question: public boolean mousePressed ( MouseEvent e ) { if ( show_plot_ && graph != null ) { int x = e . getX ( ) ; int y = e . getY ( ) ; if ( ( x >= plotX ) && ( x <= plotX + plotWidth ) && ( y >= plotY ) && ( y <= plotY + plotWidth ) ) { grabbed_plot_graphics_ = true ; prevX = x ; prevY = y ; } } return false ; }
target:  Called whenever the mouse is pressed by the user and one of the requested mouse modes is active.