Create a display scaling view

data/io.elementary.onboarding.gresource.xml

@@ -7,4 +7,8 @@
     <file compressed="true" preprocess="xml-stripblanks">appearance-dark.svg</file>
     <file compressed="true" preprocess="xml-stripblanks">appearance-scheduled.svg</file>
   </gresource>
+  <gresource prefix="io/elementary/onboarding/icons">
+    <file alias ="64x64/categories/preferences-desktop-display-scale.svg" compressed="true">icons/preferences-desktop-display.svg</file>
+    <file alias ="64x64@2/categories/preferences-desktop-display-scale.svg" compressed="true">icons/preferences-desktop-display.svg</file>
+  </gresource>
 </gresources>

po/POTFILES

@@ -10,5 +10,6 @@ src/Views/HouseKeepingView.vala
 src/Views/NightLightView.vala
 src/Views/OnlineAccountsView.vala
 src/Views/StyleView.vala
+src/Views/UIScaleView.vala
 src/Views/UpdatesView.vala
 src/Views/WelcomeView.vala

src/Application.vala

@@ -5,7 +5,7 @@
 
 public class Onboarding.App : Gtk.Application {
     construct {
-        application_id = "io.elementary.installer";
+        application_id = "io.elementary.onboarding";
         flags = ApplicationFlags.FLAGS_NONE;
         Intl.setlocale (LocaleCategory.ALL, "");
         Intl.bindtextdomain (Onboarding.GETTEXT_PACKAGE, Onboarding.LOCALEDIR);

src/Interfaces/MutterDisplayConfig.vala

@@ -0,0 +1,99 @@
+/*-
+ * Copyright (c) 2018 elementary LLC.
+ *
+ * This software is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this software; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ * Authored by: Corentin Noël <corentin@elementary.io>
+ */
+
+[DBus (name = "org.gnome.Mutter.DisplayConfig")]
+public interface MutterDisplayConfigInterface : Object {
+    public signal void monitors_changed ();
+    public abstract void get_current_state (out uint serial, out MutterReadMonitor[] monitors, out MutterReadLogicalMonitor[] logical_monitors, out GLib.HashTable<string, GLib.Variant> properties) throws Error;
+    public abstract void apply_monitors_config (uint serial, MutterApplyMethod method, MutterWriteLogicalMonitor[] logical_monitors, GLib.HashTable<string, GLib.Variant> properties) throws Error;
+}
+
+[CCode (type_signature = "u")]
+public enum MutterApplyMethod {
+    VERIFY = 0,
+    TEMPORARY = 1,
+    PERSISTENT = 2
+}
+
+[CCode (type_signature = "u")]
+public enum DisplayTransform {
+    NORMAL = 0,
+    ROTATION_90 = 1,
+    ROTATION_180 = 2,
+    ROTATION_270 = 3,
+    FLIPPED = 4,
+    FLIPPED_ROTATION_90 = 5,
+    FLIPPED_ROTATION_180 = 6,
+    FLIPPED_ROTATION_270 = 7;
+}
+
+public struct MutterReadMonitorInfo {
+    public string connector;
+    public string vendor;
+    public string product;
+    public string serial;
+    public uint hash {
+        get {
+            return (connector + vendor + product + serial).hash ();
+        }
+    }
+}
+
+public struct MutterReadMonitorMode {
+    public string id;
+    public int width;
+    public int height;
+    public double frequency;
+    public double preferred_scale;
+    public double[] supported_scales;
+    public GLib.HashTable<string, GLib.Variant> properties;
+}
+
+public struct MutterReadMonitor {
+    public MutterReadMonitorInfo monitor;
+    public MutterReadMonitorMode[] modes;
+    public GLib.HashTable<string, GLib.Variant> properties;
+}
+
+public struct MutterReadLogicalMonitor {
+    public int x;
+    public int y;
+    public double scale;
+    public DisplayTransform transform;
+    public bool primary;
+    public MutterReadMonitorInfo[] monitors;
+    public GLib.HashTable<string, GLib.Variant> properties;
+}
+
+public struct MutterWriteMonitor {
+    public string connector;
+    public string monitor_mode;
+    public GLib.HashTable<string, GLib.Variant> properties;
+}
+
+public struct MutterWriteLogicalMonitor {
+    public int x;
+    public int y;
+    public double scale;
+    public DisplayTransform transform;
+    public bool primary;
+    public MutterWriteMonitor[] monitors;
+}