General Constants

alignment Constants

Declared in: interface/InterfaceDefs.h

enum alignment {
    B_ALIGN_LEFT,
    B_ALIGN_RIGHT,
    B_ALIGN_CENTER

These constants define the alignment data type. They determine how lines of text and labels are aligned by BTextView, BStringView, and BMenuField objects.

See also: BTextView::SetAlignment()

border_style Constants

Declared in: interface/InterfaceDefs.h

enum border_style {
    B_PLAIN_BORDER,
    B_FANCY_BORDER,
    B_NO_BORDER

These constants define how BBox objects and BScrollViews are bordered.

Character Constants

Declared in: interface/InterfaceDefs.h

Constant	Character value
B_BACKSPACE	0x08 (same as ‘b’)
B_ENTER	0x0a (same as ‘n’)
B_RETURN	0x0a (synonym for B_ENTER)
B_SPACE	0x20 (same as ‘ ‘)
B_TAB	0x09 (same as ‘t’)
B_ESCAPE	0x1b
B_LEFT_ARROW	0x1c
B_RIGHT_ARROW	0x1d
B_UP_ARROW	0x1e
B_DOWN_ARROW	0x1f
B_INSERT	0x05
B_DELETE	0x7f
B_HOME	0x01
B_END	0x04
B_PAGE_UP	0x0b
B_PAGE_DOWN	0x0c
B_FUNCTION_KEY	0x10
B_UTF8_ELLIPSIS	“xE2x80xA6”
B_UTF8_OPEN_QUOTE	“xE2x80x9C”
B_UTF8_CLOSE_QUOTE	“xE2x80x9D”
B_UTF8_COPYRIGHT	“xC2xA9”
B_UTF8_REGISTERED	“xC2xAE”
B_UTF8_TRADEMARK	“xE2x84xA2”
B_UTF8_SMILING_FACE	“xE2x98xBB”
B_UTF8_HIROSHI	“xE5xBCx98”

Constants in the first group stand for the ASCII characters they name. They’re defined only for characters that normally don’t have visible symbols.

Constants in the second group are Unicode UTF-8 encodings of common characters that have multibyte representations. These constants are strings that can be concatenated with other strings—for example, to set a button label that ends in an ellipsis:

myButton->SetLabel("Options"B_UTF_ELLIPSIS);

See also: “Function Key Constants” below

color_space

Declared in: interface/GraphicsDefs.h

Constant	Description
B_NO_COLOR_SPACE	Undefined color space
B_RGB32	xRGB 8:8:8:8, stored as little endian uint32
B_RGBA32	ARGB 8:8:8:8, stored as little endian uint32
B_RGB24	Currently unused
B_RGB16	xRGB 5:6:5, stored as little endian uint16
B_RGB15	RGB 1:5:5:5, stored as little endian uint16
B_RGBA15	ARGB 1:5:5:5, stored as little endian uint16
B_CMAP8	256-color index into the color table.
B_GRAY8	256-color greyscale value.
B_GRAY1	Each bit represents a single pixel, where 0 is the view’s low color and 1 is the high color.
B_RGB32_BIG	xRGB 8:8:8:8, stored as big endian uint32
B_RGBA32_BIG	ARGB 8:8:8:8, stored as big endian uint32
B_RGB24_BIG	Currently unused
B_RGB16_BIG	RGB 5:6:5, stored as big endian uint16
B_RGB15_BIG	xRGB 1:5:5:5, stored as big endian uint16
B_RGBA15_BIG	ARGB 1:5:5:5, stored as big endian uint16
B_YCbCr422	Currently unused.
B_YCbCr411	Currently unused.
B_YCbCr444	Currently unused.
B_YCbCr420	Currently unused.
B_YUV422	Currently unused.
B_YUV411	Currently unused.
B_YUV420	Currently unused.
B_YUV444	Currently unused.
B_YUV9	Currently unused.
B_YUV12	Currently unused.
B_UVL24	Currently unused.
B_UVL32	Currently unused.
B_UVLA32	Currently unused.
B_LAB24	Currently unused.
B_LAB32	Currently unused.
B_LABA32	Currently unused.
B_HSI24	Hue, saturation, and intensity: x:8:8:8 format
B_HSI32	Hue, saturation, and intensity: 8:8:8 format
B_HSIA32	Hue, saturation, intensity, and alpha: 8:8:8:8 format
B_HSV24	Hue, saturation, and value: x:8:8:8 format
B_HSV32	Hue, saturation, and value: 8:8:8 format
B_HSVA32	Hue, saturation, value, and alpha: 8:8:8:8 format
B_HLS24	Hue, lightness, and saturation: x:8:8:8 format
B_HLS32	Hue, lightness, and saturation: 8:8:8 format
B_HLSA32	Hue, lightness, saturation, and alpha: 8:8:8:8 format
B_CMY24	Cyan, magenta, and yellow: x:8:8:8 format
B_CMY32	Cyan, magenta, and yellow: 8:8:8 format
B_CMYA32	Cyan, magenta, yellow, and alpha: 8:8:8:8 format
B_CMYK32	Cyan, magenta, yellow, and black: 8:8:8:8 format
B_MONOCHROME_1_BIT	For compatibility only: use B_GRAY1
B_GRAYSCALE_8_BIT	For compatibility only; use B_GRAY8
B_COLOR_8_BIT	For compatibility only; use B_CMAP8
B_RGB_32_BIT	For compatibility only; use B_RGB32
B_RGB_16_BIT	For compatibility only; use B_RGB15
B_BIG_RGB_32_BIT	For compatibility only; use B_RGB32_BIG
B_BIG_RGB_16_BIT	For compatibility only; use B_RGB15_BIG

