system class

class system

superclass(es)	object
subclass(es)	-
description	The system class describes the interface of the system instance. There is always a single instance called 'system'.
remarks	It is not possible to create an instance of the system class and it is not necessary because there is always an instance, called 'system', present. This static instance is defined in the module win.txt.
see also	scrollBar

With the system instance it is possible to get information about various system related things like the width and height of icons, cursors, menu checkmarks, scrollBar and the number of processors inside the computer being used. With the method errorBeep/0 an 'error' sound can be generated and there are a number of methods for setting the image and position cursor of the mouse. Playing sounds can be done with the method playSound/3.

International settings that can influence how a date, time or currency value must be displayed can be queried with the system instance.

methods

iconHeight(Output)

func	Get the preferred height of an icon.
pre	TRUE.
post	The height of an icon in pixels was assigned to Output.

iconWidth(Output)

func	Get the preferred width of an icon.
pre	TRUE.
post	The width of an icon in pixels was assigned to Output.

cursorHeight(Output)

func	Get the preferred height of a cursor.
pre	TRUE.
post	The height of a cursor in pixels was assigned to Output.

cursorWidth(Output)

func	Get the preferred width of a cursor.
pre	TRUE.
post	The width of a cursor in pixels was assigned to Output.

widthVerScroll(Output)

func	Get the preferred width of a vertical scrollbar.
pre	TRUE.
post	The width of a vertical scrollbar was assigned to Output.
	see also: scrollBar

heightHorScroll(Output)

func	Get the preferred height of a horizontal scrollbar.
pre	TRUE.
post	The height of a horizontal scrollbar was assigned to Output.
	see also: scrollBar

widthThumbHorScroll(Output)

func	Get the width of a scrollbar thumb for a horizontal scrollbar.
pre	TRUE.
post	The width of a scrollbar thumb for a horizontal scrollbar was unified with the parameter Output.
	see also: scrollBar

heightThumbVerScroll(Output)

func	Get the height of a scrollbar thumb for a vertical scrollbar.
pre	TRUE.
post	The height of a scrollbar thumb for a vertical scrollbar was unified with the parameter Output.
	see also: scrollBar

captionHeight(Output)

func	Get the height of the caption of a normal window.
pre	TRUE.
post	The height of a window caption was assigned to Output.

smallCaptionHeight(Output)

func	Get the height of a small caption of a window. A frame window with the toolFrameStyle has a small caption window.
pre	TRUE.
post	The height of a small window caption was assigned to Output.

borderWidth(Output)

func	Get the width of a window border.
pre	TRUE.
post	The width of a window border was assigned to Output.

menuCheckmarkHeight(Output)

func	Get the preferred height of a checkmark image for a menu item.
pre	TRUE.
post	The height of a checkmark image of a menu item was assigned to Output.

menuCheckmarkWidth(Output)

func	Get the preferred width of a checkmark image for a menu item.
pre	TRUE.
post	The width of a checkmark image of a menu item was assigned to Output.

menuCheckmarkDimensions(point(X, Y))

func	Get the preferred width and height of a checkmark image for a menu item.
pre	TRUE.
post	The width and height of a checkmark image of a menu item were assigned to the variables X and Y.

numProcessors(Output)

func	Get the number of processors that the operating system can use.
pre	TRUE.
post	The number of processors was assigned to the variable Output.
	The number of processors an operating system can use can be different from the number of processors a computer has. Because Windows 95 cannot use more than 1 processor 1 is always assigned to Output if prolog runs on Windows 95, even on a multiprocessor computer.

errorBeep

func	Generate a sound associated with an error.
pre	TRUE.
post	A sound was generated.

putCursor(Cursor)

func	Set the cursor of the mouse.
pre	The variable Cursor must refer to an instance of the class cursor.
post	The cursor was set to the the value of the variable Cursor.

putWaitCursor

func	Set the cursor of the mouse to the 'waiting' cursor.
pre	TRUE.
post	A 'waiting' cursor was displayed.

putDefaultCursor

func	Set the cursor of the mouse to the 'default' cursor.
pre	TRUE.
post	A 'default' cursor was displayed.

putHandCursor

func	Set the cursor of the mouse to the 'hand' cursor.
pre	TRUE.
post	A 'hand' cursor was displayed.

putTextBeamCursor

func	Set the cursor of the mouse to the 'text beam' cursor. This is the flashing line that indicates the current position in a text editor.
pre	TRUE.
post	A 'text beam' cursor was displayed.

putDragDropCursor

func	Set the cursor of the mouse to the 'drag-drop' cursor.
pre	TRUE.
post	A 'drag-drop' cursor was displayed.

changeWaitCursor(Cursor)

func	Change the image of the 'waiting' cursor.
pre	The variable Cursor must refer to an instance of the class cursor.
post	The next time the 'waiting' cursor is displayed the value of the parameter will be used.

changeDefaultCursor(Cursor)

func	Change the image of the 'default' cursor.
pre	The variable Cursor must refer to an instance of the class cursor.
post	The next time the 'default' cursor is displayed the value of the parameter will be used.

