[Editor] Refactor dragging and dropping an editor (bugs 1802895, 1844618)

It'll help to have a full control on what's happening when moving an editor.

src/display/editor/annotation_editor_layer.js

@@ -24,7 +24,6 @@
 
 import { AnnotationEditorType, FeatureTest } from "../../shared/util.js";
 import { AnnotationEditor } from "./editor.js";
-import { bindEvents } from "./tools.js";
 import { FreeTextEditor } from "./freetext.js";
 import { InkEditor } from "./ink.js";
 import { setLayerDimensions } from "../display_utils.js";
@@ -345,7 +344,7 @@ class AnnotationEditorLayer {
    * being dragged and droped from a page to another.
    * @param {AnnotationEditor} editor
    */
-  #changeParent(editor) {
+  changeParent(editor) {
     if (editor.parent === this) {
       return;
     }
@@ -370,7 +369,7 @@ class AnnotationEditorLayer {
    * @param {AnnotationEditor} editor
    */
   add(editor) {
-    this.#changeParent(editor);
+    this.changeParent(editor);
     this.#uiManager.addEditor(editor);
     this.attach(editor);
 
@@ -579,36 +578,19 @@ class AnnotationEditorLayer {
   }
 
   /**
-   * Drag callback.
+   *
-   * @param {DragEvent} event
+   * @param {AnnotationEditor} editor
+   * @param {number} x
+   * @param {number} y
+   * @returns
    */
-  drop(event) {
+  findNewParent(editor, x, y) {
-    const id = event.dataTransfer.getData("text/plain");
+    const layer = this.#uiManager.findParent(x, y);
-    const editor = this.#uiManager.getEditor(id);
+    if (layer === null || layer === this) {
-    if (!editor) {
+      return false;
-      return;
     }
-
+    layer.changeParent(editor);
-    event.preventDefault();
+    return true;
-    event.dataTransfer.dropEffect = "move";
-
-    this.#changeParent(editor);
-
-    const rect = this.div.getBoundingClientRect();
-    const endX = event.clientX - rect.x;
-    const endY = event.clientY - rect.y;
-
-    editor.translate(endX - editor.startX, endY - editor.startY);
-    this.moveEditorInDOM(editor);
-    editor.div.focus();
-  }
-
-  /**
-   * Dragover callback.
-   * @param {DragEvent} event
-   */
-  dragover(event) {
-    event.preventDefault();
   }
 
   /**
@@ -650,7 +632,6 @@ class AnnotationEditorLayer {
   render({ viewport }) {
     this.viewport = viewport;
     setLayerDimensions(this.div, viewport);
-    bindEvents(this, this.div, ["dragover", "drop"]);
     for (const editor of this.#uiManager.getEditors(this.pageIndex)) {
       this.add(editor);
     }

src/display/editor/editor.js

@@ -57,6 +57,8 @@ class AnnotationEditor {
 
   _uiManager = null;
 
+  #isDraggable = false;
+
   #zIndex = AnnotationEditor._zIndex++;
 
   static _colorManager = new ColorManager();
@@ -148,6 +150,15 @@ class AnnotationEditor {
     return [];
   }
 
+  get _isDraggable() {
+    return this.#isDraggable;
+  }
+
+  set _isDraggable(value) {
+    this.#isDraggable = value;
+    this.div?.classList.toggle("draggable", value);
+  }
+
   /**
    * Add some commands into the CommandManager (undo/redo stuff).
    * @param {Object} params
@@ -237,18 +248,6 @@ class AnnotationEditor {
     this._uiManager.addToAnnotationStorage(this);
   }
 
