pdf-lib
Version:
Create and modify PDF files with JavaScript
175 lines • 7.02 kB
JavaScript
import { __extends } from "tslib";
import PDFArray from "../objects/PDFArray";
import PDFDict from "../objects/PDFDict";
import PDFName from "../objects/PDFName";
import PDFNumber from "../objects/PDFNumber";
import PDFPageLeaf from "./PDFPageLeaf";
import { InvalidTargetIndexError, CorruptPageTreeError } from "../errors";
var PDFPageTree = /** @class */ (function (_super) {
__extends(PDFPageTree, _super);
function PDFPageTree() {
return _super !== null && _super.apply(this, arguments) || this;
}
PDFPageTree.prototype.Parent = function () {
return this.lookup(PDFName.of('Parent'));
};
PDFPageTree.prototype.Kids = function () {
return this.lookup(PDFName.of('Kids'), PDFArray);
};
PDFPageTree.prototype.Count = function () {
return this.lookup(PDFName.of('Count'), PDFNumber);
};
PDFPageTree.prototype.pushTreeNode = function (treeRef) {
var Kids = this.Kids();
Kids.push(treeRef);
};
PDFPageTree.prototype.pushLeafNode = function (leafRef) {
var Kids = this.Kids();
this.insertLeafKid(Kids.size(), leafRef);
};
/**
* Inserts the given ref as a leaf node of this page tree at the specified
* index (zero-based). Also increments the `Count` of each page tree in the
* hierarchy to accomodate the new page.
*
* Returns the ref of the PDFPageTree node into which `leafRef` was inserted,
* or `undefined` if it was inserted into the root node (the PDFPageTree upon
* which the method was first called).
*/
PDFPageTree.prototype.insertLeafNode = function (leafRef, targetIndex) {
var Kids = this.Kids();
var Count = this.Count().asNumber();
if (targetIndex > Count) {
throw new InvalidTargetIndexError(targetIndex, Count);
}
var leafsRemainingUntilTarget = targetIndex;
for (var idx = 0, len = Kids.size(); idx < len; idx++) {
if (leafsRemainingUntilTarget === 0) {
// Insert page and return
this.insertLeafKid(idx, leafRef);
return undefined;
}
var kidRef = Kids.get(idx);
var kid = this.context.lookup(kidRef);
if (kid instanceof PDFPageTree) {
if (kid.Count().asNumber() > leafsRemainingUntilTarget) {
// Dig in
return (kid.insertLeafNode(leafRef, leafsRemainingUntilTarget) || kidRef);
}
else {
// Move on
leafsRemainingUntilTarget -= kid.Count().asNumber();
}
}
if (kid instanceof PDFPageLeaf) {
// Move on
leafsRemainingUntilTarget -= 1;
}
}
if (leafsRemainingUntilTarget === 0) {
// Insert page at the end and return
this.insertLeafKid(Kids.size(), leafRef);
return undefined;
}
// Should never get here if `targetIndex` is valid
throw new CorruptPageTreeError(targetIndex, 'insertLeafNode');
};
/**
* Removes the leaf node at the specified index (zero-based) from this page
* tree. Also decrements the `Count` of each page tree in the hierarchy to
* account for the removed page.
*
* If `prune` is true, then intermediate tree nodes will be removed from the
* tree if they contain 0 children after the leaf node is removed.
*/
PDFPageTree.prototype.removeLeafNode = function (targetIndex, prune) {
if (prune === void 0) { prune = true; }
var Kids = this.Kids();
var Count = this.Count().asNumber();
if (targetIndex >= Count) {
throw new InvalidTargetIndexError(targetIndex, Count);
}
var leafsRemainingUntilTarget = targetIndex;
for (var idx = 0, len = Kids.size(); idx < len; idx++) {
var kidRef = Kids.get(idx);
var kid = this.context.lookup(kidRef);
if (kid instanceof PDFPageTree) {
if (kid.Count().asNumber() > leafsRemainingUntilTarget) {
// Dig in
kid.removeLeafNode(leafsRemainingUntilTarget, prune);
if (prune && kid.Kids().size() === 0)
Kids.remove(idx);
return;
}
else {
// Move on
leafsRemainingUntilTarget -= kid.Count().asNumber();
}
}
if (kid instanceof PDFPageLeaf) {
if (leafsRemainingUntilTarget === 0) {
// Remove page and return
this.removeKid(idx);
return;
}
else {
// Move on
leafsRemainingUntilTarget -= 1;
}
}
}
// Should never get here if `targetIndex` is valid
throw new CorruptPageTreeError(targetIndex, 'removeLeafNode');
};
PDFPageTree.prototype.ascend = function (visitor) {
visitor(this);
var Parent = this.Parent();
if (Parent)
Parent.ascend(visitor);
};
/** Performs a Post-Order traversal of this page tree */
PDFPageTree.prototype.traverse = function (visitor) {
var Kids = this.Kids();
for (var idx = 0, len = Kids.size(); idx < len; idx++) {
var kidRef = Kids.get(idx);
var kid = this.context.lookup(kidRef);
if (kid instanceof PDFPageTree)
kid.traverse(visitor);
visitor(kid, kidRef);
}
};
PDFPageTree.prototype.insertLeafKid = function (kidIdx, leafRef) {
var Kids = this.Kids();
this.ascend(function (node) {
var newCount = node.Count().asNumber() + 1;
node.set(PDFName.of('Count'), PDFNumber.of(newCount));
});
Kids.insert(kidIdx, leafRef);
};
PDFPageTree.prototype.removeKid = function (kidIdx) {
var Kids = this.Kids();
var kid = Kids.lookup(kidIdx);
if (kid instanceof PDFPageLeaf) {
this.ascend(function (node) {
var newCount = node.Count().asNumber() - 1;
node.set(PDFName.of('Count'), PDFNumber.of(newCount));
});
}
Kids.remove(kidIdx);
};
PDFPageTree.withContext = function (context, parent) {
var dict = new Map();
dict.set(PDFName.of('Type'), PDFName.of('Pages'));
dict.set(PDFName.of('Kids'), context.obj([]));
dict.set(PDFName.of('Count'), context.obj(0));
if (parent)
dict.set(PDFName.of('Parent'), parent);
return new PDFPageTree(dict, context);
};
PDFPageTree.fromMapWithContext = function (map, context) {
return new PDFPageTree(map, context);
};
return PDFPageTree;
}(PDFDict));
export default PDFPageTree;
//# sourceMappingURL=PDFPageTree.js.map