changeHandCursor(Cursor)

func	Change the image of the 'hand' cursor.
pre	The variable Cursor must refer to an instance of the class cursor.
post	The next time the 'hand' cursor is displayed the value of the parameter will be used.

changeTextBeamCursor(Cursor)

func	Change the image of the 'text beam' cursor.
pre	The variable Cursor must refer to an instance of the class cursor.
post	The next time the 'text beam' cursor is displayed the value of the parameter will be used.

changeDragDropCursor(Cursor)

func	Change the image of the 'drag-drop' cursor.
pre	The variable Cursor must refer to an instance of the class cursor.
post	The next time the 'drag-drop' cursor is displayed the value of the parameter will be used.

cursor(Output)

func	Get the current cursor of the system.
pre	TRUE.
post	The current cursor was assigned to the variable Output. If no prolog instance was associated with the current cursor then no value was assigned to Output.

currentCursorPos(point(X, Y))

func	Get the current position of the cursor. The coordinates returned are relative to the upper-left corner of the screen.
pre	TRUE.
post	The current position of the cursor was assigned to the variables X and Y.

putCursorPos(point(X, Y))

func	Set the current position of the cursor. The coordinates must be relative to the upper-left corner of the screen.
pre	X and Y must both be positive integers.
post	The current position of the cursor was changed to the values of the parameters.

decimalSymbol(Output)/1

func	Get the symbol that is used to separate decimals of a floating point number.
pre	TRUE.
post	The decimal symbol currently used was assigned to the variable Output.

digitGroupSymbol(Output)

func	Get the symbol that is used to separate groups of digits in a floating point number.
pre	TRUE.
post	The digit grouping symbol currently used was assigned to the variable Output.

negativeSignSymbol(Output)

func	Get the symbol that is used to indicate that a number is negative.
pre	TRUE.
post	The negative sign symbol currently used was assigned to the variable Output.

numDigitsAfterDecimal(Output)

func	Get the number of digits that may appear after the decimal symbol.
pre	TRUE.
post	The number of digits that may appear after the decimal symbol used was assigned to the variable Output.

numDigitsInGroup(Output)

func	Get the number of digits that may appear in a single group.
pre	TRUE.
post	The number of digits of a group was assigned to the variable Output.

dateSymbol(Output)

func	Get the symbol that is used to separate parts of a date.
pre	TRUE.
post	The symbol used to separate parts of a date was assigned to the variable Output.

dateFormat(Output)

func	Get the format to display a date.
pre	TRUE.
post	The date format was assigned to the variable Output. This could be one of the following three values: mdy, dmy or ymd.
	mdy = Month-Day-Year dmy = Day-Month-Year ymd = Year-Month-Day

timeSymbol(Output)

func	Get the symbol that is used to separate parts of a time.
pre	TRUE.
post	The symbol used to separate parts of a time was assigned to the variable Output.

timeFormat(Output)

func	Get the format to display a time.
pre	TRUE.
post	The time format was assigned to the variable Output. This could be one of the following two values: twelveHours or twentyFourHours.
	If the time format is twelveHours then 'AM' and 'PM' strings must also be displayed.

currencySymbol(Output)

func	Get the symbol that is used to separate parts of a currency value.
pre	TRUE.
post	The symbol used to separate parts of a currency value was assigned to the variable Output.

currencyFormat(Output)

func	Get the format to display a currency value.
pre	TRUE.
post	The currency format was assigned to the variable Output. This could be one of the following four values: prefixNoSep, suffixNoSep, prefixSep or suffixSep.
	prefixNoSep = prefix a currency symbol and no separators suffixNoSep = suffix a currency symbol and no separators prefixSep = prefix a currency symbol and use separators suffixSep = suffix a currency symbol and use separators

currencyNumDigitsAfterDecimal(Output)

func	Get the number of digits that may appear after a decimal symbol of the currency value.
pre	TRUE.
post	The number of digits after the decimal symbol of a currency value was assigned to the variable Output.

playSound(Name, OptionsList, Result)

func	Play the sound specified by the value of the parameter Name. How name is interpreted is defined by the contents of the OptionsList. The OptionsList may contain the following atomic values: file: the Name parameter specifies a file. alias: the Alias parameter specifies an alias for a name that is in the file win.ini. async: the function does not wait for the end of a sound. sync: the function returns after a sound has been played. loop: keep repeating the sound, this flag must be used with the 'async' option. nostop: if a sound is already being played then with this option that current sound is not stopped. nowait: if the system is busy with playing sounds then the method immediately returns. nodefault: if the specified sound is not found then the default sound is not played.
pre	The Name parameter must contain a text and the OptionsList must be a valid list with options.
post	The value true was unified with the parameter Result if the sound was successfully played, else was false unified with Result.

stopPlaySound( Result)

func	Stop playing a sound.
pre	TRUE.
post	The value true was unified with the parameter Result if playing a sound was successfully stopped, else was false unified with Result.

class system

tasks

methods