AccessibleComponent Interface

AccessibleComponent Interface — An interface implemented by objects which occupy area on screen.

Functions

Types and Values

Description

The Component interface is implemented by objects which are visible, or are potentially visible, onscreen. The interface exposes onscreen bounds, the approximate "layer" in which the object resides, sometimes including z-order information, and allows objects to explicitly be told to request focus.

Functions

AccessibleComponent_ref ()

void
AccessibleComponent_ref (AccessibleComponent *obj);

Increment the reference count for an AccessibleComponent.

Parameters

obj

a pointer to an object implementing AccessibleComponent on which to operate.

 

AccessibleComponent_unref ()

void
AccessibleComponent_unref (AccessibleComponent *obj);

Decrement the reference count for an AccessibleComponent.

Parameters

obj

a pointer to the object implementing AccessibleComponent on which to operate.

 

AccessibleComponent_contains ()

SPIBoolean
AccessibleComponent_contains (AccessibleComponent *obj,
                              long int x,
                              long int y,
                              AccessibleCoordType ctype);

Query whether a given AccessibleComponent contains a particular point.

Parameters

obj

a pointer to the AccessibleComponent to query.

 

x

a long specifying the x coordinate in question.

 

y

a long specifying the y coordinate in question.

 

ctype

the desired coordinate system of the point (x , y ) (e.g. SPI_COORD_TYPE_WINDOW, SPI_COORD_TYPE_SCREEN).

 

Returns

a TRUE if the specified component contains the point (x , y ), otherwise FALSE.


AccessibleComponent_getAccessibleAtPoint ()

Accessible *
AccessibleComponent_getAccessibleAtPoint
                               (AccessibleComponent *obj,
                                long int x,
                                long int y,
                                AccessibleCoordType ctype);

Get the accessible child at a given coordinate within an AccessibleComponent.

Parameters

obj

a pointer to the AccessibleComponent to query.

 

x

a long specifying the x coordinate of the point in question.

 

y

a long specifying the y coordinate of the point in question.

 

ctype

the coordinate system of the point (x , y ) (e.g. SPI_COORD_TYPE_WINDOW, SPI_COORD_TYPE_SCREEN).

 

Returns

a pointer to an Accessible child of the specified component which contains the point (x , y ), or NULL of no child contains the point.


AccessibleComponent_getExtents ()

void
AccessibleComponent_getExtents (AccessibleComponent *obj,
                                long int *x,
                                long int *y,
                                long int *width,
                                long int *height,
                                AccessibleCoordType ctype);

Get the bounding box of the specified AccessibleComponent.

Parameters

obj

a pointer to the AccessibleComponent to query.

 

x

a pointer to a long into which the minimum x coordinate will be returned.

 

y

a pointer to a long into which the minimum y coordinate will be returned.

 

width

a pointer to a long into which the x extents (width) will be returned.

 

height

a pointer to a long into which the y extents (height) will be returned.

 

ctype

the desired coordinate system into which to return the results, (e.g. SPI_COORD_TYPE_WINDOW, SPI_COORD_TYPE_SCREEN).

 

AccessibleComponent_getPosition ()

void
AccessibleComponent_getPosition (AccessibleComponent *obj,
                                 long int *x,
                                 long int *y,
                                 AccessibleCoordType ctype);

Get the minimum x and y coordinates of the specified AccessibleComponent.

Parameters

obj

a pointer to the AccessibleComponent to query.

 

x

a pointer to a long into which the minimum x coordinate will be returned.

 

y

a pointer to a long into which the minimum y coordinate will be returned.

 

ctype

the desired coordinate system into which to return the results, (e.g. SPI_COORD_TYPE_WINDOW, SPI_COORD_TYPE_SCREEN).

 

AccessibleComponent_getSize ()

void
AccessibleComponent_getSize (AccessibleComponent *obj,
                             long int *width,
                             long int *height);

Get the size of the specified AccessibleComponent.

Parameters

obj

a pointer to the AccessibleComponent to query.

 

width

a pointer to a long into which the x extents (width) will be returned.

 

height

a pointer to a long into which the y extents (height) will be returned.

 

AccessibleComponent_getLayer ()

AccessibleComponentLayer
AccessibleComponent_getLayer (AccessibleComponent *obj);

Query which layer the component is painted into, to help determine its visibility in terms of stacking order.

Parameters

obj

a pointer to the AccessibleComponent to query.

 

Returns

the AccessibleComponentLayer into which this component is painted.


AccessibleComponent_getMDIZOrder ()

short
AccessibleComponent_getMDIZOrder (AccessibleComponent *obj);

Query the z stacking order of a component which is in the MDI or window layer. (Bigger z-order numbers mean nearer the top)

Parameters

obj

a pointer to the AccessibleComponent to query.

 

Returns

a short integer indicating the stacking order of the component in the MDI layer, or -1 if the component is not in the MDI layer.


AccessibleComponent_grabFocus ()

SPIBoolean
AccessibleComponent_grabFocus (AccessibleComponent *obj);

Attempt to set the keyboard input focus to the specified AccessibleComponent.

Parameters

obj

a pointer to the AccessibleComponent on which to operate.

 

Returns

TRUE if successful, FALSE otherwise.


AccessibleComponent_getAlpha ()

double
AccessibleComponent_getAlpha (AccessibleComponent *obj);

Get the opacity/alpha value of a component, if alpha blending is in use.

Parameters

obj

The AccessibleComponent to be queried.

 

Returns

the opacity value of a component, as a double between 0.0 and 1.0.

Types and Values

enum AccessibleCoordType

Specifies how xy coordinates are to be interpreted. Used by functions such as AccessibleComponent_getPosition() and AccessibleText_getCharacterExtents()

Members

SPI_COORD_TYPE_SCREEN

specifies xy coordinates relative to the screen

 

SPI_COORD_TYPE_WINDOW

specifies xy coordinates relative to an object's top-level window

 

enum AccessibleComponentLayer

Describes the layer of a component.

These enumerated "layer values" are used when determining which UI rendering layer a component is drawn into, which can help in making determinations of when components occlude one another.

Members

SPI_LAYER_INVALID

The layer cannot be determined or is somehow undefined.

 

SPI_LAYER_BACKGROUND

Component belongs to the destop background.

 

SPI_LAYER_CANVAS

Component is a canvas backdrop or drawing area.

 

SPI_LAYER_WIDGET

Component is a 'normal' widget.

 

SPI_LAYER_MDI

Component is drawn in the MDI layer and may have valid Z-information relative to other MDI-layer components.

 

SPI_LAYER_POPUP

Component is in the popup layer, above other widgets and MDI components.

 

SPI_LAYER_OVERLAY

Component is in the overlay plane - this value is reserved for future use.

 

SPI_LAYER_WINDOW

Component is in the window layer and have valid Z-information relative to other window-layer components.

 

SPI_LAYER_LAST_DEFINED

Used to determine the last valid value in the enum, should not be encountered.