314 lines
10 KiB
JavaScript
314 lines
10 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 2012 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 mozL10n, RenderingStates, Promise */
|
|
|
|
'use strict';
|
|
|
|
var THUMBNAIL_WIDTH = 98; // px
|
|
var THUMBNAIL_CANVAS_BORDER_WIDTH = 1; // px
|
|
|
|
/**
|
|
* @typedef {Object} PDFThumbnailViewOptions
|
|
* @property {HTMLDivElement} container - The viewer element.
|
|
* @property {number} id - The thumbnail's unique ID (normally its number).
|
|
* @property {PageViewport} defaultViewport - The page viewport.
|
|
* @property {IPDFLinkService} linkService - The navigation/linking service.
|
|
* @property {PDFRenderingQueue} renderingQueue - The rendering queue object.
|
|
*/
|
|
|
|
/**
|
|
* @class
|
|
* @implements {IRenderableView}
|
|
*/
|
|
var PDFThumbnailView = (function PDFThumbnailViewClosure() {
|
|
function getTempCanvas(width, height) {
|
|
var tempCanvas = PDFThumbnailView.tempImageCache;
|
|
if (!tempCanvas) {
|
|
tempCanvas = document.createElement('canvas');
|
|
PDFThumbnailView.tempImageCache = tempCanvas;
|
|
}
|
|
tempCanvas.width = width;
|
|
tempCanvas.height = height;
|
|
|
|
// Since this is a temporary canvas, we need to fill the canvas with a white
|
|
// background ourselves. |_getPageDrawContext| uses CSS rules for this.
|
|
var ctx = tempCanvas.getContext('2d');
|
|
ctx.save();
|
|
ctx.fillStyle = 'rgb(255, 255, 255)';
|
|
ctx.fillRect(0, 0, width, height);
|
|
ctx.restore();
|
|
return tempCanvas;
|
|
}
|
|
|
|
/**
|
|
* @constructs PDFThumbnailView
|
|
* @param {PDFThumbnailViewOptions} options
|
|
*/
|
|
function PDFThumbnailView(options) {
|
|
var container = options.container;
|
|
var id = options.id;
|
|
var defaultViewport = options.defaultViewport;
|
|
var linkService = options.linkService;
|
|
var renderingQueue = options.renderingQueue;
|
|
|
|
this.id = id;
|
|
this.renderingId = 'thumbnail' + id;
|
|
|
|
this.pdfPage = null;
|
|
this.rotation = 0;
|
|
this.viewport = defaultViewport;
|
|
this.pdfPageRotate = defaultViewport.rotation;
|
|
|
|
this.linkService = linkService;
|
|
this.renderingQueue = renderingQueue;
|
|
|
|
this.hasImage = false;
|
|
this.resume = null;
|
|
this.renderingState = RenderingStates.INITIAL;
|
|
|
|
this.pageWidth = this.viewport.width;
|
|
this.pageHeight = this.viewport.height;
|
|
this.pageRatio = this.pageWidth / this.pageHeight;
|
|
|
|
this.canvasWidth = THUMBNAIL_WIDTH;
|
|
this.canvasHeight = (this.canvasWidth / this.pageRatio) | 0;
|
|
this.scale = this.canvasWidth / this.pageWidth;
|
|
|
|
var anchor = document.createElement('a');
|
|
anchor.href = linkService.getAnchorUrl('#page=' + id);
|
|
anchor.title = mozL10n.get('thumb_page_title', {page: id}, 'Page {{page}}');
|
|
anchor.onclick = function stopNavigation() {
|
|
linkService.page = id;
|
|
return false;
|
|
};
|
|
|
|
var div = document.createElement('div');
|
|
div.id = 'thumbnailContainer' + id;
|
|
div.className = 'thumbnail';
|
|
this.div = div;
|
|
|
|
if (id === 1) {
|
|
// Highlight the thumbnail of the first page when no page number is
|
|
// specified (or exists in cache) when the document is loaded.
