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Move text layer building logic into src/display/text_layer.js

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This commit is contained in:
Yury Delendik 2015-11-10 09:45:03 -06:00
parent 2f34fd46cb
commit 56ccaea99b
9 changed files with 268 additions and 144 deletions
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1
examples/acroforms/index.html
View File

@ -13,6 +13,7 @@
<script src="../../src/display/font_loader.js"></script>
<script src="../../src/display/dom_utils.js"></script>
<script src="../../src/display/annotation_helper.js"></script>
<script src="../../src/display/text_layer.js"></script>
<script>
// Specify the main script used to create a new PDF.JS web worker.

1
examples/helloworld/index.html
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@ -13,6 +13,7 @@
<script src="../../src/display/font_loader.js"></script>
<script src="../../src/display/dom_utils.js"></script>
<script src="../../src/display/annotation_helper.js"></script>
<script src="../../src/display/text_layer.js"></script>
<script>
// Specify the main script used to create a new PDF.JS web worker.

1
make.js
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@ -532,6 +532,7 @@ target.bundle = function(args) {
'display/font_loader.js',
'display/dom_utils.js',
'display/annotation_helper.js',
'display/text_layer.js',
'display/svg.js'
]);

237
src/display/text_layer.js Normal file
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@ -0,0 +1,237 @@
/* Copyright 2015 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 PDFJS, createPromiseCapability */
'use strict';
/**
* Text layer render parameters.
*
* @typedef {Object} TextLayerRenderParameters
* @property {TextContent} textContent - Text content to render (the object is
* returned by the page's getTextContent() method).
* @property {HTMLElement} container - HTML element that will contain text runs.
* @property {PDFJS.PageViewport} viewport - The target viewport to properly
* layout the text runs.
* @property {Array} textDivs - (optional) HTML elements that are correspond
* the text items of the textContent input. This is output and shall be
* initially be set to empty array.
* @property {number} timeout - (optional) Delay in milliseconds before
* rendering of the text runs occurs.
*/
var renderTextLayer = (function renderTextLayerClosure() {
var MAX_TEXT_DIVS_TO_RENDER = 100000;
var NonWhitespaceRegexp = /\S/;
function isAllWhitespace(str) {
return !NonWhitespaceRegexp.test(str);
}
function appendText(textDivs, viewport, geom, styles) {
var style = styles[geom.fontName];
var textDiv = document.createElement('div');
textDivs.push(textDiv);
if (isAllWhitespace(geom.str)) {
textDiv.dataset.isWhitespace = true;
return;
}
var tx = PDFJS.Util.transform(viewport.transform, geom.transform);
var angle = Math.atan2(tx[1], tx[0]);
if (style.vertical) {
angle += Math.PI / 2;
}
var fontHeight = Math.sqrt((tx[2] * tx[2]) + (tx[3] * tx[3]));
var fontAscent = fontHeight;
if (style.ascent) {
fontAscent = style.ascent * fontAscent;
} else if (style.descent) {
fontAscent = (1 + style.descent) * fontAscent;
}
var left;
var top;
if (angle === 0) {
left = tx[4];
top = tx[5] - fontAscent;
} else {
left = tx[4] + (fontAscent * Math.sin(angle));
top = tx[5] - (fontAscent * Math.cos(angle));
}
textDiv.style.left = left + 'px';
textDiv.style.top = top + 'px';
textDiv.style.fontSize = fontHeight + 'px';
textDiv.style.fontFamily = style.fontFamily;
textDiv.textContent = geom.str;
// |fontName| is only used by the Font Inspector. This test will succeed
// when e.g. the Font Inspector is off but the Stepper is on, but it's
// not worth the effort to do a more accurate test.
if (PDFJS.pdfBug) {
textDiv.dataset.fontName = geom.fontName;
}
