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Merge pull request #7766 from Rob--W/printing-refactor-split-from-7721
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Printing refactor split from 7721
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@yurydelendik
yurydelendik authored Oct 31, 2016
2 parents 1c3fb17 + 5945922 commit a740d69
Showing 1 changed file with 105 additions and 65 deletions.
170 changes: 105 additions & 65 deletions web/pdf_print_service.js
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Original file line number Diff line number Diff line change
Expand Up @@ -35,13 +35,10 @@

var activeService = null;

// Using one canvas for all paint operations -- painting one canvas at a time.
var scratchCanvas = null;

function renderPage(pdfDocument, pageNumber, size, wrapper) {
if (!scratchCanvas) {
scratchCanvas = document.createElement('canvas');
}
// Renders the page to the canvas of the given print service, and returns
// the suggested dimensions of the output page.
function renderPage(activeServiceOnEntry, pdfDocument, pageNumber, size) {
var scratchCanvas = activeService.scratchCanvas;

// The size of the canvas in pixels for printing.
var PRINT_RESOLUTION = 150;
Expand All @@ -50,9 +47,8 @@
scratchCanvas.height = Math.floor(size.height * PRINT_UNITS);

// The physical size of the img as specified by the PDF document.
var img = document.createElement('img');
img.style.width = Math.floor(size.width * CSS_UNITS) + 'px';
img.style.height = Math.floor(size.height * CSS_UNITS) + 'px';
var width = Math.floor(size.width * CSS_UNITS) + 'px';
var height = Math.floor(size.height * CSS_UNITS) + 'px';

var ctx = scratchCanvas.getContext('2d');
ctx.save();
Expand All @@ -68,38 +64,28 @@
intent: 'print'
};
return pdfPage.render(renderContext).promise;
}).then(function() {
if (!activeService) {
return Promise.reject(new Error('cancelled'));
}
if (('toBlob' in scratchCanvas) &&
!pdfjsLib.PDFJS.disableCreateObjectURL) {
scratchCanvas.toBlob(function (blob) {
img.src = URL.createObjectURL(blob);
});
} else {
img.src = scratchCanvas.toDataURL();
}
wrapper.appendChild(img);
return new Promise(function(resolve, reject) {
img.onload = resolve;
img.onerror = reject;
});
}).then(function () {
return {
width: width,
height: height,
};
});
}

function PDFPrintService(pdfDocument, pagesOverview, printContainer) {
this.pdfDocument = pdfDocument;
this.pagesOverview = pagesOverview;
this.printContainer = printContainer;
this.wrappers = [];
this.currentPage = -1;
// The temporary canvas where renderPage paints one page at a time.
this.scratchCanvas = document.createElement('canvas');
}

PDFPrintService.prototype = {
layout: function () {
this.throwIfInactive();

var pdfDocument = this.pdfDocument;
var printContainer = this.printContainer;
var body = document.querySelector('body');
body.setAttribute('data-pdfjsprinting', true);

Expand Down Expand Up @@ -130,29 +116,23 @@
'@page { size: ' + pageSize.width + 'pt ' + pageSize.height + 'pt;}' +
'}';
body.appendChild(this.pageStyleSheet);

for (var i = 0, ii = this.pagesOverview.length; i < ii; ++i) {
var wrapper = document.createElement('div');
printContainer.appendChild(wrapper);
this.wrappers[i] = wrapper;
}
},

