Implement speed dial based on recent history (#15)

![screenshot from 2018-08-18 20-45-09](https://user-images.githubusercontent.com/1204189/44302400-03a58a80-a328-11e8-8c4f-88be485e7920.png)
The speed dial is implemented as an "internal" scheme handler, which won't require special-casing on the UX side except using "internal:speed-dial" as a default URI in Midori.Tab and recognizing it as "empty" in Midori.Urlbar.
All items are populated automatically from the history and use favicons.

6 files changed, 163 insertions, 19 deletions

diff --git a/core/app.vala b/core/app.vala
index 1fdd4d48..2c0e3b35 100644
--- a/core/app.vala
+++ b/core/app.vala
@@ -60,22 +60,17 @@ namespace Midori {
             Gtk.Window.set_default_icon_name (Config.PROJECT_NAME);
 
             var context = WebKit.WebContext.get_default ();
+            context.register_uri_scheme ("internal", (request) => {
+                request.ref ();
+                internal_scheme.begin (request);
+            });
+            context.register_uri_scheme ("favicon", (request) => {
+                request.ref ();
+                favicon_scheme.begin (request);
+            });
             context.register_uri_scheme ("stock", (request) => {
-                string icon_name = request.get_path ().substring (1, -1);
-                int icon_size = 48;
-                Gtk.icon_size_lookup ((Gtk.IconSize)Gtk.IconSize.DIALOG, out icon_size, null);
-                try {
-                    var icon = Gtk.IconTheme.get_default ().load_icon (icon_name, icon_size, Gtk.IconLookupFlags.FORCE_SYMBOLIC);
-                    var output = new MemoryOutputStream (null, realloc, free);
-                    icon.save_to_stream (output, "png");
-                    output.close ();
-                    uint8[] data = output.steal_data ();
-                    data.length = (int)output.get_data_size ();
-                    var stream = new MemoryInputStream.from_data (data, free);
-                    request.finish (stream, -1, null);
-                } catch (Error error) {
-                    critical ("Failed to load icon %s: %s", icon_name, error.message);
-                }
+                request.ref ();
+                stock_scheme.begin (request);
             });
             context.register_uri_scheme ("res", (request) => {
                 try {
@@ -83,6 +78,7 @@ namespace Midori {
                                                         ResourceLookupFlags.NONE);
                     request.finish (stream, -1, null);
                 } catch (Error error) {
+                    request.finish_error (error);
                     critical ("Failed to load resource %s: %s", request.get_uri (), error.message);
                 }
             });
@@ -119,6 +115,79 @@ namespace Midori {
             }
         }
 
+        async void internal_scheme (WebKit.URISchemeRequest request) {
+            try {
+                var shortcuts = yield HistoryDatabase.get_default ().query (null, 9);
+                string content = "";
+                uint index = 0;
+                foreach (var shortcut in shortcuts) {
+                    index++;
+                    content += """
+                        <div class="shortcut">
+                          <a href="%s" accesskey="%u">
+                            <img src="%s" />
+                            <span class="title">%s</span>
+                          </a>
+                        </div>""".printf (shortcut.uri, index, "favicon:///" + shortcut.uri, shortcut.title);
+                }
+                string stylesheet = (string)resources_lookup_data ("/data/about.css",
+                                                                    ResourceLookupFlags.NONE).get_data ();
+                string html = ((string)resources_lookup_data ("/data/speed-dial.html",
+                                                             ResourceLookupFlags.NONE).get_data ())
+                    .replace ("{title}", _("Speed Dial"))
+                    .replace ("{icon}", "view-grid")
+                    .replace ("{content}", content)
+                    .replace ("{stylesheet}", stylesheet);
+                var stream = new MemoryInputStream.from_data (html.data, free);
+                request.finish (stream, html.length, "text/html");
+            } catch (Error error) {
+                request.finish_error (error);
+                critical ("Failed to render %s: %s", request.get_uri (), error.message);
+            }
+            request.unref ();
+        }
+
+        void request_finish_pixbuf (WebKit.URISchemeRequest request, Gdk.Pixbuf pixbuf) throws Error {
+            var output = new MemoryOutputStream (null, realloc, free);
+            pixbuf.save_to_stream (output, "png");
+            output.close ();
+            uint8[] data = output.steal_data ();
+            data.length = (int)output.get_data_size ();
+            var stream = new MemoryInputStream.from_data (data, free);
+            request.finish (stream, -1, null);
+        }
+
+        async void favicon_scheme (WebKit.URISchemeRequest request) {
+            string page_uri = request.get_path ().substring (1, -1);
+            try {
+                var database = WebKit.WebContext.get_default ().get_favicon_database ();
+                var surface = yield database.get_favicon (page_uri, null);
+                if (surface != null) {
+                    var image = (Cairo.ImageSurface)surface;
+                    var icon = Gdk.pixbuf_get_from_surface (image, 0, 0, image.get_width (), image.get_height ());
+                    request_finish_pixbuf (request, icon);
+                }
+            } catch (Error error) {
+                request.finish_error (error);
+                debug ("Failed to render favicon for %s: %s", page_uri, error.message);
+            }
+            request.unref ();
+        }
+
+        async void stock_scheme (WebKit.URISchemeRequest request) {
+            string icon_name = request.get_path ().substring (1, -1);
+            int icon_size = 48;
+            Gtk.icon_size_lookup ((Gtk.IconSize)Gtk.IconSize.DIALOG, out icon_size, null);
+            try {
+                var icon = Gtk.IconTheme.get_default ().load_icon (icon_name, icon_size, Gtk.IconLookupFlags.FORCE_SYMBOLIC);
+                request_finish_pixbuf (request, icon);
+            } catch (Error error) {
+                request.finish_error (error);
+                critical ("Failed to load icon %s: %s", icon_name, error.message);
+            }
+            request.unref ();
+        }
+
         void win_new_activated (Action action, Variant? parameter) {
             var browser = incognito
                 ? new Browser.incognito (this)
diff --git a/core/tab.vala b/core/tab.vala
index ef8916e7..1592e719 100644
--- a/core/tab.vala
+++ b/core/tab.vala
@@ -55,7 +55,7 @@ namespace Midori {
             get_settings ().enable_developer_extras = true;
 
