[gnome-music/wip/jfelder/searchview-new-style: 8/9] searchview: Limit album results to two rows

[Marinus Schraal <mschraal src gnome org>]

commit 8b54bd02edd222e0efbba601a369c7306590f2ea
Author: Jean Felder <jfelder src gnome org>
Date:   Sun Aug 4 21:01:32 2019 +0200

    searchview: Limit album results to two rows
    
    Album results need to be displayed on only two rows at most (each row
    can have up to 6 results). But, on smaller screens, the rows can be
    changed into multiple rows. In that event, the latest results should
    be hidden to display only two rows.
    
    Fix the issue by listening to the "size-allocate" signal of the
    flowbox. If the window is too small, the latest results are hidden. If
    the window becomes wider, they are displayed again.

 gnomemusic/views/searchview.py | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
---
diff --git a/gnomemusic/views/searchview.py b/gnomemusic/views/searchview.py
index 45082d52..8335e11c 100644
--- a/gnomemusic/views/searchview.py
+++ b/gnomemusic/views/searchview.py
@@ -94,6 +94,8 @@ class SearchView(Gtk.Stack):
             "items-changed", self._on_album_model_items_changed)
         self._album_flowbox.bind_model(
             self._album_filter, self._create_album_widget)
+        self._album_flowbox.connect(
+            "size-allocate", self._on_album_flowbox_size_allocate)
         self._on_album_model_items_changed(self._album_filter, 0, 0, 0)
 
         self._artist_filter.connect_after(
@@ -227,6 +229,40 @@ class SearchView(Gtk.Stack):
 
         return True
 
+    def _on_album_flowbox_size_allocate(self, widget, allocation, data=None):
+        nb_children = self._album_filter.get_n_items()
+        if nb_children == 0:
+            return
+
+        first_child = self._album_flowbox.get_child_at_index(0)
+        child_height = first_child.get_allocation().height
+        if allocation.height > 2.5 * child_height:
+            for i in range(nb_children - 1, -1, -1):
+                child = self._album_flowbox.get_child_at_index(i)
+                if child.props.visible is True:
+                    child.props.visible = False
+                    return
+
+        children_hidden = False
+        for idx in range(nb_children):
+            child = self._album_flowbox.get_child_at_index(idx)
+            if not child.props.visible:
+                children_hidden = True
+                break
+        if children_hidden is False:
+            return
+
+        last_visible_child = self._album_flowbox.get_child_at_index(idx - 1)
+        first_row_last = self._album_flowbox.get_child_at_index((idx - 1) // 2)
+        second_row_pos = last_visible_child.get_allocation().x
+        first_row_pos = first_row_last.get_allocation().x
+        child_width = last_visible_child.get_allocation().width
+        nb_children_to_add = (first_row_pos - second_row_pos) // child_width
+        nb_children_to_add = min(nb_children_to_add + idx, nb_children)
+        for i in range(idx, nb_children_to_add):
+            child = self._album_flowbox.get_child_at_index(i)
+            child.props.visible = True
+
     @Gtk.Template.Callback()
     def _on_album_activated(self, widget, child, user_data=None):
         corealbum = child.props.corealbum