Allow the formats list to use less height

Also remove some wasted margins in various sub layouts

src/calibre/gui2/metadata/basic_widgets.py

@@ -811,6 +811,10 @@ def __init__(self, parent):
         _FormatList.__init__(self, parent)
         self.setContextMenuPolicy(Qt.ContextMenuPolicy.DefaultContextMenu)
 
+    def sizeHint(self):
+        sz = self.iconSize()
+        return QSize(sz.width() * 7, sz.height() * 3)
+
     def contextMenuEvent(self, event):
         item = self.itemFromIndex(self.currentIndex())
         originals = [self.item(x).ext.upper() for x in range(self.count())]
@@ -850,6 +854,7 @@ def remove_format(self, fmt):
 class FormatsManager(QWidget):
 
     data_changed = pyqtSignal()
+    ICON_SIZE = 32
 
     @property
     def changed(self):
@@ -868,29 +873,30 @@ def __init__(self, parent, copy_fmt):
         self._changed = False
 
         self.l = l = QGridLayout()
+        l.setContentsMargins(0, 0, 0, 0)
         self.setLayout(l)
         self.cover_from_format_button = QToolButton(self)
         self.cover_from_format_button.setToolTip(
                 _('Set the cover for the book from the selected format'))
         self.cover_from_format_button.setIcon(QIcon(I('default_cover.png')))
-        self.cover_from_format_button.setIconSize(QSize(32, 32))
+        self.cover_from_format_button.setIconSize(QSize(self.ICON_SIZE, self.ICON_SIZE))
 
         self.metadata_from_format_button = QToolButton(self)
         self.metadata_from_format_button.setIcon(QIcon(I('edit_input.png')))
-        self.metadata_from_format_button.setIconSize(QSize(32, 32))
+        self.metadata_from_format_button.setIconSize(QSize(self.ICON_SIZE, self.ICON_SIZE))
         self.metadata_from_format_button.setToolTip(
                 _('Set metadata for the book from the selected format'))
 
         self.add_format_button = QToolButton(self)
         self.add_format_button.setIcon(QIcon(I('add_book.png')))
-        self.add_format_button.setIconSize(QSize(32, 32))
+        self.add_format_button.setIconSize(QSize(self.ICON_SIZE, self.ICON_SIZE))
         self.add_format_button.clicked.connect(self.add_format)
         self.add_format_button.setToolTip(
                 _('Add a format to this book'))
 
         self.remove_format_button = QToolButton(self)
         self.remove_format_button.setIcon(QIcon(I('trash.png')))
-        self.remove_format_button.setIconSize(QSize(32, 32))
+        self.remove_format_button.setIconSize(QSize(self.ICON_SIZE, self.ICON_SIZE))
         self.remove_format_button.clicked.connect(self.remove_format)
         self.remove_format_button.setToolTip(
                 _('Remove the selected format from this book'))
@@ -904,8 +910,7 @@ def __init__(self, parent, copy_fmt):
         self.formats.delete_format.connect(self.remove_format)
         self.formats.itemDoubleClicked.connect(self.show_format)
         self.formats.setDragDropMode(QAbstractItemView.DragDropMode.DropOnly)
-        self.formats.setIconSize(QSize(32, 32))
-        self.formats.setMaximumWidth(200)
+        self.formats.setIconSize(QSize(self.ICON_SIZE, self.ICON_SIZE))
 
         l.addWidget(self.cover_from_format_button, 0, 0, 1, 1)
         l.addWidget(self.metadata_from_format_button, 2, 0, 1, 1)

src/calibre/gui2/metadata/single.py

@@ -1176,24 +1176,28 @@ def create_row(row, widget, tab_to, button=None, icon=None, span=1):
         # First the cover & buttons
         cover_group_box = QGroupBox(_('Cover'), tab0)
         cover_layout = QVBoxLayout()
+        cover_layout.setContentsMargins(0, 0, 0, 0)
         cover_group_box.setLayout(cover_layout)
         cover_layout.addWidget(self.cover)
         sto(self.manage_authors_button, self.cover.buttons[0])
         # First row of cover buttons
         hl = QHBoxLayout()
+        hl.setContentsMargins(0, 0, 0, 0)
         for i, b in enumerate(self.cover.buttons[:3]):
             hl.addWidget(b)
             sto(b, self.cover.buttons[i+1])
         cover_layout.addLayout(hl)
         # Second row of cover buttons
         hl = QHBoxLayout()
+        hl.setContentsMargins(0, 0, 0, 0)
         for b in self.cover.buttons[3:]:
             hl.addWidget(b)
         cover_layout.addLayout(hl)
         sto(self.cover.buttons[-2], self.cover.buttons[-1])
         # Layout for both cover & formats boxes
         cover_and_formats = QVBoxLayout()
-        cover_and_formats.addWidget(cover_group_box, stretch = 10)
+        cover_and_formats.setContentsMargins(0, 0, 0, 0)
+        cover_and_formats.addWidget(cover_group_box, stretch=100)
         cover_and_formats.addWidget(self.formats_manager)
         l.addLayout(cover_and_formats, 0, 2, 2, 1)
         sto(self.cover.buttons[-1], self.formats_manager)