Add a UI to undo cut/delete and cancel a copy (bug 2021352, bug 2010832)

l10n/en-US/viewer.ftl

@@ -764,6 +764,7 @@ pdfjs-views-manager-status-warning-copy-label = Couldn’t copy. Refresh page an
 pdfjs-views-manager-status-warning-delete-label = Couldn’t delete. Refresh page and try again.
 pdfjs-views-manager-status-warning-save-label = Couldn’t save. Refresh page and try again.
 pdfjs-views-manager-status-undo-button-label = Undo
+pdfjs-views-manager-status-done-button-label = Done
 pdfjs-views-manager-status-close-button =
     .title = Close
 pdfjs-views-manager-status-close-button-label = Close

src/display/api.js

@@ -2406,6 +2406,8 @@ class WorkerTransport {
 
   #copiedPageInfo = null;
 
+  #savedPageInfo = null;
+
   constructor(
     messageHandler,
     loadingTask,
@@ -2477,13 +2479,36 @@ class WorkerTransport {
       return;
     }
 
+    if (type === "cancelCopy") {
+      this.#copiedPageInfo = null;
+      return;
+    }
+
     if (type === "delete") {
+      this.#savedPageInfo = {
+        pageCache: new Map(this.#pageCache),
+        pagePromises: new Map(this.#pagePromises),
+      };
       for (const pageNum of pageNumbers) {
         this.#pageCache.delete(pageNum - 1);
         this.#pagePromises.delete(pageNum - 1);
       }
     }
 
+    if (type === "cancelDelete") {
+      if (this.#savedPageInfo) {
+        this.#pageCache = this.#savedPageInfo.pageCache;
+        this.#pagePromises = this.#savedPageInfo.pagePromises;
+        this.#savedPageInfo = null;
+      }
+      return;
+    }
+
+    if (type === "cleanSavedData") {
+      this.#savedPageInfo = null;
+      return;
+    }
+
     const newPageCache = new Map();
     const newPromiseCache = new Map();
     const { pagesMapper } = this;

src/display/display_utils.js

@@ -1082,6 +1082,8 @@ class PagesMapper {
    */
   #copiedPageNumbers = null;
 
+  #savedData = null;
+
   /**
    * Gets the total number of pages.
    * @returns {number} The number of pages.
@@ -1253,6 +1255,13 @@ class PagesMapper {
     const pageNumberToId = this.#pageNumberToId;
     const prevIdToPageNumber = this.#idToPageNumber;
 
+    this.#savedData = {
+      pageNumberToId: pageNumberToId.slice(),
+      idToPageNumber: new Map(prevIdToPageNumber),
+      pageNumber: this.#pagesNumber,
+      prevPageNumbers: this.#prevPageNumbers.slice(),
+    };
+
     this.pagesNumber -= pagesToDelete.length;
     this.#init(false);
     const newPageNumberToId = this.#pageNumberToId;
@@ -1279,6 +1288,22 @@ class PagesMapper {
     this.#updateListeners({ type: "delete", pageNumbers: pagesToDelete });
   }
 
+  cancelDelete() {
+    if (this.#savedData) {
+      this.#pageNumberToId = this.#savedData.pageNumberToId;
+      this.#idToPageNumber = this.#savedData.idToPageNumber;
+      this.pagesNumber = this.#savedData.pageNumber;
+      this.#prevPageNumbers = this.#savedData.prevPageNumbers;
+      this.#savedData = null;
+      this.#updateListeners({ type: "cancelDelete" });
+    }
+  }
+
+  cleanSavedData() {
+    this.#savedData = null;
+    this.#updateListeners({ type: "cleanSavedData" });
+  }
+
   /**
    * Copies a set of pages while keeping ID→number mappings in sync.
    * @param {Uint32Array} pagesToCopy - Page numbers to copy (1-indexed).
@@ -1292,6 +1317,12 @@ class PagesMapper {
     this.#updateListeners({ type: "copy", pageNumbers: pagesToCopy });
   }
 
+  cancelCopy() {
+    this.#copiedPageIds = null;
+    this.#copiedPageNumbers = null;
+    this.#updateListeners({ type: "cancelCopy" });
+  }
+
   /**
    * Pastes a set of pages while keeping ID→number mappings in sync.
    * @param {number} index - Zero-based insertion index in the page-number list.
@@ -1323,6 +1354,7 @@ class PagesMapper {
     this.#updateListeners({ type: "paste" });
 
     this.#copiedPageIds = null;
+    this.#copiedPageNumbers = null;
   }
 
   /**
@@ -1455,7 +1487,7 @@ class PagesMapper {
   }
 
   getMapping() {
-    return this.#pageNumberToId.subarray(0, this.pagesNumber);
+    return this.#pageNumberToId?.subarray(0, this.pagesNumber);
   }
 }