feat(chromium): basic drag and drop support

src/server/chromium/crDragDrop.ts

@@ -0,0 +1,301 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+import { CRPage } from './crPage';
+import * as types from '../types';
+import * as dragScriptSource from '../../generated/dragScriptSource';
+import { assert } from '../../utils/utils';
+
+export class DragManager {
+  private _page: CRPage;
+  private _setup = false;
+  private _dragState: {
+    data: DataTransferJSON,
+    x: number,
+    y: number
+  } | null = null;
+  constructor(page: CRPage) {
+    this._page = page;
+  }
+
+  async _setupIfNeeded() {
+    if (this._setup)
+      return false;
+    const page = this._page;
+    await page.exposeInternalBinding('dragStarted', (source, data: DataTransferJSON) => {
+      this._dragState = {
+        x: NaN,
+        y: NaN,
+        data
+      };
+    });
+    await page.evaluateOnNewDocument(dragScriptSource.source, 'utility');
+    await Promise.all(page._page.frames().map(frame => frame._evaluateExpression(dragScriptSource.source, false, {}, 'utility').catch(e => {})));
+  }
+
+  async cancel() {
+    if (!this._dragState)
+      return false;
+    await this._dispatchDragEvent('dragend');
+    this._dragState = null;
+    return true;
+  }
+
+  async move(x: number, y: number, button: types.MouseButton | 'none', buttons: Set<types.MouseButton>, modifiers: Set<types.KeyboardModifier>, moveCallback: () => Promise<void>): Promise<void> {
+    if (this._dragState) {
+      await this._moveDrag(x, y);
+      return;
+    }
+    if (button !== 'left')
+      return moveCallback();
+
+    await this._setupIfNeeded();
+    await moveCallback();
+    // thread the renderer to wait for the drag callback
+    await this._page._page.mainFrame()._evaluateExpression('', false, null);
+    if (this._dragState) {
+      this._dragState!.x = x;
+      this._dragState!.y = y;
+    }
+  }
+  async _moveDrag(x: number, y: number) {
+    assert(this._dragState, 'missing drag state');
+    if (x === this._dragState.x && y === this._dragState.y)
+      return;
+    this._dragState.x = x;
+    this._dragState.y = y;
+    await this._dispatchDragEvent('dragover');
+  }
+
+  isDragging() {
+    return !!this._dragState;
+  }
+
+  async down(x: number, y: number, button: types.MouseButton | 'none', buttons: Set<types.MouseButton>, modifiers: Set<types.KeyboardModifier>): Promise<boolean> {
+    return !!this._dragState;
+  }
+
+  async up(x: number, y: number, button: types.MouseButton, buttons: Set<types.MouseButton>, modifiers: Set<types.KeyboardModifier>) {
+    // await this._moveDrag(x, y);
+    assert(this._dragState, 'missing drag state');
+    this._dragState.x = x;
+    this._dragState.y = y;
+    await this._dispatchDragEvent('drop');
+    this._dragState = null;
+  }
+
+  async _dispatchDragEvent(type: 'dragover'|'drop'|'dragend') {
+    assert(this._dragState, 'missing drag state');
+    const {backendNodeId, frameId} = await this._page._mainFrameSession._client.send('DOM.getNodeForLocation', {
+      x: Math.round(this._dragState.x),
+      y: Math.round(this._dragState.y),
+      ignorePointerEventsNone: false,
+      includeUserAgentShadowDOM: false
+    });
+    const frame = this._page._page.frames().find(x => x._id === frameId)!;
+
+    const context = await frame._utilityContext();
+    const elementHandle = await this._page._mainFrameSession._adoptBackendNodeId(backendNodeId, context);
+    // console.log(elementHandle);
+    return await elementHandle.evaluate(dispatchDragEvent, {
+      json: type === 'dragend' ? null : this._dragState.data,
+      type,
+      x: this._dragState.x,
+      y: this._dragState.y,
+    });
+  }
+}
+
+
+async function dispatchDragEvent(element: Node, {type, x, y, json}: {type: 'dragover'|'drop'|'dragend', x: number, y: number, json: DataTransferJSON|null}) {
+  const node = element; // document.elementFromPoint(x, y);
+  if (!node)
+    throw new Error(`could not find node at (${x},${y})`);
+  const dataTransfer = jsonToDataTransfer(json);
+  const lastDragNode = (window as any).__lastDragNode as Node;
+  if (lastDragNode !== node) {
+    if (node) {
+      node.dispatchEvent(new DragEvent('dragenter', {
+        dataTransfer,
+        bubbles: true,
+        cancelable: false
+      }));
+    }
+    if (lastDragNode) {
+      lastDragNode.dispatchEvent(new DragEvent('dragleave', {
+        dataTransfer,
+        bubbles: true,
+        cancelable: false
+      }));
+    }
+    (window as any).__lastDragNode = node;
+  }
+  const dragOverEvent = new DragEvent('dragover', {
+    dataTransfer,
+    bubbles: true,
+    cancelable: true
