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xeventcontroller(event) Event xeventcontroller(event)

NAME

xeventcontroller

SUPERCLASS

inputcontroller

DESCRIPTION

The xeventcontroller object maps X events into the abstract LYMB events represented by objects of the event class.

INSTANCE VARIABLES

No new instance variables are defined in this class.

MESSAGES

event: XEvent This message accepts a pointer to an XEvent structure as a single argument. It maps that structure into an abstract event and sends it to the object named in its state instance variable. Abstract events, represented by strings, are passed to the superclass.

The X event type is mapped into the string name of the event, preceded by "X_". For instance, an X ButtonPress event becomes "X_ButtonPress". Note that the case of the string is preserved, and significant in all comparisons.

For ButtonPress and ButtonRelease events, the button, x, and y instance variables of the generated event object are set. For KeyPress and KeyRelease events, the key, x, and y instance variables of the generated event object are set. For MotionNotify, EnterNotify, and LeaveNotify events, the x and y instance variables of the generated event object are set.

EXAMPLE

-- sample event script

-- pressing button 1, dragging the mouse, then releasing button 1 causes an -- area select message to be displayed -- clicking button 1 causes an object select message to be displayed -- clicking button 2 causes a button called "Hi" to be displayed -- clicking button 3 causes a button called "Quit" to be displayed

<xinit

ui Application="Event test" create! ;

ui_row_column new: wkspc parent=ui @ "height" : 300 @ "width" : 300 input_mask=( ButtonPressMask, ButtonReleaseMask, ButtonMotionMask ) create! ;

ui on! ;

ui_button new: button3 parent=wkspc label= "Quit" action= quit_action create! off! ;

ui_button new: button2 parent=wkspc label= "Hi" action= hi_action create! off! ;

xdisplay sync!;

string new: str;

actions new: object_action tick_actions=` str = `Object selected' print:value; ' ;

actions new: area_action tick_actions=` str = `Area selected' print:value; ' ;

event new: press type=`X_ButtonPress' window=[wkspc window_id?] button=1 ;

event new: release type=`X_ButtonRelease' window=[wkspc window_id?] button=1 ;

event new: motion type=`X_MotionNotify' window=[wkspc window_id?] button=1 ;

event new: menupress type=`X_ButtonPress' window=[wkspc window_id?] button=3 ;

event new: middlepress type=`X_ButtonPress' window=[wkspc window_id?] button=2 ;

actions new: quit_action tick_actions=` str = `BYE!' print:value; ui exit!; ' ;

actions new: hi_action tick_actions=` str = `HI!' print:value; ' ;

actions new: popquit tick_actions=` str = "Quit button enabled" print:value; button3 on!; ' ;

actions new: pophi tick_actions=` str = "Hi button enabled" print:value; button2 on!; ' ;

xeventcontroller new: xev -- we don't care about unspecified events ignore_unknown_events!

-- define state machine and its transitions -- current state -- event -- next state -- transition action transition:(start, menupress, start, `popquit') transition:(start, middlepress, start, `pophi') transition:(start, press, buttondown, `') transition:(buttondown, motion, buttondownmoved, `') transition:(buttondown, release, start, object_action) transition:(buttondownmoved, release, start, area_action) transition:(buttondownmoved, motion, buttondownmoved, `') -- define the start state state=start -- start accepting events start! ;

ui event= `xev' start! ;