-  /**
-   * We use drag-and-drop in order to move an editor on a page.
-   * @param {DragEvent} event
-   */
-  dragstart(event) {
-    const rect = this.parent.div.getBoundingClientRect();
-    this.startX = event.clientX - rect.x;
-    this.startY = event.clientY - rect.y;
-    event.dataTransfer.setData("text/plain", this.id);
-    event.dataTransfer.effectAllowed = "move";
-  }
-
   /**
    * Set the editor position within its parent.
    * @param {number} x
@@ -446,8 +445,8 @@ class AnnotationEditor {
     event.preventDefault();
     this.#resizePosition = [event.clientX, event.clientY];
     const boundResizerPointermove = this.#resizerPointermove.bind(this, name);
-    const savedDraggable = this.div.draggable;
+    const savedDraggable = this._isDraggable;
-    this.div.draggable = false;
+    this._isDraggable = false;
     const resizingClassName = `resizing${name
       .charAt(0)
       .toUpperCase()}${name.slice(1)}`;
@@ -462,7 +461,7 @@ class AnnotationEditor {
       // Stop the undo accumulation in order to have an undo action for each
       // resize session.
       this._uiManager.stopUndoAccumulation();
-      this.div.draggable = savedDraggable;
+      this._isDraggable = savedDraggable;
       this.parent.div.classList.remove(resizingClassName);
       window.removeEventListener(
         "pointermove",
@@ -718,7 +717,7 @@ class AnnotationEditor {
     const [tx, ty] = this.getInitialTranslation();
     this.translate(tx, ty);
 
-    bindEvents(this, this.div, ["dragstart", "pointerdown"]);
+    bindEvents(this, this.div, ["pointerdown"]);
 
     return this.div;
   }
@@ -746,6 +745,90 @@ class AnnotationEditor {
     }
 
     this.#hasBeenSelected = true;
+
+    this.#setUpDragSession(event);
+  }
+
+  #setUpDragSession(event) {
+    if (!this._isDraggable) {
+      return;
+    }
+
+    // Avoid to have spurious text selection in the text layer when dragging.
+    this._uiManager.disableUserSelect(true);
+
+    const savedParent = this.parent;
+    const savedX = this.x;
+    const savedY = this.y;
+
+    const pointerMoveOptions = { passive: true, capture: true };
+    const pointerMoveCallback = e => {
+      const [parentWidth, parentHeight] = this.parentDimensions;
+      const [tx, ty] = this.screenToPageTranslation(e.movementX, e.movementY);
+      this.x += tx / parentWidth;
+      this.y += ty / parentHeight;
+      if (this.x < 0 || this.x > 1 || this.y < 0 || this.y > 1) {
+        // The element will be outside of its parent so change the parent.
+        const { x, y } = this.div.getBoundingClientRect();
+        if (this.parent.findNewParent(this, x, y)) {
+          this.x -= Math.floor(this.x);
+          this.y -= Math.floor(this.y);
+        }
+      }
+
+      this.div.style.left = `${(100 * this.x).toFixed(2)}%`;
+      this.div.style.top = `${(100 * this.y).toFixed(2)}%`;
+      this.div.scrollIntoView({ block: "nearest" });
+    };
+    window.addEventListener(
+      "pointermove",
+      pointerMoveCallback,
+      pointerMoveOptions
+    );
+
+    const pointerUpCallback = () => {
+      this._uiManager.disableUserSelect(false);
+      window.removeEventListener("pointerup", pointerUpCallback);
+      window.removeEventListener("blur", pointerUpCallback);
+      window.removeEventListener(
+        "pointermove",
+        pointerMoveCallback,
+        pointerMoveOptions
+      );
+      const newParent = this.parent;
+      const newX = this.x;
+      const newY = this.y;
+      if (newParent === savedParent && newX === savedX && newY === savedY) {
+        return;
+      }
+
+      this.addCommands({
+        cmd: () => {
+          newParent.changeParent(this);
+          this.x = newX;
+          this.y = newY;
+          this.fixAndSetPosition();
+          newParent.moveEditorInDOM(this);
+        },
+        undo: () => {
+          savedParent.changeParent(this);
+          this.x = savedX;
+          this.y = savedY;
+          this.fixAndSetPosition();
+          savedParent.moveEditorInDOM(this);
+        },
+        mustExec: false,
+      });
+
+      this.fixAndSetPosition();
+      this.parent.moveEditorInDOM(this);
+      this.div.focus();
+    };
+    window.addEventListener("pointerup", pointerUpCallback);
+    // If the user is using alt+tab during the dragging session, the pointerup
+    // event could be not fired, but a blur event is fired so we can use it in
+    // order to interrupt the dragging session.
+    window.addEventListener("blur", pointerUpCallback);
   }
 
