1// Custom reveal.js integration
2var RevealZoom = (function(){
3
4	return {
5		init: function() {
6
7			Reveal.getRevealElement().addEventListener( 'mousedown', function( event ) {
8				var defaultModifier = /Linux/.test( window.navigator.platform ) ? 'ctrl' : 'alt';
9
10				var modifier = ( Reveal.getConfig().zoomKey ? Reveal.getConfig().zoomKey : defaultModifier ) + 'Key';
11				var zoomLevel = ( Reveal.getConfig().zoomLevel ? Reveal.getConfig().zoomLevel : 2 );
12
13				if( event[ modifier ] && !Reveal.isOverview() ) {
14					event.preventDefault();
15
16					zoom.to({
17						x: event.clientX,
18						y: event.clientY,
19						scale: zoomLevel,
20						pan: false
21					});
22				}
23			} );
24
25		}
26	}
27
28})();
29
30Reveal.registerPlugin( 'zoom', RevealZoom );
31
32/*!
33 * zoom.js 0.3 (modified for use with reveal.js)
34 * http://lab.hakim.se/zoom-js
35 * MIT licensed
36 *
37 * Copyright (C) 2011-2014 Hakim El Hattab, http://hakim.se
38 */
39var zoom = (function(){
40
41	// The current zoom level (scale)
42	var level = 1;
43
44	// The current mouse position, used for panning
45	var mouseX = 0,
46		mouseY = 0;
47
48	// Timeout before pan is activated
49	var panEngageTimeout = -1,
50		panUpdateInterval = -1;
51
52	// Check for transform support so that we can fallback otherwise
53	var supportsTransforms = 	'WebkitTransform' in document.body.style ||
54								'MozTransform' in document.body.style ||
55								'msTransform' in document.body.style ||
56								'OTransform' in document.body.style ||
57								'transform' in document.body.style;
58
59	if( supportsTransforms ) {
60		// The easing that will be applied when we zoom in/out
61		document.body.style.transition = 'transform 0.8s ease';
62		document.body.style.OTransition = '-o-transform 0.8s ease';
63		document.body.style.msTransition = '-ms-transform 0.8s ease';
64		document.body.style.MozTransition = '-moz-transform 0.8s ease';
65		document.body.style.WebkitTransition = '-webkit-transform 0.8s ease';
66	}
67
68	// Zoom out if the user hits escape
69	document.addEventListener( 'keyup', function( event ) {
70		if( level !== 1 && event.keyCode === 27 ) {
71			zoom.out();
72		}
73	} );
74
75	// Monitor mouse movement for panning
76	document.addEventListener( 'mousemove', function( event ) {
77		if( level !== 1 ) {
78			mouseX = event.clientX;
79			mouseY = event.clientY;
80		}
81	} );
82
83	/**
84	 * Applies the CSS required to zoom in, prefers the use of CSS3
85	 * transforms but falls back on zoom for IE.
86	 *
87	 * @param {Object} rect
88	 * @param {Number} scale
89	 */
90	function magnify( rect, scale ) {
91
92		var scrollOffset = getScrollOffset();
93
94		// Ensure a width/height is set
95		rect.width = rect.width || 1;
96		rect.height = rect.height || 1;
97
98		// Center the rect within the zoomed viewport
99		rect.x -= ( window.innerWidth - ( rect.width * scale ) ) / 2;
100		rect.y -= ( window.innerHeight - ( rect.height * scale ) ) / 2;
101
102		if( supportsTransforms ) {
103			// Reset
104			if( scale === 1 ) {
105				document.body.style.transform = '';
106				document.body.style.OTransform = '';
107				document.body.style.msTransform = '';
108				document.body.style.MozTransform = '';
109				document.body.style.WebkitTransform = '';
110			}
111			// Scale
112			else {
113				var origin = scrollOffset.x +'px '+ scrollOffset.y +'px',
114					transform = 'translate('+ -rect.x +'px,'+ -rect.y +'px) scale('+ scale +')';
115
116				document.body.style.transformOrigin = origin;
117				document.body.style.OTransformOrigin = origin;
118				document.body.style.msTransformOrigin = origin;
119				document.body.style.MozTransformOrigin = origin;
120				document.body.style.WebkitTransformOrigin = origin;
121
122				document.body.style.transform = transform;
123				document.body.style.OTransform = transform;
124				document.body.style.msTransform = transform;
125				document.body.style.MozTransform = transform;
126				document.body.style.WebkitTransform = transform;
127			}
128		}
129		else {
130			// Reset
131			if( scale === 1 ) {
132				document.body.style.position = '';
133				document.body.style.left = '';
134				document.body.style.top = '';
135				document.body.style.width = '';
136				document.body.style.height = '';
137				document.body.style.zoom = '';
138			}
139			// Scale
140			else {
141				document.body.style.position = 'relative';
142				document.body.style.left = ( - ( scrollOffset.x + rect.x ) / scale ) + 'px';
143				document.body.style.top = ( - ( scrollOffset.y + rect.y ) / scale ) + 'px';
144				document.body.style.width = ( scale * 100 ) + '%';
145				document.body.style.height = ( scale * 100 ) + '%';
146				document.body.style.zoom = scale;
147			}
148		}
149
150		level = scale;
151
152		if( document.documentElement.classList ) {
153			if( level !== 1 ) {
154				document.documentElement.classList.add( 'zoomed' );
155			}
156			else {
157				document.documentElement.classList.remove( 'zoomed' );
158			}
159		}
160	}
161
162	/**
163	 * Pan the document when the mosue cursor approaches the edges
164	 * of the window.
