Merge pull request #565 from danvk/gulp

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

diff --git a/src/extras/unzoom.js b/src/extras/unzoom.js
new file mode 100644 (file)
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--- /dev/null
+++ b/src/extras/unzoom.js
@@ -0,0 +1,105 @@
+// Copyright (c) 2013 Google, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+/*global Dygraph:false */
+
+/**
+ * @fileoverview Plug-in for providing unzoom-on-hover.
+ *
+ * @author konigsberg@google.com (Robert Konigsberg)
+ */
+Dygraph.Plugins.Unzoom = (function() {
+
+  "use strict";
+
+  /**
+   * Create a new instance.
+   *
+   * @constructor
+   */
+  var unzoom = function() {
+    this.button_ = null;
+
+    // True when the mouse is over the canvas. Must be tracked
+    // because the unzoom button state can change even when the
+    // mouse-over state hasn't.
+    this.over_ = false;
+  };
+
+  unzoom.prototype.toString = function() {
+    return 'Unzoom Plugin';
+  };
+
+  unzoom.prototype.activate = function(g) {
+    return {
+      willDrawChart: this.willDrawChart
+    };
+  };
+
+  unzoom.prototype.willDrawChart = function(e) {
+    var g = e.dygraph;
+
+    if (this.button_ !== null) {
+      // short-circuit: show the button only when we're moused over, and zoomed in.
+      var showButton = g.isZoomed() && this.over_;
+      this.show(showButton);
+      return;
+    }
+
+    this.button_ = document.createElement('button');
+    this.button_.innerHTML = 'Reset Zoom';
+    this.button_.style.display = 'none';
+    this.button_.style.position = 'absolute';
+    var area = g.plotter_.area;
+    this.button_.style.top = (area.y + 4) + 'px';
+    this.button_.style.left = (area.x + 4) + 'px';
+    this.button_.style.zIndex = 11;
+    var parent = g.graphDiv;
+    parent.insertBefore(this.button_, parent.firstChild);
+
+    var self = this;
+    this.button_.onclick = function() {
+      g.resetZoom();
+    };
+
+    g.addAndTrackEvent(parent, 'mouseover', function() {
+      if (g.isZoomed()) {
+        self.show(true);
+      }
+      self.over_ = true;
+    });
+
+    g.addAndTrackEvent(parent, 'mouseout', function() {
+      self.show(false);
+      self.over_ = false;
+    });
+  };
+
+  unzoom.prototype.show = function(enabled) {
+    this.button_.style.display = enabled ? '' : 'none';
+  };
+
+  unzoom.prototype.destroy = function() {
+    this.button_.parentElement.removeChild(this.button_);
+  };
+
+  return unzoom;
+
+})();