From b558f742990f08659348146c2bf3527ed99d519f Mon Sep 17 00:00:00 2001 From: Hakim El Hattab Date: Mon, 19 May 2014 09:26:44 +0200 Subject: [PATCH] zoom viewport is centered on target element #900 --- plugin/zoom-js/zoom.js | 116 ++++++++++++++++++++++------------------- 1 file changed, 62 insertions(+), 54 deletions(-) diff --git a/plugin/zoom-js/zoom.js b/plugin/zoom-js/zoom.js index cd5b06f..a672af4 100644 --- a/plugin/zoom-js/zoom.js +++ b/plugin/zoom-js/zoom.js @@ -16,11 +16,11 @@ })(); /*! - * zoom.js 0.2 (modified version for use with reveal.js) + * zoom.js 0.3 (modified for use with reveal.js) * http://lab.hakim.se/zoom-js * MIT licensed * - * Copyright (C) 2011-2012 Hakim El Hattab, http://hakim.se + * Copyright (C) 2011-2014 Hakim El Hattab, http://hakim.se */ var zoom = (function(){ @@ -35,8 +35,6 @@ var zoom = (function(){ var panEngageTimeout = -1, panUpdateInterval = -1; - var currentOptions = null; - // Check for transform support so that we can fallback otherwise var supportsTransforms = 'WebkitTransform' in document.body.style || 'MozTransform' in document.body.style || @@ -58,7 +56,7 @@ var zoom = (function(){ if( level !== 1 && event.keyCode === 27 ) { zoom.out(); } - }, false ); + } ); // Monitor mouse movement for panning document.addEventListener( 'mousemove', function( event ) { @@ -66,38 +64,56 @@ var zoom = (function(){ mouseX = event.clientX; mouseY = event.clientY; } - }, false ); + } ); /** - * Applies the CSS required to zoom in, prioritizes use of CSS3 + * Applies the CSS required to zoom in, prefers the use of CSS3 * transforms but falls back on zoom for IE. * - * @param {Number} pageOffsetX - * @param {Number} pageOffsetY - * @param {Number} elementOffsetX - * @param {Number} elementOffsetY + * @param {Object} rect * @param {Number} scale */ - function magnify( pageOffsetX, pageOffsetY, elementOffsetX, elementOffsetY, 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 ) { - var origin = pageOffsetX +'px '+ pageOffsetY +'px', - transform = 'translate('+ -elementOffsetX +'px,'+ -elementOffsetY +'px) scale('+ scale +')'; + // Reset + if( scale === 1 ) { + document.body.style.transform = ''; + document.body.style.OTransform = ''; + document.body.style.msTransform = ''; + document.body.style.MozTransform = ''; + document.body.style.WebkitTransform = ''; + } + // 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.OTransformOrigin = origin; - document.body.style.msTransformOrigin = origin; - document.body.style.MozTransformOrigin = origin; - document.body.style.WebkitTransformOrigin = origin; + document.body.style.transformOrigin = origin; + document.body.style.OTransformOrigin = origin; + document.body.style.msTransformOrigin = origin; + document.body.style.MozTransformOrigin = origin; + document.body.style.WebkitTransformOrigin = origin; - document.body.style.transform = transform; - document.body.style.OTransform = transform; - document.body.style.msTransform = transform; - document.body.style.MozTransform = transform; - document.body.style.WebkitTransform = transform; + document.body.style.transform = transform; + document.body.style.OTransform = transform; + document.body.style.msTransform = transform; + document.body.style.MozTransform = transform; + document.body.style.WebkitTransform = transform; + } } else { - // Reset all values + // Reset if( scale === 1 ) { document.body.style.position = ''; document.body.style.left = ''; @@ -106,11 +122,11 @@ var zoom = (function(){ document.body.style.height = ''; document.body.style.zoom = ''; } - // Apply scale + // Scale else { document.body.style.position = 'relative'; - document.body.style.left = ( - ( pageOffsetX + elementOffsetX ) / scale ) + 'px'; - document.body.style.top = ( - ( pageOffsetY + elementOffsetY ) / scale ) + 'px'; + 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; @@ -119,11 +135,13 @@ var zoom = (function(){ level = scale; - if( level !== 1 && document.documentElement.classList ) { - document.documentElement.classList.add( 'zoomed' ); - } - else { - document.documentElement.classList.remove( 'zoomed' ); + if( document.documentElement.classList ) { + if( level !== 1 ) { + document.documentElement.classList.add( 'zoomed' ); + } + else { + document.documentElement.classList.remove( 'zoomed' ); + } } } @@ -159,7 +177,7 @@ var zoom = (function(){ function getScrollOffset() { return { x: window.scrollX !== undefined ? window.scrollX : window.pageXOffset, - y: window.scrollY !== undefined ? window.scrollY : window.pageXYffset + y: window.scrollY !== undefined ? window.scrollY : window.pageYOffset } } @@ -175,6 +193,7 @@ var zoom = (function(){ * - 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 ) { @@ -188,11 +207,12 @@ var zoom = (function(){ if( !!options.element ) { // Space around the zoomed in element to leave on screen var padding = 20; + var bounds = options.element.getBoundingClientRect(); - options.width = options.element.getBoundingClientRect().width + ( padding * 2 ); - options.height = options.element.getBoundingClientRect().height + ( padding * 2 ); - options.x = options.element.getBoundingClientRect().left - padding; - options.y = options.element.getBoundingClientRect().top - padding; + 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 @@ -204,13 +224,7 @@ var zoom = (function(){ options.x *= options.scale; options.y *= options.scale; - var scrollOffset = getScrollOffset(); - - if( options.element ) { - scrollOffset.x -= ( window.innerWidth - ( options.width * options.scale ) ) / 2; - } - - magnify( scrollOffset.x, scrollOffset.y, options.x, options.y, options.scale ); + magnify( options, options.scale ); if( options.pan !== false ) { @@ -222,8 +236,6 @@ var zoom = (function(){ } } - - currentOptions = options; } }, @@ -234,13 +246,7 @@ var zoom = (function(){ clearTimeout( panEngageTimeout ); clearInterval( panUpdateInterval ); - var scrollOffset = getScrollOffset(); - - if( currentOptions && currentOptions.element ) { - scrollOffset.x -= ( window.innerWidth - ( currentOptions.width * currentOptions.scale ) ) / 2; - } - - magnify( scrollOffset.x, scrollOffset.y, 0, 0, 1 ); + magnify( { x: 0, y: 0 }, 1 ); level = 1; }, @@ -256,3 +262,5 @@ var zoom = (function(){ })(); + +