[pitivi] timeline: Remove Timeline._layers

[Alexandru Băluț <alexbalut src gnome org>]

commit 14be51b5873ee619d079bbb3ac8bcad46692d931
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Sun Oct 30 21:03:17 2016 +0100

    timeline: Remove Timeline._layers
    
    Moved the __update_layers call from _removeLayer to _layerRemovedCb
    because the other place where _removeLayer was called is in setProject
    when all the layers were being removed, and then it does not make sense
    update the remaining layers. This optimization was required because the
    layer ui was already missing when __update_layers was called when
    closing the project.
    
    Reviewed-by: Thibault Saunier <tsaunier gnome org>
    Differential Revision: https://phabricator.freedesktop.org/D1430

 pitivi/timeline/timeline.py     |   32 +++++++++++++++++---------------
 tests/test_timeline_timeline.py |    5 +++--
 2 files changed, 20 insertions(+), 17 deletions(-)
---
diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index 17c9c18..b4543b4 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -322,7 +322,6 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         # it should be kept that way if it makes sense.
         self.zoomed_fitted = True
 
-        self._layers = []
         # A list of (controls separator, layers separator) tuples.
         self._separators = []
         # Whether the user is dragging a layer.
@@ -500,10 +499,16 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         self.update_snapping_distance()
 
     # Gtk.Widget virtual methods implementation
-    def do_get_preferred_height(self):
-        natural_height = max(1, len(self._layers)) * (LAYER_HEIGHT + 20)
 
-        return LAYER_HEIGHT, natural_height
+    def do_get_preferred_height(self):
+        minimum = SEPARATOR_HEIGHT + LAYER_HEIGHT + SEPARATOR_HEIGHT
+        if not self.ges_timeline:
+            count = 0
+        else:
+            count = len(self.ges_timeline.get_layers())
+        count = max(1, count)
+        natural = SEPARATOR_HEIGHT + count * (LAYER_HEIGHT + SEPARATOR_HEIGHT)
+        return minimum, natural
 
     def __setLayoutSize(self):
         if self.ges_timeline:
@@ -766,8 +771,8 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         self.__marquee.hide()
 
     def updatePosition(self):
-        for layer in self._layers:
-            layer.updatePosition()
+        for ges_layer in self.ges_timeline.get_layers():
+            ges_layer.ui.updatePosition()
 
     def __create_clips(self, x, y):
         """Creates the clips for an asset drag operation.
@@ -934,7 +939,6 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         if not self._separators:
             # Make sure the first layer has separators above it.
             self.__add_separators()
-        self._layers.append(layer)
 
         control = LayerControls(ges_layer, self.app)
         control.show_all()
@@ -968,10 +972,9 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         if priorities != list(range(len(priorities))):
             self.debug("Layers still being shuffled, not updating widgets: %s", priorities)
             return
-        self._layers.sort(key=lambda layer: layer.ges_layer.props.priority)
         self.debug("Updating layers widgets positions")
-        for i, layer in enumerate(self._layers):
-            self.__update_layer(layer.ges_layer)
+        for i, ges_layer in enumerate(self.ges_timeline.get_layers()):
+            self.__update_layer(ges_layer)
 
     def _removeLayer(self, ges_layer):
         self.info("Removing layer: %s", ges_layer.props.priority)
@@ -984,7 +987,6 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         self.layers_vbox.remove(separator)
         self._layers_controls_vbox.remove(controls_separator)
 
-        self._layers.remove(ges_layer.ui)
         ges_layer.ui.release()
         ges_layer.ui = None
         ges_layer.control_ui = None
@@ -1212,9 +1214,9 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
 
             if self.__on_separators and self.__got_dragged and not self.__clickedHandle:
                 priority = self.separator_priority(self.__on_separators[1])
-                layer = self.createLayer(priority)
+                ges_layer = self.createLayer(priority)
                 position = self.editing_context.new_position
-                self.editing_context.edit_to(position, layer)
+                self.editing_context.edit_to(position, ges_layer)
             self.layout.props.width = self._timelineLengthInPixels()
 
             self.editing_context.finish()
@@ -1224,8 +1226,8 @@ class Timeline(Gtk.EventBox, Zoomable, Loggable):
         self.__got_dragged = False
         self.editing_context = None
 
-        for layer in self.ges_timeline.get_layers():
-            layer.ui.checkMediaTypes()
+        for ges_layer in self.ges_timeline.get_layers():
+            ges_layer.ui.checkMediaTypes()
 
         self._setSeparatorsPrelight(False)
         self.__on_separators = []
diff --git a/tests/test_timeline_timeline.py b/tests/test_timeline_timeline.py
index 53f0223..249ff99 100644
--- a/tests/test_timeline_timeline.py
+++ b/tests/test_timeline_timeline.py
@@ -89,12 +89,13 @@ class TestLayers(BaseTestTimeline):
             ges_layer.ui.set_allocation(rect)
             y += height + SEPARATOR_HEIGHT
 
-        ges_layers = [layer.ges_layer for layer in timeline._layers]
+        ges_layers = timeline.ges_timeline.get_layers()
         if preferred is None:
             preferred_ges_layer = None
         else:
             preferred_ges_layer = ges_layers[preferred]
-        h = [layer.get_allocation().height for layer in timeline._layers]
+        # The heights of the layers.
+        h = [ges_layer.ui.get_allocation().height for ges_layer in ges_layers]
         s = SEPARATOR_HEIGHT
 
         def assertLayerAt(ges_layer, y):