Optimize scrolling to an EPUB locator with a CSS selector (readium#520)

Author: mickael-menu

CHANGELOG.md

@@ -12,6 +12,12 @@ All notable changes to this project will be documented in this file. Take a look
 
 * EPUB: The `scroll` preference is now forced to `true` when rendering vertical text (e.g. CJK vertical). [See this discussion for the rationale](https://github.com/readium/swift-toolkit/discussions/370).
 
+### Fixed
+
+#### Navigator
+
+* Optimized scrolling to an EPUB text-based locator if it contains a CSS selector.
+
 
 ## [3.0.0-beta.1]
 

readium/navigator/src/main/assets/_scripts/src/index.js

@@ -16,7 +16,7 @@ import {
   scrollToId,
   scrollToPosition,
   scrollToStart,
-  scrollToText,
+  scrollToLocator,
   setProperty,
   setCSSProperties,
 } from "./utils";
@@ -29,7 +29,7 @@ window.readium = {
   // utils
   scrollToId: scrollToId,
   scrollToPosition: scrollToPosition,
-  scrollToText: scrollToText,
+  scrollToLocator: scrollToLocator,
   scrollLeft: scrollLeft,
   scrollRight: scrollRight,
   scrollToStart: scrollToStart,

readium/navigator/src/main/assets/_scripts/src/utils.js

@@ -129,15 +129,14 @@ export function scrollToPosition(position) {
 
 // Scrolls to the first occurrence of the given text snippet.
 //
-// The expected text argument is a Locator Text object, as defined here:
+// The expected text argument is a Locator object, as defined here:
 // https://readium.org/architecture/models/locators/
-export function scrollToText(text) {
-  let range = rangeFromLocator({ text });
+export function scrollToLocator(locator) {
+  let range = rangeFromLocator(locator);
   if (!range) {
     return false;
   }
-  scrollToRange(range);
-  return true;
+  return scrollToRange(range);
 }
 
 function scrollToRange(range) {

readium/navigator/src/main/assets/readium/scripts/readium-fixed.js

@@ -509,9 +509,9 @@ internal open class R2BasicWebView(context: Context, attrs: AttributeSet) : WebV
         runJavaScript("readium.scrollToPosition(\"$progression\");")
     }
 
-    suspend fun scrollToText(text: Locator.Text): Boolean {
-        val json = text.toJSON().toString()
-        return runJavaScriptSuspend("readium.scrollToText($json);").toBoolean()
+    suspend fun scrollToLocator(locator: Locator): Boolean {
+        val json = locator.toJSON().toString()
+        return runJavaScriptSuspend("readium.scrollToLocator($json);").toBoolean()
     }
 
     fun setScrollMode(scrollMode: Boolean) {

readium/navigator/src/main/assets/readium/scripts/readium-reflowable.js

@@ -435,9 +435,8 @@ internal class R2EpubPageFragment : Fragment() {
         readingProgression: ReadingProgression,
         locator: Locator
     ) {
-        val text = locator.text
-        if (text.highlight != null) {
-            if (webView.scrollToText(text)) {
+        if (locator.text.highlight != null) {
+            if (webView.scrollToLocator(locator)) {
                 return
             }
         }