[pitivi] Provide a custom UI for frei0r-filter-alphaspot

[Alexandru Băluț <alexbalut src gnome org>]

commit 4787953fd10be0d14a431f00c21af6210b846b1d
Author: Michał Górny <mgorny gentoo org>
Date:   Fri Sep 29 17:57:10 2017 +0200

    Provide a custom UI for frei0r-filter-alphaspot

 data/ui/customwidgets/frei0r-filter-alphaspot.ui |  618 ++++++++++++++++++++++
 pitivi/utils/custom_effect_widgets.py            |  132 +++++
 2 files changed, 750 insertions(+), 0 deletions(-)
---
diff --git a/data/ui/customwidgets/frei0r-filter-alphaspot.ui 
b/data/ui/customwidgets/frei0r-filter-alphaspot.ui
new file mode 100644
index 0000000..9814a25
--- /dev/null
+++ b/data/ui/customwidgets/frei0r-filter-alphaspot.ui
@@ -0,0 +1,618 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.20.0 -->
+<interface>
+  <requires lib="gtk+" version="3.0"/>
+  <object class="GtkAdjustment" id="adjustment_max">
+    <property name="upper">1</property>
+    <property name="value">1</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkAdjustment" id="adjustment_min">
+    <property name="upper">1</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkAdjustment" id="adjustment_position-x">
+    <property name="upper">1</property>
+    <property name="value">0.5</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkAdjustment" id="adjustment_position-y">
+    <property name="upper">1</property>
+    <property name="value">0.5</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkAdjustment" id="adjustment_size-x">
+    <property name="lower">0.01</property>
+    <property name="upper">1</property>
+    <property name="value">0.10000000000000001</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkAdjustment" id="adjustment_size-y">
+    <property name="lower">0.01</property>
+    <property name="upper">1</property>
+    <property name="value">0.10000000000000001</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkAdjustment" id="adjustment_tilt">
+    <property name="upper">1</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkAdjustment" id="adjustment_transition-width">
+    <property name="upper">1</property>
+    <property name="value">0.20000000000000001</property>
+    <property name="step_increment">0.01</property>
+    <property name="page_increment">0.10000000000000001</property>
+  </object>
+  <object class="GtkImage" id="image1">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkImage" id="image10">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkImage" id="image2">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkImage" id="image3">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkImage" id="image4">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkImage" id="image6">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkImage" id="image7">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkImage" id="image9">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-clear-all-symbolic</property>
+  </object>
+  <object class="GtkGrid" id="base_table">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="border_width">12</property>
+    <property name="row_spacing">8</property>
+    <property name="column_spacing">6</property>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::position-x::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image1</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">3</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::position-y::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image2</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">4</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::size-x::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image3</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">5</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::size-y::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image4</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">6</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::position-x">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_position-x</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">3</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::position-y">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_position-y</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">4</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::size-x">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_size-x</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">5</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::size-y">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_size-y</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">6</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::position-x::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">3</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::position-y::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">4</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::size-x::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">5</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::size-y::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">6</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkSeparator" id="separator2">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="margin_right">328</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">2</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkComboBox" id="frei0r-filter-alphaspot::shape">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">0</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">Shape:</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">0</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">x</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">3</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">y</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">4</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">width</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">5</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">height</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">6</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">Operation:</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">1</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkComboBox" id="frei0r-filter-alphaspot::operation">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">1</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">tilt</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">7</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">trans. width</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">8</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">min alpha</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">9</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkLabel">
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="label" translatable="yes">max alpha</property>
+      </object>
+      <packing>
+        <property name="left_attach">0</property>
+        <property name="top_attach">10</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::tilt">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_tilt</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">7</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::transition-width">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_transition-width</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">8</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::min">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_min</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">9</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkScale" id="frei0r-filter-alphaspot::max">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="adjustment">adjustment_max</property>
+        <property name="restrict_to_fill_level">False</property>
+        <property name="fill_level">1</property>
+        <property name="round_digits">2</property>
+        <property name="digits">2</property>
+        <property name="value_pos">left</property>
+      </object>
+      <packing>
+        <property name="left_attach">1</property>
+        <property name="top_attach">10</property>
+        <property name="width">2</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::transition-width::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">8</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::tilt::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">7</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::min::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">9</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkToggleButton" id="frei0r-filter-alphaspot::max::keyframe">
+        <property name="label" translatable="yes">◇</property>
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="relief">none</property>
+      </object>
+      <packing>
+        <property name="left_attach">3</property>
+        <property name="top_attach">10</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::tilt::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image6</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">7</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::transition-width::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image7</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">8</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::max::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image9</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">10</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="frei0r-filter-alphaspot::min::reset">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="receives_default">True</property>
+        <property name="image">image10</property>
+        <property name="relief">none</property>
+        <property name="image_position">top</property>
+      </object>
+      <packing>
+        <property name="left_attach">4</property>
+        <property name="top_attach">9</property>
+      </packing>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+  </object>
+</interface>
diff --git a/pitivi/utils/custom_effect_widgets.py b/pitivi/utils/custom_effect_widgets.py
index 50801ea..7a8286a 100644
--- a/pitivi/utils/custom_effect_widgets.py
+++ b/pitivi/utils/custom_effect_widgets.py
@@ -26,6 +26,7 @@ from gi.repository import Gtk
 
 from pitivi import configure
 from pitivi.utils.loggable import Loggable
+from pitivi.utils.ui import model
 from pitivi.utils.widgets import ColorPickerButton
 
