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To handle events on CSS circles properly, we have to ignore the corners of their bounding boxes. (found this copy/pasted on many blogs, thought I would keep here to clean up eventually)
$.CircleEventManager = function( options, element ) {
this.$el = $( element );
this._init( options );
};
$.CircleEventManager.defaults = {
onMouseEnter : function() { return false },
onMouseLeave : function() { return false },
onClick : function() { return false }
};
$.CircleEventManager.prototype = {
_init : function( options ) {
this.options = $.extend( true, {}, $.CircleEventManager.defaults, options );
// set the default cursor on the element
this.$el.css( 'cursor', 'default' );
this._initEvents();
},
_initEvents : function() {
var _self = this;
this.$el.on({
'mouseenter.circlemouse' : function( event ) {
var el = $(event.target),
circleWidth = el.outerWidth( true ),
circleHeight = el.outerHeight( true ),
circleLeft = el.offset().left,
circleTop = el.offset().top,
circlePos = {
x : circleLeft + circleWidth / 2,
y : circleTop + circleHeight / 2,
radius: circleWidth / 2
};
// save cursor type
var cursor = 'default';
if( _self.$el.css('cursor') === 'pointer' || _self.$el.is('a') )
cursor = 'pointer';
el.data( 'cursor', cursor );
el.on( 'mousemove.circlemouse', function( event ) {
var distance = Math.sqrt( Math.pow( event.pageX - circlePos.x, 2 ) + Math.pow( event.pageY - circlePos.y, 2 ) );
if( !Modernizr.borderradius ) {
// inside element / circle
el.css( 'cursor', el.data('cursor') ).data( 'inside', true );
_self.options.onMouseEnter( _self.$el );
}
else {
if( distance <= circlePos.radius && !el.data('inside') ) { // inside element / circle el.css( 'cursor', el.data('cursor') ).data( 'inside', true ); _self.options.onMouseEnter( _self.$el ); } else if( distance > circlePos.radius && el.data('inside') ) {
// inside element / outside circle
el.css( 'cursor', 'default' ).data( 'inside', false );
_self.options.onMouseLeave( _self.$el );
}
}
});
},
'mouseleave.circlemouse' : function( event ) {
var el = $(event.target);
el.off('mousemove');
if( el.data( 'inside' ) ) {
el.data( 'inside', false );
_self.options.onMouseLeave( _self.$el );
}
},
'click.circlemouse' : function( event ) {
// allow the click only when inside the circle
var el = $(event.target);
if( !el.data( 'inside' ) )
return false;
else
_self.options.onClick( _self.$el );
}
});
},
destroy : function() {
this.$el.unbind('.circlemouse').removeData('inside').removeData('cursor');
}
}
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