             if (pinned) {
-                load_uri (uri ?? "about:blank");
+                load_uri (uri ?? "internal:speed-dial");
                 Plugins.get_default ().plug (this);
             } else {
                 load_uri_delayed.begin (uri, title);
@@ -63,7 +63,7 @@ namespace Midori {
         }
 
         async void load_uri_delayed (string? uri, string? title) {
-            display_uri = uri ?? "about:blank";
+            display_uri = uri ?? "internal:speed-dial";
             display_title = title ?? display_uri;
             item = new DatabaseItem (display_uri, display_title, 0);
 
diff --git a/core/urlbar.vala b/core/urlbar.vala
index 8cba903a..7f54cb88 100644
--- a/core/urlbar.vala
+++ b/core/urlbar.vala
@@ -35,7 +35,7 @@ namespace Midori {
             }
             primary_icon_activatable = !blank;
         } }
-        bool blank { get { return uri == "about:blank"; } }
+        bool blank { get { return uri == "about:blank" || uri == "internal:speed-dial"; } }
 
         [GtkChild]
         Gtk.Popover? suggestions;
@@ -164,7 +164,7 @@ namespace Midori {
                     complete ();
                     return true;
                 case Gdk.Key.Escape:
-                    text = uri;
+                    text = blank ? "" : uri;
                     // Propagate to allow Escape to stop loading
                     return false;
             }
diff --git a/data/about.css b/data/about.css
index a346ef09..ab1d85ff 100644
--- a/data/about.css
+++ b/data/about.css
@@ -71,3 +71,53 @@ button {
     font-size: 14pt;
     text-align: right;
 }
+
+#grid {
+    margin: auto auto;
+}
+
+.shortcut {
+    width: 27%;
+    max-width: 32%;
+    height: 30%;
+    margin: 1%;
+    display: inline-table;
+    box-sizing: border-box;
+    overflow: hidden;
+}
+
+.shortcut a {
+    width: 100%;
+    height: 100%;
+    display: block;
+    text-decoration: none;
+}
+
+.shortcut a img {
+    width: 50%;
+    height: 50%;
+    margin: auto;
+    margin-bottom: .5em;
+    display: block;
+    border-radius: 12px;
+    box-shadow: 0 1px 3px rgba(0,0,0,0.12),
+                0 1px 2px rgba(0,0,0,0.24);
+}
+
+.shortcut a:hover img {
+    box-shadow: 0 3px 5px rgba(0,0,0,0.24),
+                0 3px 4px rgba(0,0,0,0.48);
+}
+
+.shortcut a .title {
+    width: 90%;
+    color: #222222;
+    text-align: center;
+    text-overflow: ellipsis;
+    word-wrap: nowrap;
+    max-height: 2em;
+    line-height: 1em;
+    overflow: hidden;
+    display: block;
+    font-size: 70%;
+}
diff --git a/data/speed-dial.html b/data/speed-dial.html
new file mode 100644
index 00000000..c1e89d36
--- /dev/null
+++ b/data/speed-dial.html
@@ -0,0 +1,24 @@
+<!--
+ Copyright (C) 2018 Christian Dywan <christian@twotoats.de>
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ See the file COPYING for the full license text.
+-->
+<html>
+  <head>
+    <title>{title}</title>
+    <link ref="shortcut icon" href="stock:///{icon}" />
+    <style type="text/css">
+      {stylesheet}
+    </style>
+  </head>
+  <body>
+    <div id="grid">
+      {content}
+    </div>
+  </body>
+</html>
diff --git a/gresource.xml b/gresource.xml
index 0aaa1b4e..86a438ed 100644
--- a/gresource.xml
+++ b/gresource.xml
@@ -13,6 +13,7 @@
   <gresource prefix="/">
     <file compressed="true">data/about.css</file>
     <file compressed="true">data/error.html</file>
+    <file compressed="true">data/speed-dial.html</file>
     <file compressed="true">data/gtk3.css</file>
     <file compressed="true">data/logo-shade.svg</file>
     <file compressed="true">data/history/Create.sql</file>