+  });
+
+  node.dispatchEvent(dragOverEvent);
+  if (type === 'dragend') {
+    endDrag();
+    return;
+  }
+  if (type === 'dragover') return;
+
+  // TODO(einbinder) This should check if the effect is allowed
+  // by the DataTransfer, but currently the user can't set the effect.
+  if (dragOverEvent.defaultPrevented) {
+    const dropEvent = new DragEvent('drop', {
+      dataTransfer,
+      bubbles: true,
+      cancelable: true
+    });
+    node.dispatchEvent(dropEvent);
+    if (dropEvent.defaultPrevented) {
+      endDrag();
+      return;
+    }
+  }
+  doDefaultDrop();
+  endDrag();
+
+  function endDrag() {
+    if ((window as any).__draggingElement) {
+      const draggingElement: Element = (window as any).__draggingElement;
+      delete (window as any).__draggingElement;
+      draggingElement.dispatchEvent(new DragEvent('dragend', {
+        dataTransfer: new DataTransfer(),
+        bubbles: true,
+        cancelable: false
+      }));
+    }
+  }
+
+  function doDefaultDrop() {
+    const htmlItem = json!.items.find(x => x.type === 'text/html');
+    const textItem = json!.items.find(x => x.type.startsWith('text/'));
+    if (!htmlItem && !textItem)
+      return;
+    // const html = document.createElement('')
+    const editableTarget = editableAncestor(node);
+    if (!editableTarget)
+      return;
+    editableTarget.focus();
+    if (htmlItem)
+      document.execCommand('insertHTML', false, itemToString(htmlItem));
+    else if (textItem)
+      document.execCommand('insertText', false, itemToString(textItem));
+  }
+
+  function jsonToDataTransfer(json: DataTransferJSON|null): DataTransfer {
+    const transfer = new DataTransfer();
+    // Chromium doesn't allow setting these properties on a DataTransfer that wasn't
+    // specifically created for drag and drop. Redefining them lets us set them,
+    // but its mostly futile because this doesn't effect the main execution context.
+    Object.defineProperty(transfer, 'effectAllowed', {value: transfer.effectAllowed, writable: true});
+    Object.defineProperty(transfer, 'dropEffect', {value: transfer.dropEffect, writable: true});
+    if (json) {
+      for (const {data, type} of json.items) {
+        if (typeof data === 'string')
+          transfer.items.add(data, type);
+        else
+          transfer.items.add(jsonToFile(data));
+      }
+      transfer.effectAllowed = json.effectAllowed;
+      transfer.dropEffect = json.dropEffect;
+    }
+    return transfer;
+  }
+
+
+  function binaryDataURLToString(url: string) {
+    return atob(url.slice(url.indexOf(',') + 1));
+  }
+
+  function jsonToFile(json: FileJSON): File {
+    const data = atob(binaryDataURLToString(json.dataURL));
+    const file = new File([data], json.name, {
+      lastModified: json.lastModified,
+      type: json.type,
+    });
+    return file;
+  }
+
+  function itemToString({data}: ItemJSON) {
+    if (typeof data === 'string')
+      return data;
+    return binaryDataURLToString(data.dataURL);
+  }
+
+  function editableAncestor(node: Node|null): HTMLElement|null {
+    if (!node)
+      return null;
+    if (isEditable(node))
+      return node as HTMLElement;
+    return editableAncestor(node.parentElement);
+  }
+
+  function isEditable(node: Node) {
+    if (node.nodeType !== Node.ELEMENT_NODE)
+      return false;
+    const element = node as Element;
+    if (element.nodeName.toLowerCase() === 'input') {
+      const input = element as HTMLInputElement;
+      const type = (input.getAttribute('type') || '').toLowerCase();
+      const kDateTypes = new Set(['date', 'time', 'datetime', 'datetime-local']);
+      const kTextInputTypes = new Set(['', 'email', 'number', 'password', 'search', 'tel', 'text', 'url']);
+      if (!kTextInputTypes.has(type) && !kDateTypes.has(type))
+        return false;
+      if (input.disabled)
+        return false;
+      if (input.readOnly)
+        return false;
+      return true;
+    } else if (element.nodeName.toLowerCase() === 'textarea') {
+      const textarea = element as HTMLTextAreaElement;
+      if (textarea.disabled)
+        return false;
+      if (textarea.readOnly)
+        return false;
+    } else if (!(element as HTMLElement).isContentEditable) {
+      return false;
+    }
+    return true;
+  }
+
+}
+
+type DataTransferJSON = {
+  dropEffect: string;
+  effectAllowed: string;
+  items: ItemJSON[];
+};
+
+type FileJSON = {
+  lastModified: number;
+  name: string;
+  dataURL: string;
+  type: string;
+  // only exists for electron
+  path?: string;
+};
+
+type ItemJSON = {
+  data: string|FileJSON;
+  kind: string;
+  type: string;
+};
+

