[gnome-control-center] online-accounts: Align the panel widgets in the middle

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 1594d8c7a1637a53394b0debdefbafcb5211cee6
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Nov 10 19:16:27 2016 -0200

    online-accounts: Align the panel widgets in the middle
    
    The current implementation of the Online Accounts panel allows
    2 states: either the widgets of the panel fill the whole horizontal
    space, or they shrink and fill only the absolutely minimum. The
    ideal solution, however, is to make them grow with the panel.
    
    Fix that by turn the main box into a GtkGrid, and adding stub widgets
    that expand horizontally and pull the main widgets to the middle,
    allowing them to cover at most 1/3 of the screen. The widgets themselves
    are inside a GtkBox, so that hiding them automatically removes the
    spacing in between.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=774222

 panels/online-accounts/online-accounts.ui |  133 +++++++++++++++++++----------
 1 files changed, 88 insertions(+), 45 deletions(-)
---
diff --git a/panels/online-accounts/online-accounts.ui b/panels/online-accounts/online-accounts.ui
index fa6f27b..d85939b 100644
--- a/panels/online-accounts/online-accounts.ui
+++ b/panels/online-accounts/online-accounts.ui
@@ -70,10 +70,11 @@
             <property name="hscrollbar_policy">never</property>
             <property name="min_content_height">350</property>
             <child>
-              <object class="GtkBox">
+              <object class="GtkGrid">
                 <property name="visible">True</property>
                 <property name="can_focus">False</property>
-                <property name="spacing">18</property>
+                <property name="row-spacing">18</property>
+                <property name="column-spacing">18</property>
                 <property name="orientation">vertical</property>
                 <property name="margin_start">32</property>
                 <property name="margin_end">32</property>
@@ -81,71 +82,109 @@
                 <property name="margin_bottom">18</property>
                 <property name="hexpand">True</property>
                 <property name="width-request">300</property>
+
+                <!--
+                  Stub boxes to pull the widgets to the middle, and yet allow them to
+                  grow and cover a third of the available space
+                -->
                 <child>
-                  <object class="GtkLabel">
+                  <object class="GtkBox">
                     <property name="visible">True</property>
-                    <property name="can_focus">False</property>
-                    <property name="label" translatable="yes">Connect to your data in the cloud</property>
-                    <attributes>
-                      <attribute name="scale" value="1.66" />
-                    </attributes>
+                    <property name="hexpand">True</property>
                   </object>
+                  <packing>
+                    <property name="top-attach">0</property>
+                    <property name="left-attach">0</property>
+                  </packing>
                 </child>
+
                 <child>
-                  <object class="GtkLabel" id="offline_label">
+                  <object class="GtkBox">
                     <property name="visible">True</property>
-                    <property name="can_focus">False</property>
-                    <property name="wrap">True</property>
-                    <property name="label" translatable="yes">No internet connection — connect to setup new 
online accounts</property>
+                    <property name="hexpand">True</property>
                   </object>
+                  <packing>
+                    <property name="top-attach">0</property>
+                    <property name="left-attach">2</property>
+                  </packing>
                 </child>
+
                 <child>
-                  <object class="GtkFrame" id="accounts_frame">
+                  <object class="GtkBox">
                     <property name="visible">True</property>
                     <property name="can_focus">False</property>
+                    <property name="spacing">18</property>
+                    <property name="orientation">vertical</property>
+                    <property name="hexpand">True</property>
+                    <property name="width-request">300</property>
+
                     <child>
-                      <object class="GtkListBox" id="accounts_listbox">
+                      <object class="GtkLabel">
                         <property name="visible">True</property>
-                        <property name="can_focus">True</property>
-                        <property name="selection_mode">none</property>
-                        <signal name="row-activated" handler="on_listbox_row_activated" object="CcGoaPanel" 
swapped="yes" />
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Connect to your data in the 
cloud</property>
+                        <attributes>
+                          <attribute name="scale" value="1.66" />
+                        </attributes>
                       </object>
                     </child>
-                  </object>
-                </child>
-                <child>
-                  <object class="GtkLabel">
-                    <property name="visible">True</property>
-                    <property name="can_focus">False</property>
-                    <property name="margin-top">24</property>
-                    <property name="xalign">0</property>
-                    <property name="label" translatable="yes">Add an account</property>
-                    <attributes>
-                      <attribute name="weight" value="bold" />
-                    </attributes>
-                  </object>
-                </child>
-                <child>
-                  <object class="GtkFrame">
-                    <property name="visible">True</property>
-                    <property name="can_focus">False</property>
                     <child>
-                      <object class="GtkListBox" id="providers_listbox">
+                      <object class="GtkLabel" id="offline_label">
                         <property name="visible">True</property>
-                        <property name="can_focus">True</property>
-                        <property name="selection_mode">none</property>
-                        <signal name="row-activated" handler="on_provider_row_activated" object="CcGoaPanel" 
swapped="yes" />
+                        <property name="can_focus">False</property>
+                        <property name="wrap">True</property>
+                        <property name="label" translatable="yes">No internet connection — connect to setup 
new online accounts</property>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkFrame" id="accounts_frame">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <child>
+                          <object class="GtkListBox" id="accounts_listbox">
+                            <property name="visible">True</property>
+                            <property name="can_focus">True</property>
+                            <property name="selection_mode">none</property>
+                            <signal name="row-activated" handler="on_listbox_row_activated" 
object="CcGoaPanel" swapped="yes" />
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="margin-top">24</property>
+                        <property name="xalign">0</property>
+                        <property name="label" translatable="yes">Add an account</property>
+                        <attributes>
+                          <attribute name="weight" value="bold" />
+                        </attributes>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkFrame">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
                         <child>
-                          <object class="GtkListBoxRow" id="more_providers_row">
+                          <object class="GtkListBox" id="providers_listbox">
                             <property name="visible">True</property>
                             <property name="can_focus">True</property>
+                            <property name="selection_mode">none</property>
+                            <signal name="row-activated" handler="on_provider_row_activated" 
object="CcGoaPanel" swapped="yes" />
                             <child>
-                              <object class="GtkImage">
+                              <object class="GtkListBoxRow" id="more_providers_row">
                                 <property name="visible">True</property>
-                                <property name="can_focus">False</property>
-                                <property name="hexpand">True</property>
-                                <property name="margin">12</property>
-                                <property name="icon-name">view-more-symbolic</property>
+                                <property name="can_focus">True</property>
+                                <child>
+                                  <object class="GtkImage">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="hexpand">True</property>
+                                    <property name="margin">12</property>
+                                    <property name="icon-name">view-more-symbolic</property>
+                                  </object>
+                                </child>
                               </object>
                             </child>
                           </object>
@@ -153,6 +192,10 @@
                       </object>
                     </child>
                   </object>
+                  <packing>
+                    <property name="top-attach">0</property>
+                    <property name="left-attach">1</property>
+                  </packing>
                 </child>
               </object>
             </child>