The size of the `src/core/obj.js` file has increased slowly over the years, and it also contains a fair amount of *distinct* functionality.
In order to improve readability and make it easier to navigate through the code, this patch moves the `FileSpec` into its own file.
The size of the `src/core/obj.js` file has increased slowly over the years, and it also contains a fair amount of *distinct* functionality.
In order to improve readability and make it easier to navigate through the code, this patch moves the `ObjectLoader` into its own file.
Remove the unused "GetIsPureXfa" message handler; and avoid unnecessary parsing when no structTree is available (PR 13069 follow-up, PR 13221 follow-up)
With the current implementation of `PDFDocument.hasJSActions`, in the worker-thread, we're not actually handling not-yet-loaded data correctly. This can thus fail in *two* different ways:
- The `PDFDocument.fieldObjects` getter (and its helper method), while it may *return* a Promise, still fetches all of its data synchronously and it can thus throw a `MissingDataException` during parsing.
- The `Catalog.jsActions` getter, which is completely synchronous, can obviously throw a `MissingDataException` during parsing.
If either of these cases occur currently, the `PDFDocumentProxy.hasJSActions` method in the API can either return a *rejected* Promise (which it never should) or possibly "hang" and never resolve.
*Please note:* While I've not *yet* seen this error in an actual PDF document, it can happen during loading if you're unlucky enough with e.g. the structure of the PDF document and/or the download speed offered by the server.
This patch is thus based on code-inspection *and* on manually throwing a `MissingDataException` on the first access of `Catalog.jsActions` to simulate this situation.
Finally, this patch adds a couple of *API* unit-tests for this (since none existed).
Given that this only an internal helper method, used by the `Catalog.{javaScript, jsActions}` getters, this change simplifies iteration of the returned data.
We can also (slightly) re-factor the code of the `jsActions` getter, and remove an obsolete[1] JSDoc-comment from the `openAction` getter.
---
[1] Not really relevant now that we've got proper scripting support.
Similar to all other data accesses, note e.g. the "GetDocJSActions" handler just above, we need to ensure that a `MissingDataException` isn't propagated to the main-thread if this data is accessed while the PDF document is still loading.
It's obviously (a bit) more efficient to return early in `Page.getStructTree`, rather than trying to first "parse" an *empty* structTree-root.
*Somehow I didn't think of this yesterday, but this feels like a much better solution overall; sorry about the churn here!*
Looking at the API, there's no code which actually sends this message. Most likely it's a left-over from a previous version of PR 13069, since the `isPureXfa` parameter is being included in the "GetDoc" message.
This is first of all consistent with existing API-methods, where we return `null` when the data in question doesn't exist. Secondly, it should also be (slightly) more efficient since there's less dummy-data that we need to transfer between threads.
Finally, this prevents us from adding an empty/unnecessary span to *every* single page even in documents without any structure tree data.
- but don't validate them for now;
- Firefox will display a bar to warn that the signature validation is not supported (see https://bugzilla.mozilla.org/show_bug.cgi?id=854315)
- almost all (all ?) pdf readers display signatures;
- validation is done in edge but for now it's behind a pref.
When a PDF is "marked" we now generate a separate DOM that represents
the structure tree from the PDF. This DOM is inserted into the <canvas>
element and allows screen readers to walk the tree and have more
information about headings, images, links, etc. To link the structure
tree DOM (which is empty) to the text layer aria-owns is used. This
required modifying the text layer creation so that marked items are
now tracked.
The fontName, as defined in the PDF document, cannot be found in *any* of the "name"-tables in the TrueType Collection font. To work-around that, this patch adds a *fallback* code-path to allow using an approximately matching fontName rather than outright failing.
Given that what we actually want is only to keep track of the loadedFont-names, rather than storing any actual data, using an object isn't really necessary here. Furthermore, in the current code, we're also using `in` when checking if the data exists, which is generally less efficient than just checking for the value directly.
