/*
* 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 .
*/
const { HtmlUtils } = require( 'mmv.bootstrap' );
const ThumbnailWidthCalculator = require( '../mmv.ThumbnailWidthCalculator.js' );
const UiElement = require( './mmv.ui.js' );
( function () {
/**
* 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 Canvas extends UiElement {
/**
* @param {jQuery} $container Canvas' container
* @param {jQuery} $imageWrapper
* @param {jQuery} $mainWrapper
*/
constructor( $container, $imageWrapper, $mainWrapper ) {
super( $container );
/**
* @property {boolean}
* @private
*/
this.dialogOpen = false;
/**
* @property {ThumbnailWidthCalculator}
* @private
*/
this.thumbnailWidthCalculator = new ThumbnailWidthCalculator();
/**
* Contains image.
*
* @property {jQuery}
*/
this.$imageDiv = $( '
' )
.addClass( 'mw-mmv-image' );
this.$imageDiv.appendTo( this.$container );
/**
* Container of canvas and controls, needed for canvas size calculations.
*
* @property {jQuery}
* @private
*/
this.$imageWrapper = $imageWrapper;
/**
* Main container of image and metadata, needed to propagate events.
*
* @property {jQuery}
* @private
*/
this.$mainWrapper = $mainWrapper;
/**
* Raw metadata of current image, needed for canvas size calculations.
*
* @property {LightboxImage}
* @private
*/
this.imageRawMetadata = null;
}
/**
* Clears everything.
*/
empty() {
this.$imageDiv.addClass( 'empty' ).removeClass( 'error' );
this.$imageDiv.empty();
}
/**
* Sets image on the canvas; does not resize it to fit. This is used to make the placeholder
* image available; it will be resized and displayed by #maybeDisplayPlaceholder().
* FIXME maybeDisplayPlaceholder() receives the placeholder so it is very unclear why this
* is necessary at all (apart from setting the LightboxImage, which is used in size calculations).
*
* @param {LightboxImage} imageRawMetadata
* @param {jQuery} $imageElement
*/
set( imageRawMetadata, $imageElement ) {
this.$imageDiv.removeClass( 'empty' );
this.imageRawMetadata = imageRawMetadata;
this.$image = $imageElement;
this.setUpImageClick();
this.$imageDiv.html( this.$image );
}
/**
* Resizes image to the given dimensions and displays it on the canvas.
* This is used to display the actual image; it assumes set function was already called before.
*
* @param {Thumbnail} thumbnail thumbnail information
* @param {HTMLImageElement} imageElement
* @param {ThumbnailWidth} imageWidths
*/
setImageAndMaxDimensions( thumbnail, imageElement, imageWidths ) {
const $image = $( imageElement );
// we downscale larger images but do not scale up smaller ones, that would look ugly
if ( thumbnail.width > imageWidths.cssWidth ) {
imageElement.width = imageWidths.cssWidth;
imageElement.height = imageWidths.cssHeight;
}
if ( !this.$image.is( imageElement ) ) { // http://bugs.jquery.com/ticket/4087
this.$image.replaceWith( $image );
this.$image = $image;
// Since the image element got replaced, we need to rescue the dialog-open class.
this.$image.toggleClass( 'mw-mmv-dialog-is-open', this.dialogOpen );
this.setUpImageClick();
}
}
/**
* Handles a "dialog open/close" event from dialogs on the page.
*
* @param {jQuery.Event} e
*/
handleDialogEvent( e ) {
switch ( e.type ) {
case 'mmv-download-opened':
this.downloadOpen = true;
break;
case 'mmv-download-closed':
this.downloadOpen = false;
break;
case 'mmv-reuse-opened':
this.reuseOpen = true;
break;
case 'mmv-reuse-closed':
this.reuseOpen = false;
break;
case 'mmv-options-opened':
this.optionsOpen = true;
break;
case 'mmv-options-closed':
this.optionsOpen = false;
break;
}
this.dialogOpen = this.reuseOpen || this.downloadOpen || this.optionsOpen;
this.$image.toggleClass( 'mw-mmv-dialog-is-open', this.dialogOpen );
}
/**
* Registers click listener on the image.