// Storing into dataset will convert number into string.
if (angle !== 0) {
textDiv.dataset.angle = angle * (180 / Math.PI);
}
// We don't bother scaling single-char text divs, because it has very
// little effect on text highlighting. This makes scrolling on docs with
// lots of such divs a lot faster.
if (geom.str.length > 1) {
if (style.vertical) {
textDiv.dataset.canvasWidth = geom.height * viewport.scale;
} else {
textDiv.dataset.canvasWidth = geom.width * viewport.scale;
}
}
}
function render(task) {
if (task._canceled) {
return;
}
var textLayerFrag = task._container;
var textDivs = task._textDivs;
var capability = task._capability;
var textDivsLength = textDivs.length;
// No point in rendering many divs as it would make the browser
// unusable even after the divs are rendered.
if (textDivsLength > MAX_TEXT_DIVS_TO_RENDER) {
capability.resolve();
return;
}
var canvas = document.createElement('canvas');
//#if MOZCENTRAL || FIREFOX || GENERIC
canvas.mozOpaque = true;
//#endif
var ctx = canvas.getContext('2d', {alpha: false});
var lastFontSize;
var lastFontFamily;
for (var i = 0; i < textDivsLength; i++) {
var textDiv = textDivs[i];
if (textDiv.dataset.isWhitespace !== undefined) {
continue;
}
var fontSize = textDiv.style.fontSize;
var fontFamily = textDiv.style.fontFamily;
// Only build font string and set to context if different from last.
if (fontSize !== lastFontSize || fontFamily !== lastFontFamily) {
ctx.font = fontSize + ' ' + fontFamily;
lastFontSize = fontSize;
lastFontFamily = fontFamily;
}
var width = ctx.measureText(textDiv.textContent).width;
if (width > 0) {
textLayerFrag.appendChild(textDiv);
var transform;
if (textDiv.dataset.canvasWidth !== undefined) {
// Dataset values come of type string.
var textScale = textDiv.dataset.canvasWidth / width;
transform = 'scaleX(' + textScale + ')';
} else {
transform = '';
}
var rotation = textDiv.dataset.angle;
if (rotation) {
transform = 'rotate(' + rotation + 'deg) ' + transform;
}
if (transform) {
PDFJS.CustomStyle.setProp('transform' , textDiv, transform);
}
}
}
capability.resolve();
}
/**
* Text layer rendering task.
*
* @param {TextContent} textContent
* @param {HTMLElement} container
* @param {PDFJS.PageViewport} viewport
* @param {Array} textDivs
* @private
*/
function TextLayerRenderTask(textContent, container, viewport, textDivs) {
this._textContent = textContent;
this._container = container;
this._viewport = viewport;
textDivs = textDivs || [];
this._textDivs = textDivs;
this._canceled = false;
this._capability = createPromiseCapability();
this._renderTimer = null;
}
TextLayerRenderTask.prototype = {
get promise() {
return this._capability.promise;
},
cancel: function TextLayer_cancel() {
this._canceled = true;
if (this._renderTimer !== null) {
clearTimeout(this._renderTimer);
this._renderTimer = null;
}
this._capability.reject('canceled');
},
_render: function TextLayer_render(timeout) {
var textItems = this._textContent.items;
var styles = this._textContent.styles;
var textDivs = this._textDivs;
var viewport = this._viewport;
for (var i = 0, len = textItems.length; i < len; i++) {
appendText(textDivs, viewport, textItems[i], styles);
}
if (!timeout) { // Render right away
render(this);
} else { // Schedule
var self = this;
this._renderTimer = setTimeout(function() {
render(self);
self._renderTimer = null;
}, timeout);
}
}
};
/**
* Starts rendering of the text layer.
*
* @param {TextLayerRenderParameters} renderParameters
* @returns {TextLayerRenderTask}
*/
function renderTextLayer(renderParameters) {
var task = new TextLayerRenderTask(renderParameters.textContent,
renderParameters.container,
renderParameters.viewport,
renderParameters.textDivs);
task._render(renderParameters.timeout);
return task;
}
return renderTextLayer;
})();
PDFJS.renderTextLayer = renderTextLayer;