Currently the `fontName`-property contains an actual /Name-instance, which is a problem given that its fallback value is an empty string; see ca7f546828/src/core/default_appearance.js (L35)
The reason that this is a problem can be seen in ca7f546828/src/core/primitives.js (L30-L34), since an empty string short-circuits the cache. Essentially, in PDF documents, a /Name-instance cannot be empty and the way that the `DefaultAppearanceEvaluator` does things is unfortunately not entirely correct.
Hence the `fontName`-property is changed to instead contain a string, rather than a /Name-instance, which simplifies the code overall.
*Please note:* I'm tagging this patch with "[api-minor]", since PR 12831 is included in the current pre-release (although we're not using the `fontName`-property in the display-layer).
Fixes#13107
In the issue, some TrueType glyph names have the format `uniXXXX`.
Font's `Encoding` dictionary has the entry `Differences` but no
`BaseEncoding`. `uniXXXX` names are converted to glyph indices
using font's `post` table but currently that is done only when
`BaseEncoding` exists. We must enable the conversion also when only
`Differences` exists.
The reasons for making this change are:
- This property is not, nor has it ever been, used anywhere in the PDF.js display-layer.
- Related to the previous point, the format of the `defaultAppearance`-string is such that it'd be difficult to use it as-is in the display-layer anyway.
- It (usually) contains the "raw" appearance-string, from the PDF document, which is neither parsed nor validated and could thus be bogus.
- We now expose a `defaultAppearanceData`-property, which is first of all used in the display-layer and secondly contains actually parsed/validated data.
- In the event that a third-party implementation needs the `defaultAppearance`-string, it could be easily constructed from the recently added `defaultAppearanceData`-property.
All-in-all, I'm thus suggesting that we stop exposing an unused and unnecessary property on all Annotation-instances.
* JS - Handle correctly hierarchy of fields
- it aims to fix#13132;
- annotations can inherit their actions from the parent field;
- there are some fields which act as a container for other fields:
- they can be access through js so need to add them with an empty type (nothing in the spec about that but checked in Acrobat);
- calculation order list (CO) can reference them so need make them through this.getField;
- getArray method must return kids.
- field values are number, string, ... depending of their type but nothing in the spec on how to know what's the type:
- according to the comment for Canonical Format: https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf#page=461
- it seems that this "type" can be guessed from js action Format (when setting a type in Acrobat DC, the only affected thing is this action).
- util.scand with an empty string returns the current date.
- implement few positioning properties: position, width, height, anchor;
- implement font element;
- implement fill element (used by font) and its children (linear, radial, ...);
- font property is inherited from ancestor container (see https://www.pdfa.org/wp-content/uploads/2020/07/XFA-3_3.pdf#page=43) so let CSS handles that stuff;
- in order to reduce the number of properties to set, only set non default properties and put the default in CSS;
- set a background to some containers to be able to see them (will be removed in a future commit).
- add an option to enable XFA rendering if any;
- for now, let the canvas layer: it could be useful to implement XFAF forms (embedded pdf in xml stream for the background and xfa form for the foreground);
- ui elements in template DOM are pretty close to their html counterpart so we generate a fake html DOM from template one:
- it makes easier to translate template properties to html ones;
- it makes faster the creation of the html element in the main thread.
While there is nothing *outright* wrong with the existing implementation, it can however lead to increased memory usage in one particular case (that I completely overlooked when implementing this):
For "data:"-URLs, which by definition contains the entire PDF document and can thus be arbitrarily large, we obviously want to avoid sending, storing, and/or logging the "raw" docBaseUrl in that case.
To address this, this patch makes the following changes:
- Ignore any non-string in the `docBaseUrl` option passed to `getDocument`, since those are unsupported anyway, already on the main-thread.
- Ignore "data:"-URLs in the `docBaseUrl` option passed to `getDocument`, to avoid having to send what could potentially be a *very* long string to the worker-thread.
