Simulator — interaction map¶

Every control, key, and gesture in SimulatorApp, traced to its handler and the engine call it makes. Status is HOW IT IS — verified against the code with file:line citations — unless a row is explicitly marked otherwise. Tables follow the repo element schema: each row shows hop 1 (shell control handler → event it raises) and hop 2 (app subscription → app handler), plus whether anything leaves the process (Engine call?).

The window is a MainWindowShell with the default IsPlaybackTabVisible=true (src/SimulatorApp/MainWindow.axaml:20–21); the shell supplies the chrome, the app fills the four regions (MainWindow.axaml:23–67). All playback state (DispatcherTimer, _simMoveIndex, _isPlaying, _playSpeed, _autoPause, _wasPlayingBeforeScrub) is owned by the app's MainWindow (MainWindow.axaml.cs:54–65); the shell panels are pure UI surfaces that raise events. There is no MVVM, no ICommand — all wiring is code-behind events.

flowchart TB
  subgraph W["SimulatorApp.MainWindow"]
    L["LeftRegion<br/>LayerSlider · Load button"]
    V["ViewportRegion<br/>Canvas 600x600 + ViewportToolbar"]
    I["InspectorRegion<br/>OverlayPanel + FindingsPanel + PlaybackPanel"]
    S["StatusRegion<br/>StatusBar ← Shell.StatusText"]
  end
  L --> ES["EngineSession"]
  V --> VC["ViewportController"]
  I --> VC
  I --> PT["DispatcherTimer (app-owned)"]
  ES --> ABI["NpsAbi → native engine"]
  VC --> ABI

Left bar¶

Declared in MainWindow.axaml:23–34.

The slider maximum 10 is hard-coded; the generated demo toolpath has 5 layers (MainWindow.axaml.cs:245–250), and the XAML header comment calls this region a "layer nav stub" (MainWindow.axaml:12).

Viewport toolbar¶

Code-built in ViewportToolbar.cs:40–107 (no .axaml); events declared at :18–27, raised by lambdas at :70–81; icons assigned from theme resources Icon.Viewport.* in SetIconGeometries (:145–157). App subscriptions at MainWindow.axaml.cs:91–100. Both toggles default IsChecked = true (ViewportToolbar.cs:61, 64).

Overlay panel¶

Declared in OverlayPanel.axaml:10–14; hop 1 is OnRadioButtonChecked (OverlayPanel.axaml.cs:98–108) raising ModeChanged (:66); the app wires hop 2 at MainWindow.axaml.cs:115.

Notes on the apply path: after a load, OnLoadAnalyzeClick forces the mode to Thermal and calls ApplyCurrentOverlay unconditionally (MainWindow.axaml.cs:282–295), because Avalonia suppresses equal-value property changes and ModeChanged would not fire on a second load. "None" is motion-type — type-colored extrudes, not a true off state. Legend low/high and stats text are written back to the panel at MainWindow.axaml.cs:477–497.

Findings panel¶

Declared in FindingsPanel.axaml; chips at :38–64, list at :70, detail pane at :97–118. Initially IsVisible="False" (MainWindow.axaml:52); the app subscribes FindingSelected inside LoadFindings (MainWindow.axaml.cs:322–323, unsubscribe-first to avoid double-wiring).

Selecting a finding with layer >= 0 widens _maxLayer to at least layer + 1 (MainWindow.axaml.cs:405–408); a finding with moveIndex >= 0 jumps the playhead (:413–417). Unpinned findings (moveIndex = -1) update the detail pane but do not move the playhead. There is no search TextBox — filtering is chips-only (verified: zero TextBox in FindingsPanel.axaml).

Playback panel¶

Declared in PlaybackPanel.axaml (root x:Name="PanelPlayback"); initially IsVisible="False" (MainWindow.axaml:58); events wired at MainWindow.axaml.cs:124–133. The panel raises intent events only; the app owns the timer.

Auto-pause rule (HOW IT IS): on a forward step only, if auto-pause is enabled and any finding has moveIndex >= 0 less than 2 moves from the playhead (Math.Abs(...) < 2, i.e. distance 0 or 1), the timer stops and the status reads "Auto-paused at finding." (MainWindow.axaml.cs:645–656). Scrubbing deliberately does not auto-pause — the user is driving (MainWindow.axaml.cs:549–553).

Window keys¶

KeyDown="OnKeyDown" on the window (MainWindow.axaml:8) → OnKeyDown (MainWindow.axaml.cs:188) → shared dispatcher ShellKeybindings.Handle (ShellKeybindings.cs:82) with app-supplied actions in the readonly struct ShellKeybindings.Actions (ShellKeybindings.cs:58–71; supplied at MainWindow.axaml.cs:190–200).

Canvas and scrubber gestures¶

Viewport pointer events reach the app through the shell: the app content is a fixed 600×600 Canvas (ViewportCanvas, MainWindow.axaml:39); AttachViewportHandlers subscribes the ViewportHost (MainWindowShell.axaml.cs:269–274) and forwards to ViewportPointer* (events MainWindowShell.axaml.cs:35–37, raised :278–291); the app subscribes at MainWindow.axaml.cs:87–89.

Two suppression flags keep the scrubber and timer from fighting (PlaybackPanel.axaml.cs:143–162): _suppressScrubberEvent blocks the echo when the app pushes SimIndex into the panel (:463–467), and _isUserScrubbing parks intermediate value changes during a drag so the app sees a single commit on release.

Sidebar collapse, activity tabs, status bar¶

Declared in MainWindowShell.axaml; all chrome is shell-owned and UI-only.

Related pages¶

• Simulator — how it is — load/gen/analyze pipeline behind the Load button.
• Simulator — UI workflows — click-level end-to-end chains (gesture → engine → UI) with test coverage per workflow.
• Slicer — interaction map — the sibling app's surface; toolbar, layer slider, pointer math, and key dispatch are verbatim-shared.
• Sharing — duplication map — which of these handler blocks are clones.
• Sharing — plan — the stated direction for moving shared glue into the shell.