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Basic Concepts

Understanding these core concepts will help you use window-art effectively.

The Desktop Singleton

window-art uses a singleton pattern for managing the SDL2 subsystem and all windows. The Desktop class handles:

  • SDL2 initialization
  • Event loop processing
  • Window tracking
  • Timing and frame management

You rarely interact with it directly. Instead, use the module-level functions:

import window_art as wa

# These all delegate to Desktop.get()
wa.init()           # Initialize SDL2
wa.window(...)      # Create a window
wa.update()         # Process one frame
wa.quit()           # Clean up

Auto-Initialization

The first call to wa.window() automatically initializes SDL2 if needed:

import window_art as wa

# No explicit init() needed
win = wa.window(100, 100, 200, 200)  # Auto-initializes

The run() Context Manager

The recommended way to use window-art:

import window_art as wa

with wa.run():
    # SDL2 initialized, windows can be created
    win = wa.window(100, 100, 200, 200)
    wa.wait(1)
# Automatic cleanup when exiting the context

Immediate-Mode Animation

Animation functions like move(), fade(), and resize() are blocking. They run to completion before returning:

import window_art as wa

with wa.run():
    win = wa.window(100, 100, 100, 100)

    wa.move(win, 500, 100, duration=1.0)  # Blocks for 1 second
    wa.move(win, 100, 100, duration=1.0)  # Then blocks for another second
    # Total time: 2 seconds

This makes animations predictable and easy to reason about.

Non-Blocking Alternatives

For advanced use cases, _async variants return generators:

import window_art as wa

with wa.run():
    win = wa.window(100, 100, 100, 100)

    # Get animation generator
    anim = wa.move_async(win, 500, 100, duration=1.0)

    # Run it manually
    wa.run_animation(anim)

The Update Loop

The update() function processes one frame:

  1. Handles SDL events (window, keyboard, mouse)
  2. Updates animation state
  3. Applies pending changes to windows
  4. Returns False if quit was requested
import window_art as wa

wa.init()
win = wa.window(100, 100, 100, 100)

while wa.update():
    # Custom per-frame logic
    win.x += 1

wa.quit()

Frame Timing

Access timing information via:

wa.delta_time()  # Seconds since last update()
wa.get_time()    # Seconds since init()

Window Properties

Windows have many readable and writable properties:

win = wa.window(100, 100, 200, 200, color="red")

# Position
win.x = 150
win.y = 200
win.position = (150, 200)  # Set both at once

# Size
win.w = 300
win.h = 250
win.size = (300, 250)  # Set both at once

# Appearance
win.color = "blue"
win.opacity = 0.8
win.title = "My Window"

# Behavior
win.borderless = False
win.always_on_top = True
win.resizable = True
win.shadow = False  # macOS only

Dirty Flag Optimization

Property changes are batched internally. When you set win.x and win.y separately, the actual SDL calls happen together in the next update():

# These don't cause two separate window moves
win.x = 100
win.y = 200
# Both applied in next update()

This reduces WindowServer overhead significantly.

Color System

Colors can be specified in multiple ways:

# CSS named colors (147 supported)
win.color = "coral"
win.color = "dodgerblue"

# Hex codes
win.color = "#ff6347"
win.color = "#f00"      # Short form

# RGB tuples
win.color = (255, 99, 71)

# RGBA tuples
win.color = (255, 99, 71, 128)

# Color objects
from window_art import Color
win.color = Color(255, 99, 71)

See Colors Guide for the full list of named colors.

Coordinate System

Coordinates use screen pixels with origin at the top-left of the primary display:

(0, 0) ─────────────────────► X
  │
  │      (x, y)
  │        ┌────────┐
  │        │ Window │
  │        └────────┘
  │
  ▼
  Y

Multiple monitors extend this coordinate space. Use wa.screens() to query monitor geometry:

for screen in wa.screens():
    print(f"Screen {screen.index}: {screen.w}x{screen.h} at ({screen.x}, {screen.y})")

Window Lifecycle

# Creation
win = wa.window(100, 100, 200, 200)

# Visibility
win.hide()
win.show()

# Z-order
win.raise_window()

# Destruction
win.close()  # Explicit
# or let it be garbage collected

All windows are automatically closed when using the run() context manager.

Next Steps