Module text_field 

TextField — single-line editable text input.

See text_field_core for the internal helpers, shared edit state, and undo command type.

Feature set mirrors C# agg-sharp InternalTextEditWidget:

• Character / word navigation (arrows, Ctrl+arrow, Home, End)
• Keyboard selection (Shift+movement), Ctrl+A select-all
• Mouse click to position cursor, drag to extend selection
• Double-click to select the word under the cursor
• Cut / Copy / Paste (Ctrl+X/C/V, Shift+Del, Ctrl/Shift+Ins) — requires the clipboard crate feature; silently no-ops without it
• Undo / Redo via the shared UndoBuffer
• Blinking cursor (500 ms half-period from the moment focus is gained)
• Horizontal scroll to keep cursor visible
• Placeholder text, read-only mode, SelectAllOnFocus
• Callbacks: on_change, on_enter, on_edit_complete

Structs

TextField

Single-line editable text field.