ui: use backend capabilities

src/backends/display-backend.vala

@@ -11,6 +11,24 @@ namespace TunerDisplays {
         public abstract string id { get; }
         public abstract string title { owned get; }
         public abstract bool can_apply { get; }
+        public virtual bool requires_connected_layout { get { return false; } }
+        public virtual bool preserves_disabled_monitor_position { get { return true; } }
+        public virtual bool supports_monitor_change_events { get { return false; } }
+        public virtual bool supports_global_mirroring { get { return false; } }
+        public virtual bool supports_primary_display { get { return false; } }
+        public virtual bool uses_separate_refresh_rate_controls { get { return false; } }
+        public virtual bool supports_output_mirroring { get { return false; } }
+        public virtual bool supports_description_identifier { get { return false; } }
+        public virtual bool supports_bit_depth { get { return false; } }
+        public virtual bool supports_vrr_modes { get { return false; } }
+        public virtual bool supports_adaptive_sync { get { return false; } }
+        public virtual bool supports_color_management { get { return false; } }
+        public virtual bool supports_hdr_metadata { get { return false; } }
+        public virtual bool supports_focus_at_startup { get { return false; } }
+        public virtual bool supports_backdrop_color { get { return false; } }
+        public virtual bool supports_hot_corners { get { return false; } }
+        public virtual bool supports_underscanning { get { return false; } }
+        public virtual bool supports_hdr_toggle { get { return false; } }
 
         public abstract Gee.ArrayList<MonitorConfig> load() throws Error;
         public abstract void apply(Gee.ArrayList<MonitorConfig> monitors) throws Error;

src/backends/gnome-backend.vala

@@ -13,6 +13,14 @@ namespace TunerDisplays {
         public override string id { get { return "gnome"; } }
         public override string title { owned get { return "GNOME"; } }
         public override bool can_apply { get { return true; } }
+        public override bool requires_connected_layout { get { return true; } }
+        public override bool preserves_disabled_monitor_position { get { return false; } }
+        public override bool supports_monitor_change_events { get { return true; } }
+        public override bool supports_global_mirroring { get { return true; } }
+        public override bool supports_primary_display { get { return true; } }
+        public override bool uses_separate_refresh_rate_controls { get { return true; } }
+        public override bool supports_underscanning { get { return true; } }
+        public override bool supports_hdr_toggle { get { return true; } }
 
         public override Gee.ArrayList<MonitorConfig> load() throws Error {
             var state = call_display_config("GetCurrentState", null, null);

src/backends/hyprland-backend.vala

@@ -22,6 +22,12 @@ namespace TunerDisplays {
         public override string id { get { return "hyprland"; } }
         public override string title { owned get { return "Hyprland"; } }
         public override bool can_apply { get { return true; } }
+        public override bool supports_output_mirroring { get { return true; } }
+        public override bool supports_description_identifier { get { return true; } }
+        public override bool supports_bit_depth { get { return true; } }
+        public override bool supports_vrr_modes { get { return true; } }
+        public override bool supports_color_management { get { return true; } }
+        public override bool supports_hdr_metadata { get { return true; } }
 
         public override Gee.ArrayList<MonitorConfig> load() throws Error {
             var monitors = new Gee.ArrayList<MonitorConfig>();

src/backends/niri-backend.vala

@@ -30,6 +30,10 @@ namespace TunerDisplays {
         public override string id { get { return "niri"; } }
         public override string title { owned get { return "niri"; } }
         public override bool can_apply { get { return true; } }
+        public override bool supports_adaptive_sync { get { return true; } }
+        public override bool supports_focus_at_startup { get { return true; } }
+        public override bool supports_backdrop_color { get { return true; } }
+        public override bool supports_hot_corners { get { return true; } }
 
         public override Gee.ArrayList<MonitorConfig> load() throws Error {
             var monitors = new Gee.ArrayList<MonitorConfig>();

src/plugin.vala

@@ -79,7 +79,7 @@ namespace TunerDisplays {
         }
 
         private MonitorSettingsContent create_monitor_page_content(MonitorConfig monitor) {
-            var content = new MonitorSettingsContent(monitor, view.backend_id, view.monitor_configs);
+            var content = new MonitorSettingsContent(monitor, view.display_backend, view.monitor_configs);
             content.monitor_changed.connect(view.refresh_from_monitors);
             return content;
         }

