hover.js

/**
* Copyright 2012-2015, Plotly, Inc.
* All rights reserved.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/


'use strict';

var Plotly = require('../../plotly');
var Color = require('../../components/color');


module.exports = function hoverPoints(pointData, xval, yval, hovermode) {
    var cd = pointData.cd,
        trace = cd[0].trace,
        t = cd[0].t,
        xa = pointData.xa,
        ya = pointData.ya,
        barDelta = (hovermode==='closest') ?
            t.barwidth/2 : t.dbar*(1-xa._td._fullLayout.bargap)/2,
        barPos;

    if(hovermode!=='closest') barPos = function(di) { return di.p; };
    else if(trace.orientation==='h') barPos = function(di) { return di.y; };
    else barPos = function(di) { return di.x; };

    var dx, dy;
    if(trace.orientation==='h') {
        dx = function(di){
            // add a gradient so hovering near the end of a
            // bar makes it a little closer match
            return Plotly.Fx.inbox(di.b-xval, di.x-xval) + (di.x-xval)/(di.x-di.b);
        };
        dy = function(di){
            var centerPos = barPos(di) - yval;
            return Plotly.Fx.inbox(centerPos - barDelta, centerPos + barDelta);
        };
    }
    else {
        dy = function(di){
            return Plotly.Fx.inbox(di.b-yval, di.y-yval) + (di.y-yval)/(di.y-di.b);
        };
        dx = function(di){
            var centerPos = barPos(di) - xval;
            return Plotly.Fx.inbox(centerPos - barDelta, centerPos + barDelta);
        };
    }

    var distfn = Plotly.Fx.getDistanceFunction(hovermode, dx, dy);
    Plotly.Fx.getClosest(cd, distfn, pointData);

    // skip the rest (for this trace) if we didn't find a close point
    if(pointData.index===false) return;

    // the closest data point
    var di = cd[pointData.index],
        mc = di.mcc || trace.marker.color,
        mlc = di.mlcc || trace.marker.line.color,
        mlw = di.mlw || trace.marker.line.width;
    if(Color.opacity(mc)) pointData.color = mc;
    else if(Color.opacity(mlc) && mlw) pointData.color = mlc;

    if(trace.orientation==='h') {
        pointData.x0 = pointData.x1 = xa.c2p(di.x, true);
        pointData.xLabelVal = di.s;

        pointData.y0 = ya.c2p(barPos(di) - barDelta, true);
        pointData.y1 = ya.c2p(barPos(di) + barDelta, true);
        pointData.yLabelVal = di.p;
    }
    else {
        pointData.y0 = pointData.y1 = ya.c2p(di.y,true);
        pointData.yLabelVal = di.s;

        pointData.x0 = xa.c2p(barPos(di) - barDelta, true);
        pointData.x1 = xa.c2p(barPos(di) + barDelta, true);
        pointData.xLabelVal = di.p;
    }

    if(di.tx) pointData.text = di.tx;

    Plotly.ErrorBars.hoverInfo(di, trace, pointData);

    return [pointData];
};