PromptPlus

# PromptPlus ## **TableMultiSelect<T> — Operations** [![NuGet](https://img.shields.io/badge/NuGet-PromptPlus-blue)](https://www.nuget.org/packages/PromptPlus) [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT) [![.NET](https://img.shields.io/badge/.NET-8%20%7C%209%20%7C%2010-512BD4)](https://dotnet.microsoft.com/)

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How the TableMultiSelect<T> control behaves while it is running: keyboard, checkboxes, ranges, filtering, horizontal scrolling, paging, history, and view-only mode.

Anatomy of the control

Select products: Notebook Pro            ← prompt + live answer (follows the cursor + column)
Category: Electronics                     ← description (optional / dynamic)
+---------------------------------------+
|   |  Id  | Name          |   Price    |  ← header row
+---+------+---------------+------------+
| x |    1 | Notebook Pro  |  $ 1299.99 |  ← focused, checked row
|   |    2 | Wireless Mouse|  $   29.90 |  ← unchecked row
+---------------------------------------+
Filter: note                              ← live filter text (when filtering)
Page 1/2                                  ← pagination
Space: check  Enter: confirm  Esc: cancel ← tooltip

The answer line updates as you navigate: without a TextSelector it shows the value of the row under the cursor in whichever column is currently Tab-focused (Tab/ Shift+Tab change it); with a TextSelector, that fixed text is shown instead, regardless of column. Once confirmed (Enter), the final answer shown is the checked-rows summary (comma-joined), resolved the same way per row.

Every region can be recolored — see Styles.

Keyboard

Key	Action
`↑` / `↓`	Move focus up / down (rows)
`Page Up` / `Page Down`	Jump one page
`Ctrl+Home` / `Ctrl+End`	First / last row
`Space`	Toggle the checkbox on the focused row
`Tab` / `Shift+Tab`	Move the focused column; wraps around at the first/last column
`Enter`	Confirm the checked set (enforces `Range`)
`Esc`	Abort → `IsAborted == true`
Any printable character	Type to filter (when `Filter` is not `Disabled`)
`Backspace`	Edit the filter text
`F2`	Toggle all rows on / off (respects the check predicate)
`F3`	Show only the checked rows / restore the full list
`F1`	Cycle tooltip content
`Ctrl+F1`	Show / hide the tooltip

Disabled rows are skipped and cannot be toggled.

The exact physical keys for toggle-all / filter-selected are configurable — the tooltip line always shows the active bindings. See Keyboard Bindings.

Checking rows

Space toggles the focused row. A row can only be checked if the check predicate allows it; otherwise the row stays unchecked and an error line is shown.
AddItem / AddItems can start rows checked with ischecked: true.
Default(values) pre-checks matching rows; its values take precedence over the per-item ischecked flag.
F2 toggles every eligible row on or off at once; F3 narrows the view to the checked rows and back.

Range constraints

Range(min, max?) is enforced on Enter:

If fewer than min rows are checked, the control stays open with a “minimum” error.
If more than max rows are checked, it stays open with a “maximum” error.
max of null means unlimited.

Columns

AddColumn is header-first: header text, then a Func<T, object> selector, then optional formatter, width, alignment, and filterable flag.
Width is either fixed (width: n) or auto-sized from the header and all cell values at Run time.
Content that exceeds the column width is truncated with an ellipsis.

Column alignment

ColumnAlignment sets per-column horizontal alignment:

Value	Effect
`Left`	Align cell content to the left (default)
`Right`	Align cell content to the right (typical for numbers)
`Center`	Center cell content

Horizontal scrolling

Tab / Shift+Tab always move the focused column, wrapping around at the first/last column — this works even when every column already fits on screen and nothing needs to scroll. HorizontalScroll only changes what happens once scrolling is actually needed (the columns don’t all fit within the console width):

Full (default) — shifts the visible viewport as a full column window.
Column — focuses one column at a time.

Layout & border regions

LayoutMode picks the box-drawing character set: SingleBox (default), DoubleBox, SingleASCII, DoubleASCII, or None.
HideElements hides individual regions — RowSeparator, Header, ColumnSeparator, OuterBorder — and combines with |. HideTable.None (default) shows everything.

Filtering

When Filter is Contains or StartsWith, typing narrows the visible rows in real time:

The match is case-insensitive.
FilterTableMode.Answer matches against the answer text (TextSelector).
FilterTableMode.ColumnFilters matches against the concatenated text of every column declared with isFilterable: true.
Rows already checked keep their checked state while filtered in or out; the returned array reflects the full checked set regardless of the current filter.
Clearing the filter (Backspace) restores the full list.

Disabled (the default) turns typing off entirely — arrow keys only.

Initial checked set & history

Default(values) pre-checks rows; provide DefaultMatchBy for records/classes so the right rows are located.
With EnableHistory, the checked array is stored on disk as JSON; UseDefaultHistory restores it on the next run.
History options (MinPrefixLength, MaxItems, ExpirationTime, FilterType, PageSize) match the Input history options.

View-only mode

ViewOnly() renders the table for display only:

Arrow and column keys still navigate, but checkboxes cannot be toggled.
Rows marked via Default remain shown as checked (read-only).
On Enter the pre-checked set is returned unchanged.

Options that change behavior

Set per instance via Options(...), or globally on PromptPlus.Config:

Option	Effect on `TableMultiSelect<T>`
`EnabledAbortKey(false)`	Removes Esc — the user must confirm
`HideAfterFinish(true)`	Erases the table after confirm — the whole control is erased, not just the interactive part
`ShowTooltip(false)`	Hides the keyboard hint line
`Prompt(...)` / `Description(...)`	Overrides the prompt / description text

PageSize can be set per control (PageSize) or globally (PromptPlus.Config.PageSize).

Edge cases & gotchas

Configuration is required. Run throws ValidationException unless at least one column and one row have been added.
Nothing checked returns an empty array (.Content.Length == 0), not null — this is distinct from an aborted result. Branch on IsAborted first.
No .Value wrapper. Iterating .Content yields each T directly, unlike Table<T> which returns a single TableSelectResult<T>.
Custom types need equality. Without DefaultMatchBy, Default on a record/class may not match the intended rows.
Async callbacks block the UI thread — keep predicates, selectors, and description callbacks fast.