Docs / Reference / Properties A-Z

Properties Reference A-Z

This page documents every property available across HarbourBuilder controls. Properties are grouped by category and include the property type (PT_STRING, PT_NUMBER, PT_LOGICAL, PT_COLOR, PT_FONT) and the controls that support each one.

Property Types

Each property in the Object Inspector has an associated type that determines how it is edited and stored:

Type	Description	Example
`PT_STRING`	Text string	`"Hello"`
`PT_NUMBER`	Numeric value (integer or float)	`120`
`PT_LOGICAL`	Boolean (.T. / .F.)	`.T.`
`PT_COLOR`	RGB color value	`CLR_RED` or `"#FF0000"`
`PT_FONT`	Font descriptor (name, size, style)	`"Segoe UI", 10`

Appearance Properties

These properties control how a control looks on screen — colors, borders, styles, and visual state.

Property	Type	Description	Available For
`nBackColor`	PT_COLOR	Background color of the control	All visual controls
`nFontColor`	PT_COLOR	Text (foreground) color	All controls with text
`cCaption`	PT_STRING	Display text on the control	Button, GroupBox, Label, CheckBox, Radio, TabControl, Form
`cValue`	PT_STRING	Current value / text content	Edit, Memo, MaskEdit, StaticText, LabeledEdit
`nBorderStyle`	PT_NUMBER	Border style (0=none, 1=single, 2=raised, 3=sunken)	Edit, Memo, GroupBox, Panel, Bevel, ScrollBox
`lBorder`	PT_LOGICAL	Show a visible border around the control	Form, Panel, ScrollBox, GroupBox
`nBevelWidth`	PT_NUMBER	Width of the bevel edge in pixels	Bevel, Panel, GroupBox
`nBevelStyle`	PT_NUMBER	Bevel style (0=none, 1=raised, 2=sunken)	Bevel, Panel
`lFlat`	PT_LOGICAL	Use flat appearance instead of 3D	Button, SpeedBtn, BitBtn
`nAlignment`	PT_NUMBER	Text alignment (0=left, 1=center, 2=right)	Label, Edit, Memo, Button, StaticText
`nTextAlignment`	PT_NUMBER	Text alignment within the control bounds	Label, StaticText
`nImageIndex`	PT_NUMBER	Index of the image in the associated image list	Button, BitBtn, SpeedBtn, Image, TabControl, TreeView, ListView
`lTransparent`	PT_LOGICAL	Control background is transparent	Label, Image, Shape, StaticText, Panel
`nShapeType`	PT_NUMBER	Shape to draw (0=rectangle, 1=ellipse, 2=rounded rect, 3=triangle)	Shape
`nPenColor`	PT_COLOR	Outline/pen color for shapes	Shape, PaintBox
`nBrushColor`	PT_COLOR	Fill color for shapes	Shape, PaintBox
`nPenWidth`	PT_NUMBER	Width of the pen/stroke in pixels	Shape, PaintBox
`nPenStyle`	PT_NUMBER	Pen style (0=solid, 1=dash, 2=dot, 3=dash-dot)	Shape, PaintBox
`cHint`	PT_STRING	Tooltip text shown on mouse hover	All visual controls
`nProgress`	PT_NUMBER	Current progress value (0 to nMax)	ProgressBar
`nMin`	PT_NUMBER	Minimum value for range-based controls	ProgressBar, TrackBar, UpDown, ScrollBar
`nMax`	PT_NUMBER	Maximum value for range-based controls	ProgressBar, TrackBar, UpDown, ScrollBar
`nPosition`	PT_NUMBER	Current slider/thumb position	TrackBar, ScrollBar

Position and Size

These properties determine where a control is placed and how large it is.

Property	Type	Description	Available For
`nLeft`	PT_NUMBER	X coordinate of the control's left edge (pixels from parent's left)	All visual controls
`nTop`	PT_NUMBER	Y coordinate of the control's top edge (pixels from parent's top)	All visual controls
`nWidth`	PT_NUMBER	Width of the control in pixels	All visual controls
`nHeight`	PT_NUMBER	Height of the control in pixels	All visual controls
`lCentered`	PT_LOGICAL	Center the form on screen at activation	Form, Dialog
`nClientWidth`	PT_NUMBER	Width of the form's client area (excluding borders/title bar)	Form
`nClientHeight`	PT_NUMBER	Height of the form's client area	Form
`lResizable`	PT_LOGICAL	Whether the form can be resized by the user	Form, Dialog
`nMinWidth`	PT_NUMBER	Minimum allowed width when resizing	Form
`nMinHeight`	PT_NUMBER	Minimum allowed height when resizing	Form

Behavior Properties

These properties affect how a control behaves and responds to user interaction.

