Move to the proper directory

[dygraphs.git] / src / extras / crosshair.js

diff --git a/src/extras/crosshair.js b/src/extras/crosshair.js
new file mode 100644 (file)
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+++ b/src/extras/crosshair.js
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+/**
+ * @license
+ * Copyright 2015 Petr Shevtsov (petr.shevtsov@gmail.com)
+ * MIT-licensed (http://opensource.org/licenses/MIT)
+ */
+
+/*global Dygraph:false */
+/*jshint globalstrict: true */
+Dygraph.Plugins.Crosshair = (function() {
+  "use strict";
+
+  /**
+   * Creates the crosshair
+   *
+   * @constructor
+   */
+
+  var crosshair = function(opt_options) {
+    this.canvas_ = document.createElement("canvas");
+    opt_options = opt_options || {};
+    this.direction_ = opt_options.direction || null;
+  };
+
+  crosshair.prototype.toString = function() {
+    return "Crosshair Plugin";
+  };
+
+  /**
+   * @param {Dygraph} g Graph instance.
+   * @return {object.<string, function(ev)>} Mapping of event names to callbacks.
+   */
+  crosshair.prototype.activate = function(g) {
+    g.graphDiv.appendChild(this.canvas_);
+
+    return {
+      select: this.select,
+      deselect: this.deselect
+    };
+  };
+
+  crosshair.prototype.select = function(e) {
+    if (this.direction_ === null) {
+      return;
+    }
+
+    var width = e.dygraph.width_;
+    var height = e.dygraph.height_;
+    this.canvas_.width = width;
+    this.canvas_.height = height;
+    this.canvas_.style.width = width + "px";    // for IE
+    this.canvas_.style.height = height + "px";  // for IE
+
+    var ctx = this.canvas_.getContext("2d");
+    ctx.clearRect(0, 0, width, height);
+    ctx.strokeStyle = "rgba(0, 0, 0,0.3)";
+    ctx.beginPath();
+
+    var canvasx = Math.floor(e.dygraph.selPoints_[0].canvasx) + 0.5; // crisper rendering
+
+    if (this.direction_ === "vertical" || this.direction_ === "both") {
+      ctx.moveTo(canvasx, 0);
+      ctx.lineTo(canvasx, height);
+    }
+
+    if (this.direction_ === "horizontal" || this.direction_ === "both") {
+      for (var i = 0; i < e.dygraph.selPoints_.length; i++) {
+        var canvasy = Math.floor(e.dygraph.selPoints_[i].canvasy) + 0.5; // crisper rendering
+        ctx.moveTo(0, canvasy);
+        ctx.lineTo(width, canvasy);
+      }
+    }
+
+    ctx.stroke();
+    ctx.closePath();
+  };
+
+  crosshair.prototype.deselect = function(e) {
+    var ctx = this.canvas_.getContext("2d");
+    ctx.clearRect(0, 0, this.canvas_.width, this.canvas_.height);
+  };
+
+  crosshair.prototype.destroy = function() {
+    this.canvas_ = null;
+  };
+
+  return crosshair;
+})();