src/ui/displays-view.vala

@@ -18,7 +18,7 @@ namespace TunerDisplays {
         [GtkChild] private unowned Adw.PreferencesGroup status_group;
         public bool can_apply { get { return backend.can_apply; } }
         public Gee.ArrayList<MonitorConfig> monitor_configs { get { return monitors; } }
-        public string backend_id { owned get { return backend.id; } }
+        public DisplayBackend display_backend { get { return backend; } }
         public signal void monitor_settings_requested(MonitorConfig monitor);
 
         construct {
@@ -33,7 +33,7 @@ namespace TunerDisplays {
             layout = new MonitorLayout() {
                 height_request = 320,
                 hexpand = true,
-                require_connected = backend.id == "gnome",
+                require_connected = backend.requires_connected_layout,
                 can_focus = false,
                 focusable = false
             };
@@ -145,7 +145,7 @@ namespace TunerDisplays {
             } else {
                 add_gnome_primary_row();
                 foreach (var monitor in monitors) {
-                    var row = new MonitorRow(monitor, monitor_settings_page_id(), monitors, backend.id);
+                    var row = new MonitorRow(monitor, monitor_settings_page_id(), monitors, backend);
                     row.monitor_selected.connect(monitor => monitor_settings_requested(monitor));
                     row.monitor_changed.connect(() => layout.recenter());
                     monitors_group.add(row);
@@ -164,7 +164,7 @@ namespace TunerDisplays {
         }
 
         private void add_gnome_mirror_row() {
-            if (backend.id != "gnome" || monitors.size <= 1)
+            if (!backend.supports_global_mirroring || monitors.size <= 1)
                 return;
 
             var row = new Adw.SwitchRow() {
@@ -193,7 +193,7 @@ namespace TunerDisplays {
             if (monitors.size != 1)
                 return;
 
-            single_monitor_content = new MonitorSettingsContent(monitors[0], backend.id, monitors, false);
+            single_monitor_content = new MonitorSettingsContent(monitors[0], backend, monitors, false);
             single_monitor_content.monitor_changed.connect(refresh_from_monitors);
 
             while (single_monitor_content.get_group(0) != null) {
@@ -312,7 +312,7 @@ namespace TunerDisplays {
         }
 
         private void add_gnome_primary_row() {
-            if (backend.id != "gnome" || monitors.size <= 1)
+            if (!backend.supports_primary_display || monitors.size <= 1)
                 return;
 
             var model = new Gtk.StringList(null);
@@ -358,7 +358,7 @@ namespace TunerDisplays {
         }
 
         private bool gnome_mirror_enabled() {
-            return backend.id == "gnome" && monitors.size > 0 && monitors[0].mirrored;
+            return backend.supports_global_mirroring && monitors.size > 0 && monitors[0].mirrored;
         }
 
         private bool single_monitor_mode() {
@@ -366,7 +366,7 @@ namespace TunerDisplays {
         }
 
         private void subscribe_monitor_changes() {
-            if (backend.id != "gnome")
+            if (!backend.supports_monitor_change_events)
                 return;
 
             try {

src/ui/monitor-row.vala

@@ -4,13 +4,13 @@ namespace TunerDisplays {
         private MonitorConfig monitor;
         private Gee.ArrayList<MonitorConfig> all_monitors;
         private string page_id;
-        private string backend_id;
+        private DisplayBackend backend;
         private Gtk.Switch enabled_switch;
 
         public signal void monitor_changed();
         public signal void monitor_selected(MonitorConfig monitor);
 
-        public MonitorRow(MonitorConfig monitor, string page_id, Gee.ArrayList<MonitorConfig> all_monitors, string backend_id) {
+        public MonitorRow(MonitorConfig monitor, string page_id, Gee.ArrayList<MonitorConfig> all_monitors, DisplayBackend backend) {
             Object(
                 title: monitor.title,
                 subtitle: "%dx%d@%.2f  scale %.2f  %dx%d".printf(
@@ -20,7 +20,7 @@ namespace TunerDisplays {
             this.monitor = monitor;
             this.all_monitors = all_monitors;
             this.page_id = page_id;
-            this.backend_id = backend_id;
+            this.backend = backend;
             build();
         }
 
