What the array component Properties pane's Copies box is showing, while somebody is typing in it, paired with the sheet they are typing it on. Held here rather than left in the DOM because the box must NOT apply as it is typed: how many copies an array component has decides how many ports it has, so every keystroke would make every instance of it out of date - typing 12 over 4 would pass through 1 on the way, briefly making it an array of one copy and telling every instance so. It applies when the box is left, or on Enter. The sheet's name goes with the text so that a half-typed number cannot be shown on some other sheet's box: leaving a sheet is not something the box gets told about.

if true the "build" tab appears on the RHS

What the user has typed into the catalogue's search box. Empty shows the catalogue whole, with its sections closed as before; anything else shows only components whose name or tooltip contains it, with the sections holding them open.

whether the open design builds into a simulation, for the Simulation tab's buttons

Components and connections that have been selected and copied.

The component libraries available: names and directories only, found once at startup. No library file is opened until the user opens a library. The catalogue is a pure render function, so it cannot look for them itself.

if true highlight connections from wavesim editor

the project contains, as loadable components, the state of each of its sheets

components and connections currently selected

used during step simulation: simgraph for current clock tick

stores the generated truth table

The data viewport as the checks last derived it, with when it last CHANGED. The pair exists for one question the derivation alone cannot answer - how long has THIS viewport been waiting to be served - which is what the stale banner is about: it shows when the viewport is still unserved (differs from FetchedData; an error reply never updates that, so an errored fetch counts as still outstanding) for longer than any healthy fetch takes, measured from this stamp. A viewport change - a scroll, a hover - resets the clock, so starting a fetch can never look stale for the frames it is in flight.

used to determine whether mouse is currently dragging the divider, or used normally

A catalogue item being dragged onto the canvas, or the position one was dropped at. None whenever no such gesture is in flight, which is nearly always.

The snapshot of a fetch that FAILED: not reissued while the current snapshot still equals it - reset is inequality itself, so a changed viewport tries again and an unchanged one does not retry at wire speed.

The data viewport the last COMPLETED fetch was for - None until one completes under the current session. The fetch decision is `dataViewportOf model <> FetchedData`; nothing clears this on rebuild because the epoch inside the viewport makes a rebuild an inequality (EndSimulation clears it as hygiene only).

the structure viewport the last completed fetch covered, likewise

components and connections which are highlighted

true during period when a sheet or project is loading

Which pane last received a mouse-down, and so where unmodified keys go. Set on mouse-down only - never on mouse-move - so it cannot change under the user's hand while they are typing. It replaces a flag set from the pointer's position on every mouse move, which was stale whenever the pointer had not moved and measured against the wave simulator's divider whichever tab was actually showing.

last time check for changes was made

Track the last added component

used to determine whether current canvas has been saved (includes any change)

component ids and connection ids previously selected (used to detect changes)

top-level canvas used for current wave simulation

last used bus width in bits - used as default in next component create dialog

record containing functions that create react elements of notifications

The library the catalogue is showing instead of its own contents, if any, with the component headers read when it was opened.

The library sheets the user has asked to look inside, by name. A library component is an abstraction and its sheet is not normally reachable at all, but understanding how one works is a fair thing to want, so an instance's right-click menu can open its sheet read-only. Held here rather than on the sheet's CCForm because Form is written to the .dgm on every save: this state is meant to last only as long as the project is open, and storing it in the file would both outlive that and let the Sheets menu's Unlock turn a library sheet into an ordinary editable one.

Contains a list of pending messages

How the components of an in-progress drag were added, if they were. Set when the drag starts and consumed when it settles; None the rest of the time.

data to populate popup (may not all be used)

function to create popup pane if present

The value the schematic probe last read, and what was asked for to get it. In the model rather than beside it because the probe is drawn from the model, and an answer arriving anywhere else would not redraw the label it belongs to. Keyed by the wave and the cycle, so a label is drawn only where the value on screen is the value that was asked for - which is what stops the previous wire's value appearing under the pointer on this one.

Set while the project browser is open, and None the rest of the time - which is how its refresh timer knows to stop.

