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OutlineViewer is a simple, lightweight tool for viewing and editing NetworkTables values. It provides a straightforward interface for monitoring data published by your robot program.

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Overview

OutlineViewer is designed as a simple NetworkTables client that displays all published topics in a tree structure. It’s perfect for quick debugging sessions where you need to check or modify values without the overhead of a full dashboard.

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Features

  • Simple Interface: Clean, minimalist UI focused on NetworkTables data
  • Real-time Updates: See values change as your robot publishes updates
  • Edit Values: Modify NetworkTables entries directly from the interface
  • Connection Status: Clear indication of connection state
  • Logging: Built-in logging for NetworkTables events and errors

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Running OutlineViewer

1

Navigate to the WPILib repository

Open a terminal and navigate to the root of the WPILib repository:
cd /path/to/allwpilib
2

Run OutlineViewer using Gradle

Execute the OutlineViewer application using the Gradle wrapper:
./gradlew outlineviewer:run
On Windows:
gradlew.bat outlineviewer:run
3

Connect to your robot

Once OutlineViewer opens, configure the connection:
  • Access NetworkTables Settings from the menu
  • Enter your robot’s IP address or team number
  • Click Apply to connect

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Connection Modes

OutlineViewer can operate in different NetworkTables modes:

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Client Mode

Connect to a robot or simulation as a NetworkTables client. This is the most common usage mode.

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Server Mode

Run OutlineViewer as a NetworkTables server. This is useful for:
  • Testing robot code that expects to connect to a NetworkTables server
  • Viewing data from multiple NetworkTables clients

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Understanding the Interface

The OutlineViewer title bar shows the current connection status:
  • DISCONNECTED: Not connected to any NetworkTables instance
  • Connected (IP address): Successfully connected to a robot or server
  • X Client(s) Connected: Running as server with X clients connected

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Topic Tree

NetworkTables entries are displayed in a hierarchical tree structure based on their topic names. For example: 
SmartDashboard/
├── Autonomous/
│   └── Selected
├── DriveMotors/
│   ├── LeftSpeed
│   └── RightSpeed
└── Sensors/
    ├── Gyro
    └── LeftEncoder

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Editing Values

To edit a NetworkTables value:
  1. Locate the entry in the topic tree
  2. Click on the value field
  3. Enter the new value
  4. Press Enter to publish the change

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Use Cases

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Debugging

Quickly check if your robot is publishing expected values:
  • Verify sensor readings
  • Monitor motor outputs
  • Check autonomous mode selection

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Tuning

Adjust PID constants or other tuning parameters in real-time:
  • Publish tuning values from your code
  • Modify them in OutlineViewer
  • Observe the effects immediately

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Testing

Simulate driver station inputs or test specific conditions:
  • Manually set values that would normally come from controls
  • Trigger specific states or modes
  • Test edge cases

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NetworkTables Logging

OutlineViewer includes a log viewer that displays NetworkTables system messages:
  • INFO: General information about connections and operations
  • WARNING: Non-critical issues that may need attention
  • ERROR: Errors that prevent normal operation
  • CRITICAL: Severe errors requiring immediate attention
Access the log from the View menu.

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Building OutlineViewer

To build OutlineViewer from source: 
./gradlew outlineviewer:build
The compiled executable will be available in the build output directory.

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System Requirements

  • Java Development Kit (JDK) 17 or later
  • C++ Compiler:
    • Linux: GCC 11 or greater
    • Windows: Visual Studio 2022 with C++ support
    • macOS: Xcode 14 or later command-line tools

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Comparison with Other Tools

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OutlineViewer vs Glass

OutlineViewer is lighter weight and focused solely on NetworkTables viewing and editing. Glass provides advanced visualization features including:
  • Field visualization
  • Camera streams
  • Hardware-specific widgets
  • Plotting capabilities

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OutlineViewer vs Shuffleboard

OutlineViewer is designed for development and debugging. Shuffleboard is designed for competition use with:
  • Customizable layouts
  • Widget system
  • Camera stream management
  • Competition-focused UI
  • Glass - Advanced visualization and debugging tool
  • Shuffleboard - Dashboard for competition
  • SysId - System identification tool

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