|
|
div.classList.add('selected');
|
|
}
|
|
|
|
var ring = document.createElement('div');
|
|
ring.className = 'thumbnailSelectionRing';
|
|
var borderAdjustment = 2 * THUMBNAIL_CANVAS_BORDER_WIDTH;
|
|
ring.style.width = this.canvasWidth + borderAdjustment + 'px';
|
|
ring.style.height = this.canvasHeight + borderAdjustment + 'px';
|
|
this.ring = ring;
|
|
|
|
div.appendChild(ring);
|
|
anchor.appendChild(div);
|
|
container.appendChild(anchor);
|
|
}
|
|
|
|
PDFThumbnailView.prototype = {
|
|
setPdfPage: function PDFThumbnailView_setPdfPage(pdfPage) {
|
|
this.pdfPage = pdfPage;
|
|
this.pdfPageRotate = pdfPage.rotate;
|
|
var totalRotation = (this.rotation + this.pdfPageRotate) % 360;
|
|
this.viewport = pdfPage.getViewport(1, totalRotation);
|
|
this.reset();
|
|
},
|
|
|
|
reset: function PDFThumbnailView_reset() {
|
|
if (this.renderTask) {
|
|
this.renderTask.cancel();
|
|
}
|
|
this.hasImage = false;
|
|
this.resume = null;
|
|
this.renderingState = RenderingStates.INITIAL;
|
|
|
|
this.pageWidth = this.viewport.width;
|
|
this.pageHeight = this.viewport.height;
|
|
this.pageRatio = this.pageWidth / this.pageHeight;
|
|
|
|
this.canvasHeight = (this.canvasWidth / this.pageRatio) | 0;
|
|
this.scale = (this.canvasWidth / this.pageWidth);
|
|
|
|
this.div.removeAttribute('data-loaded');
|
|
var ring = this.ring;
|
|
var childNodes = ring.childNodes;
|
|
for (var i = childNodes.length - 1; i >= 0; i--) {
|
|
ring.removeChild(childNodes[i]);
|
|
}
|
|
var borderAdjustment = 2 * THUMBNAIL_CANVAS_BORDER_WIDTH;
|
|
ring.style.width = this.canvasWidth + borderAdjustment + 'px';
|
|
ring.style.height = this.canvasHeight + borderAdjustment + 'px';
|
|
|
|
if (this.canvas) {
|
|
// Zeroing the width and height causes Firefox to release graphics
|
|
// resources immediately, which can greatly reduce memory consumption.
|
|
this.canvas.width = 0;
|
|
this.canvas.height = 0;
|
|
delete this.canvas;
|
|
}
|
|
},
|
|
|
|
update: function PDFThumbnailView_update(rotation) {
|
|
if (typeof rotation !== 'undefined') {
|
|
this.rotation = rotation;
|
|
}
|
|
var totalRotation = (this.rotation + this.pdfPageRotate) % 360;
|
|
this.viewport = this.viewport.clone({
|
|
scale: 1,
|
|
rotation: totalRotation
|
|
});
|
|
this.reset();
|
|
},
|
|
|
|
/**
|
|
* @private
|
|
*/
|
|
_getPageDrawContext: function PDFThumbnailView_getPageDrawContext() {
|
|
var canvas = document.createElement('canvas');
|
|
canvas.id = this.renderingId;
|
|
|
|
canvas.width = this.canvasWidth;
|
|
canvas.height = this.canvasHeight;
|
|
canvas.className = 'thumbnailImage';
|
|
canvas.setAttribute('aria-label', mozL10n.get('thumb_page_canvas',
|
|
{page: this.id}, 'Thumbnail of Page {{page}}'));
|
|
|
|
this.canvas = canvas;
|
|
this.div.setAttribute('data-loaded', true);
|
|
this.ring.appendChild(canvas);
|
|
|
|
return canvas.getContext('2d');
|
|
},
|
|
|
|
draw: function PDFThumbnailView_draw() {
|
|
if (this.renderingState !== RenderingStates.INITIAL) {
|
|
console.error('Must be in new state before drawing');
|
|
}
|
|
if (this.hasImage) {
|
|
return Promise.resolve(undefined);
|
|
}
|
|
this.hasImage = true;
|
|
this.renderingState = RenderingStates.RUNNING;
|
|
|
|
var resolveRenderPromise, rejectRenderPromise;
|
|
var promise = new Promise(function (resolve, reject) {
|
|
resolveRenderPromise = resolve;
|
|
rejectRenderPromise = reject;
|
|
});
|
|
|
|
var self = this;
|
|
function thumbnailDrawCallback(error) {
|
|
// The renderTask may have been replaced by a new one, so only remove
|
|
// the reference to the renderTask if it matches the one that is
|
|
// triggering this callback.
