Graphics and UI Modules

Relevant source files

• build.gradle
• docs/build.gradle
• modules/canvasfx/build.gradle
• modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java
• modules/main/build.gradle
• modules/server/build.gradle
• modules/socket/build.gradle
• modules/socket/src/main/java/com/annimon/ownlang/modules/socket/socket.java
• ownlang-core/build.gradle
• ownlang-desktop/build.gradle
• ownlang-parser/build.gradle
• ownlang-utils/build.gradle
• settings.gradle

This document covers the graphics and UI capabilities provided by OwnLang's visual modules, primarily the canvasfx module which integrates JavaFX for 2D graphics rendering, canvas operations, and visual effects. This module enables creation of graphical applications with drawing capabilities, event handling, and sophisticated visual effects.

For network-based UI applications, see Server Module. For basic I/O and system interaction, see Standard Library Modules.

Module Architecture

The graphics and UI system in OwnLang is built around JavaFX integration through the canvasfx module, which provides a comprehensive graphics API accessible from OwnLang scripts.

Sources: modules/canvasfx/build.gradle1-24 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java1-48 settings.gradle9-14

Module Configuration and Dependencies

The canvasfx module is configured as a separate Gradle subproject with specific JavaFX dependencies and shadow JAR packaging for distribution.

Configuration	Value	Purpose
Module ID	canvasfx	Module identifier in OwnLang
Version	1.1.0	Current module version
JavaFX Version	21	Required JavaFX runtime
JavaFX Modules	javafx.controls, javafx.swing	Core and Swing bridge components
Build Plugin	org.openjfx.javafxplugin	JavaFX Gradle plugin
Distribution	Shadow JAR	Self-contained executable JAR

The module follows the standard OwnLang module interface pattern, implementing both constants() and functions() methods to expose functionality to OwnLang scripts.

Sources: modules/canvasfx/build.gradle1-24 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java88-195

Core Graphics Components

The canvasfx module provides several key components that work together to enable graphics programming in OwnLang.

Sources: modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java48-195 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java632-705

Graphics Context API

The GraphicsFXValue class provides a comprehensive wrapper around JavaFX's GraphicsContext, exposing over 60 drawing and rendering methods to OwnLang scripts.

Drawing Operations

Category	Methods	Description
Path Operations	beginPath, closePath, moveTo, lineTo	Path construction and management
Shape Drawing	fillRect, strokeRect, fillOval, strokeOval	Basic shape rendering
Complex Shapes	fillPolygon, strokePolygon, fillArc, strokeArc	Advanced geometric shapes
Text Rendering	fillText, strokeText, setTextAlign, setTextBaseline	Text drawing with alignment
Image Operations	drawImage, createImage, getPixels	Image rendering and manipulation
Transformations	translate, rotate, scale, transform	Coordinate system transformations

State Management

Operation	Methods	Purpose
Graphics State	save, restore	State stack management
Fill/Stroke	setFill, setStroke, getFill, getStroke	Color and pattern settings
Line Properties	setLineWidth, setLineCap, setLineJoin	Stroke appearance
Blending	setGlobalBlendMode, setGlobalAlpha	Compositing controls
Effects	setEffect, applyEffect	Visual effect application

Sources: modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java632-950

Color System

The module provides a comprehensive color system with multiple color space support and predefined color constants.

The color system supports:

• ARGB Constructor: Direct 32-bit integer color values
• RGB Components: Separate red, green, blue, alpha values (0.0-1.0)
• HSB Color Space: Hue, saturation, brightness representation
• Web Colors: CSS-style color strings (#FF0000, red, etc.)
• Named Constants: All JavaFX predefined colors (BLACK, WHITE, RED, etc.)

Sources: modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java92-105 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java246-298

Visual Effects System

The module provides access to JavaFX's comprehensive effects engine through wrapper functions that create EffectValue objects.

Available Effects

Effect Type	Constructor Function	Parameters
Blur Effects	BloomEffect, BoxBlurEffect, GaussianBlurEffect, MotionBlurEffect	Threshold, radius, iterations, angle
Shadow Effects	DropShadowEffect, InnerShadowEffect, ShadowEffect	Blur type, color, radius, offsets
Color Effects	ColorAdjustEffect, ColorInputEffect, SepiaToneEffect	Hue, saturation, brightness, contrast
Composite Effects	BlendEffect, ReflectionEffect	Blend mode, opacity, reflection parameters
Lighting Effects	LightingEffect, GlowEffect	Light sources, surface properties, glow level
Transform Effects	PerspectiveTransformEffect	Corner point coordinates

Effect Application

Sources: modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java175-190 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java346-558

Event Handling System

The module provides comprehensive event handling for user interaction through the JavaFX event system.

Event Categories

Event Category	Event Types	Handler Registration
Mouse Events	MOUSE_CLICKED, MOUSE_PRESSED, MOUSE_RELEASED, MOUSE_MOVED, MOUSE_DRAGGED	addEventHandler, addEventFilter
Keyboard Events	KEY_PRESSED, KEY_RELEASED, KEY_TYPED	Event type constants with KeyCode mapping
Touch Events	SWIPE_UP, SWIPE_DOWN, SWIPE_LEFT, SWIPE_RIGHT	Gesture recognition support
Drag Events	DRAG_DETECTED, MOUSE_ENTERED_TARGET, MOUSE_EXITED_TARGET	Drag and drop operations

Event Constants and Enums

The module exposes several enumeration constants for event handling:

• Events: Mapped to Events enum with ordinal values
• MouseButton: PRIMARY, SECONDARY, MIDDLE button constants
• KeyCode: Complete JavaFX KeyCode enumeration for keyboard handling

Sources: modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java56-86 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java149-166 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java191-194

Image Processing

The ImageFXValue class provides image creation, loading, and pixel-level manipulation capabilities.

Image Creation Methods

Method	Signature	Purpose
Load from URL	createImage(url)	Load image from file or web URL
Create Blank	createImage(width, height)	Create empty WritableImage
From Pixel Data	createImage(width, height, pixels)	Create image from ARGB pixel array

Image Properties and Operations

• Properties: width, height, preserveRatio, smooth (read-only)
• Pixel Access: getPixels() method returns ARGB integer array
• Pixel Format: Uses WritablePixelFormat.getIntArgbInstance() for consistent ARGB handling
• Integration: Seamless use with GraphicsContext.drawImage() for rendering

Sources: modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java601-630 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java561-599

Window Management

The module integrates with Java Swing through JFXPanel to provide windowing capabilities that bridge Swing and JavaFX.

Core Window Functions

Function	Purpose	Implementation
window(width, height, title)	Create main application window	Uses JFrame with embedded JFXPanel
repaint()	Force canvas redraw	Triggers JavaFX Platform update

Threading Model

The module handles JavaFX threading requirements through Platform.runLater() calls, ensuring proper thread safety when integrating with Swing applications and the OwnLang runtime.

Sources: modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java53-55 modules/canvasfx/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java172-173