dock_demo

A proof-of-concept docking/tiling panel GUI in Slint, evaluating Slint for the ImSwitch GUI rewrite. See FINDINGS.md for the assessment.

Part of an initiative to replace micromanager-ImageJ GUI. tech demo only

Build & run

Using the Makefile:

make all        # profile release build (cargo build --release)
make run        # build release, then start the GUI (panel gallery)
make run-dock   # build release, then start the docking demo
make test       # run the unit tests
make clean      # cargo clean

Or with cargo directly:

cargo build --release              # release build
cargo run --release -- --gallery   # panel gallery
cargo run --release                # docking demo (default, no args)

Requirements: a Rust toolchain and a C/C++ compiler (for native deps); no Skia build is needed. build.rs enables the Slint experimental features automatically. First build is slow (large dependency tree); rebuilds are fast.

What it does

• Two dock regions split by a draggable divider.
• Each region has a tab strip; drag a tab from one region and drop it into the other to re-dock it.
• Tab content is a dynamically-loaded panel (compiled at runtime by the Slint interpreter), chosen by the tab's kind:
  • form — Laser-Control-style widgets (slider / spinbox / checkbox / button)
  • plot — a live waveform (animated)
  • image — a live procedural "camera" pattern (animated)

Layout

• ui/app.slint — dock shell: regions, tab strip, splitter, drag-drop, ComponentContainers.
• src/main.rs — Rust-owned dock model (VecModels), the move-tab docking logic (with unit tests), and wiring of panel factories.
• src/panels.rs — the three panel .slint sources + interpreter-backed ComponentFactory construction.
• build.rs — compiles ui/app.slint and enables Slint experimental features (DragArea/DropArea).

Notes

• Requires the experimental flag (set automatically in build.rs) for drag-and-drop.
• Depends on slint-interpreter's internal feature for embedding dynamic panels.
• Tested on macOS with the femtovg/software renderer (no Skia build required).

Test

cargo test   # covers the docking move logic

Headless screenshot

Window::take_snapshot() lets the app render a frame to a PNG with no screen-recording permission — handy for automated visual checks:

cargo run -- --screenshot out.png
# start the right region on the Image tab (verification aid):
IMSWITCH_DEMO_IMAGE_FIRST=1 cargo run -- --screenshot out.png

Panel component collection

ui/panels/*.slint is a library of ~13 self-contained panel components resembling the ImSwitch widget screenshots (Laser, Positioner, Recording, Focus Lock, Scan, Detector, SLM, FFT, Bead Rec, Rotation Scan, Rotator, Tiling, Data). Browse them with the gallery:

cargo run -- --gallery                 # sidebar list + preview (click to switch)
cargo run -- --gallery --panel 6       # preselect panel 6 (SLM), e.g. for screenshots
SLINT_SCALE_FACTOR=1 cargo run -- --gallery --panel 6 --screenshot slm.png

--panel N (N = 0..12) is the deterministic way to view/screenshot a specific panel.

Driver mode (automated UI testing)

--driver reads newline commands from stdin and drives the live UI with synthetic pointer/key events (via Window::dispatch_event) plus on-demand screenshots. This lets the GUI be exercised and visually checked entirely programmatically. Coordinates are in logical pixels, which equal screenshot pixels (1:1).

printf '%s\n' \
  'sleep 900' \
  'shot before.png' \
  'click 572 19' \
  'drag 147 19 670 300' \
  'shot after.png' \
  'quit' | cargo run -- --driver

Commands: move X Y, click X Y, press X Y, release X Y, drag X1 Y1 X2 Y2, key TEXT, shot PATH, sleep MS, quit (see src/driver.rs).

Reliability notes (important for automated testing):

• --screenshot, --panel N, move, and drag are reliable. drag works because Slint processes moved synchronously.
• Synthetic click is FLAKY. Slint emits clicked on a later event-loop tick, so it only fires if the loop keeps ticking after the release. click pumps extra moves to help, and it lands most reliably on animated windows / DragArea-wrapped targets (e.g. the dock tabs), but it is not guaranteed — especially on fully static plain-TouchArea targets (e.g. the gallery sidebar). Prefer --panel N / state flags over clicking for deterministic verification.
• Set SLINT_SCALE_FACTOR=1 when driving: the window's scale factor is otherwise nondeterministic between launches (snapshots come out 1120×720 or 2240×1440), which breaks fixed click coordinates. Forcing scale 1 makes snapshot px == logical px == click coordinates.
• For continuous/interactive control, run --driver as a background process with stdin connected to a FIFO and write commands to it over time; screenshots appear as files.