Implement network proxy settings (#174)

- Implement WebKit.NetworkProxy{Mode,Settings}
- Expose the settings under Network preferences

![screenshot from 2018-11-19 22-09-55](https://user-images.githubusercontent.com/1204189/48732351-19d52680-ec48-11e8-923a-b5bb43d444ad.png)

Fixes: #125

3 files changed, 129 insertions, 4 deletions

diff --git a/core/app.vala b/core/app.vala
index 454b1753..7c3e8bd4 100644
--- a/core/app.vala
+++ b/core/app.vala
@@ -133,6 +133,16 @@ namespace Midori {
                 context.get_cookie_manager ().set_accept_policy (
                     settings.first_party_cookies_only ? WebKit.CookieAcceptPolicy.NO_THIRD_PARTY : WebKit.CookieAcceptPolicy.ALWAYS);
             });
+            apply_proxy_settings (settings, context);
+            settings.notify["proxy-type"].connect ((pspec) => {
+                apply_proxy_settings (settings, context);
+            });
+            settings.notify["http-proxy"].connect ((pspec) => {
+                apply_proxy_settings (settings, context);
+            });
+            settings.notify["proxy-port"].connect ((pspec) => {
+                apply_proxy_settings (settings, context);
+            });
 
             add_action_entries (actions, this);
 
@@ -239,6 +249,23 @@ namespace Midori {
             request.unref ();
         }
 
+        void apply_proxy_settings (CoreSettings settings, WebKit.WebContext context) {
+            switch (settings.proxy_type) {
+                case ProxyType.AUTOMATIC:
+                    context.set_network_proxy_settings (WebKit.NetworkProxyMode.DEFAULT, null);
+                    break;
+                case ProxyType.HTTP:
+                    string proxy_uri = "%s:%d".printf (settings.http_proxy, settings.http_proxy_port);
+                    context.set_network_proxy_settings (
+                        WebKit.NetworkProxyMode.CUSTOM,
+                        new WebKit.NetworkProxySettings (proxy_uri, null));
+                    break;
+                case ProxyType.NONE:
+                    context.set_network_proxy_settings (WebKit.NetworkProxyMode.NO_PROXY, null);
+                    break;
+            }
+        }
+
         internal WebKit.WebContext ephemeral_context () {
             var context = new WebKit.WebContext.ephemeral ();
             context.register_uri_scheme ("internal", (request) => {
@@ -270,6 +297,16 @@ namespace Midori {
                 context.get_cookie_manager ().set_accept_policy (
                     settings.first_party_cookies_only ? WebKit.CookieAcceptPolicy.NO_THIRD_PARTY : WebKit.CookieAcceptPolicy.ALWAYS);
             });
+            apply_proxy_settings (settings, context);
+            settings.notify["proxy-type"].connect ((pspec) => {
+                apply_proxy_settings (settings, context);
+            });
+            settings.notify["http-proxy"].connect ((pspec) => {
+                apply_proxy_settings (settings, context);
+            });
+            settings.notify["proxy-port"].connect ((pspec) => {
+                apply_proxy_settings (settings, context);
+            });
             return context;
         }
 
diff --git a/core/preferences.vala b/core/preferences.vala
index 3e406c64..8834d2d9 100644
--- a/core/preferences.vala
+++ b/core/preferences.vala
@@ -17,13 +17,22 @@ namespace Midori {
     }
 
     public class LabelWidget : Gtk.Box {
-        public string title { get; construct set; }
+        public string? title { get; construct set; }
+        protected Gtk.Label label { get; set; }
         public Gtk.Widget? widget { get; construct set; }
+        Gtk.SizeGroup sizegroup = new Gtk.SizeGroup (Gtk.SizeGroupMode.HORIZONTAL);
 
-        public LabelWidget (string title, Gtk.Widget? widget=null) {
+        public LabelWidget (string? title, Gtk.Widget? widget=null) {
             Object (title: title, widget: widget);
         }
 
+        public override void add (Gtk.Widget widget) {
+            base.add (widget);
+            if (widget is LabelWidget) {
+                sizegroup.add_widget (((LabelWidget)widget).label);
+            }
+        }
+
         internal LabelWidget.for_days (string title, Object object, string property) {
             var combo = new Gtk.ComboBoxText ();
             combo.append ("0", _("1 hour"));
@@ -45,14 +54,15 @@ namespace Midori {
             bool header = widget == null;
             orientation = header ? Gtk.Orientation.VERTICAL : Gtk.Orientation.HORIZONTAL;
             halign = Gtk.Align.START;
-            var label = new Gtk.Label.with_mnemonic (header ? "<b>%s</b>".printf (title) : title);
+            label = new Gtk.Label.with_mnemonic (header ? "<b>%s</b>".printf (title) : title);
             label.use_markup = header;
             label.halign = Gtk.Align.START;
             pack_start (label, false, false, 4);
             if (widget != null) {
                 label.mnemonic_widget = widget;
+                widget.margin = 4;
                 set_center_widget (widget);
-                if (widget is Gtk.Entry) {
+                if (widget is Gtk.Entry && !(widget is Gtk.SpinButton)) {
                     ((Gtk.Entry)widget).width_chars = 30;
                 }
             }
@@ -67,6 +77,8 @@ namespace Midori {
         Gtk.Box content_box;
         [GtkChild]
         Gtk.Stack categories;
+        Gtk.SearchEntry proxy;
+        Gtk.SpinButton port;
 
         public Preferences (Gtk.Window parent) {
             Object (transient_for: parent);
@@ -136,6 +148,46 @@ namespace Midori {
             box.show_all ();
             add (_("Browsing"), box);
 
