pdf.js/web/pdf_viewer.js
Jonas Jenwald ffeba9c630 Move the page switching code into set currentPageNumber in PDFViewer instead of placing it in the pagechange event handler
The reason that this code can be moved is that the `if (this.loading && page === 1)` check, in the `pagechange` event handler in viewer.js, is never satisfied since `this.loading` is not defined in that scope.
This *could* be considered a regression from PR 5295, since prior to that `this.loading` was using the `PDFViewerApplication` scope (or `PDFView` as it were).
However, I don't think that we need to fix that since we've been shipping this code in no less than *three* Firefox releases (uplifted in https://bugzilla.mozilla.org/show_bug.cgi?id=1084158), without breaking the world.

An explanation of why the `pagechange` code works, despite `this.loading === undefined`, is that `set currentPageNumber` (in `PDFViewer`) returns early whenever `this.pdfDocument` isn't set. This check is, for all intents and purposes, functionally equivalent to checking `PDFViewerApplication.loading`.
Hence we can move the page switching code into `PDFViewer`, and also remove `PDFViewerApplication.loading` since it's not used any more.
(The `this.loading` property was added in PR 686, which was before the current viewer even existed.)

*Note:* The changes in this patch should also be beneficial to the viewer `components`, since requiring every implementer to provide their own `pagechange` event handler just to get `PDFViewer.currentPageNumber` to actually work seems like an unnecessary complication.
2015-06-24 14:07:07 +02:00

797 lines
24 KiB
JavaScript

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* Copyright 2014 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*globals watchScroll, PDFPageView, UNKNOWN_SCALE,
SCROLLBAR_PADDING, VERTICAL_PADDING, MAX_AUTO_SCALE, CSS_UNITS,
DEFAULT_SCALE, scrollIntoView, getVisibleElements, RenderingStates,
PDFJS, Promise, TextLayerBuilder, PDFRenderingQueue,
AnnotationsLayerBuilder */
'use strict';
var PresentationModeState = {
UNKNOWN: 0,
NORMAL: 1,
CHANGING: 2,
FULLSCREEN: 3,
};
var IGNORE_CURRENT_POSITION_ON_ZOOM = false;
var DEFAULT_CACHE_SIZE = 10;
//#include pdf_rendering_queue.js
//#include pdf_page_view.js
//#include text_layer_builder.js
//#include annotations_layer_builder.js
/**
* @typedef {Object} PDFViewerOptions
* @property {HTMLDivElement} container - The container for the viewer element.
* @property {HTMLDivElement} viewer - (optional) The viewer element.
* @property {IPDFLinkService} linkService - The navigation/linking service.
* @property {PDFRenderingQueue} renderingQueue - (optional) The rendering
* queue object.
* @property {boolean} removePageBorders - (optional) Removes the border shadow
* around the pages. The default is false.
*/
/**
* Simple viewer control to display PDF content/pages.
