802c31b57cd88a81c93ed4d0e8037c95b5fd5b08
[dygraphs.git] / extras / unzoom.js
1 // Copyright (c) 2013 Google, Inc.
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining a copy
4 // of this software and associated documentation files (the "Software"), to deal
5 // in the Software without restriction, including without limitation the rights
6 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7 // copies of the Software, and to permit persons to whom the Software is
8 // furnished to do so, subject to the following conditions:
9 //
10 // The above copyright notice and this permission notice shall be included in
11 // all copies or substantial portions of the Software.
12 //
13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19 // THE SOFTWARE.
20
21 /*global Dygraph:false */
22
23 /**
24 * @fileoverview Plug-in for providing unzoom-on-hover.
25 *
26 * @author konigsberg@google.com (Robert Konigsberg)
27 */
28 Dygraph.Plugins.Unzoom = (function() {
29
30 "use strict";
31
32 /**
33 * Create a new instance.
34 *
35 * @constructor
36 */
37 var unzoom = function() {
38 this.button_ = null;
39
40 // True when the mouse is over the canvas. Must be tracked
41 // because the unzoom button state can change even when the
42 // mouse-over state hasn't.
43 this.over_ = false;
44 };
45
46 unzoom.prototype.toString = function() {
47 return 'Unzoom Plugin';
48 };
49
50 unzoom.prototype.activate = function(g) {
51 return {
52 willDrawChart: this.willDrawChart
53 };
54 };
55
56 unzoom.prototype.willDrawChart = function(e) {
57 var g = e.dygraph;
58
59 if (this.button_ !== null) {
60 // short-circuit: show the button only when we're moused over, and zoomed in.
61 var showButton = g.isZoomed() && this.over_;
62 this.show(showButton);
63 return;
64 }
65
66 this.button_ = document.createElement('button');
67 this.button_.innerHTML = 'Reset Zoom';
68 this.button_.style.display = 'none';
69 this.button_.style.position = 'absolute';
70 var area = g.plotter_.area;
71 this.button_.style.top = (area.y + 4) + 'px';
72 this.button_.style.left = (area.x + 4) + 'px';
73 this.button_.style.zIndex = 11;
74 var parent = g.graphDiv;
75 parent.insertBefore(this.button_, parent.firstChild);
76
77 var self = this;
78 this.button_.onclick = function() {
79 g.resetZoom();
80 };
81
82 g.addEvent(parent, 'mouseover', function() {
83 if (g.isZoomed()) {
84 self.show(true);
85 }
86 self.over_ = true;
87 });
88
89 g.addEvent(parent, 'mouseout', function() {
90 self.show(false);
91 self.over_ = false;
92 });
93 };
94
95 unzoom.prototype.show = function(enabled) {
96 this.button_.style.display = enabled ? '' : 'none';
97 };
98
99 unzoom.prototype.destroy = function() {
100 this.button_.parentElement.removeChild(this.button_);
101 };
102
103 return unzoom;
104
105 })();