Moved text selection utils to td_ui.

Telegram/SourceFiles/layout/layout_selection.cpp

@@ -0,0 +1,42 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "layout/layout_selection.h"
+
+bool IsSubGroupSelection(TextSelection selection) {
+	return (selection.from == 0xFFFF) && (selection.to != 0xFFFF);
+}
+
+bool IsGroupItemSelection(
+		TextSelection selection,
+		int index) {
+	Expects(index >= 0 && index < 0x0F);
+
+	return IsSubGroupSelection(selection) && (selection.to & (1 << index));
+}
+
+TextSelection AddGroupItemSelection(
+		TextSelection selection,
+		int index) {
+	Expects(index >= 0 && index < 0x0F);
+
+	const auto bit = uint16(1U << index);
+	return TextSelection(
+		0xFFFF,
+		IsSubGroupSelection(selection) ? (selection.to | bit) : bit);
+}
+
+TextSelection RemoveGroupItemSelection(
+		TextSelection selection,
+		int index) {
+	Expects(index >= 0 && index < 0x0F);
+
+	const auto bit = uint16(1U << index);
+	return IsSubGroupSelection(selection)
+		? TextSelection(0xFFFF, selection.to & ~bit)
+		: selection;
+}

Telegram/SourceFiles/layout/layout_selection.h

@@ -0,0 +1,26 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+#include "ui/text/text.h"
+
+constexpr auto FullSelection = TextSelection { 0xFFFF, 0xFFFF };
+
+[[nodiscard]] bool IsSubGroupSelection(TextSelection selection);
+
+[[nodiscard]] bool IsGroupItemSelection(
+		TextSelection selection,
+		int index);
+
+[[nodiscard]] TextSelection AddGroupItemSelection(
+		TextSelection selection,
+		int index);
+
+[[nodiscard]] TextSelection RemoveGroupItemSelection(
+		TextSelection selection,
+		int index);