* @class
* @implements {IRenderableView}
*/
var PDFViewer = (function pdfViewer() {
function PDFPageViewBuffer(size) {
var data = [];
this.push = function cachePush(view) {
var i = data.indexOf(view);
if (i >= 0) {
data.splice(i, 1);
}
data.push(view);
if (data.length > size) {
data.shift().destroy();
}
};
this.resize = function (newSize) {
size = newSize;
while (data.length > size) {
data.shift().destroy();
}
};
}
/**
* @constructs PDFViewer
* @param {PDFViewerOptions} options
*/
function PDFViewer(options) {
this.container = options.container;
this.viewer = options.viewer || options.container.firstElementChild;
this.linkService = options.linkService || new SimpleLinkService(this);
this.removePageBorders = options.removePageBorders || false;
this.defaultRenderingQueue = !options.renderingQueue;
if (this.defaultRenderingQueue) {
// Custom rendering queue is not specified, using default one
this.renderingQueue = new PDFRenderingQueue();
this.renderingQueue.setViewer(this);
} else {
this.renderingQueue = options.renderingQueue;
}
this.scroll = watchScroll(this.container, this._scrollUpdate.bind(this));
this.updateInProgress = false;
this.presentationModeState = PresentationModeState.UNKNOWN;
this._resetView();
if (this.removePageBorders) {
this.viewer.classList.add('removePageBorders');
}
}
PDFViewer.prototype = /** @lends PDFViewer.prototype */{
get pagesCount() {
return this._pages.length;
},
getPageView: function (index) {
return this._pages[index];
},
get currentPageNumber() {
return this._currentPageNumber;
},
set currentPageNumber(val) {
if (!this.pdfDocument) {
this._currentPageNumber = val;
return;
}
var event = document.createEvent('UIEvents');
event.initUIEvent('pagechange', true, true, window, 0);
event.updateInProgress = this.updateInProgress;
if (!(0 < val && val <= this.pagesCount)) {
event.pageNumber = this._currentPageNumber;
event.previousPageNumber = val;
this.container.dispatchEvent(event);
return;
}
event.previousPageNumber = this._currentPageNumber;
this._currentPageNumber = val;
event.pageNumber = val;
this.container.dispatchEvent(event);
// Check if the caller is `PDFViewer_update`, to avoid breaking scrolling.
if (this.updateInProgress) {
return;
}
this.scrollPageIntoView(val);
},
/**
* @returns {number}
*/
get currentScale() {
return this._currentScale;
},
/**
* @param {number} val - Scale of the pages in percents.
*/
set currentScale(val) {
if (isNaN(val)) {
throw new Error('Invalid numeric scale');
}
if (!this.pdfDocument) {
this._currentScale = val;
this._currentScaleValue = val.toString();
return;
}
this._setScale(val, false);
},
/**
* @returns {string}
*/
get currentScaleValue() {
return this._currentScaleValue;
},
/**
* @param val - The scale of the pages (in percent or predefined value).
*/
set currentScaleValue(val) {
if (!this.pdfDocument) {
this._currentScale = isNaN(val) ? UNKNOWN_SCALE : val;
this._currentScaleValue = val;
return;
}
this._setScale(val, false);
},
/**
* @returns {number}
*/
get pagesRotation() {
return this._pagesRotation;
},
/**
* @param {number} rotation - The rotation of the pages (0, 90, 180, 270).
*/
set pagesRotation(rotation) {
this._pagesRotation = rotation;
for (var i = 0, l = this._pages.length; i < l; i++) {
var pageView = this._pages[i];
pageView.update(pageView.scale, rotation);
}
this._setScale(this._currentScaleValue, true);
},
/**
* @param pdfDocument {PDFDocument}
*/
setDocument: function (pdfDocument) {
if (this.pdfDocument) {
this._resetView();
}
this.pdfDocument = pdfDocument;
if (!pdfDocument) {
return;
}
var pagesCount = pdfDocument.numPages;
var self = this;
var resolvePagesPromise;
var pagesPromise = new Promise(function (resolve) {
resolvePagesPromise = resolve;
});
this.pagesPromise = pagesPromise;
pagesPromise.then(function () {
var event = document.createEvent('CustomEvent');
event.initCustomEvent('pagesloaded', true, true, {
pagesCount: pagesCount
});
self.container.dispatchEvent(event);
});
var isOnePageRenderedResolved = false;
var resolveOnePageRendered = null;
var onePageRendered = new Promise(function (resolve) {
resolveOnePageRendered = resolve;
});
this.onePageRendered = onePageRendered;
var bindOnAfterAndBeforeDraw = function (pageView) {
pageView.onBeforeDraw = function pdfViewLoadOnBeforeDraw() {
// Add the page to the buffer at the start of drawing. That way it can
// be evicted from the buffer and destroyed even if we pause its
// rendering.
