Function brush

d3-3.2.8/d3.js:7917–7946

(g)

  d3.svg.brush = function() {
    var event = d3_eventDispatch(brush, "brushstart", "brush", "brushend"), x = null, y = null, resizes = d3_svg_brushResizes[0], extent = [ [ 0, 0 ], [ 0, 0 ] ], clamp = [ true, true ], extentDomain;
    function brush(g) {
      g.each(function() {
        var g = d3.select(this), bg = g.selectAll(".background").data([ 0 ]), fg = g.selectAll(".extent").data([ 0 ]), tz = g.selectAll(".resize").data(resizes, String), e;
        g.style("pointer-events", "all").on("mousedown.brush", brushstart).on("touchstart.brush", brushstart);
        bg.enter().append("rect").attr("class", "background").style("visibility", "hidden").style("cursor", "crosshair");
        fg.enter().append("rect").attr("class", "extent").style("cursor", "move");
        tz.enter().append("g").attr("class", function(d) {
          return "resize " + d;
        }).style("cursor", function(d) {
          return d3_svg_brushCursor[d];
        }).append("rect").attr("x", function(d) {
          return /[ew]$/.test(d) ? -3 : null;
        }).attr("y", function(d) {
          return /^[ns]/.test(d) ? -3 : null;
        }).attr("width", 6).attr("height", 6).style("visibility", "hidden");
        tz.style("display", brush.empty() ? "none" : null);
        tz.exit().remove();
        if (x) {
          e = d3_scaleRange(x);
          bg.attr("x", e[0]).attr("width", e[1] - e[0]);
          redrawX(g);
        }
        if (y) {
          e = d3_scaleRange(y);
          bg.attr("y", e[0]).attr("height", e[1] - e[0]);
          redrawY(g);
        }
        redraw(g);
      });
    }
    function redraw(g) {
      g.selectAll(".resize").attr("transform", function(d) {
        return "translate(" + extent[+/e$/.test(d)][0] + "," + extent[+/^s/.test(d)][1] + ")";