1
test/font/font_test.html
View File

@ -37,6 +37,7 @@
<script src="../../src/core/ps_parser.js"></script>
<script src="../../src/display/pattern_helper.js"></script>
<script src="../../src/display/annotation_helper.js"></script>
<script src="../../src/display/text_layer.js"></script>
<script src="../../src/core/stream.js"></script>
<script src="../../src/core/worker.js"></script>
<script src="../../src/display/metadata.js"></script>

1
test/test_slave.html
View File

@ -27,6 +27,7 @@ limitations under the License.
<script src="../src/display/font_loader.js"></script>
<script src="../src/display/dom_utils.js"></script>
<script src="../src/display/annotation_helper.js"></script>
<script src="../src/display/text_layer.js"></script>
<script src="driver.js"></script>
</head>
<body>

1
test/unit/unit_test.html
View File

@ -38,6 +38,7 @@
<script src="../../src/display/font_loader.js"></script>
<script src="../../src/display/dom_utils.js"></script>
<script src="../../src/display/annotation_helper.js"></script>
<script src="../../src/display/text_layer.js"></script>
<script src="../../src/core/stream.js"></script>
<script src="../../src/core/worker.js"></script>
<script src="../../src/display/metadata.js"></script>

168
web/text_layer_builder.js
View File

@ -16,14 +16,6 @@
'use strict';
var MAX_TEXT_DIVS_TO_RENDER = 100000;
var NonWhitespaceRegexp = /\S/;
function isAllWhitespace(str) {
return !NonWhitespaceRegexp.test(str);
}
/**
* @typedef {Object} TextLayerBuilderOptions
* @property {HTMLDivElement} textLayerDiv - The text layer container.
@ -50,6 +42,7 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
this.viewport = options.viewport;
this.textDivs = [];
this.findController = options.findController || null;
this.textLayerRenderTask = null;
this._bindMouse();
}
@ -68,67 +61,6 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
this.textLayerDiv.dispatchEvent(event);
},
renderLayer: function TextLayerBuilder_renderLayer() {
var textLayerFrag = document.createDocumentFragment();
var textDivs = this.textDivs;
var textDivsLength = textDivs.length;
var canvas = document.createElement('canvas');
//#if MOZCENTRAL || FIREFOX || GENERIC
canvas.mozOpaque = true;
//#endif
var ctx = canvas.getContext('2d', {alpha: false});
// No point in rendering many divs as it would make the browser
// unusable even after the divs are rendered.
if (textDivsLength > MAX_TEXT_DIVS_TO_RENDER) {
this._finishRendering();
return;
}
var lastFontSize;
var lastFontFamily;
for (var i = 0; i < textDivsLength; i++) {
var textDiv = textDivs[i];
if (textDiv.dataset.isWhitespace !== undefined) {
continue;
}
var fontSize = textDiv.style.fontSize;
var fontFamily = textDiv.style.fontFamily;
// Only build font string and set to context if different from last.
if (fontSize !== lastFontSize || fontFamily !== lastFontFamily) {
ctx.font = fontSize + ' ' + fontFamily;
lastFontSize = fontSize;
lastFontFamily = fontFamily;
}
var width = ctx.measureText(textDiv.textContent).width;
if (width > 0) {
textLayerFrag.appendChild(textDiv);
var transform;
if (textDiv.dataset.canvasWidth !== undefined) {
// Dataset values come of type string.
var textScale = textDiv.dataset.canvasWidth / width;
transform = 'scaleX(' + textScale + ')';
} else {
transform = '';
}
var rotation = textDiv.dataset.angle;
if (rotation) {
transform = 'rotate(' + rotation + 'deg) ' + transform;
}
if (transform) {
PDFJS.CustomStyle.setProp('transform' , textDiv, transform);
}
}
}
this.textLayerDiv.appendChild(textLayerFrag);
this._finishRendering();
this.updateMatches();
},
/**
* Renders the text layer.
