EPUB/Snapshot: More cleanup

src/dom/common/lib/nodes.ts

@@ -58,3 +58,14 @@ export function getContainingBlock(element: Element): Element | null {
 	}
 	return null;
 }
+
+export function iterateWalker(walker: TreeWalker | NodeIterator): Iterable<Node> {
+	return {
+		[Symbol.iterator]: function* () {
+			let node: Node | null;
+			while ((node = walker.nextNode())) {
+				yield node;
+			}
+		}
+	};
+}

src/dom/common/lib/range.ts

@@ -1,4 +1,5 @@
 import { isFirefox, isWin } from "../../../common/lib/utilities";
+import { iterateWalker } from "./nodes";
 
 /**
  * Wraps the properties of a Range object in a static structure so that they don't change when the DOM changes.
@@ -73,8 +74,7 @@ export function moveRangeEndsIntoTextNodes(range: Range): Range {
 		if (!endNode || endNode.nodeType !== Node.TEXT_NODE) {
 			// Get the last text node inside the container/child
 			let walker = doc.createTreeWalker(endNode || range.endContainer, NodeFilter.SHOW_TEXT);
-			let node;
-			while ((node = walker.nextNode())) {
+			for (let node of iterateWalker(walker)) {
 				endNode = node;
 			}
 		}

src/dom/common/lib/selector.ts

@@ -1,4 +1,5 @@
 import { moveRangeEndsIntoTextNodes } from "./range";
+import { iterateWalker } from "./nodes";
 
 // We generate and support a very limited subset of the Web Annotation Data Model:
 // https://www.w3.org/TR/annotation-model/#selectors
@@ -72,8 +73,7 @@ export function textPositionFromRange(range: Range, root: Element): TextPosition
 		type: 'TextPositionSelector'
 	};
 	let pos = 0;
-	let node: Node | null = null;
-	while ((node = iter.nextNode())) {
+	for (let node of iterateWalker(iter)) {
 		if (node === range.startContainer) {
 			selector.start = pos + range.startOffset;
 		}
@@ -94,8 +94,7 @@ export function textPositionToRange(selector: TextPositionSelector, root: Elemen
 	let iter = root.ownerDocument.createNodeIterator(root, NodeFilter.SHOW_TEXT);
 	let range = root.ownerDocument.createRange();
 	let pos = 0;
-	let node: Node | null = null;
-	while ((node = iter.nextNode())) {
+	for (let node of iterateWalker(iter)) {
 		if (!node.nodeValue) {
 			continue;
 		}

src/dom/epub/flow.ts

@@ -395,6 +395,11 @@ export class PaginatedFlow extends AbstractFlow {
 		this._iframeDocument.body.classList.remove('flow-mode-paginated');
 	}
 
+	private get _spreadWidth(): number {
+		return this._sectionsContainer.offsetWidth
+			+ parseFloat(getComputedStyle(this._sectionsContainer).columnGap);
+	}
+
 	get currentSectionIndex(): number {
 		return this._currentSectionIndex;
 	}
@@ -437,8 +442,7 @@ export class PaginatedFlow extends AbstractFlow {
 		if (options?.block === 'center') {
 			x += rect.width / 2;
 		}
-		let gap = parseFloat(getComputedStyle(this._sectionsContainer).columnGap);
-		let spreadWidth = this._sectionsContainer.offsetWidth + gap;
+		let spreadWidth = this._spreadWidth;
 		this._sectionsContainer.scrollTo({
 			left: Math.floor(x / spreadWidth) * spreadWidth,
 			top: 0
@@ -495,9 +499,8 @@ export class PaginatedFlow extends AbstractFlow {
 			this._onViewUpdate();
 			return;
 		}
-		let gap = parseFloat(getComputedStyle(this._sectionsContainer).columnGap);
 		this._sectionsContainer.scrollBy({
-			left: -this._sectionsContainer.offsetWidth - gap,
+			left: -this._spreadWidth,
 			behavior: 'auto' // TODO 'smooth' once annotation positioning is fixed
 		});
 		this._onViewUpdate();
@@ -508,9 +511,8 @@ export class PaginatedFlow extends AbstractFlow {
 			this.navigateToNextSection();
 			return;
 		}
-		let gap = parseFloat(getComputedStyle(this._sectionsContainer).columnGap);
 		this._sectionsContainer.scrollBy({
-			left: this._sectionsContainer.offsetWidth + gap,
+			left: this._spreadWidth,
 			behavior: 'auto' // TODO 'smooth' once annotation positioning is fixed
 		});
 		this._onViewUpdate();

src/dom/epub/section-renderer.ts

@@ -1,5 +1,5 @@
 import Section from "epubjs/types/section";
-import { getPotentiallyVisibleTextNodes } from "../common/lib/nodes";
+import { getPotentiallyVisibleTextNodes, iterateWalker } from "../common/lib/nodes";
 import {
 	sanitizeAndRender,
 	StyleScoper
@@ -118,9 +118,8 @@ class SectionRenderer {
 				? NodeFilter.FILTER_ACCEPT
 				: NodeFilter.FILTER_SKIP;
 		});
-		let node = null;
 		let bestRange = null;
-		while ((node = iter.nextNode())) {
+		for (let node of iterateWalker(iter)) {
 			let range = this._document.createRange();
 			if (node.nodeType == Node.ELEMENT_NODE) {
 				range.selectNode(node);

src/dom/snapshot/snapshot-view.ts

@@ -23,7 +23,8 @@ import DOMView, {
 } from "../common/dom-view";
 import { getUniqueSelectorContaining } from "../common/lib/unique-selector";
 import {
-	getVisibleTextNodes
+	getVisibleTextNodes,
+	iterateWalker
 } from "../common/lib/nodes";
 import DefaultFindProcessor, { createSearchContext } from "../common/find";
 
@@ -211,8 +212,7 @@ class SnapshotView extends DOMView<SnapshotViewState, SnapshotViewData> {
 	private _getSortIndex(range: Range) {
 		let iter = this._iframeDocument.createNodeIterator(this._iframeDocument.documentElement, NodeFilter.SHOW_TEXT);
 		let count = 0;
-		let node: Node | null;
-		while ((node = iter.nextNode())) {
+		for (let node of iterateWalker(iter)) {
 			if (range.startContainer.contains(node)) {
 				return String(count + range.startOffset).padStart(8, '0');
 			}