[gnome-music] playlistview: Fix right-click popover position

[Jean Felder <jfelder src gnome org>]

commit 78b0e9680ed6e9b478e5f6b656e1f984d28d9f09
Author: Harry Xie <harryjordan9208 gmail com>
Date:   Mon Jan 14 20:12:54 2019 -0500

    playlistview: Fix right-click popover position
    
    Issue #214 points out that right-click popover in the playlist view
    sometimes appears at odd positions. This is because the rectangle the
    popover points to is too tall. When the window is small, there isn't
    enough space at the bottom, so the popover chooses to appear on the
    side of the rectangle, which is far away from the user's mouse.
    
    To fix this, change the way the rectangle is created by taking into
    account the position of the mouse cursor inside the row. Add half the
    height of a cell to the vertical position of the popover to make sure
    it is always displayed at the center of the cell.
    
    Closes: #214

 gnomemusic/views/playlistview.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/gnomemusic/views/playlistview.py b/gnomemusic/views/playlistview.py
index eb9433c6..093cb320 100644
--- a/gnomemusic/views/playlistview.py
+++ b/gnomemusic/views/playlistview.py
@@ -362,12 +362,13 @@ class PlaylistView(BaseView):
 
     @log
     def _on_view_right_clicked(self, gesture, n_press, x, y):
-        (path, _, _, _) = self._view.get_path_at_pos(x, y)
+        (path, column, cell_x, cell_y) = self._view.get_path_at_pos(x, y)
         self._view.get_selection().select_path(path)
+        row_height = self._view.get_cell_area(path, None).height
 
-        rect = self._view.get_visible_rect()
-        rect.x = x - rect.width / 2.0
-        rect.y = y - rect.height + 5
+        rect = Gdk.Rectangle()
+        rect.x = x
+        rect.y = y - cell_y + 0.5 * row_height
 
         self._song_popover.set_relative_to(self._view)
         self._song_popover.set_pointing_to(rect)