 
@@ -53,6 +54,8 @@ def create_custom_prop_widget_cb(unused_effect_prop_manager, effect_widget, effe
     effect_name = effect.get_property("bin-description")
     if effect_name == "alpha":
         return create_custom_alpha_prop_widget(effect_widget, effect, prop, prop_value)
+    elif effect_name == "frei0r-filter-alphaspot":
+        return create_custom_alphaspot_prop_widget(effect_widget, effect, prop, prop_value)
 
 
 def create_custom_widget_cb(effect_prop_manager, effect_widget, effect):
@@ -67,6 +70,9 @@ def create_custom_widget_cb(effect_prop_manager, effect_widget, effect):
     elif effect_name == "frei0r-filter-3-point-color-balance":
         widget = create_3point_color_balance_widget(effect_prop_manager, effect_widget, effect)
         return widget
+    elif effect_name == "frei0r-filter-alphaspot":
+        widget = create_alphaspot_widget(effect_prop_manager, effect_widget, effect)
+        return widget
 
     # Check if there is a UI file available as a glade file
     # Assuming a GtkGrid called base_table exists
@@ -339,3 +345,129 @@ def create_3point_color_balance_widget(effect_prop_manager, element_setting_widg
     highlights_wheel.set_color(0, 0, 1)
 
     return color_balance_grid
+
+
+def create_alphaspot_widget(effect_prop_manager, element_setting_widget, element):
+    """Creates the UI for the `alpha` effect."""
+    builder = setup_from_ui_file(element_setting_widget, os.path.join(CUSTOM_WIDGETS_DIR, 
"frei0r-filter-alphaspot.ui"))
+
+    # Shape picker
+
+    shape_picker = builder.get_object("frei0r-filter-alphaspot::shape")
+    shape_list = model((str, float), [
+        # ouch...
+        ("rectangle", 0.0),
+        ("ellipse", 0.26),
+        ("triangle", 0.51),
+        ("diamond shape", 0.76),
+    ])
+    shape_picker.set_model(shape_list)
+    shape_text_renderer = Gtk.CellRendererText()
+    shape_picker.pack_start(shape_text_renderer, 0)
+    shape_picker.add_attribute(shape_text_renderer, "text", 0)
+
+    def get_current_shape():
+        """Gets the shape index used by the effect."""
+        res, flid = element.get_child_property("shape")
+        assert res
+        for index, vals in reversed(list(enumerate(shape_list))):
+            if flid >= vals[1]:
+                return index
+        assert False
+
+    shape_picker.set_active(get_current_shape())
+
+    def shape_picker_value_changed_cb(unused):
+        """Handles the selection of shape via combobox."""
+        v = shape_list[shape_picker.get_active()][1]
+
+        from pitivi.undo.timeline import CommitTimelineFinalizingAction
+        pipeline = effect_prop_manager.app.project_manager.current_project.pipeline
+        action_log = effect_prop_manager.app.action_log
+        with action_log.started("Effect property change",
+                                finalizing_action=CommitTimelineFinalizingAction(pipeline),
+                                toplevel=True):
+            element.set_child_property("shape", v)
+
+    shape_picker.connect("changed", shape_picker_value_changed_cb)
+
+    # Operation picker
+
+    op_picker = builder.get_object("frei0r-filter-alphaspot::operation")
+    op_list = model((str, float), [
+        # ouch...
+        ("write on clear", 0.0),
+        ("max", 0.21),
+        ("min", 0.41),
+        ("add", 0.61),
+        ("subtract", 0.81),
+    ])
+    op_picker.set_model(op_list)
+    op_text_renderer = Gtk.CellRendererText()
+    op_picker.pack_start(op_text_renderer, 0)
+    op_picker.add_attribute(op_text_renderer, "text", 0)
+
+    def get_current_op():
+        """Gets the op index used by the effect."""
+        res, flid = element.get_child_property("operation")
+        assert res
+        for index, vals in reversed(list(enumerate(op_list))):
+            if flid >= vals[1]:
+                return index
+        assert False
+
+    op_picker.set_active(get_current_op())
+
+    def op_picker_value_changed_cb(unused):
+        """Handles the selection of op via combobox."""
+        v = op_list[op_picker.get_active()][1]
+
+        from pitivi.undo.timeline import CommitTimelineFinalizingAction
+        pipeline = effect_prop_manager.app.project_manager.current_project.pipeline
+        action_log = effect_prop_manager.app.action_log
+        with action_log.started("Effect property change",
+                                finalizing_action=CommitTimelineFinalizingAction(pipeline),
+                                toplevel=True):
+            element.set_child_property("operation", v)
+
+    op_picker.connect("changed", op_picker_value_changed_cb)
+
+    def property_changed_cb(unused_effect, gst_element, pspec):
+        """Handles the change of a GObject property."""
+        if gst_element.get_control_binding(pspec.name):
+            Loggable().log("%s controlled, not displaying value", pspec.name)
+            return
+
+        widget = element_setting_widget.properties.get(pspec)
+        if not widget:
+            return
+
+        res, value = element_setting_widget.element.get_child_property(pspec.name)
+        assert res
+
+        if pspec.name in ("shape",):
+            shape_picker.set_active(get_current_shape())
+            widget.block_signals()
+            try:
+                widget.setWidgetValue(value)
+            finally:
+                widget.unblock_signals()
+        elif pspec.name in ("operation",):
+            op_picker.set_active(get_current_op())
+            widget.block_signals()
+            try:
+                widget.setWidgetValue(value)
+            finally:
+                widget.unblock_signals()
+        else:
+            widget.setWidgetValue(value)
+
+    element.connect("deep-notify", property_changed_cb)
+
+    return builder.get_object("base_table")
+
+
+def create_custom_alphaspot_prop_widget(unused_element_setting_widget, unused_element, unused_prop, 
unused_prop_value):
+    """Not implemented yet."""
+    # In the auto-generated UI, replace a property widget with a custom one
+    return None