GetMouse

FreeBASIC

GetMouse
 
Retrieves the status of the mouse pointing device

Syntax

Declare Function GetMouse ( ByRef x As Integer, ByRef y As Integer, ByRef wheel As Integer = 0, ByRef buttons As Integer = 0, ByRef clip As Integer = 0 ) As Long

Usage

result = GetMouse (x, y [, [ wheel ] [, [ buttons ] [, [ clip ]]]])

Parameters

x
x coordinate value
y
y coordinate value
wheel
scroll wheel value
buttons
button status
clip
clip status

Return Value

0 on success, or 1 on error (for example because the mouse is outside the graphic window) or on failure. (sets a runtime error)

Description

GetMouse retrieves the mouse position and buttons status; information is returned in the variables passed to this function by reference. If a mouse is not available, all variables will contain the -1 value.

If in console mode, the x and y coordinates are the character cell coordinates the mouse is currently on; the upper left corner of the screen is at coordinates 0, 0. If the mouse moves out of the console window, GetMouse returns the last coordinate on the window that the mouse was on. If in console mode and fullscreen, the scroll wheel value is not returned.

If in graphics mode, x and y will always be returned in pixel coordinates still relative to the upper left corner of the screen, which is at 0,0 in this case; custom coordinates system set via View or Window do not affect the coordinates returned by GetMouse.
If the mouse runs off the graphic window, all values are set to -1 and the return value of the function is set to 1. This may result in misinterpretation for the buttons and wheel if the return value of the function is not also tested.

Wheel is the mouse wheel counter; rotating the wheel away from you makes the count to increase, rotating the wheel toward you makes it to decrease. At program startup or when a new graphics mode is set via Screen, wheel position is reset to 0. FreeBASIC may not always support mouse wheels for a given platform, in which case 0 is always returned.

Buttons stores the buttons status as a bitmask: bit 0 is set if left mouse button is down; bit 1 is set if right mouse button is down; bit 2 is set if middle mouse button / wheel is down.

Clip stores the mouse clipping status; if 1, the mouse is currently clipped to the graphics window; if 0, the mouse is not clipped.

Example

Dim As Integer x, y, buttons, res 
' Set video mode and enter loop
ScreenRes 640, 480, 8
Do
    ' Get mouse x, y and buttons. Discard wheel position.
    res = GetMouse (x, y, , buttons)
    Locate 1, 1
    If res <> 0 Then '' Failure

#ifdef __FB_DOS__
        Print "Mouse or mouse driver not available"
#else
        Print "Mouse not available or not on window"
#endif

    Else
        Print Using "Mouse position: ###:###  Buttons: "; x; y;
        If buttons And 1 Then Print "L";
        If buttons And 2 Then Print "R";
        If buttons And 4 Then Print "M";
        Print "   "
    End If
Loop While Inkey = ""
End

'Example 2: type-union-type structure
Type mouse
    As Integer res
    As Integer x, y, wheel, clip
    Union
        buttons As Integer
        Type
            Left:1 As Integer
            Right:1 As Integer
            middle:1 As Integer
        End Type
    End Union
End Type
 
Screen 11
Dim As mouse m

Do
    m.res = GetMouse( m.x, m.y, m.wheel, m.buttons, m.clip )
    ScreenLock
    Cls
    Print Using "res = #"; m.res
    Print Using "x = ###; y = ###; wheel = +###; clip = ##"; m.x; m.y; m.wheel; m.clip
    Print Using "buttons = ##; left = #; middle = #; right = #"; m.buttons; m.left; m.middle; m.right
    ScreenUnlock
    Sleep 10, 1
Loop While Inkey = ""


Dialect Differences

  • Not available in the -lang qb dialect unless referenced with the alias __Getmouse. The variables passed must also be of type Long instead of Integer.

Platform Differences

  • On Win32, scroll wheel changes are not guaranteed to be detected in full-screen console mode.
  • In DOS, the "clip" value has no relevance. Additionally the wheel and middle button will not work unless supported and enabled by the mouse driver. See also FaqDOS.

Differences from QB

  • New to FreeBASIC

See also