destroy: function () {
if (activeService !== this) {
// |activeService| cannot be replaced without calling destroy() first,
// so if it differs then an external consumer has a stale reference to
// us.
return;
}
this.printContainer.textContent = '';
this.wrappers = null;
if (this.pageStyleSheet && this.pageStyleSheet.parentNode) {
this.pageStyleSheet.parentNode.removeChild(this.pageStyleSheet);
this.pageStyleSheet = null;
}
if (activeService !== this) {
return; // no need to clean up shared resources
}
this.scratchCanvas.width = this.scratchCanvas.height = 0;
this.scratchCanvas = null;
activeService = null;
if (scratchCanvas) {
scratchCanvas.width = scratchCanvas.height = 0;
scratchCanvas = null;
}
ensureOverlay().then(function () {
if (OverlayManager.active !== 'printServiceOverlay') {
return; // overlay was already closed
Expand All @@ -164,23 +144,76 @@
renderPages: function () {
var pageCount = this.pagesOverview.length;
var renderNextPage = function (resolve, reject) {
if (activeService !== this) {
reject(new Error('cancelled'));
return;
}
this.throwIfInactive();
if (++this.currentPage >= pageCount) {
renderProgress(pageCount, pageCount);
resolve();
return;
}
var index = this.currentPage;
renderProgress(index, pageCount);
renderPage(this.pdfDocument, index + 1,
this.pagesOverview[index], this.wrappers[index]).then(
function () { renderNextPage(resolve, reject); }, reject);
renderPage(this, this.pdfDocument, index + 1, this.pagesOverview[index])
.then(this.useRenderedPage.bind(this))
.then(function () {
renderNextPage(resolve, reject);
}, reject);
}.bind(this);
return new Promise(renderNextPage);
},

useRenderedPage: function (printItem) {
this.throwIfInactive();
var img = document.createElement('img');
img.style.width = printItem.width;
img.style.height = printItem.height;

var scratchCanvas = this.scratchCanvas;
if (('toBlob' in scratchCanvas) &&
!pdfjsLib.PDFJS.disableCreateObjectURL) {
scratchCanvas.toBlob(function (blob) {
img.src = URL.createObjectURL(blob);
});
} else {
img.src = scratchCanvas.toDataURL();
}

var wrapper = document.createElement('div');
wrapper.appendChild(img);
this.printContainer.appendChild(wrapper);

return new Promise(function (resolve, reject) {
img.onload = resolve;
img.onerror = reject;
});
},

performPrint: function () {
this.throwIfInactive();
return new Promise(function (resolve) {
// Push window.print in the macrotask queue to avoid being affected by
// the deprecation of running print() code in a microtask, see
// https://github.com/mozilla/pdf.js/issues/7547.
setTimeout(function () {
if (!this.active) {
resolve();
return;
}
print.call(window);
// Delay promise resolution in case print() was not synchronous.
setTimeout(resolve, 20); // Tidy-up.
}.bind(this), 0);
}.bind(this));
},

get active() {
return this === activeService;
},

throwIfInactive: function () {
if (!this.active) {
throw new Error('This print request was cancelled or completed.');
}
},
};


Expand All @@ -191,16 +224,36 @@
return;
}
ensureOverlay().then(function () {
OverlayManager.open('printServiceOverlay');
if (activeService) {
OverlayManager.open('printServiceOverlay');
}
});

try {
dispatchEvent('beforeprint');
} finally {
if (!activeService) {
console.error('Expected print service to be initialized.');
if (OverlayManager.active === 'printServiceOverlay') {
OverlayManager.close('printServiceOverlay');
}
return;
}
activeService.renderPages().then(startPrint, abort);
var activeServiceOnEntry = activeService;
activeService.renderPages().then(function () {
return activeServiceOnEntry.performPrint();
}).catch(function () {
// Ignore any error messages.
}).then(function () {
// aborts acts on the "active" print request, so we need to check
// whether the print request (activeServiceOnEntry) is still active.
// Without the check, an unrelated print request (created after aborting
// this print request while the pages were being generated) would be
// aborted.
if (activeServiceOnEntry.active) {
abort();
}
});
}
};

Expand All @@ -210,19 +263,6 @@
window.dispatchEvent(event);
}

function startPrint() {
// Push window.print in the macrotask queue to avoid being affected by
// the deprecation of running print() code in a microtask, see
// https://github.com/mozilla/pdf.js/issues/7547.
setTimeout(function() {
if (!activeService) {
return; // Print task cancelled by user.
}
print.call(window);
setTimeout(abort, 20); // Tidy-up
}, 0);
}

function abort() {
if (activeService) {
activeService.destroy();
Expand Down

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