Property	Type	Description	Available For
`lVisible`	PT_LOGICAL	Whether the control is visible on screen	All visual controls
`lEnabled`	PT_LOGICAL	Whether the control responds to user input	All visual controls
`lReadOnly`	PT_LOGICAL	Content cannot be edited by the user (display only)	Edit, Memo, MaskEdit, StringGrid, DBEdit, DBMemo
`lWordWrap`	PT_LOGICAL	Wrap text to the next line when it exceeds the control width	Label, Memo, Edit, StaticText, DBMemo
`lMultiLine`	PT_LOGICAL	Allow multiple lines of text	Edit, Button
`lPassword`	PT_LOGICAL	Mask input characters (password field)	Edit
`lCheck`	PT_LOGICAL	Checked state of the control	CheckBox, Radio
`lChecked`	PT_LOGICAL	Checked state (alias for lCheck on some controls)	CheckBox
`lSelected`	PT_LOGICAL	Whether a list item is selected	ListBox, ComboBox, TreeView, ListView, StringGrid
`nTabIndex`	PT_NUMBER	Tab order index (determines focus traversal order)	All focusable controls
`lTabStop`	PT_LOGICAL	Whether the control can receive focus via Tab key	All focusable controls
`cMask`	PT_STRING	Input mask pattern (e.g., "99/99/9999" for dates)	MaskEdit
`nInterval`	PT_NUMBER	Timer interval in milliseconds	Timer
`lRunning`	PT_LOGICAL	Whether the timer is currently active	Timer
`nScrollBars`	PT_NUMBER	Scrollbar style (0=none, 1=horizontal, 2=vertical, 3=both)	Edit, Memo, ScrollBox, StringGrid, DBGrid, Browse
`lAutoSize`	PT_LOGICAL	Automatically size the control to fit its content	Label, Image, StaticText
`lModal`	PT_LOGICAL	Whether the form blocks interaction with other windows	Form, Dialog

Font Properties

Font-related properties control the typography of text displayed on controls.

Property	Type	Description	Available For
`cFontName`	PT_FONT	Name of the font family (e.g., "Segoe UI", "Arial")	All controls with text
`nFontSize`	PT_NUMBER	Font size in points	All controls with text
`lFontBold`	PT_LOGICAL	Bold text style	All controls with text
`lFontItalic`	PT_LOGICAL	Italic text style	All controls with text
`lFontUnderline`	PT_LOGICAL	Underlined text style	All controls with text
`lFontStrikeout`	PT_LOGICAL	Strikethrough text style	All controls with text
`oFont`	PT_FONT	Complete font object (wraps all font properties)	All controls with text

Inherited fonts

Controls inherit the font of their parent by default. Set oFont on a form to change the font for all child controls at once, unless a child overrides it with its own font settings.

Data Properties

Properties related to data binding, content, and data-aware controls.

Property	Type	Description	Available For
`cDataSource`	PT_STRING	Name or reference to the data source object	DBEdit, DBMemo, DBComboBox, DBCheckBox, DBText, DBGrid, DBNavigator, Browse
`cDataField`	PT_STRING	Field name in the data source to bind to	DBEdit, DBMemo, DBComboBox, DBCheckBox, DBText
`cItems`	PT_STRING	Array or list of items (for list-based controls)	ListBox, ComboBox, StringGrid, TreeView, ListView, TabControl
`nColCount`	PT_NUMBER	Number of columns in a grid or table control	StringGrid, DBGrid, Browse
`nRowCount`	PT_NUMBER	Number of rows in a grid or table control	StringGrid, DBGrid, Browse
`nCol`	PT_NUMBER	Current selected column index	StringGrid, DBGrid, Browse
`nRow`	PT_NUMBER	Current selected row index	StringGrid, DBGrid, Browse
`nItemIndex`	PT_NUMBER	Index of the currently selected item	ListBox, ComboBox, ListView, TreeView, TabControl
`cText`	PT_STRING	Text content of the control	Edit, Memo, Label, StaticText, LabeledEdit
`cPrompt`	PT_STRING	Label text displayed on the control	Button, CheckBox, Radio, GroupBox
`lHeader`	PT_LOGICAL	Show column headers in grid controls	StringGrid, DBGrid, Browse
`cAlias`	PT_STRING	Database table alias name	DbfTable, MySQL, MariaDB, PostgreSQL, SQLite, Firebird, SQLServer, Oracle, MongoDB
`cTableName`	PT_STRING	Database table name	DbfTable, MySQL, MariaDB, PostgreSQL, SQLite, Firebird, SQLServer, Oracle, MongoDB

Control-Specific Properties

These properties are unique to specific control types and are not shared broadly.

