bug #2154 [Dropzone] Enable file replacement via "drag-and-drop" (rrr63)

This PR was squashed before being merged into the 2.x branch.

Discussion
----------

[Dropzone] Enable file replacement via "drag-and-drop"

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| Issues        | Fix #1480
| License       | MIT

Adding `dragenter` event to allow file replacement

Commits
-------

a78fdf4 [Dropzone] Enable file replacement via "drag-and-drop"

Author: smnandre

src/Dropzone/CHANGELOG.md

@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## 2.20
+
+-   Enable file replacement via "drag-and-drop"
+
 ## 2.13.2
 
 -   Revert "Change JavaScript package to `type: module`"

src/Dropzone/assets/dist/controller.d.ts

@@ -13,5 +13,7 @@ export default class extends Controller {
     clear(): void;
     onInputChange(event: any): void;
     _populateImagePreview(file: Blob): void;
+    onDragEnter(): void;
+    onDragLeave(event: any): void;
     private dispatchEvent;
 }

src/Dropzone/assets/dist/controller.js

@@ -4,16 +4,22 @@ class default_1 extends Controller {
     initialize() {
         this.clear = this.clear.bind(this);
         this.onInputChange = this.onInputChange.bind(this);
+        this.onDragEnter = this.onDragEnter.bind(this);
+        this.onDragLeave = this.onDragLeave.bind(this);
     }
     connect() {
         this.clear();
         this.previewClearButtonTarget.addEventListener('click', this.clear);
         this.inputTarget.addEventListener('change', this.onInputChange);
+        this.element.addEventListener('dragenter', this.onDragEnter);
+        this.element.addEventListener('dragleave', this.onDragLeave);
         this.dispatchEvent('connect');
     }
     disconnect() {
         this.previewClearButtonTarget.removeEventListener('click', this.clear);
         this.inputTarget.removeEventListener('change', this.onInputChange);
+        this.element.removeEventListener('dragenter', this.onDragEnter);
+        this.element.removeEventListener('dragleave', this.onDragLeave);
     }
     clear() {
         this.inputTarget.value = '';
@@ -51,6 +57,19 @@ class default_1 extends Controller {
         });
         reader.readAsDataURL(file);
     }
+    onDragEnter() {
+        this.inputTarget.style.display = 'block';
+        this.placeholderTarget.style.display = 'block';
+        this.previewTarget.style.display = 'none';
+    }
+    onDragLeave(event) {
+        event.preventDefault();
+        if (!this.element.contains(event.relatedTarget)) {
+            this.inputTarget.style.display = 'none';
+            this.placeholderTarget.style.display = 'none';
+            this.previewTarget.style.display = 'block';
+        }
+    }
     dispatchEvent(name, payload = {}) {
         this.dispatch(name, { detail: payload, prefix: 'dropzone' });
     }

src/Dropzone/assets/src/controller.ts

@@ -22,6 +22,8 @@ export default class extends Controller {
     initialize() {
         this.clear = this.clear.bind(this);
         this.onInputChange = this.onInputChange.bind(this);
+        this.onDragEnter = this.onDragEnter.bind(this);
+        this.onDragLeave = this.onDragLeave.bind(this);
     }
 
     connect() {
@@ -34,12 +36,20 @@ export default class extends Controller {
         // Listen on input change and display preview
         this.inputTarget.addEventListener('change', this.onInputChange);
 
+        // Add dragenter event listener
+        this.element.addEventListener('dragenter', this.onDragEnter);
+
+        // Add dragleave event listener
+        this.element.addEventListener('dragleave', this.onDragLeave);
+
         this.dispatchEvent('connect');
     }
 
     disconnect() {
         this.previewClearButtonTarget.removeEventListener('click', this.clear);
         this.inputTarget.removeEventListener('change', this.onInputChange);
+        this.element.removeEventListener('dragenter', this.onDragEnter);
+        this.element.removeEventListener('dragleave', this.onDragLeave);
     }
 
     clear() {
@@ -93,6 +103,23 @@ export default class extends Controller {
         reader.readAsDataURL(file);
     }
 
+    onDragEnter() {
+        this.inputTarget.style.display = 'block';
+        this.placeholderTarget.style.display = 'block';
+        this.previewTarget.style.display = 'none';
+    }
+
+    onDragLeave(event: any) {
+        event.preventDefault();
+
+        // Check if we really leave the main drag area
+        if (!this.element.contains(event.relatedTarget as Node)) {
+            this.inputTarget.style.display = 'none';
+            this.placeholderTarget.style.display = 'none';
+            this.previewTarget.style.display = 'block';
+        }
+    }
+
     private dispatchEvent(name: string, payload: any = {}) {
         this.dispatch(name, { detail: payload, prefix: 'dropzone' });
     }

src/Dropzone/assets/test/controller.test.ts

@@ -130,4 +130,27 @@ describe('DropzoneController', () => {
         expect(dispatched).not.toBeNull();
         expect(dispatched.detail).toStrictEqual(file);
     });
+
+    it('on drag', async () => {
+        startStimulus();
+
+        // Simulate dragenter event
+        const dragEnterEvent = new Event('dragenter');
+        getByTestId(container, 'container').dispatchEvent(dragEnterEvent);
+
+        // Check that the input and placeholder are visible, and preview hidden
+        await waitFor(() => expect(getByTestId(container, 'input')).toHaveStyle({ display: 'block' }));
+        await waitFor(() => expect(getByTestId(container, 'placeholder')).toHaveStyle({ display: 'block' }));
+        await waitFor(() => expect(getByTestId(container, 'preview')).toHaveStyle({ display: 'none' }));
+
+        // Simulate dragleave event with relatedTarget set to outside the dropzone
+        const dragLeaveEvent = new Event('dragleave', { bubbles: true });
+        Object.defineProperty(dragLeaveEvent, 'relatedTarget', { value: document.body });
+        getByTestId(container, 'container').dispatchEvent(dragLeaveEvent);
+
+        // Check that the input and placeholder are hidden, and preview shown
+        await waitFor(() => expect(getByTestId(container, 'input')).toHaveStyle({ display: 'none' }));
+        await waitFor(() => expect(getByTestId(container, 'placeholder')).toHaveStyle({ display: 'none' }));
+        await waitFor(() => expect(getByTestId(container, 'preview')).toHaveStyle({ display: 'block' }));
+    });
 });