Regions#

import numpy as np

import scenex as snx
import scenex.app.events as events
from scenex.utils.projections import zoom_to_fit

try:
    from imageio.v3 import imread

    data = np.asarray(imread("imageio:astronaut.png")).astype(np.uint8)[::-1, :, :]
except Exception:
    data = np.zeros((256, 256, 3), dtype=np.uint8)
    for i in range(256):
        data[i, :, 0] = i
        data[i, :, 2] = 255 - i
    for j in range(256):
        data[:, j, 1] = j


REGIONS: list[tuple[str, str, str, str, str]] = [
    # Full canvas (default)
    ("Full canvas:", "0%", "100%", "0%", "100%"),
    # Right half, full height
    ("Right half:", "50%", "100%", "0%", "100%"),
    # Fixed 400x400 region at (50, 50)
    ("Fixed 400x400 at (50, 50):", "50px", "450px", "50px", "450px"),
    # Fixed 400x400 region at bottom right corner
    ("Fixed 400x400 at bottom right corner:", "-400px", "100%", "-400px", "100%"),
    # 50px inset on all four sides using negative pixels for far edges
    ("50px inset all sides:", "50px", "-50px", "50px", "-50px"),
    # Centered 200px-wide strip using compound Dim expressions
    (
        "Centered 200px-wide strip (50% - 100px, 50% + 100px):",
        "50% - 100px",
        "50% + 100px",
        "0%",
        "100%",
    ),
]


img = snx.Image(data=data, clims=(0, 255))
view = snx.View(
    scene=snx.Scene(children=[img]),
    camera=snx.Camera(),
)
canvas = snx.Canvas(views=[view], width=600, height=600, visible=True)

region_idx = 0


def _on_click(event: events.Event) -> bool:
    global region_idx
    if isinstance(event, events.MousePressEvent):
        region_idx = (region_idx + 1) % len(REGIONS)
        name, x_start, x_end, y_start, y_end = REGIONS[region_idx]
        view.layout.x = x_start, x_end
        view.layout.y = y_start, y_end
        print(f"[{region_idx + 1}/{len(REGIONS)}] {name}")
    return False


view.set_event_filter(_on_click)

name, *_ = REGIONS[region_idx]
print(f"[{region_idx + 1}/{len(REGIONS)}] {name}")
print("Click the view to cycle through layout options.")

snx.show(canvas)
zoom_to_fit(view)
snx.run()