These constants define the color_space data type. A color space describes three properties of screens and bitmap images:

• How many bits of information there are per pixel (the depth of the image)

• How those bits are to be interpreted (whether as colors or on a grayscale, what the color components are, and so on).

• How are components are arranged

A number of these aren’t actually usable as screen display color spaces, but are intended for use in identifying the color format for video media buffers and other offscreen graphics data.

See the “Color Spaces” section in the “Drawing” section of this chapter for a fuller explanation of these color spaces.

See also: the BBitmap and BScreen classes

Control Values

Declared in: interface/Control.h

Constant	Value
B_CONTROL_ON	1
B_CONTROL_OFF	0

These constants define the bipolar states of a typical control device.

See also: BControl::SetValue()

Cursor Transit Constants

Declared in: interface/View.h

Constant	Description
B_ENTERED_VIEW	The cursor has just entered a view.
B_INSIDE_VIEW	The cursor has moved within the view.
B_EXITED_VIEW	The cursor has left the view

These constants describe the cursor’s transit through a view. Each MouseMoved() notification includes one of these constants as an argument, to inform the BView whether the cursor has entered the view, moved while inside the view, or exited the view.

Dead-Key Mapping

Declared in: interface/InterfaceDefs.h

Constant
B_CONTROL_TABLE
B_OPTION_CAPS_SHIFT_TABLE
B_OPTION_CAPS_TABLE
B_OPTION_SHIFT_TABLE
B_OPTION_TABLE
B_CAPS_SHIFT_TABLE
B_CAPS_TABLE
B_SHIFT_TABLE
B_NORMAL_TABLE

These constants determine which combinations of modifiers can cause a key to be the “dead” member of a two-key combination.

See also: get_key_map()

drawing_mode Constants

Declared in: interface/GraphicsDefs.h

enum drawing_mode {
    B_OP_COPY,
    B_OP_OVER,
    B_OP_ERASE,
    B_OP_INVERT,
    B_OP_SELECT,
    B_OP_ALPHA,
    B_OP_ADD,
    B_OP_SUBTRACT,
    B_OP_BLEND,
    B_OP_MIN,
    B_OP_MAX

These constants define the drawing_mode data type. The drawing mode is a BView graphics parameter that determines how the image being drawn interacts with the image already in place in the area where it’s drawn. The various modes are explained under “Drawing Modes” in the “Drawing” section of this chapter.

