mediawiki-extensions-Multim.../resources/mmv/ui/mmv.ui.canvas.js

327 lines
9.6 KiB
JavaScript
Raw Normal View History

/*
* This file is part of the MediaWiki extension MediaViewer.
*
* MediaViewer is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* MediaViewer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MediaViewer. If not, see <http://www.gnu.org/licenses/>.
*/
( function( mw, $, oo ) {
var C;
/**
* UI component that contains the multimedia element to be displayed.
* This first version assumes an image but it can be extended to other
* media types (video, sound, presentation, etc.).
*
* @class mw.mmv.ui.Canvas
* @extends mw.mmv.ui.Element
* @constructor
* @param {jQuery} $container Canvas' container
* @param {jQuery} $imageWrapper
* @param {jQuery} $mainWrapper
*/
function Canvas( $container, $imageWrapper, $mainWrapper ) {
mw.mmv.ui.Element.call( this, $container );
/**
* @property {mw.mmv.ThumbnailWidthCalculator}
* @private
*/
this.thumbnailWidthCalculator = new mw.mmv.ThumbnailWidthCalculator();
/**
* Contains image.
* @property {jQuery}
*/
this.$imageDiv = $( '<div>' )
.addClass( 'mw-mmv-image' );
this.$imageDiv.appendTo( this.$container );
/**
* Container of canvas and controls, needed for canvas size calculations.
* @property {jQuery}
* @private
*/
this.$imageWrapper = $imageWrapper;
/**
* Main container of image and metadata, needed to propagate resize events.
* @property {jQuery}
* @private
*/
this.$mainWrapper = $mainWrapper;
/**
* Raw metadata of current image, needed for canvas size calculations.
* @property {mw.mmv.LightboxImage}
* @private
*/
this.imageRawMetadata = null;
}
oo.inheritClass( Canvas, mw.mmv.ui.Element );
C = Canvas.prototype;
/**
* Maximum blownup factor tolerated
* @property mw.mmv.ui.Canvas.MAX_BLOWUP_FACTOR
* @static
*/
Canvas.MAX_BLOWUP_FACTOR = 11;
/**
* Blowup factor threshold at which blurring kicks in
* @property mw.mmv.ui.Canvas.BLUR_BLOWUP_FACTOR_THRESHOLD
* @static
*/
Canvas.BLUR_BLOWUP_FACTOR_THRESHOLD = 2;
/**
* Clears everything.
*/
C.empty = function() {
this.$imageDiv.addClass( 'empty' ).removeClass( 'error' );
this.$imageDiv.empty();
};
/**
* Sets contained image.
* @param {mw.mmv.LightboxImage} imageRawMetadata
* @param {jQuery} $imageElement
*/
C.set = function( imageRawMetadata, $imageElement ) {
this.$imageDiv.removeClass( 'empty' );
this.imageRawMetadata = imageRawMetadata;
this.$image = $imageElement;
this.$imageDiv.html( this.$image );
};
/**
* Sets contained image and also the max dimensions. Called while resizing the viewer.
* Assumes set function called before.
* @param {mw.mmv.model.Thumbnail} thumbnail thumbnail information
* @param {HTMLImageElement} imageEle
* @param {mw.mmv.model.ThumbnailWidth} imageWidths
*/
C.setImageAndMaxDimensions = function( thumbnail, imageEle, imageWidths ) {
var $image = $( imageEle );
function makeMaxMatchParent ( $image ) {
$image.css( {
maxHeight : $image.parent().height(),
maxWidth : $image.parent().width()
} );
}
// we downscale larger images but do not scale up smaller ones, that would look ugly
if ( thumbnail.width > imageWidths.cssWidth ) {
imageEle.width = imageWidths.cssWidth;
}
if ( this.$image.is( imageEle ) ) { // http://bugs.jquery.com/ticket/4087
// We may be changing the width of the image when we resize, we should also
// update the max dimensions otherwise the image is not scaled properly
makeMaxMatchParent( this.$image );
return;
}
this.$image.replaceWith( $image );
this.$image = $image;
makeMaxMatchParent( this.$image );
};
/**
* Registers listeners.
*/
C.attach = function() {
var canvas = this;
// TODO: Try to use Element.handleEvent() instead !
if ( !this.resizeListener ) {
this.resizeListener = function () {
canvas.$mainWrapper.trigger( $.Event( 'mmv-resize') );
};
window.addEventListener( 'resize', this.resizeListener );
}
};
/**
* Clears listeners.
*/
C.unattach = function() {
this.clearEvents();
if ( this.resizeListener ) {
window.removeEventListener( 'resize', this.resizeListener );
this.resizeListener = null;
}
};
/**
* Sets page thumbnail for display if blowupFactor <= MAX_BLOWUP_FACTOR. Otherwise thumb is not set.
* The image gets also blured to avoid pixelation if blowupFactor > BLUR_BLOWUP_FACTOR_THRESHOLD.
* We set SVG files to the maximum screen size available.
* Assumes set function called before.
*
* @param {mw.mmv.model.Image} imageInfo
* @param {jQuery} $imagePlaceholder Image placeholder to be displayed while the real image loads.