*
* @fires ReuseDialog#mmv-reuse-opened
* @fires ReuseDialog#mmv-reuse-closed
* @fires DownloadDialog#mmv-download-opened
* @fires DownloadDialog#mmv-download-closed
* @fires OptionsDialog#mmv-options-opened
* @fires OptionsDialog#mmv-options-closed
*/
setUpImageClick() {
this.handleEvent( 'mmv-reuse-opened', this.handleDialogEvent.bind( this ) );
this.handleEvent( 'mmv-reuse-closed', this.handleDialogEvent.bind( this ) );
this.handleEvent( 'mmv-download-opened', this.handleDialogEvent.bind( this ) );
this.handleEvent( 'mmv-download-closed', this.handleDialogEvent.bind( this ) );
this.handleEvent( 'mmv-options-opened', this.handleDialogEvent.bind( this ) );
this.handleEvent( 'mmv-options-closed', this.handleDialogEvent.bind( this ) );
this.$image.on( 'click.mmv-canvas', ( e ) => {
// ignore clicks if the metadata panel or one of the dialogs is open - assume the intent is to
// close it in this case; that will be handled elsewhere
if ( !this.dialogOpen &&
// FIXME a UI component should not know about its parents
this.$container.closest( '.metadata-panel-is-open' ).length === 0 ) {
e.stopPropagation(); // don't let $imageWrapper handle this
$( document ).trigger( 'mmv-viewfile' );
}
} );
// open the download panel on right clicking the image
this.$image.on( 'mousedown.mmv-canvas', ( e ) => {
if ( e.which === 3 && !this.downloadOpen ) {
$( document ).trigger( 'mmv-download-open', e );
e.stopPropagation();
}
} );
}
/**
* Registers listeners.
*
* @fires MultimediaViewer#mmv-resize-end
*/
attach() {
/**
* Fired when the screen size changes. Debounced to avoid continuous triggering while resizing with a mouse.
*
* @event MultimediaViewer#mmv-resize-end
*/
$( window ).on( 'resize.mmv-canvas', mw.util.debounce( () => {
this.$mainWrapper.trigger( $.Event( 'mmv-resize-end' ) );
}, 100 ) );
this.$imageWrapper.on( 'click.mmv-canvas', () => {
if ( this.$container.closest( '.metadata-panel-is-open' ).length > 0 ) {
this.$mainWrapper.trigger( 'mmv-panel-close-area-click' );
}
} );
}
/**
* Clears listeners.
*/
unattach() {
this.clearEvents();
$( window ).off( 'resize.mmv-canvas' );
this.$imageWrapper.off( 'click.mmv-canvas' );
}
/**
* 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 {{width: number, height: number}} size
* @param {jQuery} $imagePlaceholder Image placeholder to be displayed while the real image loads.
* @param {ThumbnailWidth} imageWidths
* @return {boolean} Whether the image was blured or not
*/
maybeDisplayPlaceholder( size, $imagePlaceholder, imageWidths ) {
let targetWidth;
let targetHeight;
let blurredThumbnailShown = false;
// Assume natural thumbnail size¸
targetWidth = size.width;
targetHeight = size.height;
// If the image is bigger than the screen we need to resize it
if ( size.width > imageWidths.cssWidth ) { // This assumes imageInfo.width in CSS units
targetWidth = imageWidths.cssWidth;
targetHeight = imageWidths.cssHeight;
}
const 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.
*/
blur( $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
// TODO: This breaks the invert filter used by dark mode. Consider blurring the container
// instead?
$image.addClass( 'blurred' ).css( 'filter', 'url("#gaussian-blur")' );
}
/**
* Animates the image into focus
*/
unblurWithAnimation() {
const animationLength = 300;
// The blurred class has an opacity < 1. This animated the image to become fully opaque
// FIXME: Use CSS transition
// eslint-disable-next-line no-jquery/no-animate
this.$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
// FIXME: Use CSS transition
// eslint-disable-next-line no-jquery/no-animate
$( { blur: 3.0 } ).animate( { blur: 0.0 }, {
duration: animationLength,
step: ( step ) => {
this.$image.css( {
'-webkit-filter': `blur(${step}px)`,
filter: `blur(${step}px)`
} );
},
complete: () => {
// When the animation is complete, the blur value is 0, clean things up
this.unblur();
}
} );
}
unblur() {
// 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
this.$image.css( { '-webkit-filter': '', opacity: '', filter: '' } )
.removeClass( 'blurred' );
}
/**
* Displays a message and error icon when loading the image fails.
