From b660b37a7b4b229d64c43a166cb0a8c024baab02 Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Fri, 5 Aug 2022 19:22:51 +0200
Subject: [PATCH] Chat List: Allow chat selection when dragging file (#1962)

---
 src/App.tsx                                   | 26 +++++++++++++++++++
 src/components/common/UiLoader.tsx            |  2 +-
 src/components/left/main/Chat.tsx             |  8 ++++++
 src/components/left/main/ChatList.tsx         | 23 +++++++++++++++-
 src/components/main/Main.tsx                  |  3 +--
 .../middle/composer/AttachmentModal.scss      |  3 ++-
 .../middle/composer/AttachmentModal.tsx       |  2 +-
 src/components/middle/composer/DropArea.tsx   |  8 +++++-
 src/components/middle/composer/DropTarget.tsx |  4 +--
 src/components/ui/InfiniteScroll.tsx          | 18 ++++++++-----
 src/components/ui/ListItem.tsx                |  3 +++
 11 files changed, 85 insertions(+), 15 deletions(-)

diff --git a/src/App.tsx b/src/App.tsx
index ac6918dcb..4b759a269 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -55,6 +55,32 @@ const App: FC<StateProps> = ({
     });
   }, [disconnect, markInactive]);
 
+  // Prevent drop on elements that do not accept it
+  useEffect(() => {
+    const body = document.body;
+    const handleDrag = (e: DragEvent) => {
+      e.preventDefault();
+      if (!e.dataTransfer) return;
+      if (!(e.target as HTMLElement).dataset.dropzone) {
+        e.dataTransfer.dropEffect = 'none';
+      } else {
+        e.dataTransfer.dropEffect = 'copy';
+      }
+    };
+    const handleDrop = (e: DragEvent) => {
+      e.preventDefault();
+    };
+    body.addEventListener('drop', handleDrop);
+    body.addEventListener('dragover', handleDrag);
+    body.addEventListener('dragenter', handleDrag);
+
+    return () => {
+      body.removeEventListener('drop', handleDrop);
+      body.removeEventListener('dragover', handleDrag);
+      body.removeEventListener('dragenter', handleDrag);
+    };
+  }, []);
+
   // return <Test />;
 
   let activeKey: number;
diff --git a/src/components/common/UiLoader.tsx b/src/components/common/UiLoader.tsx
index c010efa13..baa918768 100644
--- a/src/components/common/UiLoader.tsx
+++ b/src/components/common/UiLoader.tsx
@@ -1,10 +1,10 @@
-import type { FC } from '../../lib/teact/teact';
 import React, { useEffect } from '../../lib/teact/teact';
 import { getActions, getGlobal, withGlobal } from '../../global';
 
 import { ApiMediaFormat } from '../../api/types';
 import type { GlobalState } from '../../global/types';
 import type { ThemeKey } from '../../types';
+import type { FC } from '../../lib/teact/teact';
 
 import { getChatAvatarHash } from '../../global/helpers/chats'; // Direct import for better module splitting
 import { selectIsRightColumnShown, selectTheme, selectIsCurrentUserPremium } from '../../global/selectors';
diff --git a/src/components/left/main/Chat.tsx b/src/components/left/main/Chat.tsx
index e4742ce6b..bb79eb83b 100644
--- a/src/components/left/main/Chat.tsx
+++ b/src/components/left/main/Chat.tsx
@@ -68,6 +68,7 @@ type OwnProps = {
   animationType: ChatAnimationTypes;
   isPinned?: boolean;
   observeIntersection?: ObserveFn;
+  onDragEnter?: (chatId: string) => void;
 };
 
 type StateProps = {
@@ -113,6 +114,7 @@ const Chat: FC<OwnProps & StateProps> = ({
   canScrollDown,
   canChangeFolder,
   lastSyncTime,
+  onDragEnter,
 }) => {
   const {
     openChat,
@@ -200,6 +202,11 @@ const Chat: FC<OwnProps & StateProps> = ({
     focusLastMessage,
   ]);
 
