Data to draw within the screen.

draw_near_data.js

// require jquery
$(function(){
        var $w = $(window);
        var $h = $('html,body');
        var offset = $w.height();
        function canDraw($target, info) {
                var top = $target.position().top;
                if (info.st - offset <= top && top <= info.st + info.wh + offset) {
                        return true;
                }
                return false;
        }
        function isFinish($target, info) {
                var top = $target.position().top;
                if (info.st + info.wh + offset < top) {
                        return true;
                }
                return false;
        }
        function updateView() {
                var viewSelector = 'INPUT SELECTOR';
                $views = $(viewSelector);
                if ($views.length==0) return;

                var sizeInfo = {
                        'st':$w.scrollTop(),
                        'wh':$w.height(),
                        'vh':$h.height()
                };
                console.log('updateView: scrollTop='+sizeInfo.st+', windowHeight='+sizeInfo.wh);
                $views.each(function(){
                        var $self = $(this);
                        if (canDraw($self, sizeInfo)) {
                                console.log('view target='+$views.index($self));
                                drawView($self);
                        } else {
                                if (isFinish($self, sizeInfo)) {
                                        console.log('finish.');
                                        return false;
                                }
                        }
                        var top = $self.position().top;
                });
        }

        function drawView($target) {
		//FIXME implement.
        }
        
        updateView();
        $(window).scroll(updateView);
});