# Tree and editors

A console program that creates the Atlas VCL data controls on a form that is
never shown and verifies what each one does:

- `TAtlasTree`: builds a small hierarchy with `AddNode`, sorts children with
  `SortChildren`, finds a node with `FindCaption` (case-insensitive), moves a node
  to the root with `MoveNode` and shows that moving a node under its own child
  raises `EAtlasTreeError`. A lazy node gets its children from `OnLoadChildren`
  on the first expand only. `ToJSON`/`LoadJSON` copy the tree to a second tree,
  and a JSON document without the required fields is rejected without changing it.
- `TAtlasSheetGrid`: shows a `TAtlasWorkbook` with a `SUM` formula, follows a
  change to a referenced cell, applies a fixed-decimal format and detaches when the
  workbook is freed.
- `TAtlasInspector`: lists the published properties of a small settings component,
  assigns integer, floating-point, enumeration and Boolean values with
  `SetProperty`, rejects an invalid integer and a read-only property with
  `EAtlasPropertyError`, and detaches when the component is freed.
- `TAtlasRichEdit`: formats a selection, saves it with `SaveRTF`, loads the bytes
  into a second editor with `LoadRTF` (text and bold style survive), finds two
  matches with `FindNext` and replaces them with `ReplaceAll`.
- `TAtlasValueEdit`: validates numbers and dates, shows that a decimal comma
  is not a number, and that `Required` turns a blank value into an error.

Controls that wrap a Windows control need a window handle, so each one is given
the hidden form as `Parent` before it is used. A mismatch raises an exception,
the program prints `FAIL: ...` and exits with code 1.

## Build and run

Open `TreeAndEditors.dpr` in Delphi 13; the IDE creates the project file. Add the Atlas VCL `src` folder to the project's search path, then build and run for Win32 or Win64. No packages need to be installed. The program needs no input. It checks its own results and stops with an error if any of them differs from the output below.

## Expected output

```
TAtlasTree
  ok: children sorted by caption = Data platform
  ok: case-insensitive caption search
  ok: node moved to the root level
  ok: moving a node under its own child is rejected
  ok: a lazy node shows an expand button before loading
  ok: OnLoadChildren ran once on first expand
  ok: children are not loaded twice
  ok: JSON round trip keeps captions, expansion and lazy flags = [{"caption":"Engineering",...}]
  ok: a rejected import leaves the tree unchanged
TAtlasSheetGrid
  ok: column headers use letters = A
  ok: B1 shows the calculated value = 42
  ok: the grid follows workbook changes = 20
  ok: cell formats apply to the displayed text = 20.0
  ok: the grid detaches when its workbook is freed
TAtlasInspector
  ok: published properties are listed with their values = 3
  ok: SetProperty converts and assigns typed values
  ok: an invalid value is rejected before assignment
  ok: a read-only property is rejected
  ok: destroying the component detaches the inspector
TAtlasRichEdit
  ok: selection formatting applied
  ok: SaveRTF returns RTF bytes
  ok: LoadRTF restores the text = Atlas notes: draft one, draft two.
  ok: LoadRTF restores the formatting
  ok: FindNext selects the first match after the caret
  ok: FindNext continues from the selection
  ok: ReplaceAll reports two replacements
  ok: text after ReplaceAll = Atlas notes: revision one, revision two.
TAtlasValueEdit
  ok: a number is accepted
  ok: NormalizedValue is the stored form = 12.5
  ok: a locale decimal comma is rejected with a message
  ok: blank is valid when not required
  ok: blank is invalid when required
  ok: 2026-02-29 is not a real date
  ok: 2028-02-29 is a leap day
PASS: TreeAndEditors
```

The tree JSON line shows the format `ToJSON` writes: an array of node objects,
each with `caption`, `expanded`, `lazy` and `children`. The `Archive` node was
expanded, so it is saved as expanded with its loaded child and `lazy` false; the
never-expanded `Later` node keeps `lazy` true.

## What to change first

- Put the controls on a visible form (`Align := alClient` on a page each) to see
  them; the calls stay the same.
- Replace `TTaskSettings` with one of your own components. The inspector lists
  published string, character, integer, 64-bit integer, floating-point and
  enumeration properties (Booleans are enumerations); sets, classes and events
  are not shown.
- In `TLazyLoader.LoadChildren`, query your own data source for the children of
  `Node`. If the handler raises, the tree removes the children it added and the
  node stays lazy, so the next expand tries again.