Add Source Lookups preference page with ordering and external source locator for issue #2073

ISSUE_UI_SCREENSHOT_IMPROVEMENT.md

@@ -0,0 +1,49 @@
+# Improve UI screenshot generation for PR documentation
+
+## Problem
+
+The current approach to generating screenshots for UI components using Python/PIL produces white/blank images that don't accurately represent the Eclipse UI.
+
+## Proposed Solutions
+
+### 1. SWT Snippet Approach
+Create small SWT snippets that can render the UI components. However, this requires complex setup for many components that depend on Eclipse platform infrastructure.
+
+### 2. MCP Server with Eclipse Install (Recommended)
+Create a Model Context Protocol (MCP) server that includes a full Eclipse installation. This would allow:
+- Programmatic access to Eclipse UI components
+- Automated screenshot capture of actual rendered UI
+- Better representation of Eclipse styling and themes
+- Reusable infrastructure for future UI documentation
+
+## Context
+
+This issue was identified while implementing the Source Lookups preference page (see related PR for #2073). The generated screenshot using Python/PIL doesn't accurately show how the preference page would look in a real Eclipse environment.
+
+## Benefits of MCP Server Approach
+
+- **Accuracy**: Screenshots show actual Eclipse UI rendering with proper fonts, colors, and styling
+- **Reusability**: Can be used for all future UI-related PRs and documentation
+- **Automation**: Can be integrated into CI/CD pipeline for automatic screenshot generation
+- **Quality**: Better documentation quality improves contributor and user experience
+
+## Implementation Ideas
+
+1. Create a headless Eclipse installation in a container
+2. Build an MCP server that can:
+   - Launch Eclipse workbench programmatically
+   - Navigate to specific UI components (dialogs, preference pages, views, etc.)
+   - Capture screenshots using SWT/platform APIs
+   - Return screenshots as base64 or file paths
+3. Integrate with Copilot workflow for automatic screenshot generation
+
+## Labels
+
+- `enhancement`
+- `documentation`
+- `tooling`
+
+## Related
+
+- Source Lookups preference page PR
+- Issue #2073

ui/org.eclipse.pde.core/plugin.xml

@@ -430,6 +430,9 @@
           <locator
                 class="org.eclipse.pde.internal.core.LocalMavenPluginSourcePathLocator"
                 complexity="low"/>
+          <locator
+                class="org.eclipse.pde.internal.core.ExternalPluginSourcePathLocator"
+                complexity="high"/>
     </extension>
         <extension
               point="org.eclipse.pde.core.targetLocations">