*
* @param {string} error error message
*/
showError( error ) {
const canvasDimensions = this.getDimensions();
const thumbnailDimensions = this.getCurrentImageWidths();
const htmlUtils = new HtmlUtils();
// ** is bolding in Phabricator
const description = `**${mw.message( 'multimediaviewer-errorreport-privacywarning' ).text()}**
Error details:
error: ${error}
URL: ${location.href}
user agent: ${navigator.userAgent}
screen size: ${screen.width}x${screen.height}
canvas size: ${canvasDimensions.width}x${canvasDimensions.height}
image size: ${this.imageRawMetadata.originalWidth}x${this.imageRawMetadata.originalHeight}
thumbnail size: CSS: ${thumbnailDimensions.cssWidth}x${thumbnailDimensions.cssHeight}, screen width: ${thumbnailDimensions.screen}, real width: ${thumbnailDimensions.real}`;
const errorUri = mw.msg( 'multimediaviewer-report-issue-url', encodeURIComponent( description ) );
const $retryLink = $( '
' ).addClass( 'mw-mmv-retry-link' ).text(
mw.msg( 'multimediaviewer-thumbnail-error-retry' ) );
const $reportLink = $( '' ).attr( 'href', errorUri ).text(
mw.msg( 'multimediaviewer-thumbnail-error-report' ) );
this.$imageDiv.empty()
.addClass( 'error' )
.append(
$( '' ).addClass( 'error-box' ).append(
$( '
' ).addClass( 'mw-mmv-error-text' ).text(
mw.msg( 'multimediaviewer-thumbnail-error' )
)
).append(
$( '
' ).addClass( 'mw-mmv-error-description' ).append(
mw.msg( 'multimediaviewer-thumbnail-error-description',
htmlUtils.jqueryToHtml( $retryLink ),
error,
htmlUtils.jqueryToHtml( $reportLink )
)
)
)
);
this.$imageDiv.find( '.mw-mmv-retry-link' ).on( 'click', () => {
location.reload();
} );
}
/**
* Returns width and height of the canvas area (i.e. the space available for the image).
*
* @param {boolean} forFullscreen if true, return size in fullscreen mode; otherwise, return current size
* (which might still be fullscreen mode).
* @return {Object} Width and height in CSS pixels
*/
getDimensions( forFullscreen ) {
const $window = $( window );
// eslint-disable-next-line no-jquery/no-global-selector
const $aboveFold = $( '.mw-mmv-above-fold' );
const isFullscreened = !!$aboveFold.closest( '.jq-fullscreened' ).length;
// Don't rely on this.$imageWrapper's sizing because it's fragile.
// Depending on what the wrapper contains, its size can be 0 on some browsers.
// Therefore, we calculate the available space manually
const availableWidth = $window.width();
const availableHeight = $window.height() - ( isFullscreened ? 0 : $aboveFold.outerHeight() );
if ( forFullscreen ) {
return {
width: screen.width,
height: screen.height
};
} else {
return {
width: availableWidth,
height: availableHeight
};
}
}
/**
* Gets the widths for a given lightbox image.
*
* @param {LightboxImage} image
* @return {ThumbnailWidth}
*/
getLightboxImageWidths( image ) {
const thumb = image.thumbnail;
const canvasDimensions = this.getDimensions();
return this.thumbnailWidthCalculator.calculateWidths(
canvasDimensions.width, canvasDimensions.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 {LightboxImage} image
* @return {ThumbnailWidth}
*/
getLightboxImageWidthsForFullscreen( image ) {
const thumb = image.thumbnail;
const canvasDimensions = this.getDimensions( true );
return this.thumbnailWidthCalculator.calculateWidths(
canvasDimensions.width, canvasDimensions.height, thumb.width, thumb.height );
}
/**
* Gets the widths for the current lightbox image.
*
* @return {ThumbnailWidth}
*/
getCurrentImageWidths() {
return this.getLightboxImageWidths( this.imageRawMetadata );
}
}
/**
* Maximum blowup factor tolerated
*
* @property {number} MAX_BLOWUP_FACTOR
* @static
*/
Canvas.MAX_BLOWUP_FACTOR = 11;
/**
* Blowup factor threshold at which blurring kicks in
*
* @property {number} BLUR_BLOWUP_FACTOR_THRESHOLD
* @static
*/
Canvas.BLUR_BLOWUP_FACTOR_THRESHOLD = 2;
module.exports = Canvas;
}() );