* @param {mw.mmv.model.ThumbnailWidth} imageWidths
* @returns {boolean} Whether the image was blured or not
*/
C.maybeDisplayPlaceholder = function ( imageInfo, $imagePlaceholder, imageWidths ) {
var targetWidth,
targetHeight,
blowupFactor,
blurredThumbnailShown = false,
maxSizeFileExtensions = {
'svg' : true,
};
// There are some file types (SVG for example) for which there is no concept
// of initial size. For these cases we force a max canvas resize and no bluring.
if ( maxSizeFileExtensions[ this.imageRawMetadata.filePageTitle.getExtension().toLowerCase() ] ) {
$imagePlaceholder.width( imageWidths.cssWidth );
$imagePlaceholder.height( imageWidths.cssHeight );
this.set( this.imageRawMetadata, $imagePlaceholder.show() );
return blurredThumbnailShown;
}
// Assume natural thumbnail size¸
targetWidth = imageInfo.width;
targetHeight = imageInfo.height;
// If the image is bigger than the screen we need to resize it
if ( imageInfo.width > imageWidths.cssWidth ) { // This assumes imageInfo.width in CSS units
targetWidth = imageWidths.cssWidth;
targetHeight = imageWidths.cssHeight;
}
blowupFactor = targetWidth / $imagePlaceholder.width();
// If the placeholder is too blown up, it's not worth showing it
if ( blowupFactor > Canvas.MAX_BLOWUP_FACTOR ) {
return blurredThumbnailShown;
}
$imagePlaceholder.width( targetWidth );
$imagePlaceholder.height( targetHeight );
// Only blur the placeholder if it's blown up significantly
if ( blowupFactor > Canvas.BLUR_BLOWUP_FACTOR_THRESHOLD ) {
this.blur( $imagePlaceholder );
blurredThumbnailShown = true;
}
this.set( this.imageRawMetadata, $imagePlaceholder.show() );
return blurredThumbnailShown;
};
/**
* Blur image
* @param {jQuery} $image Image to be blurred.
*/
C.blur = function( $image ) {
// We have to apply the SVG filter here, it doesn't work when defined in the .less file
// We can't use an external SVG file because filters can't be accessed cross-domain
// We can't embed the SVG file because accessing the filter inside of it doesn't work
$image.addClass( 'blurred' ).css( 'filter', 'url("#gaussian-blur")' );
};
/**
* Animates the image into focus
*/
C.unblur = function() {
var self = this,
animationLength = 300;
// The blurred class has an opacity < 1. This animated the image to become fully opaque
this.$image
.addClass( 'blurred' )
.animate( { opacity: 1.0 }, animationLength );
// During the same amount of time (animationLength) we animate a blur value from 3.0 to 0.0
// We pass that value to an inline CSS Gaussian blur effect
$( { blur: 3.0 } ).animate( { blur: 0.0 }, {
duration: animationLength,
step: function ( step ) {
self.$image.css( { '-webkit-filter' : 'blur(' + step + 'px)',
'filter' : 'blur(' + step + 'px)' } );
},
complete: function () {
// When the animation is complete, the blur value is 0
// We apply empty CSS values to remove the inline styles applied by jQuery
// so that they don't get in the way of styles defined in CSS
self.$image.css( { '-webkit-filter' : '', 'opacity' : '' } )
.removeClass( 'blurred' );
}
} );
};
/**
* Displays a message and error icon when loading the image fails.
* @param {string} error error message
*/
C.showError = function ( error ) {
this.$imageDiv.empty()
.addClass( 'error' )
.append(
$( '<div>' ).addClass( 'mw-mmv-error-text' ).text(
mw.message( 'multimediaviewer-thumbnail-error', error ).text()
)
);
};
/**
* Gets the widths for a given lightbox image.
* @param {mw.mmv.LightboxImage} image
* @returns {mw.mmv.model.ThumbnailWidth}
*/
C.getLightboxImageWidths = function ( image ) {
var thumb = image.thumbnail;
return this.thumbnailWidthCalculator.calculateWidths(
this.$imageWrapper.width(), this.$imageWrapper.height(), thumb.width, thumb.height );
};
/**
* Gets the fullscreen widths for a given lightbox image.
* Intended for use before the viewer is in fullscreen mode
* (in fullscreen mode getLightboxImageWidths() works fine).
* @param {mw.mmv.LightboxImage} image
* @returns {mw.mmv.model.ThumbnailWidth}
*/
C.getLightboxImageWidthsForFullscreen = function ( image ) {
var thumb = image.thumbnail;
return this.thumbnailWidthCalculator.calculateWidths(
screen.width, screen.height, thumb.width, thumb.height );
};
/**
* Gets the widths for the current lightbox image.
* @returns {mw.mmv.model.ThumbnailWidth}
*/
C.getCurrentImageWidths = function () {
return this.getLightboxImageWidths( this.imageRawMetadata );
};
mw.mmv.ui.Canvas = Canvas;
}( mediaWiki, jQuery, OO ) );