+  const handleDragEnter = useCallback((e) => {
+    e.preventDefault();
+    onDragEnter?.(chatId);
+  }, [chatId, onDragEnter]);
+
   const handleDelete = useCallback(() => {
     markRenderDeleteModal();
     openDeleteModal();
@@ -299,6 +306,7 @@ const Chat: FC<OwnProps & StateProps> = ({
       ripple={!IS_SINGLE_COLUMN_LAYOUT}
       contextActions={contextActions}
       onClick={handleClick}
+      onDragEnter={handleDragEnter}
     >
       <div className="status">
         <Avatar
diff --git a/src/components/left/main/ChatList.tsx b/src/components/left/main/ChatList.tsx
index 0e2edc73f..6ade0a8cb 100644
--- a/src/components/left/main/ChatList.tsx
+++ b/src/components/left/main/ChatList.tsx
@@ -1,5 +1,5 @@
 import React, {
-  memo, useMemo, useEffect, useRef,
+  memo, useMemo, useEffect, useRef, useCallback,
 } from '../../../lib/teact/teact';
 import { getActions } from '../../../global';
 
@@ -23,6 +23,7 @@ import { useFolderManagerForOrderedIds } from '../../../hooks/useFolderManager';
 import { useChatAnimationType } from './hooks';
 import { useIntersectionObserver } from '../../../hooks/useIntersectionObserver';
 import { useHotkeys } from '../../../hooks/useHotkeys';
+import useDebouncedCallback from '../../../hooks/useDebouncedCallback';
 
 import InfiniteScroll from '../../ui/InfiniteScroll';
 import Loading from '../../ui/Loading';
@@ -39,6 +40,7 @@ type OwnProps = {
 };
 
 const INTERSECTION_THROTTLE = 200;
+const DRAG_ENTER_DEBOUNCE = 500;
 
 const ChatList: FC<OwnProps> = ({
   folderType,
@@ -50,6 +52,7 @@ const ChatList: FC<OwnProps> = ({
   const { openChat, openNextChat } = getActions();
   // eslint-disable-next-line no-null/no-null
   const containerRef = useRef<HTMLDivElement>(null);
+  const shouldIgnoreDragRef = useRef(false);
 
   const resolvedFolderId = (
     folderType === 'all' ? ALL_FOLDER_ID : folderType === 'archived' ? ARCHIVED_FOLDER_ID : folderId!
@@ -126,6 +129,22 @@ const ChatList: FC<OwnProps> = ({
     throttleMs: INTERSECTION_THROTTLE,
   });
 
+  const handleDragEnter = useDebouncedCallback((chatId: string) => {
+    if (shouldIgnoreDragRef.current) {
+      shouldIgnoreDragRef.current = false;
+      return;
+    }
+    openChat({ id: chatId, shouldReplaceHistory: true });
+  }, [], DRAG_ENTER_DEBOUNCE, true);
+
+  const handleDragLeave = useCallback((e: React.DragEvent<HTMLDivElement>) => {
+    const rect = e.currentTarget.getBoundingClientRect();
+    const x = e.clientX - rect.left;
+    const y = e.clientY - rect.top;
+    if (x < rect.width || y < rect.y) return;
+    shouldIgnoreDragRef.current = true;
+  }, []);
+
   function renderChats() {
     const viewportOffset = orderedIds!.indexOf(viewportIds![0]);
     const pinnedCount = getPinnedChatsCount(resolvedFolderId) || 0;
@@ -144,6 +163,7 @@ const ChatList: FC<OwnProps> = ({
           orderDiff={orderDiffById[id]}
           style={`top: ${(viewportOffset + i) * CHAT_HEIGHT_PX}px;`}
           observeIntersection={observe}
+          onDragEnter={handleDragEnter}
         />
       );
     });
@@ -158,6 +178,7 @@ const ChatList: FC<OwnProps> = ({
       withAbsolutePositioning
       maxHeight={(orderedIds?.length || 0) * CHAT_HEIGHT_PX}
       onLoadMore={getMore}
+      onDragLeave={handleDragLeave}
     >
       {viewportIds?.length ? (
         renderChats()
diff --git a/src/components/main/Main.tsx b/src/components/main/Main.tsx
index 3d1843110..ead646d8d 100644
--- a/src/components/main/Main.tsx
+++ b/src/components/main/Main.tsx
@@ -27,7 +27,6 @@ import { dispatchHeavyAnimationEvent } from '../../hooks/useHeavyAnimationCheck'
 import buildClassName from '../../util/buildClassName';
 import { waitForTransitionEnd } from '../../util/cssAnimationEndListeners';
 import { processDeepLink } from '../../util/deeplink';
-import stopEvent from '../../util/stopEvent';
 import windowSize from '../../util/windowSize';
 import { getAllNotificationsCount } from '../../util/folderManager';
 import useBackgroundMode from '../../hooks/useBackgroundMode';
@@ -385,7 +384,7 @@ const Main: FC<StateProps> = ({
   usePreventPinchZoomGesture(isMediaViewerOpen);
 