* @param {number} timeout (optional) if specified, the rendering waits
@ -139,87 +71,35 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
return;
}
if (this.renderTimer) {
clearTimeout(this.renderTimer);
this.renderTimer = null;
if (this.textLayerRenderTask) {
this.textLayerRenderTask.cancel();
this.textLayerRenderTask = null;
}
if (!timeout) { // Render right away
this.renderLayer();
} else { // Schedule
var self = this;
this.renderTimer = setTimeout(function() {
self.renderLayer();
self.renderTimer = null;
}, timeout);
}
},
appendText: function TextLayerBuilder_appendText(geom, styles) {
var style = styles[geom.fontName];
var textDiv = document.createElement('div');
this.textDivs.push(textDiv);
if (isAllWhitespace(geom.str)) {
textDiv.dataset.isWhitespace = true;
return;
}
var tx = PDFJS.Util.transform(this.viewport.transform, geom.transform);
var angle = Math.atan2(tx[1], tx[0]);
if (style.vertical) {
angle += Math.PI / 2;
}
var fontHeight = Math.sqrt((tx[2] * tx[2]) + (tx[3] * tx[3]));
var fontAscent = fontHeight;
if (style.ascent) {
fontAscent = style.ascent * fontAscent;
} else if (style.descent) {
fontAscent = (1 + style.descent) * fontAscent;
}
var left;
var top;
if (angle === 0) {
left = tx[4];
top = tx[5] - fontAscent;
} else {
left = tx[4] + (fontAscent * Math.sin(angle));
top = tx[5] - (fontAscent * Math.cos(angle));
}
textDiv.style.left = left + 'px';
textDiv.style.top = top + 'px';
textDiv.style.fontSize = fontHeight + 'px';
textDiv.style.fontFamily = style.fontFamily;
textDiv.textContent = geom.str;
// |fontName| is only used by the Font Inspector. This test will succeed
// when e.g. the Font Inspector is off but the Stepper is on, but it's
// not worth the effort to do a more accurate test.
if (PDFJS.pdfBug) {
textDiv.dataset.fontName = geom.fontName;
}
// Storing into dataset will convert number into string.
if (angle !== 0) {
textDiv.dataset.angle = angle * (180 / Math.PI);
}
// We don't bother scaling single-char text divs, because it has very
// little effect on text highlighting. This makes scrolling on docs with
// lots of such divs a lot faster.
if (geom.str.length > 1) {
if (style.vertical) {
textDiv.dataset.canvasWidth = geom.height * this.viewport.scale;
} else {
textDiv.dataset.canvasWidth = geom.width * this.viewport.scale;
}
}
this.textDivs = [];
var textLayerFrag = document.createDocumentFragment();
this.textLayerRenderTask = PDFJS.renderTextLayer({
textContent: this.textContent,
container: textLayerFrag,
viewport: this.viewport,
textDivs: this.textDivs,
timeout: timeout
});
this.textLayerRenderTask.promise.then(function () {
this.textLayerDiv.appendChild(textLayerFrag);
this._finishRendering();
this.updateMatches();
}.bind(this), function (reason) {
// canceled or failed to render text layer -- skipping errors
});
},
setTextContent: function TextLayerBuilder_setTextContent(textContent) {
this.textContent = textContent;
var textItems = textContent.items;
for (var i = 0, len = textItems.length; i < len; i++) {
this.appendText(textItems[i], textContent.styles);
if (this.textLayerRenderTask) {
this.textLayerRenderTask.cancel();
this.textLayerRenderTask = null;
}
this.textContent = textContent;
this.divContentDone = true;
},

1
web/viewer.html
View File

@ -62,6 +62,7 @@ See https://github.com/adobe-type-tools/cmap-resources
<script src="../src/display/font_loader.js"></script>
<script src="../src/display/dom_utils.js"></script>
<script src="../src/display/annotation_helper.js"></script>
<script src="../src/display/text_layer.js"></script>
<script>PDFJS.workerSrc = '../src/worker_loader.js';</script>
<!--#endif-->