First half of #5084. This adds the framework for the help system.

CMakeLists.txt

@@ -22,6 +22,7 @@ add_subdirectory(src)
 add_subdirectory(icons)
 add_subdirectory(sql)
 add_subdirectory(ui)
+add_subdirectory(help)
 
 #
 # Install geary.desktop

help/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(HELP_DEST share/gnome/help/geary/C)
+
+set(HELP_FILES
+    index.page
+)
+
+install(FILES ${HELP_FILES} DESTINATION ${HELP_DEST})
+

help/index.page

@@ -0,0 +1,5 @@
+<page xmlns="http://projectmallard.org/1.0/" type="guide" id="index">
+    <title>Geary Help</title>
+    <p>Documentation coming soon</p>
+</page>
+

src/client/geary-application.vala

@@ -128,7 +128,7 @@ along with Geary; if not, write to the Free Software Foundation, Inc.,
     
     public override int startup() {
         exec_dir = (File.new_for_path(Environment.find_program_in_path(args[0]))).get_parent();
-        Configuration.init(GearyApplication.instance.get_install_dir() != null, GSETTINGS_DIR);
+        Configuration.init(is_installed(), GSETTINGS_DIR);
         
         int result = base.startup();
         result = parse_arguments(args);
@@ -286,7 +286,11 @@ along with Geary; if not, write to the Free Software Foundation, Inc.,
     public File get_exec_dir() {
         return exec_dir;
     }
-    
+
+    public bool is_installed() {
+        return exec_dir.has_prefix(File.new_for_path(INSTALL_PREFIX));
+    }
+
     // Returns the installation directory, or null if we're running outside of the installation
     // directory.
     public File? get_install_dir() {

src/client/geary-controller.vala

@@ -35,6 +35,7 @@ public class GearyController {
     }
     
     // Named actions.
+    public const string ACTION_HELP = "GearyHelp";
     public const string ACTION_ABOUT = "GearyAbout";
     public const string ACTION_QUIT = "GearyQuit";
     public const string ACTION_NEW_MESSAGE = "GearyNewMessage";
@@ -126,7 +127,11 @@ public class GearyController {
             null, on_preferences };
         prefs.label = _("_Preferences");
         entries += prefs;
-        
+
+        Gtk.ActionEntry help = { ACTION_HELP, Gtk.Stock.HELP, TRANSLATABLE, null, null, on_help };
+        help.label = _("_Help");
+        entries += help;
+
         Gtk.ActionEntry about = { ACTION_ABOUT, Gtk.Stock.ABOUT, TRANSLATABLE, null, null, on_about };
         about.label = _("_About");
         entries += about;
@@ -651,7 +656,34 @@ public class GearyController {
     public void on_quit() {
         GearyApplication.instance.exit();
     }
-    
+
+    private void on_help() {
+        try {
+            if (GearyApplication.instance.is_installed()) {
+                Gtk.show_uri(null, "ghelp:geary", Gdk.CURRENT_TIME);
+            } else {
+                Pid pid;
+                File exec_dir = GearyApplication.instance.get_exec_dir();
+                string[] argv = new string[3];
+                argv[0] = "gnome-help";
+                argv[1] = exec_dir.get_parent().get_child("help").get_path();
+                argv[2] = null;
+                if (!Process.spawn_async(exec_dir.get_path(), argv, null,
+                    SpawnFlags.SEARCH_PATH | SpawnFlags.STDERR_TO_DEV_NULL, null, out pid)) {
+                    debug("Failed to launch help locally.");
+                }
+            }
+        } catch (Error error) {
+            debug("Error showing help: %s", error.message);
+            Gtk.Dialog dialog = new Gtk.Dialog.with_buttons("Error", null,
+                Gtk.DialogFlags.DESTROY_WITH_PARENT, Gtk.Stock.CLOSE, Gtk.ResponseType.CLOSE, null);
+            dialog.response.connect(() => { dialog.destroy(); });
+            dialog.get_content_area().add(new Gtk.Label("Error showing help: %s".printf(error.message)));
+            dialog.show_all();
+            dialog.run();
+        }
+    }
+
     public void on_about() {
         Gtk.show_about_dialog(main_window,
             "program-name", GearyApplication.NAME,

ui/toolbar_menu.ui

@@ -2,6 +2,7 @@
     <popup name="ToolbarMenu">
         <menuitem name="Preferences" action="GearyPreferences" />
         <separator />
+        <menuitem name="Help" action="GearyHelp" />
         <menuitem name="About" action="GearyAbout" />
         <separator />
         <menuitem name="Quit" action="GearyQuit" />