MouseWheel Event 8
Description
If enabled, this event is reported when the user rotates the mouse wheel.
The event message reported as the result of ⎕DQ, or supplied as the right argument to your callback function, is a 9-element vector as follows :
[1] |
Object | ref or character vector |
[2] |
Event | 'MouseWheel' or 8 |
[3] |
Y | y-position of mouse (number) |
[4] |
X | x-position of mouse (number) |
[5] |
Button | button pressed 1 = left button 2 = right button 4 = middle button |
[6] |
Shift State | sum of shift key codes (number) 1 = Shift key is down 2 = Ctrl key is down |
[7] |
Delta | integer |
[8] |
Lines | integer |
[9] |
Wheel Delta | integer |
The value of Delta indicates the distance that the wheel is rotated,§ expressed in multiples or divisions of Wheel Delta. A positive value indicates that the wheel was rotated forward, away from the user; a negative value indicates that the wheel was rotated backward, toward the user.
Lines specifies the number of lines to scroll when the wheel is rotated by I Mouse Delta unit. A value of ¯1 indicates that a whole screen is to be scrolled. These values are defined by the user's preferences (Control Panel/Mouse).