From 9a73323fa33fbb8009c42917f320d5807af514cb Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 7 Mar 2022 21:15:11 +0530
Subject: [PATCH] E-book viewer: Allow scrolling of the ToC, highlights,
 bookmarks, etc. with touch gestures. Fixes #1963875 [Make the Viewer TOC
 touch friendly](https://bugs.launchpad.net/calibre/+bug/1963875)

---
 src/calibre/gui2/viewer/bookmarks.py  | 8 +++++---
 src/calibre/gui2/viewer/highlights.py | 4 +++-
 src/calibre/gui2/viewer/search.py     | 7 +++++--
 src/calibre/gui2/viewer/toc.py        | 9 +++++----
 4 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/calibre/gui2/viewer/bookmarks.py b/src/calibre/gui2/viewer/bookmarks.py
index 78633d0af0..b9cb03a145 100644
--- a/src/calibre/gui2/viewer/bookmarks.py
+++ b/src/calibre/gui2/viewer/bookmarks.py
@@ -5,9 +5,9 @@
 import json
 from operator import itemgetter
 from qt.core import (
-    QAction, QComboBox, QGridLayout, QHBoxLayout, QIcon, QInputDialog,
-    QItemSelectionModel, QLabel, QListWidget, QListWidgetItem, QPushButton, Qt,
-    QWidget, pyqtSignal
+    QAbstractItemView, QAction, QComboBox, QGridLayout, QHBoxLayout, QIcon,
+    QInputDialog, QItemSelectionModel, QLabel, QListWidget, QListWidgetItem,
+    QPushButton, QScroller, Qt, QWidget, pyqtSignal
 )
 
 from calibre.gui2 import choose_files, choose_save_file
@@ -32,6 +32,8 @@ class BookmarksList(QListWidget):
         self.addAction(ac)
         self.ac_delete = ac = QAction(QIcon(I('trash.png')), _('Remove this bookmark'), self)
         self.addAction(ac)
+        QScroller.grabGesture(self.viewport(), QScroller.ScrollerGestureType.TouchGesture)
+        self.setVerticalScrollMode(QAbstractItemView.ScrollMode.ScrollPerPixel)
 
     @property
     def current_non_removed_item(self):
diff --git a/src/calibre/gui2/viewer/highlights.py b/src/calibre/gui2/viewer/highlights.py
index 2140fc35a3..9d648b51ba 100644
--- a/src/calibre/gui2/viewer/highlights.py
+++ b/src/calibre/gui2/viewer/highlights.py
@@ -10,7 +10,7 @@ from qt.core import (
     QAbstractItemView, QColor, QDialog, QFont, QHBoxLayout, QIcon, QImage,
     QItemSelectionModel, QKeySequence, QLabel, QMenu, QPainter, QPainterPath,
     QPalette, QPixmap, QPushButton, QRect, QSizePolicy, QStyle, Qt, QTextCursor,
-    QTextEdit, QTreeWidget, QTreeWidgetItem, QVBoxLayout, QWidget, pyqtSignal
+    QTextEdit, QTreeWidget, QTreeWidgetItem, QVBoxLayout, QWidget, pyqtSignal, QScroller
 )
 
 from calibre.constants import (
@@ -175,6 +175,8 @@ class Highlights(QTreeWidget):
         self.uuid_map = {}
         self.section_font = QFont(self.font())
         self.section_font.setItalic(True)
+        QScroller.grabGesture(self.viewport(), QScroller.ScrollerGestureType.TouchGesture)
+        self.setVerticalScrollMode(QAbstractItemView.ScrollMode.ScrollPerPixel)
 
     def show_context_menu(self, point):
         index = self.indexAt(point)
diff --git a/src/calibre/gui2/viewer/search.py b/src/calibre/gui2/viewer/search.py
index e645e61ce7..800fc86ea8 100644
--- a/src/calibre/gui2/viewer/search.py
+++ b/src/calibre/gui2/viewer/search.py
@@ -6,8 +6,9 @@ import regex
 from collections import Counter, OrderedDict
 from html import escape
 from qt.core import (
-    QCheckBox, QComboBox, QFont, QHBoxLayout, QIcon, QLabel, Qt, QToolButton,
-    QTreeWidget, QTreeWidgetItem, QVBoxLayout, QWidget, pyqtSignal
+    QAbstractItemView, QCheckBox, QComboBox, QFont, QHBoxLayout, QIcon, QLabel,
+    QScroller, Qt, QToolButton, QTreeWidget, QTreeWidgetItem, QVBoxLayout, QWidget,
+    pyqtSignal
 )
 from threading import Thread
 
@@ -471,6 +472,8 @@ class Results(QTreeWidget):  # {{{
         self.section_map = {}
         self.search_results = []
         self.item_map = {}
+        QScroller.grabGesture(self.viewport(), QScroller.ScrollerGestureType.TouchGesture)
+        self.setVerticalScrollMode(QAbstractItemView.ScrollMode.ScrollPerPixel)
 
     def current_item_changed(self, current, previous):
         if current is not None:
diff --git a/src/calibre/gui2/viewer/toc.py b/src/calibre/gui2/viewer/toc.py
index 388fdb98e9..0b0a975b17 100644
--- a/src/calibre/gui2/viewer/toc.py
+++ b/src/calibre/gui2/viewer/toc.py
@@ -4,11 +4,10 @@
 
 import re
 from functools import partial
-
 from qt.core import (
-    QApplication, QFont, QHBoxLayout, QIcon, QMenu, QModelIndex, QStandardItem,
-    QStandardItemModel, QStyledItemDelegate, Qt, QToolButton, QToolTip, QTreeView,
-    QWidget, pyqtSignal, QEvent
+    QAbstractItemView, QApplication, QEvent, QFont, QHBoxLayout, QIcon, QMenu,
+    QModelIndex, QScroller, QStandardItem, QStandardItemModel, QStyledItemDelegate,
+    Qt, QToolButton, QToolTip, QTreeView, QWidget, pyqtSignal
 )
 
 from calibre.gui2 import error_dialog
@@ -48,6 +47,8 @@ class TOCView(QTreeView):
         self.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)
         self.customContextMenuRequested.connect(self.context_menu)
         QApplication.instance().palette_changed.connect(self.set_style_sheet, type=Qt.ConnectionType.QueuedConnection)
+        QScroller.grabGesture(self.viewport(), QScroller.ScrollerGestureType.TouchGesture)
+        self.setVerticalScrollMode(QAbstractItemView.ScrollMode.ScrollPerPixel)
 
     def setModel(self, model):
         QTreeView.setModel(self, model)