EventHandler

EventHandler[expr, {"event1":>action1, "event2":>action2, ...}]
displays as expr, evaluating whenever occurs in connection with expr.

Details and OptionsDetails and Options

  • Standard mouse-related event specifications include:
  • "MouseClicked"mouse clicked without moving
    {"MouseClicked",i}mouse button i clicked without moving
    "MouseDown"primary mouse button depressed
    {"MouseDown",i}mouse button i depressed
    "MouseDragged"mouse moving with primary button depressed
    {"MouseDragged",i}mouse moving with button i depressed
    "MouseMoved"mouse moves in the region defined by expr
    "MouseUp"primary mouse button released
    {"MouseUp",i}mouse button i released
  • For mouse events, EventHandler[expr, ...] handles events for which the mouse is within the rectangular region defined by the display of expr.
  • Standard keyboard-related event specifications include:
  • "KeyDown"any key on the keyboard depressed
    {"KeyDown","x"}key x depressed
    "ReturnKeyDown"Return or Enter key depressed
    "EscapeKeyDown"Esc key depressed
    "LeftArrowKeyDown"left arrow key depressed
    "RightArrowKeyDown"right arrow key depressed
    "UpArrowKeyDown"up arrow key depressed
    "DownArrowKeyDown"down arrow key depressed
  • Standard interface events include:
  • {"MenuCommand","name"}menu command with specified name chosen
    "WindowClose"closing of window requested
  • If functions like MousePosition or CurrentValue are evaluated in a particular , the values they give are those associated with the event that triggered that .
  • When EventHandler expressions are nested, events are by default shared by all the expressions, with the innermost expression operating first on a particular event.
  • The following options can be given:
  • PassEventsDownAutomaticwhether to pass events to inner event handlers
    PassEventsUpTruewhether to pass events to outer event handlers
  • With the default setting PassEventsDown->Automatic, events handled by an EventHandler are not also passed to built-in event handlers in the Mathematica front end.
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