- Parse the `docBaseUrl` option *directly* in the `BasePdfManager`-constructors, on the worker-thread, to avoid having to store the "raw" docBaseUrl in the first place.
This extends PR 13033 slightly, with a heuristic to support corrupt PDF documents where the `LineAnnotation`s have an empty /Rect-entry. Please note that while I have no idea if this is "correct", this patch at least makes us output the same /BBox as re-saving in Adobe Reader does.
This is mostly done using `gulp lint --fix` with a few manual changes in
the following diff:
```diff
diff --git a/src/core/pattern.js b/src/core/pattern.js
index 365491ed3..eedd8b686 100644
--- a/src/core/pattern.js
+++ b/src/core/pattern.js
@@ -105,7 +105,7 @@ const Pattern = (function PatternClosure() {
return Pattern;
})();
-var Shadings = {};
+const Shadings = {};
// A small number to offset the first/last color stops so we can insert ones to
// support extend. Number.MIN_VALUE is too small and breaks the extend.
@@ -597,16 +597,15 @@ Shadings.Mesh = (function MeshClosure() {
if (!(0 <= f && f <= 3)) {
throw new FormatError("Unknown type6 flag");
}
- var i, ii;
const pi = coords.length;
- for (i = 0, ii = f !== 0 ? 8 : 12; i < ii; i++) {
+ for (let i = 0, ii = f !== 0 ? 8 : 12; i < ii; i++) {
coords.push(reader.readCoordinate());
}
const ci = colors.length;
- for (i = 0, ii = f !== 0 ? 2 : 4; i < ii; i++) {
+ for (let i = 0, ii = f !== 0 ? 2 : 4; i < ii; i++) {
colors.push(reader.readComponents());
}
- var tmp1, tmp2, tmp3, tmp4;
+ let tmp1, tmp2, tmp3, tmp4;
switch (f) {
// prettier-ignore
case 0:
@@ -729,16 +728,15 @@ Shadings.Mesh = (function MeshClosure() {
if (!(0 <= f && f <= 3)) {
throw new FormatError("Unknown type7 flag");
}
- var i, ii;
const pi = coords.length;
- for (i = 0, ii = f !== 0 ? 12 : 16; i < ii; i++) {
+ for (let i = 0, ii = f !== 0 ? 12 : 16; i < ii; i++) {
coords.push(reader.readCoordinate());
}
const ci = colors.length;
- for (i = 0, ii = f !== 0 ? 2 : 4; i < ii; i++) {
+ for (let i = 0, ii = f !== 0 ? 2 : 4; i < ii; i++) {
colors.push(reader.readComponents());
}
- var tmp1, tmp2, tmp3, tmp4;
+ let tmp1, tmp2, tmp3, tmp4;
switch (f) {
// prettier-ignore
case 0:
@@ -897,7 +895,7 @@ Shadings.Mesh = (function MeshClosure() {
decodeType4Shading(this, reader);
break;
case ShadingType.LATTICE_FORM_MESH:
- var verticesPerRow = dict.get("VerticesPerRow") | 0;
+ const verticesPerRow = dict.get("VerticesPerRow") | 0;
if (verticesPerRow < 2) {
throw new FormatError("Invalid VerticesPerRow");
}
```
A significant portion of the code-base has now been converted to use `let`/`const`, rather than `var`, hence it should be possible to simply enable the ESLint `no-var` rule globally.
This way we can ensure that new code won't accidentally use `var`, and it also removes the need to manually enable the rule in various folders.
Obviously it makes sense to continue the efforts to replace `var`, but that should probably happen on a file and/or folder basis.
Please note that this patch excludes the following code:
- The `extensions/` folder, since that seemed easiest for now (and I don't know exactly what the support situation is for the Chromium-extension).
- The entire `external/` folder is ignored, since most of it's currently excluded from linting.
