wf-panel: hot-reload css (#240)

* wf-shell-app: create user css directory
wf-shell-app: watch user css directory for changes
wf-panel: on css file change load changes to css

* uncrustify

* uncrustify

* panel: populate default css on first run
panel: build default css to prefix

* uncrustify

data/css/default.css

@@ -0,0 +1,9 @@
+.wf-panel .launcher image {
+    transition: 500ms linear;
+    -gtk-icon-transform: scale(0.8);
+}
+
+.wf-panel .launcher:hover image {
+    transition: 500ms linear;
+    -gtk-icon-transform: scale(1.2);
+}

data/css/meson.build

@@ -0,0 +1 @@
+install_data('default.css', install_dir: join_paths(resource_dir, 'css'))

data/meson.build

@@ -11,3 +11,5 @@ install_data(join_paths('icons', '192x192', 'wayfire.png'), install_dir: join_pa
 install_data(join_paths('icons', '256x256', 'wayfire.png'), install_dir: join_paths(get_option('prefix'), 'share', 'icons', 'hicolor', '256x256', 'apps'))
 install_data(join_paths('icons', '512x512', 'wayfire.png'), install_dir: join_paths(get_option('prefix'), 'share', 'icons', 'hicolor', '512x512', 'apps'))
 install_data(join_paths('icons', 'scalable', 'wayfire.svg'), install_dir: join_paths(get_option('prefix'), 'share', 'icons', 'hicolor', 'scalable', 'apps'))
+
+subdir('css')

meson.build

@@ -43,6 +43,7 @@ sysconf_dir = join_paths(get_option('prefix'), get_option('sysconfdir'))
 
 icon_dir = join_paths(get_option('prefix'), 'share', 'wayfire', 'icons')
 add_project_arguments('-DICONDIR="' + icon_dir + '"', language : 'cpp')
+add_project_arguments('-DRESOURCEDIR="' + resource_dir + '"', language : 'cpp')
 add_project_arguments('-DMETADATA_DIR="' + metadata_dir + '"', language : 'cpp')
 add_project_arguments('-DSYSCONF_DIR="' + sysconf_dir + '"', language : 'cpp')
 

src/panel/panel.cpp

@@ -11,6 +11,7 @@
 #include <sstream>
 
 #include <map>
+#include <filesystem>
 
 #include "panel.hpp"
 #include "../util/gtk-utils.hpp"
@@ -103,7 +104,6 @@ class WayfirePanel::impl
     };
 
     WfOption<int> minimal_panel_height{"panel/minimal_height"};
-    WfOption<std::string> css_path{"panel/css_path"};
 
     void create_window()
     {
@@ -119,18 +119,6 @@ class WayfirePanel::impl
         bg_color.set_callback(on_window_color_updated);
         on_window_color_updated(); // set initial color
 
-        if ((std::string)css_path != "")
-        {
-            auto css = load_css_from_path(css_path);
-            if (css)
-            {
-                auto screen = Gdk::Screen::get_default();
-                auto style_context = Gtk::StyleContext::create();
-                style_context->add_provider_for_screen(
-                    screen, css, GTK_STYLE_PROVIDER_PRIORITY_USER);
-            }
-        }
-
         window->show_all();
         init_widgets();
         init_layout();
@@ -390,6 +378,56 @@ void WayfirePanelApp::on_config_reload()
     }
 }
 
+void WayfirePanelApp::on_css_reload()
+{
+    clear_css_rules();
+    /* Add user directory */
+    std::string ext(".css");
+    for (auto & p : std::filesystem::directory_iterator(get_css_config_dir()))
+    {
+        if (p.path().extension() == ext)
+        {
+            add_css_file(p.path().string());
+        }
+    }
+
+    /* Add one user file */
+    auto custom_css_config = WfOption<std::string>{"panel/css_path"};
+    std::string custom_css = custom_css_config;
+    if (custom_css != "")
+    {
+        add_css_file(custom_css);
+    }
+}
+
+void WayfirePanelApp::clear_css_rules()
+{
+    auto screen = Gdk::Screen::get_default();
+    auto style_context = Gtk::StyleContext::create();
+    for (auto css_provider : css_rules)
+    {
+        style_context->remove_provider_for_screen(screen, css_provider);
+    }
+
+    css_rules.clear();
+}
+
+void WayfirePanelApp::add_css_file(std::string file)
+{
+    auto screen = Gdk::Screen::get_default();
+    auto style_context = Gtk::StyleContext::create();
+    if (file != "")
+    {
+        auto css_provider = load_css_from_path(file);
+        if (css_provider)
+        {
+            style_context->add_provider_for_screen(
+                screen, css_provider, GTK_STYLE_PROVIDER_PRIORITY_USER);
+            css_rules.push_back(css_provider);
+        }
+    }
+}
+
 void WayfirePanelApp::handle_new_output(WayfireOutput *output)
 {
     priv->panels[output] = std::unique_ptr<WayfirePanel>(

src/panel/panel.hpp

@@ -4,6 +4,7 @@
 #include <memory>
 #include <wayland-client.h>
 #include <gtkmm/window.h>
+#include <gtkmm/cssprovider.h>
 
 #include "wf-shell-app.hpp"
 
@@ -35,11 +36,16 @@ class WayfirePanelApp : public WayfireShellApp
     void handle_new_output(WayfireOutput *output) override;
     void handle_output_removed(WayfireOutput *output) override;
     void on_config_reload() override;
+    void on_css_reload() override;
 
   private:
     WayfirePanelApp(int argc, char **argv);
 