See also: BView::SetDrawingMode()

Function Key Constants

Declared in: interface/InterfaceDefs.h

Constant
B_F1_KEY
B_F2_KEY
B_F3_KEY
B_F4_KEY
B_F5_KEY
B_F6_KEY
B_F7_KEY
B_F8_KEY
B_F9_KEY
B_F10_KEY
B_F11_KEY
B_F12_KEY
B_PRINT_KEY (the “Print Screen” key)
B_SCROLL_KEY (the “Scroll Lock” key)
B_PAUSE_KEY

These constants stand for the various keys that are mapped to the B_FUNCTION_KEY character. When the B_FUNCTION_KEY character is reported in a key-down event, the application can determine which key produced the character by testing the key code against these constants. ( Control+p also produces the B_FUNCTION_KEY character.)

See also: “Character Mapping” in the Keyboard Information appendix

Interface Messages

Declared in: app/AppDefs.h

Constant
B_ZOOM
B_MINIMIZE
B_WINDOW_RESIZED
B_WINDOW_MOVED
B_WINDOW_ACTIVATED
B_QUIT_REQUESTED
B_SCREEN_CHANGED
B_WORKSPACE_ACTIVATED
B_WORKSPACES_CHANGED
B_KEY_DOWN
B_KEY_UP
B_MOUSE_DOWN
B_MOUSE_UP
B_MOUSE_MOVED
B_VIEW_RESIZED
B_VIEW_MOVED
B_VALUE_CHANGED
B_PULSE

These constants identify interface messages—system messages that are delivered to BWindow objects. Each constant conveys an instruction to do something in particular (B_ZOOM) or names a type of event (B_KEY_DOWN).

See also: “Interface Messages” in the “Responding to the User” section of this chapter

list_view_type Constants

Declared in: interface/ListView.h

Constant
B_SINGLE_SELECTION_LIST
B_MULTIPLE_SELECTION_LIST

These constants distinguish between lists that permit the user to select only one item at a time and those that allow multiple items to be selected.

See also: The BListView class

Main Screen

Declared in: interface/Screen.h

const screen_id B_MAIN_SCREEN_ID

This constant stands for the main screen, the screen that has the origin of the screen coordinate system at its left top corner. (Currently only one screen can be attached to the computer and it is the main screen.)

See also: screen_id

menu_bar_border Constants

Declared in: interface/MenuBar.h

Constant	Description
B_BORDER_FRAME	Put a border inside the entire frame rectangle.
B_BORDER_CONTENTS	Put a border around the group of items only.
B_BORDER_EACH_ITEM	Put a border around each item.

These constants can be passed as an argument to BMenuBar’s SetBorder() function.

menu_layout Constants

Declared in: interface/Menu.h

Constant	Description
B_ITEMS_IN_ROW	Menu items are arranged horizontally, in a row.
B_ITEMS_IN_COLUMN	Menu items are arranged vertically, in a column.
B_ITEMS_IN_MATRIX	Menu items are arranged in a custom fashion.

These constants define the menu_layout data type. They distinguish the ways that items can be arranged in a menu or menu bar—they can be laid out from end to end in a row like a typical menu bar, stacked from top to bottom in a column like a typical menu, or arranged in some custom fashion like a matrix.

See also: The BMenu and BMenuBar constructors

Modifier States

Declared in: interface/InterfaceDef.h

Constant
B_SHIFT_KEY
B_LEFT_SHIFT_KEY
B_RIGHT_SHIFT_KEY
B_CONTROL_KEY
B_LEFT_CONTROL_KEY
B_RIGHT_CONTROL_KEY
B_CAPS_LOCK
B_SCROLL_LOCK
B_NUM_LOCK
B_OPTION_KEY
B_LEFT_OPTION_KEY
B_RIGHT_OPTION_KEY
B_COMMAND_KEY
B_LEFT_COMMAND_KEY
B_RIGHT_COMMAND_KEY
B_MENU_KEYB_PULSE

These constants designate the Shift, Option, Control, Command, and Menu modifier keys and the lock states set by the Caps Lock, Scroll Lock, and Num Lock keys. They’re typically used to form a mask that describes the current, or required, modifier states.