For the code that isn't imported from elsewhere (and should be ignored), we should probably (at some point) bring the code up to the same linting/formatting standard as the rest of the code-base.
- Various files in the `test/` folder are ignored, as necessary, since the way that a lot of this code is loaded will require some care (or perhaps larger re-factoring) when removing `var` usage.
Note that the majority of these changes were done automatically, by using `gulp lint --fix`, and the manual changes were limited to the following diff:
```diff
diff --git a/src/core/cff_parser.js b/src/core/cff_parser.js
index d684c200e..2e2b811e4 100644
--- a/src/core/cff_parser.js
+++ b/src/core/cff_parser.js
@@ -555,7 +555,7 @@ const CFFParser = (function CFFParserClosure() {
stackSize %= 2;
validationCommand = CharstringValidationData[value];
} else if (value === 10 || value === 29) {
- var subrsIndex;
+ let subrsIndex;
if (value === 10) {
subrsIndex = localSubrIndex;
} else {
@@ -886,15 +886,15 @@ const CFFParser = (function CFFParserClosure() {
format = bytes[pos++];
switch (format & 0x7f) {
case 0:
- var glyphsCount = bytes[pos++];
+ const glyphsCount = bytes[pos++];
for (i = 1; i <= glyphsCount; i++) {
encoding[bytes[pos++]] = i;
}
break;
case 1:
- var rangesCount = bytes[pos++];
- var gid = 1;
+ const rangesCount = bytes[pos++];
+ let gid = 1;
for (i = 0; i < rangesCount; i++) {
const start = bytes[pos++];
const left = bytes[pos++];
@@ -938,7 +938,7 @@ const CFFParser = (function CFFParserClosure() {
}
break;
case 3:
- var rangesCount = (bytes[pos++] << 8) | bytes[pos++];
+ const rangesCount = (bytes[pos++] << 8) | bytes[pos++];
for (i = 0; i < rangesCount; ++i) {
let first = (bytes[pos++] << 8) | bytes[pos++];
if (i === 0 && first !== 0) {
@@ -1173,7 +1173,7 @@ class CFFDict {
}
}
-var CFFTopDict = (function CFFTopDictClosure() {
+const CFFTopDict = (function CFFTopDictClosure() {
const layout = [
[[12, 30], "ROS", ["sid", "sid", "num"], null],
[[12, 20], "SyntheticBase", "num", null],
@@ -1229,7 +1229,7 @@ var CFFTopDict = (function CFFTopDictClosure() {
return CFFTopDict;
})();
-var CFFPrivateDict = (function CFFPrivateDictClosure() {
+const CFFPrivateDict = (function CFFPrivateDictClosure() {
const layout = [
[6, "BlueValues", "delta", null],
[7, "OtherBlues", "delta", null],
@@ -1265,11 +1265,12 @@ var CFFPrivateDict = (function CFFPrivateDictClosure() {
return CFFPrivateDict;
})();
-var CFFCharsetPredefinedTypes = {
+const CFFCharsetPredefinedTypes = {
ISO_ADOBE: 0,
EXPERT: 1,
EXPERT_SUBSET: 2,
};
+
class CFFCharset {
constructor(predefined, format, charset, raw) {
this.predefined = predefined;
@@ -1695,7 +1696,7 @@ class CFFCompiler {
// For offsets we just insert a 32bit integer so we don't have to
// deal with figuring out the length of the offset when it gets
// replaced later on by the compiler.
- var name = dict.keyToNameMap[key];
+ const name = dict.keyToNameMap[key];
// Some offsets have the offset and the length, so just record the
// position of the first one.
if (!offsetTracker.isTracking(name)) {
```
Now that we have scripting support, warning about e.g. JavaScript actions doesn't seem necessary anymore. Especially considering that scripting-related actions are/will not be parsed by the `Catalog.parseDestDictionary` method anyway, since it's intended for handling "simple" actions.