   /**

src/display/editor/freetext.js

@@ -304,7 +304,7 @@ class FreeTextEditor extends AnnotationEditor {
     super.enableEditMode();
     this.overlayDiv.classList.remove("enabled");
     this.editorDiv.contentEditable = true;
-    this.div.draggable = false;
+    this._isDraggable = false;
     this.div.removeAttribute("aria-activedescendant");
     this.editorDiv.addEventListener("keydown", this.#boundEditorDivKeydown);
     this.editorDiv.addEventListener("focus", this.#boundEditorDivFocus);
@@ -323,7 +323,7 @@ class FreeTextEditor extends AnnotationEditor {
     this.overlayDiv.classList.add("enabled");
     this.editorDiv.contentEditable = false;
     this.div.setAttribute("aria-activedescendant", this.#editorDivId);
-    this.div.draggable = true;
+    this._isDraggable = true;
     this.editorDiv.removeEventListener("keydown", this.#boundEditorDivKeydown);
     this.editorDiv.removeEventListener("focus", this.#boundEditorDivFocus);
     this.editorDiv.removeEventListener("blur", this.#boundEditorDivBlur);
@@ -614,10 +614,10 @@ class FreeTextEditor extends AnnotationEditor {
       }
 
       this.#setContent();
-      this.div.draggable = true;
+      this._isDraggable = true;
       this.editorDiv.contentEditable = false;
     } else {
-      this.div.draggable = false;
+      this._isDraggable = false;
       this.editorDiv.contentEditable = true;
     }
 

src/display/editor/ink.js

@@ -294,7 +294,7 @@ class InkEditor extends AnnotationEditor {
     }
 
     super.enableEditMode();
-    this.div.draggable = false;
+    this._isDraggable = false;
     this.canvas.addEventListener("pointerdown", this.#boundCanvasPointerdown);
   }
 
@@ -305,7 +305,7 @@ class InkEditor extends AnnotationEditor {
     }
 
     super.disableEditMode();
-    this.div.draggable = !this.isEmpty();
+    this._isDraggable = !this.isEmpty();
     this.div.classList.remove("editing");
 
     this.canvas.removeEventListener(
@@ -316,7 +316,7 @@ class InkEditor extends AnnotationEditor {
 
   /** @inheritdoc */
   onceAdded() {
-    this.div.draggable = !this.isEmpty();
+    this._isDraggable = !this.isEmpty();
   }
 
   /** @inheritdoc */

src/display/editor/stamp.js

@@ -177,7 +177,7 @@ class StampEditor extends AnnotationEditor {
 
   /** @inheritdoc */
   onceAdded() {
-    this.div.draggable = true;
+    this._isDraggable = true;
     this.parent.addUndoableEditor(this);
     this.div.focus();
   }

src/display/editor/tools.js

@@ -587,6 +587,8 @@ class AnnotationEditorUIManager {
 
   #container = null;
 
+  #viewer = null;
+
   static TRANSLATE_SMALL = 1; // page units.
 
   static TRANSLATE_BIG = 10; // page units.
@@ -687,8 +689,9 @@ class AnnotationEditorUIManager {
     );
   }
 
-  constructor(container, eventBus, pdfDocument, pageColors) {
+  constructor(container, viewer, eventBus, pdfDocument, pageColors) {
     this.#container = container;
+    this.#viewer = viewer;
     this.#eventBus = eventBus;
     this.#eventBus._on("editingaction", this.#boundOnEditingAction);
     this.#eventBus._on("pagechanging", this.#boundOnPageChanging);
@@ -741,6 +744,30 @@ class AnnotationEditorUIManager {
     this.#container.focus();
   }
 
