The size of `box` along the direction an array runs.

The bounding box `copies` copies of `box` occupy once arrayed.

The direction a fragment of this shape should be arrayed in: across its short axis, so the copies stack up beside each other. A square fragment goes vertically, which is the way a row of repeated logic is normally built up.

Whether arraying `box` this way runs it along its long axis, by more than Constants.arrayAspectWarning. Copies then stack end to end into a strip, which is what the dialog warns about rather than refuses: it is occasionally what is wanted.

Where the `i`th copy of an array goes, relative to the first.

From one copy of `box` to the next: the fragment's own size along the array, plus a gap.

Returns the smallest BB containing box and point. Could be made more efficient

calculates the smallest bounding box that contains two BBs, in form with W,H > 0

The bounding box of what is on the clipboard, or None when nothing has been copied. Labels are included, and have to be: a label sits below its symbol, so a fragment measured without them leaves a gap that the label of one copy hangs into the next through. A single copied component is the case that shows it - symbolBBUnion takes the first symbol's box without its label, which for one symbol is the whole answer. Recalculated rather than read off the symbol, as symbolWireBBUnion does: the stored box is only as fresh as whatever last set it, and these symbols were put aside when they were copied.

Check that canvas is large enough to have space all round the visible area. If not, then change model by moving circuit on canvas and/or extending canvas. Keep components in same visible position during this process. returns new model with all positions updated if need be.

Finds all components that touch a bounding box (which is usually the drag-to-select box)

Finds all components (that are stored in the Sheet model) near pos Optimised a little for space

Finds all components (that are stored in the Sheet model) near pos

Returns the ports of all model.NearbyComponents

shift circuit to middle of canvas, resizing canvas to allow enough border if needed. return scroll and zoom paras to display all of circuit in middle of the given window

How much of the left of a `width` by `height` drawing area a fit should leave to a menu `menuWidth` wide: all of it, unless what is left over is a slot more than Constants.maxFitAspectRatio times as tall as it is wide (or as wide as tall), where going round the menu would shrink the circuit further than the menu ever hides it.

The window a fit should use, for the whole Issie model - which is what says whether the Sheet menu is pinned. The draw block is handed this rather than working it out, because Model.SheetMenuPinned is not draw block state: see SheetUpdate.update, which is given the whole model for exactly this. None when there is no canvas to measure, which is what the fit used to return None for.

return screen edge coords if possible

return X=CanvasDiv.scrollLeft, Y= canvasDiv.scrollTop

get scroll and zoom paras to fit box all on screen centred and occupying as much of screen as possible

could be made more efficient, since segments contain redundant info

helper used inside Map.tryFind hence the unused parameter returns true if pos is insoie boundingbox

Checks if pos is inside any of the bounding boxes of the components in boundingBoxes

Whether the sheet is still exactly where a fit to `win` would put it, and so has not been scrolled, zoomed or edited since one. Undoing a fit - as unpinning the Sheet menu does - is only ever right for a view the fit itself chose: once the user has moved it, it is theirs. A second fit of an already fitted circuit is a no-op, since the circuit is centred on the canvas already and the same box gives the same magnification, so this can ask by computing one. Compared against where the canvas is actually scrolled to, not against the model's record of it: a fit that asks to scroll past a canvas edge gets what the browser allows instead, and it is that the user is looking at.

The magnification that puts `box` in `win`, as large as the window and the zoom limit allow.

The most copies of `box` that fit on a canvas `canvasSize` square, which is the whole of what a sheet has room for. Can be below 2, which means there is no array to paste at all.

Returns what is located at pos. Priority Order: InputPort -> OutputPort -> Label -> Wire -> Component -> Canvas

Checks if pos is inside any of the ports in portList

Width of the drawing area's left edge the Sheet menu is over, and 0 when the menu is closed - which is display:none, and so has no width. Measured rather than derived because it is a rendered fact: it depends on the design's tree and on how much room the canvas gives it.

Used to filter OnScroll messages caused by recent scroll updates. These could reset scroll back to some previous value.

Used to filter out-of-sequence OnScroll messages. These could reset scroll to some previous value. Incremented by program UpdateScroll and OnScroll.

return a BB equivalent to input but with (X,Y) = LH Top coord, (X+W,Y+H) = RH bottom coord note that LH Top is lower end of the two screen coordinates

Creates a command to Symbol

Returns the smallest BB that contains all symbols, labels, and wire segments. For empty circuit a BB is returned in middle of viewable screen.

returns the symbol if pos is inside any symbol's LabelBoundingBox

HLP23 AUTHOR: BRYAN TAN if pos is inside any one of the custom symbol's corners, return the diagonally opposite corner (its position is fixed during resizing), and the index of the corner being held

True for the first view function evaluation after scroll has been programmatically updated. In that case OnScroll messages are never sent.

Classify a modified wheel event and calculate its zoom factor without touching the DOM.

Creates a command to BusWire

Returns the smallest BB that contains all segments of wire.

Calculate the scroll position that keeps a sheet point at the centre of the viewport.