Allow usage of Arrow Up and Arrow Down to edit more than just the most recent message

Telegram/SourceFiles/history/history.cpp

@@ -2763,6 +2763,51 @@ HistoryItem *History::lastEditableMessage() const {
 	return nullptr;
 }
 
+
+HistoryItem *History::editableMessageBefore(MsgId current) const {
+	if (!loadedAtBottom()) {
+		return nullptr;
+	}
+
+	bool found = false;
+	const auto now = base::unixtime::now();
+	for (const auto &block : ranges::views::reverse(blocks)) {
+		for (const auto &message : ranges::views::reverse(block->messages)) {
+			const auto item = message->data();
+			if (item->allowsEdit(now)) {
+				if(owner().groups().findItemToEdit(item)->id == current) {
+					found = true;
+				} else if(found) {
+					return owner().groups().findItemToEdit(item);
+				}
+			}
+		}
+	}
+	return nullptr;
+}
+
+HistoryItem *History::editableMessageAfter(MsgId current) const {
+	if (!loadedAtBottom()) {
+		return nullptr;
+	}
+
+	HistoryItem * previous = nullptr;
+	const auto now = base::unixtime::now();
+	for (const auto &block : ranges::views::reverse(blocks)) {
+		for (const auto &message : ranges::views::reverse(block->messages)) {
+			const auto item = message->data();
+			if (item->allowsEdit(now)) {
+				if(owner().groups().findItemToEdit(item)->id == current) {
+					return previous;
+				} else {
+					previous = owner().groups().findItemToEdit(item);
+				}
+			}
+		}
+	}
+	return nullptr;
+}
+
 void History::resizeToWidth(int newWidth) {
 	const auto resizeAllItems = (_width != newWidth);
 

Telegram/SourceFiles/history/history.h

@@ -314,6 +314,8 @@ class History final : public Dialogs::Entry {
 	MsgId maxMsgId() const;
 	MsgId msgIdForRead() const;
 	HistoryItem *lastEditableMessage() const;
+	HistoryItem *editableMessageBefore(MsgId current) const;
+	HistoryItem *editableMessageAfter(MsgId current) const;
 
 	void resizeToWidth(int newWidth);
 	void forceFullResize();

Telegram/SourceFiles/history/history_widget.cpp

@@ -6093,18 +6093,58 @@ void HistoryWidget::keyPressEvent(QKeyEvent *e) {
 	} else if (e->key() == Qt::Key_PageUp) {
 		_scroll->keyPressEvent(e);
 	} else if (e->key() == Qt::Key_Down && !commonModifiers) {
+		// If we're in a message being edited, we want to handle the down key by editing the next message.
+		if (_editMsgId && !_replyToId) {
+			const auto item = _history ? _history->editableMessageAfter(_editMsgId) : nullptr;
+				// If a change has been made, show a dialog asking if the user wants to cancel the changes
+				if (_replyEditMsg && PrepareEditText(_replyEditMsg) != _field->getTextWithTags()) {
+					controller()->show(Ui::MakeConfirmBox({
+						.text = tr::lng_cancel_edit_post_sure(),
+						.confirmed = crl::guard(this, [this, item] {
+							item ? editMessage(item) : cancelEdit();
+							Ui::hideLayer();
+						}),
+						.confirmText = tr::lng_cancel_edit_post_yes(),
+						.cancelText = tr::lng_cancel_edit_post_no(),
+					}));
+				} else {
+					item ? editMessage(item) : cancelEdit();
+				}
+			return;
+		}
+
 		_scroll->keyPressEvent(e);
 	} else if (e->key() == Qt::Key_Up && !commonModifiers) {
-		const auto item = _history
-			? _history->lastEditableMessage()
-			: nullptr;
-		if (item
-			&& _field->empty()
-			&& !_editMsgId
-			&& !_replyToId) {
-			editMessage(item);
+		if (_field->empty() && !_editMsgId && !_replyToId) {
+			// No message is currently being edited.
+			const auto item = _history ? _history->lastEditableMessage() : nullptr;
+			if(item) {
+				editMessage(item);
+			}
 			return;
 		}
+
+		// If we're in a message being edited, we want to handle the up key by instead editing the previous message.
+		if (_editMsgId && !_replyToId) {
+			const auto item = _history ? _history->editableMessageBefore(_editMsgId) : nullptr;
+			if(item) {
+				if (_replyEditMsg && PrepareEditText(_replyEditMsg) != _field->getTextWithTags()) {
+					controller()->show(Ui::MakeConfirmBox({
+						.text = tr::lng_cancel_edit_post_sure(),
+						.confirmed = crl::guard(this, [this, item] {
+							editMessage(item);
+							Ui::hideLayer();
+						}),
+						.confirmText = tr::lng_cancel_edit_post_yes(),
+						.cancelText = tr::lng_cancel_edit_post_no(),
+					}));
+				} else {
+					editMessage(item);
+				}
+			}
+			return;
+		}
+
 		_scroll->keyPressEvent(e);
 	} else if (e->key() == Qt::Key_Return || e->key() == Qt::Key_Enter) {
 		if (!_botStart->isHidden()) {