   return (
-    <div id="Main" className={className} onDrop={stopEvent} onDragOver={stopEvent}>
+    <div id="Main" className={className}>
       <LeftColumn />
       <MiddleColumn />
       <RightColumn />
diff --git a/src/components/middle/composer/AttachmentModal.scss b/src/components/middle/composer/AttachmentModal.scss
index 3ac0ed4b0..d8f3e4c3b 100644
--- a/src/components/middle/composer/AttachmentModal.scss
+++ b/src/components/middle/composer/AttachmentModal.scss
@@ -119,7 +119,8 @@
 
     .attachment-caption-wrapper,
     .document-wrapper,
-    .media-wrapper {
+    .media-wrapper,
+    .form-control {
       pointer-events: none;
     }
 
diff --git a/src/components/middle/composer/AttachmentModal.tsx b/src/components/middle/composer/AttachmentModal.tsx
index f40f0a472..31f91004b 100644
--- a/src/components/middle/composer/AttachmentModal.tsx
+++ b/src/components/middle/composer/AttachmentModal.tsx
@@ -177,7 +177,6 @@ const AttachmentModal: FC<OwnProps> = ({
 
   function handleDragOver(e: React.MouseEvent<HTMLDivElement, MouseEvent>) {
     e.preventDefault();
-    e.stopPropagation();
 
     if (hideTimeoutRef.current) {
       window.clearTimeout(hideTimeoutRef.current);
@@ -258,6 +257,7 @@ const AttachmentModal: FC<OwnProps> = ({
         onDragOver={handleDragOver}
         onDragLeave={handleDragLeave}
         data-attach-description={lang('Preview.Dragging.AddItems', 10)}
+        data-dropzone
       >
         {isQuick ? (
           <div className="media-wrapper custom-scroll">
diff --git a/src/components/middle/composer/DropArea.tsx b/src/components/middle/composer/DropArea.tsx
index 92dd5c0e3..2bec7117f 100644
--- a/src/components/middle/composer/DropArea.tsx
+++ b/src/components/middle/composer/DropArea.tsx
@@ -96,7 +96,13 @@ const DropArea: FC<OwnProps> = ({
 
   return (
     <Portal containerId="#middle-column-portals">
-      <div className={className} onDragLeave={handleDragLeave} onDragOver={handleDragOver} onDrop={onHide}>
+      <div
+        className={className}
+        onDragLeave={handleDragLeave}
+        onDragOver={handleDragOver}
+        onDrop={onHide}
+        onClick={onHide}
+      >
         <DropTarget onFileSelect={handleFilesDrop} />
         {(withQuick || prevWithQuick) && <DropTarget onFileSelect={handleQuickFilesDrop} isQuick />}
       </div>
diff --git a/src/components/middle/composer/DropTarget.tsx b/src/components/middle/composer/DropTarget.tsx
index 4ca8c2a9a..84277d086 100644
--- a/src/components/middle/composer/DropTarget.tsx
+++ b/src/components/middle/composer/DropTarget.tsx
@@ -14,7 +14,6 @@ export type OwnProps = {
 const DropTarget: FC<OwnProps> = ({ isQuick, onFileSelect }) => {
   const [isHovered, markHovered, unmarkHovered] = useFlag();
 
-  const handleDragEnter = () => { markHovered(); };
   const handleDragLeave = (e: React.DragEvent<HTMLDivElement>) => {
     const { relatedTarget: toTarget } = e;
 
