Description: Adjust settings for HiDPI display.
Author: Shih-Yuan Lee (FourDollars) <sylee@canonical.com>
Bug: https://bugs.launchpad.net/bugs/1382291
---
This patch header follows DEP-3: http://dep.debian.net/deps/dep3/
Index: unity-settings-daemon/plugins/xsettings/gsd-xsettings-manager.c
===================================================================
--- unity-settings-daemon.orig/plugins/xsettings/gsd-xsettings-manager.c	2014-10-16 14:41:43.000000000 +0800
+++ unity-settings-daemon/plugins/xsettings/gsd-xsettings-manager.c	2014-11-06 09:44:42.041249381 +0800
@@ -29,6 +29,7 @@
 #include <string.h>
 #include <errno.h>
 #include <time.h>
+#include <math.h>
 
 #include <X11/Xatom.h>
 
@@ -52,6 +53,12 @@
 #define SOUND_SETTINGS_SCHEMA     "org.gnome.desktop.sound"
 #define PRIVACY_SETTINGS_SCHEMA     "org.gnome.desktop.privacy"
 
+#define UNITY_GSETTINGS_SCHEMA "com.ubuntu.user-interface"
+#define SCALE_FACTOR_KEY       "scale-factor"
+#define UI_SCALE_DEFAULT       8.0
+#define GNOME_GSETTINGS_SCHEMA "org.gnome.desktop.interface"
+#define SCALING_FACTOR_KEY     "scaling-factor"
+
 #define XSETTINGS_PLUGIN_SCHEMA "org.gnome.settings-daemon.plugins.xsettings"
 #define XSETTINGS_OVERRIDE_KEY  "overrides"
 
@@ -960,6 +967,81 @@
                                                                NULL);
 }
 
+static GVariant*
+add_dict_entry (GVariant *dict, const char *key, int value)
+{
+        GVariantBuilder builder;
+        GVariantIter iter;
+
+        const gchar *k;
+        guint32 v;
+
+        g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{si}"));
+        g_variant_iter_init (&iter, dict);
+
+        while (g_variant_iter_next (&iter, "{&si}", &k, &v))
+        {
+                if (!g_str_equal (k, key))
+                        g_variant_builder_add (&builder, "{si}", k, v);
+        }
+        g_variant_builder_add (&builder, "{si}", key, value);
+
+        return g_variant_builder_end (&builder);
+}
+
+static void adjust_settings_for_hidpi_display ()
+{
+        GSettings *unity   = g_settings_new (UNITY_GSETTINGS_SCHEMA);
+        GVariant  *dict    = g_settings_get_value (unity, SCALE_FACTOR_KEY);
+        GdkScreen *screen  = gdk_screen_get_default ();
+        gint       primary = gdk_screen_get_primary_monitor (screen);
+        gint       length  = gdk_screen_get_n_monitors (screen);
+        gint       i;
+
+        for (i = 0; i < length; i++) {
+                GdkRectangle area;
+                gchar *monitor;
+                gint width_mm, height_mm, ppi, value;
+                gdouble diagonal, diagonal_mm;
+                GVariant *new_dict;
+
+                monitor = gdk_screen_get_monitor_plug_name (screen, i);
+
+                if (g_variant_lookup (dict, monitor, "i", &value)) {
+                        g_free (monitor);
+                        continue;
+                }
+
+                gdk_screen_get_monitor_geometry (screen, i, &area);
+
+                diagonal = sqrt (area.width * area.width + area.height * area.height);
+
+                width_mm = gdk_screen_get_monitor_width_mm (screen, i);
+                height_mm = gdk_screen_get_monitor_height_mm (screen, i);
+
+                diagonal_mm = sqrt (width_mm * width_mm + height_mm * height_mm);
+                ppi = (gint) (diagonal * 25.4 / diagonal_mm);
+
+                if (ppi >= 192 && area.height >= 1200)
+                        value = UI_SCALE_DEFAULT * 2;
+                else
+                        value = UI_SCALE_DEFAULT;
+
+                new_dict = add_dict_entry (dict, monitor, value);
+                g_settings_set_value (unity, SCALE_FACTOR_KEY, new_dict);
+                g_variant_unref (dict);
+                dict = new_dict;
+
+                if (i == primary && ppi >= 192 && area.height >= 1200) {
+                        GSettings *gnome = g_settings_new (GNOME_GSETTINGS_SCHEMA);
+                        g_settings_set_uint (gnome, SCALING_FACTOR_KEY, 2);
+                        g_object_unref (gnome);
+                }
+        }
+
+        g_object_unref (unity);
+}
+
 gboolean
 gnome_xsettings_manager_start (GnomeXSettingsManager *manager,
                                GError               **error)
@@ -978,6 +1060,8 @@
                 return FALSE;
         }
 
+        adjust_settings_for_hidpi_display();
+
         manager->priv->settings = g_hash_table_new_full (g_str_hash, g_str_equal,
                                                          NULL, (GDestroyNotify) g_object_unref);
 
Index: unity-settings-daemon/plugins/xsettings/Makefile.am
===================================================================
--- unity-settings-daemon.orig/plugins/xsettings/Makefile.am	2014-10-16 14:41:43.000000000 +0800
+++ unity-settings-daemon/plugins/xsettings/Makefile.am	2014-11-03 20:48:23.000000000 +0800
@@ -44,6 +44,7 @@
 usd_test_xsettings_CFLAGS = $(test_gtk_modules_CFLAGS)
 usd_test_xsettings_CPPFLAGS = $(test_gtk_modules_CPPFLAGS) -I$(top_srcdir)/plugins/common
 usd_test_xsettings_LDADD = $(test_gtk_modules_LDADD)
+usd_test_xsettings_LDFLAGS = -lm
 
 plugin_LTLIBRARIES = \
 	libxsettings.la		\
@@ -76,6 +77,7 @@
 	$(AM_CFLAGS)
 
 libxsettings_la_LDFLAGS = 	\
+	-lm			\
 	$(GSD_PLUGIN_LDFLAGS)	\
 	$(NULL)