self._buffer.push(this);
};
// when page is painted, using the image as thumbnail base
pageView.onAfterDraw = function pdfViewLoadOnAfterDraw() {
if (!isOnePageRenderedResolved) {
isOnePageRenderedResolved = true;
resolveOnePageRendered();
}
};
};
var firstPagePromise = pdfDocument.getPage(1);
this.firstPagePromise = firstPagePromise;
// Fetch a single page so we can get a viewport that will be the default
// viewport for all pages
return firstPagePromise.then(function(pdfPage) {
var scale = this._currentScale || 1.0;
var viewport = pdfPage.getViewport(scale * CSS_UNITS);
for (var pageNum = 1; pageNum <= pagesCount; ++pageNum) {
var textLayerFactory = null;
if (!PDFJS.disableTextLayer) {
textLayerFactory = this;
}
var pageView = new PDFPageView({
container: this.viewer,
id: pageNum,
scale: scale,
defaultViewport: viewport.clone(),
renderingQueue: this.renderingQueue,
textLayerFactory: textLayerFactory,
annotationsLayerFactory: this
});
bindOnAfterAndBeforeDraw(pageView);
this._pages.push(pageView);
}
var linkService = this.linkService;
// Fetch all the pages since the viewport is needed before printing
// starts to create the correct size canvas. Wait until one page is
// rendered so we don't tie up too many resources early on.
onePageRendered.then(function () {
if (!PDFJS.disableAutoFetch) {
var getPagesLeft = pagesCount;
for (var pageNum = 1; pageNum <= pagesCount; ++pageNum) {
pdfDocument.getPage(pageNum).then(function (pageNum, pdfPage) {
var pageView = self._pages[pageNum - 1];
if (!pageView.pdfPage) {
pageView.setPdfPage(pdfPage);
}
linkService.cachePageRef(pageNum, pdfPage.ref);
getPagesLeft--;
if (!getPagesLeft) {
resolvePagesPromise();
}
}.bind(null, pageNum));
}
} else {
// XXX: Printing is semi-broken with auto fetch disabled.
resolvePagesPromise();
}
});
var event = document.createEvent('CustomEvent');
event.initCustomEvent('pagesinit', true, true, null);
self.container.dispatchEvent(event);
if (this.defaultRenderingQueue) {
this.update();
}
if (this.findController) {
this.findController.resolveFirstPage();
}
}.bind(this));
},
_resetView: function () {
this._pages = [];
this._currentPageNumber = 1;
this._currentScale = UNKNOWN_SCALE;
this._currentScaleValue = null;
this._buffer = new PDFPageViewBuffer(DEFAULT_CACHE_SIZE);
this._location = null;
this._pagesRotation = 0;
this._pagesRequests = [];
var container = this.viewer;
while (container.hasChildNodes()) {
container.removeChild(container.lastChild);
}
},
_scrollUpdate: function () {
if (this.pagesCount === 0) {
return;
}
this.update();
for (var i = 0, ii = this._pages.length; i < ii; i++) {
this._pages[i].updatePosition();
}
},
_setScaleDispatchEvent: function pdfViewer_setScaleDispatchEvent(
newScale, newValue, preset) {
var event = document.createEvent('UIEvents');
event.initUIEvent('scalechange', true, true, window, 0);
event.scale = newScale;
if (preset) {
event.presetValue = newValue;
}
this.container.dispatchEvent(event);
},
_setScaleUpdatePages: function pdfViewer_setScaleUpdatePages(
newScale, newValue, noScroll, preset) {
this._currentScaleValue = newValue;
if (newScale === this._currentScale) {
if (preset) {
this._setScaleDispatchEvent(newScale, newValue, true);
}
return;
}
for (var i = 0, ii = this._pages.length; i < ii; i++) {
this._pages[i].update(newScale);
}
this._currentScale = newScale;
if (!noScroll) {
var page = this._currentPageNumber, dest;
if (this._location && !IGNORE_CURRENT_POSITION_ON_ZOOM &&
!(this.isInPresentationMode || this.isChangingPresentationMode)) {
page = this._location.pageNumber;
dest = [null, { name: 'XYZ' }, this._location.left,
this._location.top, null];
}
this.scrollPageIntoView(page, dest);
}
this._setScaleDispatchEvent(newScale, newValue, preset);
},
_setScale: function pdfViewer_setScale(value, noScroll) {
if (value === 'custom') {
return;
}
var scale = parseFloat(value);
if (scale > 0) {
this._setScaleUpdatePages(scale, value, noScroll, false);
} else {
var currentPage = this._pages[this._currentPageNumber - 1];
if (!currentPage) {
return;
}
var hPadding = (this.isInPresentationMode || this.removePageBorders) ?
