plugin.js (6779B)
1 /*! 2 * reveal.js Zoom plugin 3 */ 4 const Plugin = { 5 6 id: 'zoom', 7 8 init: function( reveal ) { 9 10 reveal.getRevealElement().addEventListener( 'mousedown', function( event ) { 11 var defaultModifier = /Linux/.test( window.navigator.platform ) ? 'ctrl' : 'alt'; 12 13 var modifier = ( reveal.getConfig().zoomKey ? reveal.getConfig().zoomKey : defaultModifier ) + 'Key'; 14 var zoomLevel = ( reveal.getConfig().zoomLevel ? reveal.getConfig().zoomLevel : 2 ); 15 16 if( event[ modifier ] && !reveal.isOverview() ) { 17 event.preventDefault(); 18 19 zoom.to({ 20 x: event.clientX, 21 y: event.clientY, 22 scale: zoomLevel, 23 pan: false 24 }); 25 } 26 } ); 27 28 }, 29 30 destroy: () => { 31 32 zoom.reset(); 33 34 } 35 36 }; 37 38 export default () => Plugin; 39 40 /*! 41 * zoom.js 0.3 (modified for use with reveal.js) 42 * http://lab.hakim.se/zoom-js 43 * MIT licensed 44 * 45 * Copyright (C) 2011-2014 Hakim El Hattab, http://hakim.se 46 */ 47 var zoom = (function(){ 48 49 // The current zoom level (scale) 50 var level = 1; 51 52 // The current mouse position, used for panning 53 var mouseX = 0, 54 mouseY = 0; 55 56 // Timeout before pan is activated 57 var panEngageTimeout = -1, 58 panUpdateInterval = -1; 59 60 // Check for transform support so that we can fallback otherwise 61 var supportsTransforms = 'transform' in document.body.style; 62 63 if( supportsTransforms ) { 64 // The easing that will be applied when we zoom in/out 65 document.body.style.transition = '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 } 107 // Scale 108 else { 109 var origin = scrollOffset.x +'px '+ scrollOffset.y +'px', 110 transform = 'translate('+ -rect.x +'px,'+ -rect.y +'px) scale('+ scale +')'; 111 112 document.body.style.transformOrigin = origin; 113 document.body.style.transform = transform; 114 } 115 } 116 else { 117 // Reset 118 if( scale === 1 ) { 119 document.body.style.position = ''; 120 document.body.style.left = ''; 121 document.body.style.top = ''; 122 document.body.style.width = ''; 123 document.body.style.height = ''; 124 document.body.style.zoom = ''; 125 } 126 // Scale 127 else { 128 document.body.style.position = 'relative'; 129 document.body.style.left = ( - ( scrollOffset.x + rect.x ) / scale ) + 'px'; 130 document.body.style.top = ( - ( scrollOffset.y + rect.y ) / scale ) + 'px'; 131 document.body.style.width = ( scale * 100 ) + '%'; 132 document.body.style.height = ( scale * 100 ) + '%'; 133 document.body.style.zoom = scale; 134 } 135 } 136 137 level = scale; 138 139 if( document.documentElement.classList ) { 140 if( level !== 1 ) { 141 document.documentElement.classList.add( 'zoomed' ); 142 } 143 else { 144 document.documentElement.classList.remove( 'zoomed' ); 145 } 146 } 147 } 148 149 /** 150 * Pan the document when the mosue cursor approaches the edges 151 * of the window. 152 */ 153 function pan() { 154 var range = 0.12, 155 rangeX = window.innerWidth * range, 156 rangeY = window.innerHeight * range, 157 scrollOffset = getScrollOffset(); 158 159 // Up 160 if( mouseY < rangeY ) { 161 window.scroll( scrollOffset.x, scrollOffset.y - ( 1 - ( mouseY / rangeY ) ) * ( 14 / level ) ); 162 } 163 // Down 164 else if( mouseY > window.innerHeight - rangeY ) { 165 window.scroll( scrollOffset.x, scrollOffset.y + ( 1 - ( window.innerHeight - mouseY ) / rangeY ) * ( 14 / level ) ); 166 } 167 168 // Left 169 if( mouseX < rangeX ) { 170 window.scroll( scrollOffset.x - ( 1 - ( mouseX / rangeX ) ) * ( 14 / level ), scrollOffset.y ); 171 } 172 // Right 173 else if( mouseX > window.innerWidth - rangeX ) { 174 window.scroll( scrollOffset.x + ( 1 - ( window.innerWidth - mouseX ) / rangeX ) * ( 14 / level ), scrollOffset.y ); 175 } 176 } 177 178 function getScrollOffset() { 179 return { 180 x: window.scrollX !== undefined ? window.scrollX : window.pageXOffset, 181 y: window.scrollY !== undefined ? window.scrollY : window.pageYOffset 182 } 183 } 184 185 return { 186 /** 187 * Zooms in on either a rectangle or HTML element. 188 * 189 * @param {Object} options 190 * - element: HTML element to zoom in on 191 * OR 192 * - x/y: coordinates in non-transformed space to zoom in on 193 * - width/height: the portion of the screen to zoom in on 194 * - scale: can be used instead of width/height to explicitly set scale 195 */ 196 to: function( options ) { 197 198 // Due to an implementation limitation we can't zoom in 199 // to another element without zooming out first 200 if( level !== 1 ) { 201 zoom.out(); 202 } 203 else { 204 options.x = options.x || 0; 205 options.y = options.y || 0; 206 207 // If an element is set, that takes precedence 208 if( !!options.element ) { 209 // Space around the zoomed in element to leave on screen 210 var padding = 20; 211 var bounds = options.element.getBoundingClientRect(); 212 213 options.x = bounds.left - padding; 214 options.y = bounds.top - padding; 215 options.width = bounds.width + ( padding * 2 ); 216 options.height = bounds.height + ( padding * 2 ); 217 } 218 219 // If width/height values are set, calculate scale from those values 220 if( options.width !== undefined && options.height !== undefined ) { 221 options.scale = Math.max( Math.min( window.innerWidth / options.width, window.innerHeight / options.height ), 1 ); 222 } 223 224 if( options.scale > 1 ) { 225 options.x *= options.scale; 226 options.y *= options.scale; 227 228 magnify( options, options.scale ); 229 230 if( options.pan !== false ) { 231 232 // Wait with engaging panning as it may conflict with the 233 // zoom transition 234 panEngageTimeout = setTimeout( function() { 235 panUpdateInterval = setInterval( pan, 1000 / 60 ); 236 }, 800 ); 237 238 } 239 } 240 } 241 }, 242 243 /** 244 * Resets the document zoom state to its default. 245 */ 246 out: function() { 247 clearTimeout( panEngageTimeout ); 248 clearInterval( panUpdateInterval ); 249 250 magnify( { x: 0, y: 0 }, 1 ); 251 252 level = 1; 253 }, 254 255 // Alias 256 magnify: function( options ) { this.to( options ) }, 257 reset: function() { this.out() }, 258 259 zoomLevel: function() { 260 return level; 261 } 262 } 263 264 })();