Narrow layout: Place the cover browser above the book list when the window has a narrow aspect ratio

This is similar to the behavior pre 7.3 except it is controlled by
window size instead of primary monitor size.

src/calibre/gui2/central.py

@@ -191,6 +191,9 @@ class SplitterHandle(QWidget):
 
     def __init__(self, parent: QWidget=None, orientation: Qt.Orientation = Qt.Orientation.Vertical):
         super().__init__(parent)
+        self.set_orientation(orientation)
+
+    def set_orientation(self, orientation):
         self.orientation = orientation
         if orientation is Qt.Orientation.Vertical:
             self.setCursor(Qt.CursorShape.SplitHCursor)
@@ -362,6 +365,10 @@ class CentralContainer(QWidget):
         self.top_handle = h(Qt.Orientation.Horizontal)
         self.bottom_handle = h(Qt.Orientation.Horizontal)
 
+    @property
+    def narrow_cb_on_top(self):
+        return self.width() / self.height() <= 1.4
+
     @property
     def is_visible(self):
         return self.wide_is_visible if self.layout is Layout.wide else self.narrow_is_visible
@@ -565,8 +572,10 @@ class CentralContainer(QWidget):
         self.book_list.setVisible(self.is_visible.book_list)
         self.quick_view.setVisible(self.is_visible.quick_view)
         if self.layout is Layout.wide:
+            self.right_handle.set_orientation(Qt.Orientation.Vertical)
             self.do_wide_layout()
         else:
+            self.right_handle.set_orientation(Qt.Orientation.Horizontal if self.narrow_cb_on_top else Qt.Orientation.Vertical)
             self.do_narrow_layout()
         self.update()
 
@@ -737,7 +746,59 @@ class CentralContainer(QWidget):
     def min_central_height_narrow(self):
         return max(150, self.cover_browser.minimumHeight())
 
+    def do_narrow_layout_with_cb_on_top(self):
+        s = self.style()
+        normal_handle_width = int(s.pixelMetric(QStyle.PixelMetric.PM_SplitterWidth, widget=self))
+        available_height = self.height()
+        for handle in (self.bottom_handle, self.right_handle):
+            hs = handle.state
+            height = self.bottom_handle.COLLAPSED_SIZE
+            if hs is HandleState.both_visible or hs is HandleState.only_side_visible:
+                height = normal_handle_width
+            handle.resize(self.width(), height)
+            available_height -= height
+        bd = int(self.narrow_desires.book_details_height * self.height()) if self.is_visible.book_details else 0
+        bd = max(0, min(bd, max(0, available_height - self.min_central_height_narrow() - 40)))
+        central_height = available_height - bd + self.right_handle.height()
+        self.bottom_handle.move(0, central_height - self.bottom_handle.height())
+        if self.is_visible.book_details:
+            self.book_details.setGeometry(0, self.bottom_handle.y() + self.bottom_handle.height(), self.width(), bd)
+        available_width = self.width()
+        hs = self.left_handle.state
+        width = self.left_handle.COLLAPSED_SIZE
+        if hs is HandleState.both_visible or hs is HandleState.only_side_visible:
+            width = normal_handle_width
+        self.left_handle.resize(width, central_height)
+        available_width -= width
+        tb = int(self.narrow_desires.tag_browser_width * self.width()) if self.is_visible.tag_browser else 0
+        self.left_handle.move(tb, 0)
+        if self.is_visible.tag_browser:
+            self.tag_browser.setGeometry(0, 0, tb, central_height)
+        central_x = self.left_handle.x() + self.left_handle.width()
+        central_width = self.width() - central_x
+        central_height -= self.right_handle.height()
+        cb = min(max(0, central_height - 80), int(self.height() * self.narrow_desires.cover_browser_width)) if self.is_visible.cover_browser else 0
+        if cb and cb < self.cover_browser.minimumHeight():
+            cb = min(self.cover_browser.minimumHeight(), central_height)
+        if self.is_visible.cover_browser:
+            self.cover_browser.setGeometry(central_x, 0, central_width, cb)
+        self.right_handle.resize(central_width, self.right_handle.height())
+        self.right_handle.move(central_x, cb)
+        central_top = self.right_handle.y() + self.right_handle.height()
+        central_height = self.bottom_handle.y() - central_top
+        self.top_handle.resize(central_width, normal_handle_width if self.is_visible.quick_view else 0)
+        available_height = central_height - self.top_handle.height()
+        qv = int(self.height() * self.narrow_desires.quick_view_height) if self.is_visible.quick_view else 0
+        qv = min(qv, max(0, available_height - 80))
+        bl = max(0, available_height - qv)
+        self.book_list.setGeometry(central_x, central_top, central_width, bl)
+        self.top_handle.move(central_x, self.book_list.y() + self.book_list.height())
+        if self.is_visible.quick_view:
+            self.quick_view.setGeometry(central_x, self.top_handle.y() + self.top_handle.height(), central_width, qv)
+
     def do_narrow_layout(self):
+        if self.narrow_cb_on_top:
+            return self.do_narrow_layout_with_cb_on_top()
         s = self.style()
         normal_handle_width = int(s.pixelMetric(QStyle.PixelMetric.PM_SplitterWidth, widget=self))
         available_height = self.height()
@@ -798,6 +859,8 @@ class CentralContainer(QWidget):
         if handle is self.left_handle:
             x = int(pos.x())
             available_width = self.width() - self.left_handle.width() - self.right_handle.width() - self.min_central_width_narrow()
+            if self.narrow_cb_on_top:
+                available_width += self.right_handle.width()
             self.is_visible.tag_browser = True
             if x < HIDE_THRESHOLD:
                 self.is_visible.tag_browser = False
@@ -805,15 +868,24 @@ class CentralContainer(QWidget):
             else:
                 self.narrow_desires.tag_browser_width = min(available_width, x) / self.width()
         elif handle is self.right_handle:
-            x = int(pos.x())
+            if self.narrow_cb_on_top:
-            available_width = self.width() - self.left_handle.width() - self.right_handle.width() - self.min_central_width_narrow()
+                y = int(pos.y())
-            self.is_visible.cover_browser = True
+                self.is_visible.cover_browser = True
-            w = min(available_width, self.width() - x - self.right_handle.width())
+                if y < max(self.cover_browser.minimumHeight(), HIDE_THRESHOLD):
-            if w < HIDE_THRESHOLD:
+                    self.is_visible.cover_browser = False
-                self.is_visible.cover_browser = False
+                    self.narrow_desires.cover_browser_width = 0
-                self.narrow_desires.book_details_width = 0
+                else:
+                    self.narrow_desires.cover_browser_width = max(y, self.cover_browser.minimumHeight()) / self.height()
             else:
-                self.narrow_desires.cover_browser_width = max(self.cover_browser.minimumWidth(), w) / self.width()
+                x = int(pos.x())
+                available_width = self.width() - self.left_handle.width() - self.right_handle.width() - self.min_central_width_narrow()
+                self.is_visible.cover_browser = True
+                w = min(available_width, self.width() - x - self.right_handle.width())
+                if w < HIDE_THRESHOLD:
+                    self.is_visible.cover_browser = False
+                    self.narrow_desires.book_details_width = 0
+                else:
+                    self.narrow_desires.cover_browser_width = max(self.cover_browser.minimumWidth(), w) / self.width()
         elif handle is self.bottom_handle:
             y = int(pos.y())
             h = self.height() - y - self.bottom_handle.height()