+    void clear_css_rules();
+    void add_css_file(std::string file);
+
     class impl;
+    std::vector<Glib::RefPtr<Gtk::CssProvider>> css_rules;
     std::unique_ptr<impl> priv;
 };
 

src/util/wf-shell-app.cpp

@@ -3,6 +3,7 @@
 #include <sys/inotify.h>
 #include <gdk/gdkwayland.h>
 #include <iostream>
+#include <filesystem>
 #include <memory>
 #include <wayfire/config/file.hpp>
 
@@ -29,6 +30,40 @@ std::string WayfireShellApp::get_config_file()
     return config_dir + "/wf-shell.ini";
 }
 
+std::string WayfireShellApp::get_css_config_dir()
+{
+    if (cmdline_css.has_value())
+    {
+        return cmdline_config.value();
+    }
+
+    std::string config_dir;
+
+    char *config_home = getenv("XDG_CONFIG_HOME");
+    if (config_home == NULL)
+    {
+        config_dir = std::string(getenv("HOME")) + "/.config";
+    } else
+    {
+        config_dir = std::string(config_home);
+    }
+
+    auto css_directory = config_dir + "/wf-shell/css/";
+    /* Ensure it exists */
+    bool created = std::filesystem::create_directories(css_directory);
+    if (created)
+    {
+        std::string default_css = (std::string)RESOURCEDIR + "/css/default.css";
+        std::string destination = css_directory + "default.css";
+        if (std::filesystem::exists(default_css))
+        {
+            std::filesystem::copy(default_css, destination);
+        }
+    }
+
+    return css_directory;
+}
+
 bool WayfireShellApp::parse_cfgfile(const Glib::ustring & option_name,
     const Glib::ustring & value, bool has_value)
 {
@@ -37,9 +72,25 @@ bool WayfireShellApp::parse_cfgfile(const Glib::ustring & option_name,
     return true;
 }
 
+bool WayfireShellApp::parse_cssfile(const Glib::ustring & option_name,
+    const Glib::ustring & value, bool has_value)
+{
+    std::cout << "Using custom css directory " << value << std::endl;
+    cmdline_css = value;
+    return true;
+}
+
 #define INOT_BUF_SIZE (1024 * sizeof(inotify_event))
 char buf[INOT_BUF_SIZE];
 
+static void do_reload_css(WayfireShellApp *app)
+{
+    app->on_css_reload();
+    inotify_add_watch(app->inotify_css_fd,
+        app->get_css_config_dir().c_str(),
+        IN_CREATE | IN_MODIFY | IN_DELETE | IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE);
+}
+
 /* Reload file and add next inotify watch */
 static void do_reload_config(WayfireShellApp *app)
 {
@@ -59,6 +110,15 @@ static bool handle_inotify_event(WayfireShellApp *app, Glib::IOCondition cond)
     return true;
 }
 
+static bool handle_css_inotify_event(WayfireShellApp *app, Glib::IOCondition cond)
+{
+    /* read, but don't use */
+    read(app->inotify_css_fd, buf, INOT_BUF_SIZE);
+    do_reload_css(app);
+
+    return true;
+}
+
 static void registry_add_object(void *data, struct wl_registry *registry,
     uint32_t name, const char *interface, uint32_t version)
 {
@@ -107,10 +167,15 @@ void WayfireShellApp::on_activate()
 
     inotify_fd = inotify_init();
     do_reload_config(this);
+    inotify_css_fd = inotify_init();
+    do_reload_css(this);
 
     Glib::signal_io().connect(
         sigc::bind<0>(&handle_inotify_event, this),
         inotify_fd, Glib::IO_IN | Glib::IO_HUP);
+    Glib::signal_io().connect(
+        sigc::bind<0>(&handle_css_inotify_event, this),
+        inotify_css_fd, Glib::IO_IN | Glib::IO_HUP);
 
     // Hook up monitor tracking
     auto display = Gdk::Display::get_default();
@@ -155,6 +220,9 @@ WayfireShellApp::WayfireShellApp(int argc, char **argv)
     app->add_main_option_entry(
         sigc::mem_fun(this, &WayfireShellApp::parse_cfgfile),
         "config", 'c', "config file to use", "file");
+    app->add_main_option_entry(
+        sigc::mem_fun(this, &WayfireShellApp::parse_cssfile),
+        "css", 's', "css style directory to use", "directory");
 
     // Activate app after parsing command line
     app->signal_command_line().connect_notify([=] (auto&)

src/util/wf-shell-app.hpp

@@ -42,6 +42,7 @@ class WayfireShellApp
      * wf-shell-app */
     static std::unique_ptr<WayfireShellApp> instance;
     std::optional<std::string> cmdline_config;
+    std::optional<std::string> cmdline_css;
 
     Glib::RefPtr<Gtk::Application> app;
 
@@ -53,25 +54,32 @@ class WayfireShellApp
     virtual void on_activate();
     virtual bool parse_cfgfile(const Glib::ustring & option_name,
         const Glib::ustring & value, bool has_value);
+    virtual bool parse_cssfile(const Glib::ustring & option_name,
+        const Glib::ustring & value, bool has_value);
     virtual void handle_new_output(WayfireOutput *output)
     {}
     virtual void handle_output_removed(WayfireOutput *output)
     {}
 
   public:
     int inotify_fd;
+    int inotify_css_fd;
     wf::config::config_manager_t config;
     zwf_shell_manager_v2 *wf_shell_manager = nullptr;
 
     WayfireShellApp(int argc, char **argv);
     virtual ~WayfireShellApp();
 
     virtual std::string get_config_file();
+    virtual std::string get_css_config_dir();
     virtual void run();
 
     virtual void on_config_reload()
     {}
 
+    virtual void on_css_reload()
+    {}
+
     /**
      * WayfireShellApp is a singleton class.
      * Using this function, any part of the application can get access to the