tz-onest-data/data-ui/public/SuperMap3D/examples/webgl/js/tooltip.js

function createTooltip(frameDiv) {

    var tooltip = function(frameDiv) {

        var div = document.createElement('DIV');
        div.className = "twipsy right";

        var arrow = document.createElement('DIV');
        arrow.className = "twipsy-arrow";
        div.appendChild(arrow);

        var title = document.createElement('DIV');
        title.className = "twipsy-inner";
        div.appendChild(title);

        this._div = div;
        this._title = title;
        this.message = '';

        // add to frame div and display coordinates
        frameDiv.appendChild(div);
        var that = this;
        div.onmousemove = function(evt){
            that.showAt({x : evt.clientX,y : evt.clientY},that.message);
        };
    };

    tooltip.prototype.setVisible = function(visible) {
        this._div.style.display = visible ? 'block' : 'none';
    };

    tooltip.prototype.showAt = function(position, message) {
        if(position && message) {
            this.setVisible(true);
            this._title.innerHTML = message;
            this._div.style.left = position.x + 10 + "px";
            this._div.style.top = (position.y - this._div.clientHeight / 2) + "px";
            this.message = message;
        }
    };

    return new tooltip(frameDiv);
}