0 : SCROLLBAR_PADDING;
var vPadding = (this.isInPresentationMode || this.removePageBorders) ?
0 : VERTICAL_PADDING;
var pageWidthScale = (this.container.clientWidth - hPadding) /
currentPage.width * currentPage.scale;
var pageHeightScale = (this.container.clientHeight - vPadding) /
currentPage.height * currentPage.scale;
switch (value) {
case 'page-actual':
scale = 1;
break;
case 'page-width':
scale = pageWidthScale;
break;
case 'page-height':
scale = pageHeightScale;
break;
case 'page-fit':
scale = Math.min(pageWidthScale, pageHeightScale);
break;
case 'auto':
var isLandscape = (currentPage.width > currentPage.height);
// For pages in landscape mode, fit the page height to the viewer
// *unless* the page would thus become too wide to fit horizontally.
var horizontalScale = isLandscape ?
Math.min(pageHeightScale, pageWidthScale) : pageWidthScale;
scale = Math.min(MAX_AUTO_SCALE, horizontalScale);
break;
default:
console.error('pdfViewSetScale: \'' + value +
'\' is an unknown zoom value.');
return;
}
this._setScaleUpdatePages(scale, value, noScroll, true);
}
},
/**
* Scrolls page into view.
* @param {number} pageNumber
* @param {Array} dest - (optional) original PDF destination array:
* <page-ref> </XYZ|FitXXX> <args..>
*/
scrollPageIntoView: function PDFViewer_scrollPageIntoView(pageNumber,
dest) {
var pageView = this._pages[pageNumber - 1];
if (this.isInPresentationMode) {
if (this.linkService.page !== pageView.id) {
// Avoid breaking getVisiblePages in presentation mode.
this.linkService.page = pageView.id;
return;
}
dest = null;
// Fixes the case when PDF has different page sizes.
this._setScale(this.currentScaleValue, true);
}
if (!dest) {
scrollIntoView(pageView.div);
return;
}
var x = 0, y = 0;
var width = 0, height = 0, widthScale, heightScale;
var changeOrientation = (pageView.rotation % 180 === 0 ? false : true);
var pageWidth = (changeOrientation ? pageView.height : pageView.width) /
pageView.scale / CSS_UNITS;
var pageHeight = (changeOrientation ? pageView.width : pageView.height) /
pageView.scale / CSS_UNITS;
var scale = 0;
switch (dest[1].name) {
case 'XYZ':
x = dest[2];
y = dest[3];
scale = dest[4];
// If x and/or y coordinates are not supplied, default to
// _top_ left of the page (not the obvious bottom left,
// since aligning the bottom of the intended page with the
// top of the window is rarely helpful).