Property	Type	Description	Available For
`nWindowState`	PT_NUMBER	Window state (0=normal, 1=minimized, 2=maximized)	Form
`cIcon`	PT_STRING	Path to the window icon file	Form
`lMaxButton`	PT_LOGICAL	Show the maximize button in the title bar	Form
`lMinButton`	PT_LOGICAL	Show the minimize button in the title bar	Form
`lCloseButton`	PT_LOGICAL	Show the close button in the title bar	Form
`lSysMenu`	PT_LOGICAL	Show the system menu (right-click on title bar)	Form
`nToolBar`	PT_NUMBER	Reference to the associated toolbar object	ToolBar
`nStatusBar`	PT_NUMBER	Reference to the associated status bar object	StatusBar
`nTabPos`	PT_NUMBER	Position of tab labels (0=top, 1=bottom, 2=left, 3=right)	TabControl
`lHotTrack`	PT_LOGICAL	Highlight tabs on mouse hover	TabControl
`nStyle`	PT_NUMBER	Control style flags (bitmask)	All native controls
`nExStyle`	PT_NUMBER	Extended style flags (bitmask)	All native controls
`lDoubleBuffered`	PT_LOGICAL	Use double buffering to reduce flicker	PaintBox, StringGrid, ScrollBox
`cFileName`	PT_STRING	Selected file path (for dialog controls)	OpenDialog, SaveDialog
`cFilter`	PT_STRING	File type filter for dialogs (e.g., "Text files\|*.txt")	OpenDialog, SaveDialog
`cApiKey`	PT_STRING	API key for AI service authentication	OpenAI, Gemini, Claude, DeepSeek, Grok
`cModel`	PT_STRING	AI model identifier (e.g., "gpt-4", "claude-3")	OpenAI, Gemini, Claude, DeepSeek, Grok
`nTimeout`	PT_NUMBER	Request timeout in milliseconds	OpenAI, Gemini, Claude, DeepSeek, Grok, HttpClient, WebSocket
`cHost`	PT_STRING	Server hostname or IP address	MySQL, MariaDB, PostgreSQL, SQLite, HttpClient, FtpClient, TcpServer, TcpClient, WebServer
`nPort`	PT_NUMBER	Network port number	MySQL, MariaDB, PostgreSQL, HttpClient, FtpClient, TcpServer, TcpClient, WebServer, WebSocket
`cUserName`	PT_STRING	Username for authentication	MySQL, MariaDB, PostgreSQL, FtpClient, SMTPClient
`cPassword`	PT_STRING	Password for authentication	MySQL, MariaDB, PostgreSQL, FtpClient, SMTPClient
`cDatabase`	PT_STRING	Database name	MySQL, MariaDB, PostgreSQL, SQLite, Firebird, SQLServer, Oracle, MongoDB

Setting Properties in Code

Properties can be set in code after a control is created:

local oForm, oBtn, oLabel

DEFINE FORM oForm TITLE "Properties Demo" ;
   SIZE 500, 350 FONT "Segoe UI", 10

--- Set properties on the form ---
oForm:lResizable     := .T.
oForm:lCentered      := .T.
oForm:nBackColor     := CLR_WHITE
oForm:lMaxButton     := .T.
oForm:lMinButton     := .T.

@ 30, 40 LABEL oLabel VALUE "Hello World" ;
   OF oForm SIZE 200, 28

--- Set label properties ---
oLabel:nFontColor   := CLR_BLUE
oLabel:lFontBold     := .T.
oLabel:nAlignment    := 1     /// center
oLabel:cHint         := "This is a label"

@ 70, 40 BUTTON oBtn PROMPT "Click Me" ;
   OF oForm SIZE 130, 32

--- Set button properties ---
oBtn:nBackColor     := CLR_GREEN
oBtn:nFontColor     := CLR_WHITE
oBtn:lFlat          := .T.
oBtn:lTabStop       := .T.
oBtn:nTabIndex      := 0

ACTIVATE FORM oForm CENTERED

Setting Properties in the Object Inspector

In the HarbourBuilder IDE, select any control in the Form Designer and switch to the Properties tab in the Object Inspector. Properties are grouped by category:

Appearance — Colors, borders, captions, images, hints
Position — Left, Top, Width, Height
Behavior — Visible, Enabled, ReadOnly, TabStop
Font — FontName, FontSize, Bold, Italic, Underline
Data — Items, DataSource, DataField (for data-aware controls)
Layout — Anchoring, alignment, docking

Double-click a property value to edit it inline. Color properties show a color picker; font properties open a font dialog; logical properties toggle between .T. and .F..

Live preview

Changes made in the Object Inspector are applied to the Form Designer canvas in real time. You can see the effect of every property change immediately without rebuilding.

Property Inheritance

Controls inherit certain properties from their parent container. The inheritance chain is:

graph TD A["Application defaults"] --> B["TForm / Parent Form"] B --> C["Container (Panel, ScrollBox, GroupBox)"] C --> D["Child Control (Button, Edit, Label, etc.)"] style A fill:#58a6ff,stroke:#388bfd,color:#0d1117 style B fill:#8b5cf6,stroke:#7c3aed,color:#fff style C fill:#f59e0b,stroke:#d97706,color:#0d1117 style D fill:#3fb950,stroke:#2ea043,color:#0d1117

Properties that are inherited include:

cFontName, nFontSize, lFontBold, lFontItalic — Font properties cascade down
nBackColor — If not explicitly set, the control uses the parent's background
lEnabled — Disabling a parent container disables all children
lVisible — Hiding a parent hides all children

A child control can override any inherited property by setting it explicitly.

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