diff options
Diffstat (limited to 'present/plugin/zoom/plugin.js')
| -rw-r--r-- | present/plugin/zoom/plugin.js | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/present/plugin/zoom/plugin.js b/present/plugin/zoom/plugin.js new file mode 100644 index 0000000..960fb81 --- /dev/null +++ b/present/plugin/zoom/plugin.js @@ -0,0 +1,264 @@ +/*! + * reveal.js Zoom plugin + */ +const Plugin = { + + id: 'zoom', + + init: function( reveal ) { + + reveal.getRevealElement().addEventListener( 'mousedown', function( event ) { + var defaultModifier = /Linux/.test( window.navigator.platform ) ? 'ctrl' : 'alt'; + + var modifier = ( reveal.getConfig().zoomKey ? reveal.getConfig().zoomKey : defaultModifier ) + 'Key'; + var zoomLevel = ( reveal.getConfig().zoomLevel ? reveal.getConfig().zoomLevel : 2 ); + + if( event[ modifier ] && !reveal.isOverview() ) { + event.preventDefault(); + + zoom.to({ + x: event.clientX, + y: event.clientY, + scale: zoomLevel, + pan: false + }); + } + } ); + + }, + + destroy: () => { + + zoom.reset(); + + } + +}; + +export default () => Plugin; + +/*! + * zoom.js 0.3 (modified for use with reveal.js) + * http://lab.hakim.se/zoom-js + * MIT licensed + * + * Copyright (C) 2011-2014 Hakim El Hattab, http://hakim.se + */ +var zoom = (function(){ + + // The current zoom level (scale) + var level = 1; + + // The current mouse position, used for panning + var mouseX = 0, + mouseY = 0; + + // Timeout before pan is activated + var panEngageTimeout = -1, + panUpdateInterval = -1; + + // Check for transform support so that we can fallback otherwise + var supportsTransforms = 'transform' in document.body.style; + + if( supportsTransforms ) { + // The easing that will be applied when we zoom in/out + document.body.style.transition = 'transform 0.8s ease'; + } + + // Zoom out if the user hits escape + document.addEventListener( 'keyup', function( event ) { + if( level !== 1 && event.keyCode === 27 ) { + zoom.out(); + } + } ); + + // Monitor mouse movement for panning + document.addEventListener( 'mousemove', function( event ) { + if( level !== 1 ) { + mouseX = event.clientX; + mouseY = event.clientY; + } + } ); + + /** + * Applies the CSS required to zoom in, prefers the use of CSS3 + * transforms but falls back on zoom for IE. + * + * @param {Object} rect + * @param {Number} scale + */ + function magnify( rect, scale ) { + + var scrollOffset = getScrollOffset(); + + // Ensure a width/height is set + rect.width = rect.width || 1; + rect.height = rect.height || 1; + + // Center the rect within the zoomed viewport + rect.x -= ( window.innerWidth - ( rect.width * scale ) ) / 2; + rect.y -= ( window.innerHeight - ( rect.height * scale ) ) / 2; + + if( supportsTransforms ) { + // Reset + if( scale === 1 ) { + document.body.style.transform = ''; + } + // Scale + else { + var origin = scrollOffset.x +'px '+ scrollOffset.y +'px', + transform = 'translate('+ -rect.x +'px,'+ -rect.y +'px) scale('+ scale +')'; + + document.body.style.transformOrigin = origin; + document.body.style.transform = transform; + } + } + else { + // Reset + if( scale === 1 ) { + document.body.style.position = ''; + document.body.style.left = ''; + document.body.style.top = ''; + document.body.style.width = ''; + document.body.style.height = ''; + document.body.style.zoom = ''; + } + // Scale + else { + document.body.style.position = 'relative'; + document.body.style.left = ( - ( scrollOffset.x + rect.x ) / scale ) + 'px'; + document.body.style.top = ( - ( scrollOffset.y + rect.y ) / scale ) + 'px'; + document.body.style.width = ( scale * 100 ) + '%'; + document.body.style.height = ( scale * 100 ) + '%'; + document.body.style.zoom = scale; + } + } + + level = scale; + + if( document.documentElement.classList ) { + if( level !== 1 ) { + document.documentElement.classList.add( 'zoomed' ); + } + else { + document.documentElement.classList.remove( 'zoomed' ); + } + } + } + + /** + * Pan the document when the mosue cursor approaches the edges + * of the window. + */ + function pan() { + var range = 0.12, + rangeX = window.innerWidth * range, + rangeY = window.innerHeight * range, + scrollOffset = getScrollOffset(); + + // Up + if( mouseY < rangeY ) { + window.scroll( scrollOffset.x, scrollOffset.y - ( 1 - ( mouseY / rangeY ) ) * ( 14 / level ) ); + } + // Down + else if( mouseY > window.innerHeight - rangeY ) { + window.scroll( scrollOffset.x, scrollOffset.y + ( 1 - ( window.innerHeight - mouseY ) / rangeY ) * ( 14 / level ) ); + } + + // Left + if( mouseX < rangeX ) { + window.scroll( scrollOffset.x - ( 1 - ( mouseX / rangeX ) ) * ( 14 / level ), scrollOffset.y ); + } + // Right + else if( mouseX > window.innerWidth - rangeX ) { + window.scroll( scrollOffset.x + ( 1 - ( window.innerWidth - mouseX ) / rangeX ) * ( 14 / level ), scrollOffset.y ); + } + } + + function getScrollOffset() { + return { + x: window.scrollX !== undefined ? window.scrollX : window.pageXOffset, + y: window.scrollY !== undefined ? window.scrollY : window.pageYOffset + } + } + + return { + /** + * Zooms in on either a rectangle or HTML element. + * + * @param {Object} options + * - element: HTML element to zoom in on + * OR + * - x/y: coordinates in non-transformed space to zoom in on + * - width/height: the portion of the screen to zoom in on + * - scale: can be used instead of width/height to explicitly set scale + */ + to: function( options ) { + + // Due to an implementation limitation we can't zoom in + // to another element without zooming out first + if( level !== 1 ) { + zoom.out(); + } + else { + options.x = options.x || 0; + options.y = options.y || 0; + + // If an element is set, that takes precedence + if( !!options.element ) { + // Space around the zoomed in element to leave on screen + var padding = 20; + var bounds = options.element.getBoundingClientRect(); + + options.x = bounds.left - padding; + options.y = bounds.top - padding; + options.width = bounds.width + ( padding * 2 ); + options.height = bounds.height + ( padding * 2 ); + } + + // If width/height values are set, calculate scale from those values + if( options.width !== undefined && options.height !== undefined ) { + options.scale = Math.max( Math.min( window.innerWidth / options.width, window.innerHeight / options.height ), 1 ); + } + + if( options.scale > 1 ) { + options.x *= options.scale; + options.y *= options.scale; + + magnify( options, options.scale ); + + if( options.pan !== false ) { + + // Wait with engaging panning as it may conflict with the + // zoom transition + panEngageTimeout = setTimeout( function() { + panUpdateInterval = setInterval( pan, 1000 / 60 ); + }, 800 ); + + } + } + } + }, + + /** + * Resets the document zoom state to its default. + */ + out: function() { + clearTimeout( panEngageTimeout ); + clearInterval( panUpdateInterval ); + + magnify( { x: 0, y: 0 }, 1 ); + + level = 1; + }, + + // Alias + magnify: function( options ) { this.to( options ) }, + reset: function() { this.out() }, + + zoomLevel: function() { + return level; + } + } + +})(); |