+  findParent(x, y) {
+    for (const layer of this.#allLayers.values()) {
+      const {
+        x: layerX,
+        y: layerY,
+        width,
+        height,
+      } = layer.div.getBoundingClientRect();
+      if (
+        x >= layerX &&
+        x <= layerX + width &&
+        y >= layerY &&
+        y <= layerY + height
+      ) {
+        return layer;
+      }
+    }
+    return null;
+  }
+
+  disableUserSelect(value = false) {
+    this.#viewer.classList.toggle("noUserSelect", value);
+  }
+
   addShouldRescale(editor) {
     this.#editorsToRescale.add(editor);
   }
@@ -962,6 +989,7 @@ class AnnotationEditorUIManager {
       this.#dispatchUpdateStates({
         isEditing: false,
       });
+      this.disableUserSelect(false);
     }
   }
 

test/integration/freetext_editor_spec.js

@@ -15,6 +15,7 @@
 
 const {
   closePages,
+  dragAndDropAnnotation,
   getEditors,
   getEditorSelector,
   getSelectedEditors,
@@ -891,13 +892,6 @@ describe("FreeText Editor", () => {
     it("must move an annotation", async () => {
       await Promise.all(
         pages.map(async ([browserName, page]) => {
-          if (browserName === "firefox") {
-            pending(
-              "Disabled in Firefox, because DnD isn't implemented yet (see bug 1838638)."
-            );
-          }
-
-          await page.setDragInterception(true);
           await page.click("#editorFreeText");
 
           const editorIds = await getEditors(page, "freeText");
@@ -913,16 +907,12 @@ describe("FreeText Editor", () => {
             return { x, y, width, height };
           });
 
-          await page.mouse.dragAndDrop(
+          await dragAndDropAnnotation(
-            {
+            page,
-              x: editorRect.x + editorRect.width / 2,
+            editorRect.x + editorRect.width / 2,
-              y: editorRect.y + editorRect.height / 2,
+            editorRect.y + editorRect.height / 2,
-            },
+            100,
-            {
+            100
-              x: editorRect.x + editorRect.width / 2 + 100,
-              y: editorRect.y + editorRect.height / 2 + 100,
-            },
-            { delay: 100 }
           );
 
           serialized = await getSerialized(page);

test/integration/test_utils.js

@@ -194,3 +194,11 @@ function serializeBitmapDimensions(page) {
   });
 }
 exports.serializeBitmapDimensions = serializeBitmapDimensions;
+
+async function dragAndDropAnnotation(page, startX, startY, tX, tY) {
+  await page.mouse.move(startX, startY);
+  await page.mouse.down();
+  await page.mouse.move(startX + tX, startY + tY);
+  await page.mouse.up();
+}
+exports.dragAndDropAnnotation = dragAndDropAnnotation;

web/annotation_editor_layer_builder.css

@@ -81,7 +81,7 @@
 }
 
 .annotationEditorLayer
-  :is(.freeTextEditor, .inkEditor, .stampEditor)[draggable="true"] {
+  :is(.freeTextEditor, .inkEditor, .stampEditor).draggable {
   cursor: move;
 }
 

web/pdf_viewer.css

@@ -87,6 +87,10 @@
   height: var(--viewer-container-height);
 }
 
+.pdfViewer.noUserSelect {
+  user-select: none;
+}
+
 /*#if GENERIC*/
 .pdfViewer.removePageBorders .page {
   margin: 0 auto 10px;

web/pdf_viewer.js

@@ -849,6 +849,7 @@ class PDFViewer {
           } else if (isValidAnnotationEditorMode(mode)) {
             this.#annotationEditorUIManager = new AnnotationEditorUIManager(
               this.container,
+              this.viewer,
               this.eventBus,
               pdfDocument,
               this.pageColors