simple-example.c

#include "gtk4-layer-shell.h"
#include <gtk/gtk.h>

static void activate(GtkApplication* app, void* _data) {
    (void)_data;

    // Create a normal GTK window however you like
    GtkWindow* gtk_window = GTK_WINDOW(gtk_application_window_new(app));

    // Before the window is first realized, set it up to be a layer surface
    gtk_layer_init_for_window(gtk_window);

    // Order below normal windows
    gtk_layer_set_layer(gtk_window, GTK_LAYER_SHELL_LAYER_TOP);

    // Push other windows out of the way
    gtk_layer_auto_exclusive_zone_enable(gtk_window);

    // We don't need to get keyboard input
    // gtk_layer_set_keyboard_mode(gtk_window, GTK_LAYER_SHELL_KEYBOARD_MODE_NONE); // NONE is default

    // The margins are the gaps around the window's edges
    // Margins and anchors can be set like this...
    gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_LEFT, 40);
    gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_RIGHT, 40);
    gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_TOP, 20);
    gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_BOTTOM, 0); // 0 is default

    // ... or like this
    // Anchors are if the window is pinned to each edge of the output
    static const gboolean anchors[] = {TRUE, FALSE, FALSE, TRUE};
    for (int i = 0; i < GTK_LAYER_SHELL_EDGE_ENTRY_NUMBER; i++) {
        gtk_layer_set_anchor(gtk_window, i, anchors[i]);
    }

    // Set up a widget
    GtkWidget* label = gtk_label_new("");
    gtk_label_set_markup(
        GTK_LABEL(label),
        "<span font_desc=\"100.0\">"
            "GTK Layer\nShell example!"
        "</span>"
    );
    gtk_window_set_child(gtk_window, label);
    gtk_window_present(gtk_window);
}

int main(int argc, char **argv) {
    GtkApplication* app = gtk_application_new("com.github.wmww.gtk4-layer-shell.example", G_APPLICATION_DEFAULT_FLAGS);
    g_signal_connect(app, "activate", G_CALLBACK(activate), NULL);
    int status = g_application_run(G_APPLICATION(app), argc, argv);
    g_object_unref(app);
    return status;
}