src/server/chromium/crInput.ts

@@ -20,6 +20,8 @@ import * as types from '../types';
 import { CRSession } from './crConnection';
 import { macEditingCommands } from '../macEditingCommands';
 import { isString } from '../../utils/utils';
+import { DragManager } from './crDragDrop';
+import { CRPage } from './crPage';
 
 function toModifiersMask(modifiers: Set<types.KeyboardModifier>): number {
   let mask = 0;
@@ -38,6 +40,7 @@ export class RawKeyboardImpl implements input.RawKeyboard {
   constructor(
     private _client: CRSession,
     private _isMac: boolean,
+    private _dragManger: DragManager,
   ) { }
 
   _commandsForCode(code: string, modifiers: Set<types.KeyboardModifier>) {
@@ -60,6 +63,8 @@ export class RawKeyboardImpl implements input.RawKeyboard {
   }
 
   async keydown(modifiers: Set<types.KeyboardModifier>, code: string, keyCode: number, keyCodeWithoutLocation: number, key: string, location: number, autoRepeat: boolean, text: string | undefined): Promise<void> {
+    if (code === 'Escape' && await this._dragManger.cancel())
+      return;
     const commands = this._commandsForCode(code, modifiers);
     await this._client.send('Input.dispatchKeyEvent', {
       type: text ? 'keyDown' : 'rawKeyDown',
@@ -94,22 +99,30 @@ export class RawKeyboardImpl implements input.RawKeyboard {
 
 export class RawMouseImpl implements input.RawMouse {
   private _client: CRSession;
+  private _page: CRPage;
+  private _dragManager: DragManager;
 
-  constructor(client: CRSession) {
+  constructor(page: CRPage, client: CRSession, dragManager: DragManager) {
+    this._page = page;
     this._client = client;
+    this._dragManager = dragManager;
   }
 
   async move(x: number, y: number, button: types.MouseButton | 'none', buttons: Set<types.MouseButton>, modifiers: Set<types.KeyboardModifier>): Promise<void> {
-    await this._client.send('Input.dispatchMouseEvent', {
-      type: 'mouseMoved',
-      button,
-      x,
-      y,
-      modifiers: toModifiersMask(modifiers)
+    await this._dragManager.move(x, y, button, buttons, modifiers, async () => {
+      await this._client.send('Input.dispatchMouseEvent', {
+        type: 'mouseMoved',
+        button,
+        x,
+        y,
+        modifiers: toModifiersMask(modifiers)
+      });
     });
   }
 
   async down(x: number, y: number, button: types.MouseButton, buttons: Set<types.MouseButton>, modifiers: Set<types.KeyboardModifier>, clickCount: number): Promise<void> {
+    if (this._dragManager.isDragging())
+      return;
     await this._client.send('Input.dispatchMouseEvent', {
       type: 'mousePressed',
       button,
@@ -121,6 +134,10 @@ export class RawMouseImpl implements input.RawMouse {
   }
 
   async up(x: number, y: number, button: types.MouseButton, buttons: Set<types.MouseButton>, modifiers: Set<types.KeyboardModifier>, clickCount: number): Promise<void> {
+    if (this._dragManager.isDragging()) {
+      await this._dragManager.up(x, y, button, buttons, modifiers);
+      return;
+    }
     await this._client.send('Input.dispatchMouseEvent', {
       type: 'mouseReleased',
       button,