For each variety of modifier key, there are constants that distinguish between the keys that appear at the left and right of the keyboard, as well as one that lumps both together. For example, if the user is holding the left Control key down, both B_CONTROL_KEY and B_LEFT_CONTROL_KEY will be set in the mask.

See also: modifiers(), BWindow::AddShortcut(), the BMenu constructor

Mouse Buttons

Declared in: interface/View.h

Constant
B_PRIMARY_MOUSE_BUTTON
B_SECONDARY_MOUSE_BUTTON
B_TERTIARY_MOUSE_BUTTON

These constants name the mouse buttons. Buttons are identified, not by their physical positions on the mouse, but by their roles in the user interface.

See also: BView::GetMouse(), set_mouse_map()

Orientation Constants

Declared in: interface/InterfaceDef.h

Constant
B_HORIZONTAL
B_VERTICAL

These constants define the orientation data type that distinguishes between the vertical and horizontal orientation of graphic objects. It’s currently used only to differentiate scroll bars.

See also: The BScrollBar and BScrollView classes

Pattern Constants

Declared in: interface/GraphicsDef.h

const pattern B_SOLID_HIGH =
    { 0xff, 0xff, 0xff, 0xff, 0xff,0xff, 0xff, 0xff }

const pattern B_SOLID_LOW =
    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }

const pattern B_MIXED_COLORS =
    { 0xaa, 0x55, 0xaa, 0x55, 0xaa, 0x55, 0xaa, 0x55 }

These constants name the three standard patterns defined in the Interface Kit.

B_SOLID_HIGH is a pattern that consists of the high color only. It’s the default pattern for all BView drawing functions that stroke lines and fill shapes.

B_SOLID_LOW is a pattern with only the low color. It’s used mainly to erase images (to replace them with the background color).

B_MIXED_COLORS alternates pixels between the high and low colors in a checkerboard pattern. The result is a halftone midway between the two colors. This pattern can produce fine gradations of color, especially when the high and low colors are set to two colors that are already quite similar.

See also: “Patterns” in the “Drawing” section of this chapter

Resizing Modes

Declared in: interface/View.h

Constant
B_FOLLOW_LEFT
B_FOLLOW_RIGHT
B_FOLLOW_LEFT_RIGHT
B_FOLLOW_H_CENTER
B_FOLLOW_TOP
B_FOLLOW_BOTTOM
B_FOLLOW_TOP_BOTTOM
B_FOLLOW_V_CENTER
B_FOLLOW_ALL
B_FOLLOW_NONE

These constants are used to set the behavior of a view when its parent is resized. They’re explained under the BView constructor.

See also: BView::SetResizingMode()

Screen Spaces

Declared in: interface/GraphicsDef.h

B_8_BIT_640x400
B_8_BIT_640x480    B_15_BIT_640x480
B_16_BIT_640x480   B_32_BIT_640x480

B_8_BIT_800x600    B_15_BIT_800x600
B_16_BIT_800x600   B_32_BIT_800x600

B_8_BIT_1024x768   B_15_BIT_1024x768
B_16_BIT_1024x768  B_32_BIT_1024x768

B_8_BIT_1152x900   B_15_BIT_1152x900
B_16_BIT_1152x900  B_32_BIT_1152x900

B_8_BIT_1280x1024  B_15_BIT_1280x1024
B_16_BIT_1280x1024 B_32_BIT_1280x1024

B_8_BIT_1600x1200  B_15_BIT_1600x1200
B_16_BIT_1600x1200 B_32_BIT_1600x1200

These constants are currently used to configure the screen—to set its depth and the size of the pixel grid it displays—as well as to report which configurations are possible. However, they may not be supported in the future. 15-bit depths are not currently supported

See also: set_screen_space(), get_screen_info().

ScrollBar Constants

Declared in: interface/ScrollBar.h

Constant
B_H_SCROLL_BAR_HEIGHT
B_V_SCROLL_BAR_WIDTH

These constants record the recommended thickness of scroll bars. They should be used to help define the frame rectangles passed to the BScrollBar constructor.

