taskbar: Make taskbar entries configurable

.gitignore

@@ -10,6 +10,7 @@ base/usr/*
 base/usr/share/*
 !base/usr/share/fonts
 !base/usr/share/icons
+!base/usr/share/applications
 base/etc/skel/LICENSE
 .fakeroot
 kernel/config.cmake

apps/taskbar.cpp

@@ -1,4 +1,8 @@
+#include <luna/Sort.h>
+#include <luna/StringBuilder.h>
+#include <os/Directory.h>
 #include <os/File.h>
+#include <os/FileSystem.h>
 #include <os/IPC.h>
 #include <os/Process.h>
 #include <os/ipc/Launcher.h>
@@ -19,15 +23,20 @@ void sigchld_handler(int)
     wait(nullptr);
 }
 
+void sighup_handler(int)
+{
+    // Reload the taskbar by exec-ing the executable, resetting everything.
+    StringView args[] = { "/usr/bin/taskbar" };
+    os::Process::exec(args[0], { args, 1 });
+}
+
 Result<void> create_widget_group_for_app(ui::HorizontalLayout& layout, StringView path, StringView icon)
 {
-    auto* button = new (std::nothrow) ui::Button({ 0, 0, 50, 50 });
-    if (!button) return err(ENOMEM);
+    auto* button = TRY(make<ui::Button>(ui::Rect { 0, 0, 50, 50 }));
     layout.add_widget(*button);
 
-    auto* container = new (std::nothrow)
-        ui::Container({ 0, 0, 50, 50 }, ui::VerticalAlignment::Center, ui::HorizontalAlignment::Center);
-    if (!container) return err(ENOMEM);
+    auto* container = TRY(
+        make<ui::Container>(ui::Rect { 0, 0, 50, 50 }, ui::VerticalAlignment::Center, ui::HorizontalAlignment::Center));
     button->set_widget(*container);
     button->set_action([=] {
         os::Launcher::LaunchDetachedRequest request;
@@ -43,12 +52,106 @@ Result<void> create_widget_group_for_app(ui::HorizontalLayout& layout, StringVie
     return {};
 }
 
+struct ApplicationFile
+{
+    String name;
+    String command;
+    String icon;
+};
+
+Vector<ApplicationFile> s_app_files;
+
+// Pretty much copied from init.cpp.
+static Result<void> load_application_file(const os::Path& path)
+{
+    os::println("[taskbar] reading app file: %s", path.name().chars());
+
+    auto file = TRY(os::File::open(path, os::File::ReadOnly));
+
+    ApplicationFile app_file;
+
+    while (true)
+    {
+        auto line = TRY(file->read_line());
+        if (line.is_empty()) break;
+
+        line.trim("\n");
+        if (line.is_empty()) continue;
+
+        auto parts = TRY(line.split_once('='));
+        if (parts.size() < 2 || parts[0].is_empty() || parts[1].is_empty())
+        {
+            os::println("[taskbar] file contains invalid line, aborting: '%s'", line.chars());
+            return {};
+        }
+
+        if (parts[0].view() == "Name")
+        {
+            app_file.name = move(parts[1]);
+            continue;
+        }
+
+        if (parts[0].view() == "Description")
+        {
+            // We let users specify this in the config file, but taskbar doesn't actually use it.
+            continue;
+        }
+
+        if (parts[0].view() == "Command")
+        {
+            app_file.command = move(parts[1]);
+            continue;
+        }
+
+        if (parts[0].view() == "Icon")
+        {
+            app_file.icon = move(parts[1]);
+            continue;
+        }
+
+        os::println("[taskbar] skipping unknown entry name %s", parts[0].chars());
+    }
+
+    if (app_file.icon.is_empty())
+    {
+        os::println("[taskbar] app file is missing 'Icon' entry, aborting!");
+        return {};
+    }
+
+    if (app_file.command.is_empty())
+    {
+        os::println("[taskbar] app file is missing 'Command' entry, aborting!");
+        return {};
+    }
+
+    os::println("[taskbar] loaded app %s into memory", app_file.name.chars());
+
+    TRY(s_app_files.try_append(move(app_file)));
+
+    return {};
+}
+
+static Result<void> load_app_files_from_path(StringView path)
+{
+    os::println("[taskbar] loading app files from %s", path.chars());
+
+    auto dir = TRY(os::Directory::open(path));
+
+    auto services = TRY(dir->list_names(os::Directory::Filter::ParentAndBase));
+    sort(services.begin(), services.end(), String::compare);
+
+    for (const auto& entry : services) TRY(load_application_file({ dir->fd(), entry.view() }));
+
+    return {};
+}
+
 Result<int> luna_main(int, char**)
 {
     ui::App app;
     TRY(app.init("/tmp/wsys.sock"));
 
     TRY(os::EventLoop::the().register_signal_handler(SIGCHLD, sigchld_handler));
+    TRY(os::EventLoop::the().register_signal_handler(SIGHUP, sighup_handler));
 
     launcher_client = TRY(os::IPC::Client::connect("/tmp/launch.sock", false));
 
@@ -65,10 +168,21 @@ Result<int> luna_main(int, char**)
     ui::HorizontalLayout layout(ui::Margins { 0, 0, 0, 0 }, ui::AdjustHeight::Yes, ui::AdjustWidth::No);
     window->set_main_widget(layout);
 
-    TRY(create_widget_group_for_app(layout, "/usr/bin/terminal", "/usr/share/icons/32x32/app-terminal.tga"));
-    TRY(create_widget_group_for_app(layout, "/usr/bin/about", "/usr/share/icons/32x32/app-about.tga"));
-    TRY(create_widget_group_for_app(layout, "/usr/bin/gol", "/usr/share/icons/32x32/app-gol.tga"));
-    TRY(create_widget_group_for_app(layout, "/usr/bin/clock", "/usr/share/icons/32x32/app-clock.tga"));
+    load_app_files_from_path("/usr/share/applications/");
+
+    auto home = TRY(os::FileSystem::home_directory());
+
+    StringBuilder sb;
+    TRY(sb.add(home.view()));
+    TRY(sb.add("/.applications/"_sv));
+    auto local_app_file_dir = TRY(sb.string());
+
+    load_app_files_from_path(local_app_file_dir.view());
+
+    for (const auto& app_file : s_app_files)
+    {
+        create_widget_group_for_app(layout, app_file.command.view(), app_file.icon.view());
+    }
 
     return app.run();
 }

base/usr/share/applications/00-terminal

@@ -0,0 +1,3 @@
+Name=terminal
+Icon=/usr/share/icons/32x32/app-terminal.tga
+Command=/usr/bin/terminal

base/usr/share/applications/01-about

@@ -0,0 +1,3 @@
+Name=about
+Icon=/usr/share/icons/32x32/app-about.tga
+Command=/usr/bin/about

base/usr/share/applications/02-gol

@@ -0,0 +1,3 @@
+Name=gol
+Icon=/usr/share/icons/32x32/app-gol.tga
+Command=/usr/bin/gol

base/usr/share/applications/03-clock

@@ -0,0 +1,3 @@
+Name=clock
+Icon=/usr/share/icons/32x32/app-clock.tga
+Command=/usr/bin/clock