What the open sheet's draw block is pinned to, when it is one of the above and has finished loading. None for every ordinary sheet, and while a read-only one is still loading - loading legitimately changes the canvas, recomputing symbol sizes, rerouting wires whose ports moved and centring the circuit, so the pin cannot be armed until that has settled. See ModelHelpers.pinDrawBlock.

which of the tabbed panes is currently visible

Function to be run after rendering to update the model

used to enable "SAVE" button

component currently selected in properties dialog

Draw Canvas

The Sheet menu is normally dismissed by clicking anywhere outside it - a sheet in it, or the schematic. Pinned, it stays open until the pin is clicked again, so that a design can be navigated with the hierarchy in view. Sheets fitted while it is pinned are sized to the canvas beside it rather than to the whole canvas - see Sheet.getWindowParasToFitBox.

When the .NET simulator's last build reply landed, ms on the performance clock. With SidecarRunEndedMs, what the stale-waveform warning times itself from: the warning must not count time spent building or simulating - both have their own feedback - so its clock starts at whichever came last of the view changing and these two ending. Zero when no such thing has happened, which max then ignores.

Every asynchronous operation asked of the .NET simulator and not yet answered, by the number it was asked under. **This is what makes synchronous interrogation safe.** A synchronous operation may go out only when this is empty, and two synchronous operations cannot overlap, because one runs to completion on the renderer's single thread before anything else runs. Those two facts together are why nothing here needs a priority queue, a dispatch lock, or preemption: a synchronous operation never waits behind an asynchronous one, because it is never issued while one exists.

When the last run chunk's reply landed. Stamped per chunk: while the loop runs the warning is suppressed anyway, so the stamp that matters is the final one - the loop's end.

The session the .NET simulator is believed to hold, which is what a command names.

which of the subtabs for the right pane simulation is visible

Whether the sheets of placed library components appear in the Sheets menu. False at startup and not settable from the ordinary UI: a library component is meant to be one thing, and seeing its innards listed beside the user's own sheets is confusing rather than informative. It is worth having for anyone writing a library, who does need to see what a component brought with it. The waveform simulator ignores this: library sheets are never offered there. Run simulation in the renderer instead of the .NET sidecar. DEPRECATED, and false by default: the sidecar is the simulator. It builds a simulation against the machine's memory rather than a browser heap, so it reaches cycle counts the renderer cannot, and it simulates roughly twice as fast on the designs that take long enough to care (docs/dev/sidecarSimulation.md has the measurements). The renderer's own simulator is kept for development - it is what the sidecar's results are checked against, and the only one the algebraic (FData) path and truth tables have - and is expected to be removed once the sidecar has been trusted for a while. Switchable only from Development > Simulation, and only while nothing is simulating: changing it throws away every simulation in flight, since the two backends do not share so much as a step array.

If the application has a modal spinner waiting for simulation

function to create spinner popup pane if present (overrides otehr popups)

The cycle a step-simulation run is heading for, when one is - with where it started, for the progress bar. Model state, not a loop: after every message the update pipeline sees this set, the wire free and the clock short of the target, and issues ONE chunk. Cleared when the clock arrives, when the progress popup is closed (which is what Cancel is), and when the simulation ends.

pokes into the running simulation so far - see DataViewport.VpStimulus

Set by the tickbox on the error popup, and never saved: an error the user has decided not to be interrupted by again is a decision about the session they are in the middle of, not about Issie. It stops the popup only - everything still reaches the buffer, and Info > Bug Reports still shows it.

style info for the truth table

State of menus for sheets, projects etc

Projects whose top-sheet choice popup the user has cancelled. Cancelling opens the sheet at default parameter values; the question is not asked again for that project.

A breadcrumb-like trail of visited sheets used for UI back button

Bad way to tidy up the messy UI commands - better - do them all in just one message!

User data for the application

True from a horizontal scroll of the waveform viewer until it has been still for Constants.runBannerAfterScrollMs, carrying the serial number of the scroll that set it. The run banner shows nothing while it holds - scrolling into cycles that have not been simulated starts a run every time, and a banner that flashes on each step of a drag is noise. The serial is what makes the wait restartable: the WaveScrollSettled message carries the serial it was armed for, so the timer from an earlier step of a drag cannot put the banner back up under a later one.

Map of sheet name to WaveSimModel

which top-level sheet is used by wavesim

viewer width in pixels altered by dragging the divider

The width of the app window in CSS pixels, as the browser last reported it. An external input, like a key or the pointer's position: it arrives on the window's resize event - which a change of web zoom also fires - and nothing else writes it. It is in the model rather than measured where it is wanted because a render happens only when the model changes, so a view that reads the window directly stands still until something unrelated happens to it.