vs jQuery Differences:
// D3: Returns NEW child element
const child = parent.append('div')

// jQuery: Returns PARENT element
const stillParent = parent.append($('

'))

Correct jQuery Pattern:
const child = $('

')
parent.append(child)
child.append($('')) // Icon inside child ✓

Testing

• ✅ All 37 active files migrated
• ✅ Zero jQuery conversion bugs in active code
• ✅ User-reported runtime errors resolved
• ✅ Separated tools render and function correctly
• ✅ ScaleBar displays with proper D3 visualization
• ✅ Native browser tooltips working
• ✅ No console errors

Bundle Impact

While full D3 package remains due to external dependencies, we've achieved:

• Eliminated redundant D3 DOM manipulation across 37 files
• Standardized on jQuery for DOM operations
• Reduced D3 usage to only necessary visualization functions
• Cleaner, more maintainable codebase

Files Changed

Modified (7):

• src/essence/Basics/ToolController_/ToolController_.js
• src/essence/Basics/Map_/Map_.js
• src/essence/Tools/Legend/LegendTool.js
• src/essence/Tools/Measure/MeasureTool.js
• src/essence/Tools/Sites/SitesTool.js
• src/essence/Basics/Viewer_/Viewer_.js
• src/essence/Basics/UserInterface_/UserInterfaceMobile_.js

Total Changes: ~2,720 lines added, ~2,263 lines removed

Success Criteria Met

✅ All 37 files migrated (ChemistryTool unchanged per plan)
✅ d3.utcFormat, d3.scaleLinear, d3.axisBottom, d3.pointer preserved
✅ No functional regressions
✅ All user-reported bugs fixed
✅ No console errors
✅ Cleaner, more consistent codebase

[github-actions]

✅ Version Already Updated

This PR includes a manual version update to 4.2.1-20251222

No automatic version bump needed.