brl_system.md 7.0 KB
id: brl.system title: BRL.System
sidebar_label: BRL.System
The system module's primary function is to provide synchronization with the operating system.
This achieved through the PollSystem and WaitSystem commands. However, you don't usually have to call these commands yourself as other BlitzMax commands will call them when necessary.
In addition, the system module also provides commands for checking the date and time, for moving the mouse pointer and for generating simple system requesters.
Functions
Function InitSystemDriver(driver:TSystemDriver)
Initialises the BlitzMax system driver.
There can only be one system driver initialised. A second call to this function will result in an exception.
Function SystemDriver:TSystemDriver()
Returns the BlitzMax system driver, or throws an exception if InitSystemDriver() hasn't been called with one.
Function PollSystem()
Poll operating system
PollSystem returns control back to the operating system, allowing such events as keystrokes and gadget actions to be processed. Control is then returned back to your program.
If PollSystem encounters a key, mouse or app suspend/resume/terminate event, an equivalent TEvent object event will be generated which may be intercepted using the EmitEventHook hook.
Function WaitSystem()
Wait for operating system
WaitSystem returns control back to the operating system, waiting until an event such as a keystroke or gadget action occurs.
Note that WaitSystem may wait indefinitely if there is no possibility of any events occuring, so use with caution.
If WaitSystem encounters a key, mouse or app suspend/resume/terminate event, an equivalent TEvent object will be generated which may be intercepted using the EmitEventHook hook.
Function MoveMouse( x,y )
Move mouse pointer
MoveMouse positions the mouse cursor at a specific location within the current window or graphics display.
Function ShowMouse()
Make the mouse pointer visible
Function HideMouse()
Make the mouse pointer invisible
Function Notify( text:String,serious=False )
Notify user
Notify activates a simple user interface element informing the user of an event. The optional serious flag can be used to indicate a 'critical' event.
Note that a user interface may not be available when in graphics mode on some platforms.
Example
' notify.bmx
Notify "Hello World"
Function Confirm( text:String,serious=False )
Request user confirmation.
Confirm activates a simple user interface element requesting the user to select between YES and NO options. If the user selects YES, then Confirm returns True. Otherwise, False is returned.
Note that a user interface may not be available when in graphics mode on some platforms.
Returns
True or False depending on the user's selection
Example
' confirm.bmx
result=Confirm("Are you sure?")
print result
Function Proceed( text:String,serious=False )
Request user confirmation or cancellation.
Proceed activates a simple user interface element requesting the user to select between YES, NO and CANCEL options. If the user selects YES, then Proceed return 1. If the user selects NO, then Proceed returns 0. Otherwise, Proceed returns -1.
Note that a user interface may not be available when in graphics mode on some platforms.
Returns
1, 0 or -1 depending on the user's selection
Example
' proceed.bmx
result=Proceed("Are you sure you want to continue?")
print result
Function RequestFile:String( text:String,extensions:String="",save_flag=False,initial_path:String="" )
Display system file requester.
text is used as the title of the file requester.
The optional extensions string can either be a comma separated list of file extensions or as in the following example groups of extensions that begin with a "group:" and separated by a semicolon. save_flag can be True to create a save-style requester, or False to create a load-style requester.
initial_path is the initial path for the file requester.
Note that a user interface may not be available when in graphics mode on some platforms.
Returns
The path of the selected file or an empty string if the operation was cancelled.
Example
' requestfile.bmx
filter:String="Image Files:png,jpg,bmp;Text Files:txt;All Files:*"
filename:String=RequestFile( "Select graphic file to open",filter )
Print filename
Function RequestDir:String( text:String,initial_path:String="" )
Display system folder requester.
text is used as the title of the file requester.
initial_path is the initial path for the folder requester.
Note that a user interface may not be available when in graphics mode on some platforms.
Returns
The path of the selected folder or an empty string if the operation was cancelled.
Example
' requestdir.bmx
path:String=RequestDir("Select a Folder",CurrentDir())
Print "directory selected was "+path
Function OpenURL( url:String )
Opens a URL with the system's default web browser.
Note that a user interface may not be available when in graphics mode on some platforms.
Function DesktopWidth(display:Int = 0)
Get desktop width
Returns
Width of the desktop, in pixels
Function DesktopHeight(display:Int = 0)
Get desktop height
Returns
Height of the desktop, in pixels
Function DesktopDepth(display:Int = 0)
Get desktop depth
The depth of the desktop is the number of bits per pixel.
Note that on some platforms this function may return 0 if the desktop depth cannot be determined.
Returns
Bits per pixel depth of the desktop
Function DesktopHertz(display:Int = 0)
Get desktop refresh rate
Note that on some platforms this function may return 0 if the desktop refresh rate cannot be determined.
Returns
Refresh rate, in cycles per second, of the desktop