+            box = new LabelWidget (_("Proxy server"));
+            var proxy_chooser = new Gtk.ComboBoxText ();
+            proxy_chooser.append ("0", _("Automatic (GNOME or environment)"));
+            proxy_chooser.append ("2", _("HTTP proxy server"));
+            proxy_chooser.append ("1", _("No proxy server"));
+            settings.bind_property ("proxy-type", proxy_chooser, "active", BindingFlags.SYNC_CREATE | BindingFlags.BIDIRECTIONAL);
+            box.add (new LabelWidget (null, proxy_chooser));
+            proxy = new Gtk.SearchEntry ();
+            proxy.primary_icon_name = null;
+            settings.bind_property ("http-proxy", proxy, "text", BindingFlags.SYNC_CREATE | BindingFlags.BIDIRECTIONAL);
+            box.add (new LabelWidget (_("URI"), proxy));
+            string proxy_types = "http https";
+            foreach (unowned IOExtension proxy in IOExtensionPoint.lookup (IOExtensionPoint.PROXY).get_extensions ()) {
+                if (!proxy_types.contains (proxy.get_name ())) {
+                    proxy_types += " %s".printf (proxy.get_name ());
+                }
+            }
+            proxy.search_changed.connect (() => {
+                string[] parts = settings.http_proxy.split ("://", 2);
+                if (parts[1] == "" || ":" in parts[1] || "/" in parts[1]) {
+                    proxy.get_style_context ().add_class ("error");
+                    return;
+                }
+                foreach (string type in proxy_types.split (" ")) {
+                    if (parts[0] == type) {
+                        proxy.get_style_context ().remove_class ("error");
+                        return;
+                    }
+                }
+                proxy.get_style_context ().add_class ("error");
+            });
+            box.add (new LabelWidget (_("Supported proxy types:"), new Gtk.Label (proxy_types)));
+            port = new Gtk.SpinButton.with_range (1, 65535, 1);
+            settings.bind_property ("http-proxy-port", port, "value", BindingFlags.SYNC_CREATE | BindingFlags.BIDIRECTIONAL);
+            box.add (new LabelWidget (_("Port"), port));
+            settings.notify["proxy-type"].connect (update_proxy_sensitivity);
+            update_proxy_sensitivity ();
+            box.show_all ();
+            add (_("Network"), box);
+
             box = new LabelWidget (_("Cookies and Website data"));
             checkbox = new Gtk.CheckButton.with_mnemonic (_("Only accept Cookies from sites you visit"));
             settings.bind_property ("first-party-cookies-only", checkbox, "active", BindingFlags.SYNC_CREATE | BindingFlags.BIDIRECTIONAL);
@@ -162,6 +214,12 @@ namespace Midori {
             extensions.foreach ((extensions, info, extension) => { extensions.extension_added (info, extension); });
         }
 
+        void update_proxy_sensitivity () {
+            var settings = CoreSettings.get_default ();
+            proxy.sensitive = settings.proxy_type == ProxyType.HTTP;
+            port.sensitive = settings.proxy_type == ProxyType.HTTP;
+        }
+
         /*
          * Add a new category of preferences to be shown in the dialog.
          * An appropriate margin will automatically be added.
diff --git a/core/settings.vala b/core/settings.vala
index 0d3f6ef0..7924fa94 100644
--- a/core/settings.vala
+++ b/core/settings.vala
@@ -18,6 +18,13 @@ namespace Midori {
         DELAYED_PAGES
     }
 
+    [CCode (cprefix = "MIDORI_PROXY_")]
+    public enum ProxyType {
+        AUTOMATIC,
+        HTTP,
+        NONE,
+    }
+
     public class CoreSettings : Settings {
         static CoreSettings? _default = null;
 
@@ -136,6 +143,29 @@ namespace Midori {
             }
         } }
 
+        public ProxyType proxy_type { get {
+            var proxy = get_string ("settings", "proxy-type", "MIDORI_PROXY_AUTOMATIC");
+            if (proxy.has_suffix ("AUTOMATIC")) {
+                return ProxyType.AUTOMATIC;
+            } else if (proxy.has_suffix ("HTTP")) {
+                return ProxyType.HTTP;
+            } else {
+                return ProxyType.NONE;
+            }
+        } set {
+            set_string ("settings", "proxy-type", value.to_string (), "MIDORI_PROXY_AUTOMATIC");
+        } }
+        public string http_proxy { owned get {
+            return get_string ("settings", "http-proxy", "");
+        } set {
+            set_string ("settings", "http-proxy", value);
+        } }
+        public int http_proxy_port { get {
+            return get_string ("settings", "http-proxy-port", "8080").to_int ();
+        } set {
+            set_string ("settings", "http-proxy-port", value.to_string (), "8080");
+        } }
+
         public bool first_party_cookies_only { get {
             return get_boolean ("settings", "first-party-cookies-only", true);
         } set {