[Editor] Allow to undo/redo committed text modifications for FreeText

src/display/editor/freetext.js

@@ -355,8 +355,26 @@ class FreeTextEditor extends AnnotationEditor {
     }
 
     this.disableEditMode();
-    this.#content = this.#extractText().trimEnd();
+    const savedText = this.#content;
+    const newText = (this.#content = this.#extractText().trimEnd());
+    if (savedText === newText) {
+      return;
+    }
 
+    const setText = text => {
+      this.#content = text;
+      this.#setContent();
+      this.#setEditorDimensions();
+    };
+    this.addCommands({
+      cmd: () => {
+        setText(newText);
+      },
+      undo: () => {
+        setText(savedText);
+      },
+      mustExec: false,
+    });
     this.#setEditorDimensions();
   }
 
@@ -466,14 +484,7 @@ class FreeTextEditor extends AnnotationEditor {
         this.height * parentHeight
       );
 
-      for (const line of this.#content.split("\n")) {
-        const div = document.createElement("div");
-        div.append(
-          line ? document.createTextNode(line) : document.createElement("br")
-        );
-        this.editorDiv.append(div);
-      }
-
+      this.#setContent();
       this.div.draggable = true;
       this.editorDiv.contentEditable = false;
     } else {
@@ -484,6 +495,20 @@ class FreeTextEditor extends AnnotationEditor {
     return this.div;
   }
 
+  #setContent() {
+    this.editorDiv.replaceChildren();
+    if (!this.#content) {
+      return;
+    }
+    for (const line of this.#content.split("\n")) {
+      const div = document.createElement("div");
+      div.append(
+        line ? document.createTextNode(line) : document.createElement("br")
+      );
+      this.editorDiv.append(div);
+    }
+  }
+
   get contentDiv() {
     return this.editorDiv;
   }

test/integration/freetext_editor_spec.js

@@ -343,6 +343,83 @@ describe("Editor", () => {
         })
       );
     });
+
+    it("must check that text change can be undone/redone", async () => {
+      // Run sequentially to avoid clipboard issues.
+      for (const [browserName, page] of pages) {
+        const rect = await page.$eval(".annotationEditorLayer", el => {
+          const { x, y } = el.getBoundingClientRect();
+          return { x, y };
+        });
+
+        await page.keyboard.down("Control");
+        await page.keyboard.press("a");
+        await page.keyboard.up("Control");
+
+        await page.keyboard.down("Control");
+        await page.keyboard.press("Backspace");
+        await page.keyboard.up("Control");
+
+        await page.mouse.click(rect.x + 200, rect.y + 100);
+
+        for (let i = 0; i < 5; i++) {
+          await page.type(`${getEditorSelector(9)} .internal`, "A");
+
+          const editorRect = await page.$eval(getEditorSelector(9), el => {
+            const { x, y, width, height } = el.getBoundingClientRect();
+            return { x, y, width, height };
+          });
+
+          // Commit.
+          await page.mouse.click(
+            editorRect.x,
+            editorRect.y + 2 * editorRect.height
+          );
+
+          if (i < 4) {
+            // And select it again.
+            await page.mouse.click(
+              editorRect.x + editorRect.width / 2,
+              editorRect.y + editorRect.height / 2,
+              { clickCount: 2 }
+            );
+          }
+        }
+
+        await page.keyboard.down("Control");
+        await page.keyboard.press("z");
+        await page.keyboard.up("Control");
+        await page.waitForTimeout(10);
+
+        let text = await page.$eval(`${getEditorSelector(9)} .internal`, el => {
+          return el.innerText;
+        });
+
+        expect(text).withContext(`In ${browserName}`).toEqual("AAAA");
+
+        await page.keyboard.down("Control");
+        await page.keyboard.press("z");
+        await page.keyboard.up("Control");
+        await page.waitForTimeout(10);
+
+        text = await page.$eval(`${getEditorSelector(9)} .internal`, el => {
+          return el.innerText;
+        });
+
+        expect(text).withContext(`In ${browserName}`).toEqual("AAA");
+
+        await page.keyboard.down("Control");
+        await page.keyboard.press("y");
+        await page.keyboard.up("Control");
+        await page.waitForTimeout(10);
+
+        text = await page.$eval(`${getEditorSelector(9)} .internal`, el => {
+          return el.innerText;
+        });
+
+        expect(text).withContext(`In ${browserName}`).toEqual("AAAA");
+      }
+    });
   });
 
   describe("FreeText (multiselection)", () => {