@@ -34,8 +33,9 @@ const DropTarget: FC<OwnProps> = ({ isQuick, onFileSelect }) => {
     <div
       className={className}
       onDrop={onFileSelect}
-      onDragEnter={handleDragEnter}
+      onDragEnter={markHovered}
       onDragLeave={handleDragLeave}
+      data-dropzone
     >
       <div className="target-content">
         <div className={`icon icon-${isQuick ? 'photo' : 'document'}`} />
diff --git a/src/components/ui/InfiniteScroll.tsx b/src/components/ui/InfiniteScroll.tsx
index 37ec3ad27..996e86a1e 100644
--- a/src/components/ui/InfiniteScroll.tsx
+++ b/src/components/ui/InfiniteScroll.tsx
@@ -14,9 +14,6 @@ import buildStyle from '../../util/buildStyle';
 type OwnProps = {
   ref?: RefObject<HTMLDivElement>;
   className?: string;
-  onLoadMore?: ({ direction }: { direction: LoadMoreDirection; noScroll?: boolean }) => void;
-  onScroll?: (e: UIEvent<HTMLDivElement>) => void;
-  onKeyDown?: (e: React.KeyboardEvent<any>) => void;
   items?: any[];
   itemSelector?: string;
   preloadBackwards?: number;
@@ -28,6 +25,11 @@ type OwnProps = {
   noFastList?: boolean;
   cacheBuster?: any;
   children: React.ReactNode;
+  onLoadMore?: ({ direction }: { direction: LoadMoreDirection; noScroll?: boolean }) => void;
+  onScroll?: (e: UIEvent<HTMLDivElement>) => void;
+  onKeyDown?: (e: React.KeyboardEvent<any>) => void;
+  onDragOver?: (e: React.DragEvent<HTMLDivElement>) => void;
+  onDragLeave?: (e: React.DragEvent<HTMLDivElement>) => void;
 };
 
 const DEFAULT_LIST_SELECTOR = '.ListItem';
@@ -37,9 +39,6 @@ const DEFAULT_SENSITIVE_AREA = 800;
 const InfiniteScroll: FC<OwnProps> = ({
   ref,
   className,
-  onLoadMore,
-  onScroll,
-  onKeyDown,
   items,
   itemSelector = DEFAULT_LIST_SELECTOR,
   preloadBackwards = DEFAULT_PRELOAD_BACKWARDS,
@@ -53,6 +52,11 @@ const InfiniteScroll: FC<OwnProps> = ({
   // Used to re-query `listItemElements` if rendering is delayed by transition
   cacheBuster,
   children,
+  onLoadMore,
+  onScroll,
+  onKeyDown,
+  onDragOver,
+  onDragLeave,
 }: OwnProps) => {
   // eslint-disable-next-line no-null/no-null
   let containerRef = useRef<HTMLDivElement>(null);
@@ -223,6 +227,8 @@ const InfiniteScroll: FC<OwnProps> = ({
       onScroll={handleScroll}
       teactFastList={!noFastList && !withAbsolutePositioning}
       onKeyDown={onKeyDown}
+      onDragOver={onDragOver}
+      onDragLeave={onDragLeave}
     >
       {withAbsolutePositioning && items?.length ? (
         <div
diff --git a/src/components/ui/ListItem.tsx b/src/components/ui/ListItem.tsx
index 0059bfc58..73b00895c 100644
--- a/src/components/ui/ListItem.tsx
+++ b/src/components/ui/ListItem.tsx
@@ -46,6 +46,7 @@ interface OwnProps {
   onMouseDown?: (e: React.MouseEvent<HTMLDivElement>) => void;
   onClick?: (e: React.MouseEvent<HTMLDivElement>) => void;
   onSecondaryIconClick?: (e: React.MouseEvent<HTMLButtonElement>) => void;
+  onDragEnter?: (e: React.DragEvent<HTMLDivElement>) => void;
 }
 
 const ListItem: FC<OwnProps> = ({
@@ -70,6 +71,7 @@ const ListItem: FC<OwnProps> = ({
   onMouseDown,
   onClick,
   onSecondaryIconClick,
+  onDragEnter,
 }) => {
   // eslint-disable-next-line no-null/no-null
   let containerRef = useRef<HTMLDivElement>(null);
@@ -167,6 +169,7 @@ const ListItem: FC<OwnProps> = ({
       dir={lang.isRtl ? 'rtl' : undefined}
       style={style}
       onMouseDown={onMouseDown}
+      onDragEnter={onDragEnter}
     >
       <div
         className={buildClassName('ListItem-button', isTouched && 'active', buttonClassName)}