|
|
if (renderTask === self.renderTask) {
|
|
self.renderTask = null;
|
|
}
|
|
if (error === 'cancelled') {
|
|
rejectRenderPromise(error);
|
|
return;
|
|
}
|
|
self.renderingState = RenderingStates.FINISHED;
|
|
|
|
if (!error) {
|
|
resolveRenderPromise(undefined);
|
|
} else {
|
|
rejectRenderPromise(error);
|
|
}
|
|
}
|
|
|
|
var ctx = this._getPageDrawContext();
|
|
var drawViewport = this.viewport.clone({ scale: this.scale });
|
|
var renderContinueCallback = function renderContinueCallback(cont) {
|
|
if (!self.renderingQueue.isHighestPriority(self)) {
|
|
self.renderingState = RenderingStates.PAUSED;
|
|
self.resume = function resumeCallback() {
|
|
self.renderingState = RenderingStates.RUNNING;
|
|
cont();
|
|
};
|
|
return;
|
|
}
|
|
cont();
|
|
};
|
|
|
|
var renderContext = {
|
|
canvasContext: ctx,
|
|
viewport: drawViewport,
|
|
continueCallback: renderContinueCallback
|
|
};
|
|
var renderTask = this.renderTask = this.pdfPage.render(renderContext);
|
|
|
|
renderTask.promise.then(
|
|
function pdfPageRenderCallback() {
|
|
thumbnailDrawCallback(null);
|
|
},
|
|
function pdfPageRenderError(error) {
|
|
thumbnailDrawCallback(error);
|
|
}
|
|
);
|
|
return promise;
|
|
},
|
|
|
|
setImage: function PDFThumbnailView_setImage(pageView) {
|
|
var img = pageView.canvas;
|
|
if (this.hasImage || !img) {
|
|
return;
|
|
}
|
|
if (!this.pdfPage) {
|
|
this.setPdfPage(pageView.pdfPage);
|
|
}
|
|
this.hasImage = true;
|
|
this.renderingState = RenderingStates.FINISHED;
|
|
|
|
var ctx = this._getPageDrawContext();
|
|
var canvas = ctx.canvas;
|
|
|
|
if (img.width <= 2 * canvas.width) {
|
|
ctx.drawImage(img, 0, 0, img.width, img.height,
|
|
0, 0, canvas.width, canvas.height);
|
|
return;
|
|
}
|
|
// drawImage does an awful job of rescaling the image, doing it gradually.
|
|
var MAX_NUM_SCALING_STEPS = 3;
|
|
var reducedWidth = canvas.width << MAX_NUM_SCALING_STEPS;
|
|
var reducedHeight = canvas.height << MAX_NUM_SCALING_STEPS;
|
|
var reducedImage = getTempCanvas(reducedWidth, reducedHeight);
|
|
var reducedImageCtx = reducedImage.getContext('2d');
|
|
|
|
while (reducedWidth > img.width || reducedHeight > img.height) {
|
|
reducedWidth >>= 1;
|
|
reducedHeight >>= 1;
|
|
}
|
|
reducedImageCtx.drawImage(img, 0, 0, img.width, img.height,
|
|
0, 0, reducedWidth, reducedHeight);
|
|
while (reducedWidth > 2 * canvas.width) {
|
|
reducedImageCtx.drawImage(reducedImage,
|
|
0, 0, reducedWidth, reducedHeight,
|
|
0, 0, reducedWidth >> 1, reducedHeight >> 1);
|
|
reducedWidth >>= 1;
|
|
reducedHeight >>= 1;
|
|
}
|
|
ctx.drawImage(reducedImage, 0, 0, reducedWidth, reducedHeight,
|
|
0, 0, canvas.width, canvas.height);
|
|
}
|
|
};
|
|
|
|
return PDFThumbnailView;
|
|
})();
|
|
|
|
PDFThumbnailView.tempImageCache = null;
|