x = x !== null ? x : 0;
y = y !== null ? y : pageHeight;
break;
case 'Fit':
case 'FitB':
scale = 'page-fit';
break;
case 'FitH':
case 'FitBH':
y = dest[2];
scale = 'page-width';
break;
case 'FitV':
case 'FitBV':
x = dest[2];
width = pageWidth;
height = pageHeight;
scale = 'page-height';
break;
case 'FitR':
x = dest[2];
y = dest[3];
width = dest[4] - x;
height = dest[5] - y;
var viewerContainer = this.container;
var hPadding = this.removePageBorders ? 0 : SCROLLBAR_PADDING;
var vPadding = this.removePageBorders ? 0 : VERTICAL_PADDING;
widthScale = (viewerContainer.clientWidth - hPadding) /
width / CSS_UNITS;
heightScale = (viewerContainer.clientHeight - vPadding) /
height / CSS_UNITS;
scale = Math.min(Math.abs(widthScale), Math.abs(heightScale));
break;
default:
return;
}
if (scale && scale !== this.currentScale) {
this.currentScaleValue = scale;
} else if (this.currentScale === UNKNOWN_SCALE) {
this.currentScaleValue = DEFAULT_SCALE;
}
if (scale === 'page-fit' && !dest[4]) {
scrollIntoView(pageView.div);
return;
}
var boundingRect = [
pageView.viewport.convertToViewportPoint(x, y),
pageView.viewport.convertToViewportPoint(x + width, y + height)
];
var left = Math.min(boundingRect[0][0], boundingRect[1][0]);
var top = Math.min(boundingRect[0][1], boundingRect[1][1]);
scrollIntoView(pageView.div, { left: left, top: top });
},
_updateLocation: function (firstPage) {
var currentScale = this._currentScale;
var currentScaleValue = this._currentScaleValue;
var normalizedScaleValue =
parseFloat(currentScaleValue) === currentScale ?
Math.round(currentScale * 10000) / 100 : currentScaleValue;
var pageNumber = firstPage.id;
var pdfOpenParams = '#page=' + pageNumber;
pdfOpenParams += '&zoom=' + normalizedScaleValue;
var currentPageView = this._pages[pageNumber - 1];
var container = this.container;
var topLeft = currentPageView.getPagePoint(
(container.scrollLeft - firstPage.x),
(container.scrollTop - firstPage.y));
var intLeft = Math.round(topLeft[0]);
var intTop = Math.round(topLeft[1]);
pdfOpenParams += ',' + intLeft + ',' + intTop;
this._location = {
pageNumber: pageNumber,
scale: normalizedScaleValue,
top: intTop,
left: intLeft,
pdfOpenParams: pdfOpenParams
};
},
update: function PDFViewer_update() {
var visible = this._getVisiblePages();
var visiblePages = visible.views;
if (visiblePages.length === 0) {
return;
}
this.updateInProgress = true;
var suggestedCacheSize = Math.max(DEFAULT_CACHE_SIZE,
2 * visiblePages.length + 1);
this._buffer.resize(suggestedCacheSize);
this.renderingQueue.renderHighestPriority(visible);
var currentId = this._currentPageNumber;
var firstPage = visible.first;
for (var i = 0, ii = visiblePages.length, stillFullyVisible = false;
i < ii; ++i) {
var page = visiblePages[i];
if (page.percent < 100) {
break;
}
if (page.id === currentId) {
stillFullyVisible = true;
break;
}
}
if (!stillFullyVisible) {
currentId = visiblePages[0].id;
}
if (!this.isInPresentationMode) {
this.currentPageNumber = currentId;
}
this._updateLocation(firstPage);
this.updateInProgress = false;
var event = document.createEvent('UIEvents');
event.initUIEvent('updateviewarea', true, true, window, 0);
event.location = this._location;
this.container.dispatchEvent(event);
},
containsElement: function (element) {
return this.container.contains(element);
},
focus: function () {
this.container.focus();
},
get isInPresentationMode() {
return this.presentationModeState === PresentationModeState.FULLSCREEN;
},
get isChangingPresentationMode() {
return this.PresentationModeState === PresentationModeState.CHANGING;
},
get isHorizontalScrollbarEnabled() {
return (this.isInPresentationMode ?