String Truncation Constants

Declared in: interface/Font.h

Constant
B_TRUNCATE_END
B_TRUNCATE_BEGINNING
B_TRUNCATE_MIDDLE
B_TRUNCATE_SMART

These constants instruct a BFont where it should remove characters from a set of strings to shorten them.

See also: BFont::GetTruncatedStrings()

tint_color() Constants

Declared in: interface/InterfaceDefs.h

These constants are used when calling tint_color() to alter an existing color, especially for creating disabled objects or highlighting backgrounds.

Transparency Constants

Declared in: interface/GraphicsDefs.h

const uint8 B_TRANSPARENT_8_BIT
const rgb_color B_TRANSPARENT_32_BIT

These constants set transparent pixel values in a bitmap image. B_TRANSPARENT_8_BIT designates a transparent pixel in the B_CMAP8 color space, and B_TRANSPARENT_32_BIT designates a transparent pixel in the B_RGB32 color space.

Transparency is explained in the “Drawing Modes” part of the “Drawing” section of this chapter. Drawing modes other than B_OP_COPY preserve the destination image where a source bitmap is transparent.

See also: “Drawing Modes” in the “Drawing” section of this chapter, the BBitmap class, BView::SetViewColor()

color_which Constants

Declared in: interface/InterfaceDefs.h

Constant	Description
B_PANEL_BACKGROUND_COLOR	The background color used for view panels.
B_MENU_BACKGROUND_COLOR	The background color used for menus.
B_MENU_SELECTION_BACKGROUND_COLOR	The color used for highlighting menu items when selected.
B_MENU_ITEM_TEXT_COLOR	The color used for drawing menu item labels when not selected.
B_MENU_SELECTED_ITEM_TEXT_COLOR	The color used for drawing menu item labels when selected.
B_WINDOW_TAB_COLOR	The color used to draw the window’s title tab.
B_KEYBOARD_NAVIGATION_COLOR	The color used to draw the mark indicating which control is focused for keyboard navigation.
B_DESKTOP_COLOR	The current desktop color.

When calling ui_color() to obtain the color for a user interface element, these constants are used to select the desired element.

View Flags

Declared in: interface/View.h

Constant	Description
B_FULL_UPDATE_ON_RESIZE	Include the entire view in the clipping region.
B_WILL_DRAW	Allow the BView to draw.
B_PULSE_NEEDED	Report pulse events to the BView.
B_FRAME_EVENTS	Report view-resized and view-moved events.
B_NAVIGABLE	Let users navigate to the view with the Tab key.
B_NAVIGABLE_JUMP	Mark the view for Control+Tab navigation.

These constants can be combined to form a mask that sets the behavior of a BView object. They’re explained in more detail under the class constructor. The mask is passed to the constructor, or to the SetFlags() function.

Window Flags

Declared in: interface/Window.h

Constant
B_NOT_MOVABLE B_NOT_CLOSABLE
B_NOT_H_RESIZABLE
B_NOT_ZOOMABLE
B_NOT_V_RESIZABLE
B_NOT_MINIMIZABLE
B_NOT_RESIZABLE
B_WILL_FLOAT
B_WILL_ACCEPT_FIRST_CLICK

These constants set the behavior of a window. They can be combined to form a mask that’s passed to the BWindow constructor.

window_type Constants

Declared in: interface/Window.h

Constant	Description
B_MODAL_WINDOW	The window is a modal window.
B_BORDERED_WINDOW	The window has a border but no title tab.
B_TITLED_WINDOW	The window has a border and a title tab.
B_DOCUMENT_WINDOW	The window has a border, tab and resize knob.

These constants describe the various kinds of windows that can be requested from the Application Server.

See also: The BWindow constructor

Workspace Constants

Declared in: interface/Window.h

Constant
B_CURRENT_WORKSPACE
B_ALL_WORKSPACES

These constants are used—along with designations of specific workspaces—to associate a set of one or more workspaces with a BWindow.

See also: The BWindow constructor, BWindow::SetWorkspaces()