165	 */
166	function pan() {
167		var range = 0.12,
168			rangeX = window.innerWidth * range,
169			rangeY = window.innerHeight * range,
170			scrollOffset = getScrollOffset();
171
172		// Up
173		if( mouseY < rangeY ) {
174			window.scroll( scrollOffset.x, scrollOffset.y - ( 1 - ( mouseY / rangeY ) ) * ( 14 / level ) );
175		}
176		// Down
177		else if( mouseY > window.innerHeight - rangeY ) {
178			window.scroll( scrollOffset.x, scrollOffset.y + ( 1 - ( window.innerHeight - mouseY ) / rangeY ) * ( 14 / level ) );
179		}
180
181		// Left
182		if( mouseX < rangeX ) {
183			window.scroll( scrollOffset.x - ( 1 - ( mouseX / rangeX ) ) * ( 14 / level ), scrollOffset.y );
184		}
185		// Right
186		else if( mouseX > window.innerWidth - rangeX ) {
187			window.scroll( scrollOffset.x + ( 1 - ( window.innerWidth - mouseX ) / rangeX ) * ( 14 / level ), scrollOffset.y );
188		}
189	}
190
191	function getScrollOffset() {
192		return {
193			x: window.scrollX !== undefined ? window.scrollX : window.pageXOffset,
194			y: window.scrollY !== undefined ? window.scrollY : window.pageYOffset
195		}
196	}
197
198	return {
199		/**
200		 * Zooms in on either a rectangle or HTML element.
201		 *
202		 * @param {Object} options
203		 *   - element: HTML element to zoom in on
204		 *   OR
205		 *   - x/y: coordinates in non-transformed space to zoom in on
206		 *   - width/height: the portion of the screen to zoom in on
207		 *   - scale: can be used instead of width/height to explicitly set scale
208		 */
209		to: function( options ) {
210
211			// Due to an implementation limitation we can't zoom in
212			// to another element without zooming out first
213			if( level !== 1 ) {
214				zoom.out();
215			}
216			else {
217				options.x = options.x || 0;
218				options.y = options.y || 0;
219
220				// If an element is set, that takes precedence
221				if( !!options.element ) {
222					// Space around the zoomed in element to leave on screen
223					var padding = 20;
224					var bounds = options.element.getBoundingClientRect();
225
226					options.x = bounds.left - padding;
227					options.y = bounds.top - padding;
228					options.width = bounds.width + ( padding * 2 );
229					options.height = bounds.height + ( padding * 2 );
230				}
231
232				// If width/height values are set, calculate scale from those values
233				if( options.width !== undefined && options.height !== undefined ) {
234					options.scale = Math.max( Math.min( window.innerWidth / options.width, window.innerHeight / options.height ), 1 );
235				}
236
237				if( options.scale > 1 ) {
238					options.x *= options.scale;
239					options.y *= options.scale;
240
241					magnify( options, options.scale );
242
243					if( options.pan !== false ) {
244
245						// Wait with engaging panning as it may conflict with the
246						// zoom transition
247						panEngageTimeout = setTimeout( function() {
248							panUpdateInterval = setInterval( pan, 1000 / 60 );
249						}, 800 );
250
251					}
252				}
253			}
254		},
255
256		/**
257		 * Resets the document zoom state to its default.
258		 */
259		out: function() {
260			clearTimeout( panEngageTimeout );
261			clearInterval( panUpdateInterval );
262
263			magnify( { x: 0, y: 0 }, 1 );
264
265			level = 1;
266		},
267
268		// Alias
269		magnify: function( options ) { this.to( options ) },
270		reset: function() { this.out() },
271
272		zoomLevel: function() {
273			return level;
274		}
275	}
276
277})();
278