false : (this.container.scrollWidth > this.container.clientWidth));
},
_getVisiblePages: function () {
if (!this.isInPresentationMode) {
return getVisibleElements(this.container, this._pages, true);
} else {
// The algorithm in getVisibleElements doesn't work in all browsers and
// configurations when presentation mode is active.
var visible = [];
var currentPage = this._pages[this._currentPageNumber - 1];
visible.push({ id: currentPage.id, view: currentPage });
return { first: currentPage, last: currentPage, views: visible };
}
},
cleanup: function () {
for (var i = 0, ii = this._pages.length; i < ii; i++) {
if (this._pages[i] &&
this._pages[i].renderingState !== RenderingStates.FINISHED) {
this._pages[i].reset();
}
}
},
/**
* @param {PDFPageView} pageView
* @returns {PDFPage}
* @private
*/
_ensurePdfPageLoaded: function (pageView) {
if (pageView.pdfPage) {
return Promise.resolve(pageView.pdfPage);
}
var pageNumber = pageView.id;
if (this._pagesRequests[pageNumber]) {
return this._pagesRequests[pageNumber];
}
var promise = this.pdfDocument.getPage(pageNumber).then(
function (pdfPage) {
pageView.setPdfPage(pdfPage);
this._pagesRequests[pageNumber] = null;
return pdfPage;
}.bind(this));
this._pagesRequests[pageNumber] = promise;
return promise;
},
forceRendering: function (currentlyVisiblePages) {
var visiblePages = currentlyVisiblePages || this._getVisiblePages();
var pageView = this.renderingQueue.getHighestPriority(visiblePages,
this._pages,
this.scroll.down);
if (pageView) {
this._ensurePdfPageLoaded(pageView).then(function () {
this.renderingQueue.renderView(pageView);
}.bind(this));
return true;
}
return false;
},
getPageTextContent: function (pageIndex) {
return this.pdfDocument.getPage(pageIndex + 1).then(function (page) {
return page.getTextContent();
});
},
/**
* @param {HTMLDivElement} textLayerDiv
* @param {number} pageIndex
* @param {PageViewport} viewport
* @returns {TextLayerBuilder}
*/
createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport) {
return new TextLayerBuilder({
textLayerDiv: textLayerDiv,
pageIndex: pageIndex,
viewport: viewport,
findController: this.isInPresentationMode ? null : this.findController
});
},
/**
* @param {HTMLDivElement} pageDiv
* @param {PDFPage} pdfPage
* @returns {AnnotationsLayerBuilder}
*/
createAnnotationsLayerBuilder: function (pageDiv, pdfPage) {
return new AnnotationsLayerBuilder({
pageDiv: pageDiv,
pdfPage: pdfPage,
linkService: this.linkService
});
},
setFindController: function (findController) {
this.findController = findController;
},
};
return PDFViewer;
})();
var SimpleLinkService = (function SimpleLinkServiceClosure() {
function SimpleLinkService(pdfViewer) {
this.pdfViewer = pdfViewer;
}
SimpleLinkService.prototype = {
/**
* @returns {number}
*/
get page() {
return this.pdfViewer.currentPageNumber;
},
/**
* @param {number} value
*/
set page(value) {
this.pdfViewer.currentPageNumber = value;
},
/**
* @param dest - The PDF destination object.
*/
navigateTo: function (dest) {},
/**
* @param dest - The PDF destination object.
* @returns {string} The hyperlink to the PDF object.
*/
getDestinationHash: function (dest) {
return '#';
},
/**
* @param hash - The PDF parameters/hash.
* @returns {string} The hyperlink to the PDF object.
*/
getAnchorUrl: function (hash) {
return '#';
},
/**
* @param {string} hash
*/
setHash: function (hash) {},
/**
* @param {string} action
*/
executeNamedAction: function (action) {},
/**
* @param {number} pageNum - page number.
* @param {Object} pageRef - reference to the page.
*/
cachePageRef: function (pageNum, pageRef) {}
};
return SimpleLinkService;
})();