From d0bf505312c7fd00024d2f55e094c519a0bb86b0 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 26 May 2023 10:31:54 +0200
Subject: [PATCH] Re-factor the `isPageVisible`-handling in the find-controller
 (PR 10217 follow-up)

The way that this was implemented in PR 10217 has always bothered me slightly, since the `isPageVisible`-method that I introduced there always felt quite out-of-place in the `IPDFLinkService`-implementations.
Hence this is instead replaced by a callback-function in `PDFFindController`, to handle the page-visibility checks. Note that since the `PDFViewer`-constructor always sets this callback-function, e.g. the viewer-component examples still work as-is.
---
 web/interfaces.js          |  5 -----
 web/pdf_find_controller.js | 15 +++++++++------
 web/pdf_link_service.js    | 14 --------------
 web/pdf_viewer.js          | 25 +++++--------------------
 4 files changed, 14 insertions(+), 45 deletions(-)

diff --git a/web/interfaces.js b/web/interfaces.js
index 396ea465e..24ad4b647 100644
--- a/web/interfaces.js
+++ b/web/interfaces.js
@@ -113,11 +113,6 @@ class IPDFLinkService {
    */
   cachePageRef(pageNum, pageRef) {}
 
-  /**
-   * @param {number} pageNumber
-   */
-  isPageVisible(pageNumber) {}
-
   /**
    * @param {number} pageNumber
    */
diff --git a/web/pdf_find_controller.js b/web/pdf_find_controller.js
index d070e9c91..201e71612 100644
--- a/web/pdf_find_controller.js
+++ b/web/pdf_find_controller.js
@@ -396,6 +396,12 @@ class PDFFindController {
     this._eventBus = eventBus;
     this.#updateMatchesCountOnProgress = updateMatchesCountOnProgress;
 
+    /**
+     * Callback used to check if a `pageNumber` is currently visible.
+     * @type {function}
+     */
+    this.onIsPageVisible = null;
+
     this.#reset();
     eventBus._on("find", this.#onFind.bind(this));
     eventBus._on("findbarclose", this.#onFindBarClose.bind(this));
@@ -636,15 +642,12 @@ class PDFFindController {
         // there's a risk that consecutive 'findagain' operations could "skip"
         // over matches at the top/bottom of pages thus making them completely
         // inaccessible when there's multiple pages visible in the viewer.
-        if (
+        return (
           pageNumber >= 1 &&
           pageNumber <= linkService.pagesCount &&
           pageNumber !== linkService.page &&
-          !linkService.isPageVisible(pageNumber)
-        ) {
-          return true;
-        }
-        return false;
+          !(this.onIsPageVisible?.(pageNumber) ?? true)
+        );
       case "highlightallchange":
         return false;
     }
diff --git a/web/pdf_link_service.js b/web/pdf_link_service.js
index 5c688454b..8c2740a12 100644
--- a/web/pdf_link_service.js
+++ b/web/pdf_link_service.js
@@ -569,13 +569,6 @@ class PDFLinkService {
     return this.#pagesRefCache.get(refStr) || null;
   }
 
-  /**
-   * @param {number} pageNumber
-   */
-  isPageVisible(pageNumber) {
-    return this.pdfViewer.isPageVisible(pageNumber);
-  }
-
   /**
    * @param {number} pageNumber
    */
@@ -745,13 +738,6 @@ class SimpleLinkService {
    */
   cachePageRef(pageNum, pageRef) {}
 
-  /**
-   * @param {number} pageNumber
-   */
-  isPageVisible(pageNumber) {
-    return true;
-  }
-
   /**
    * @param {number} pageNumber
    */
diff --git a/web/pdf_viewer.js b/web/pdf_viewer.js
index 143f6bd6d..499d5b5da 100644
--- a/web/pdf_viewer.js
+++ b/web/pdf_viewer.js
@@ -259,6 +259,11 @@ class PDFViewer {
     this.linkService = options.linkService || new SimpleLinkService();
     this.downloadManager = options.downloadManager || null;
     this.findController = options.findController || null;
+
+    if (this.findController) {
+      this.findController.onIsPageVisible = pageNumber =>
+        this._getVisiblePages().ids.has(pageNumber);
+    }
     this._scriptingManager = options.scriptingManager || null;
     this.#textLayerMode = options.textLayerMode ?? TextLayerMode.ENABLE;
     this.#annotationMode =
@@ -1640,26 +1645,6 @@ class PDFViewer {
     });
   }
 
-  /**
-   * @param {number} pageNumber
-   */
-  isPageVisible(pageNumber) {
-    if (!this.pdfDocument) {
-      return false;
-    }
-    if (
-      !(
-        Number.isInteger(pageNumber) &&
-        pageNumber > 0 &&
-        pageNumber <= this.pagesCount
-      )
-    ) {
-      console.error(`isPageVisible: "${pageNumber}" is not a valid page.`);
-      return false;
-    }
-    return this._getVisiblePages().ids.has(pageNumber);
-  }
-
   /**
    * @param {number} pageNumber
    */