@@ -38,7 +38,7 @@ namespace TunerDisplays {
                 can_focus = true
             };
             enabled_switch.notify["active"].connect(() => {
-                if (enabled_switch.active != monitor.enabled && backend_id == "gnome")
+                if (enabled_switch.active != monitor.enabled && !backend.preserves_disabled_monitor_position)
                     place_monitor_after_active(monitor, all_monitors);
                 monitor.enabled = enabled_switch.active;
                 monitor_changed();

src/ui/monitor-settings-content.vala

@@ -4,7 +4,7 @@ namespace TunerDisplays {
     public class MonitorSettingsContent : Adw.PreferencesPage {
         private MonitorConfig monitor;
         private Gee.ArrayList<MonitorConfig> all_monitors;
-        private string backend_id;
+        private DisplayBackend backend;
         private bool show_enabled;
         [GtkChild] private unowned Adw.SwitchRow enabled_row;
         private Adw.ExpanderRow? gnome_refresh_expander_row;
@@ -19,10 +19,10 @@ namespace TunerDisplays {
 
         public signal void monitor_changed();
 
-        public MonitorSettingsContent(MonitorConfig monitor, string backend_id, Gee.ArrayList<MonitorConfig> all_monitors, bool show_enabled = true) {
+        public MonitorSettingsContent(MonitorConfig monitor, DisplayBackend backend, Gee.ArrayList<MonitorConfig> all_monitors, bool show_enabled = true) {
             Object(title: monitor.title);
             this.monitor = monitor;
-            this.backend_id = backend_id;
+            this.backend = backend;
             this.all_monitors = all_monitors;
             this.show_enabled = show_enabled;
             build_preferences();
@@ -32,14 +32,14 @@ namespace TunerDisplays {
             enabled_row.visible = show_enabled;
             enabled_row.active = monitor.enabled;
             enabled_row.notify["active"].connect(() => {
-                if (enabled_row.active != monitor.enabled && backend_id == "gnome")
+                if (enabled_row.active != monitor.enabled && !backend.preserves_disabled_monitor_position)
                     place_monitor_after_active(monitor, all_monitors);
                 monitor.enabled = enabled_row.active;
                 emit_changed();
             });
             monitor.notify["enabled"].connect(sync_from_monitor);
 
-            if (backend_id == "gnome") {
+            if (backend.uses_separate_refresh_rate_controls) {
                 add_gnome_resolution_row(basic_group);
                 add_gnome_refresh_rate_row(basic_group);
                 add_gnome_scale_row(basic_group);
@@ -50,20 +50,18 @@ namespace TunerDisplays {
             add_transform_row(basic_group);
             add_mirror_row(basic_group);
 
-            if (backend_id == "hyprland") {
+            if (backend.supports_description_identifier
+                || backend.supports_bit_depth
+                || backend.supports_vrr_modes
+                || backend.supports_color_management
+                || backend.supports_hdr_metadata) {
                 add_hyprland_rows();
-            } else if (backend_id == "niri") {
-                add_niri_rows(basic_group);
-                hyprland_group.visible = false;
-                hdr_group.visible = false;
-            } else if (backend_id == "gnome") {
-                add_gnome_rows(basic_group);
-                hyprland_group.visible = false;
-                hdr_group.visible = false;
-            } else {
-                hyprland_group.visible = false;
-                hdr_group.visible = false;
             }
+
+            add_niri_rows(basic_group);
+            add_gnome_rows(basic_group);
+            hyprland_group.visible = hyprland_group.get_first_child() != null;
+            hdr_group.visible = hdr_group.get_first_child() != null;
         }
 
         private void add_mode_row(Adw.PreferencesGroup group) {
@@ -98,7 +96,7 @@ namespace TunerDisplays {
                     monitor.width = mode.width;
                     monitor.height = mode.height;
                     monitor.refresh = mode.refresh;
-                    if (backend_id == "gnome" && !mode.supports_scale(monitor.scale))
+                    if (backend.uses_separate_refresh_rate_controls && !mode.supports_scale(monitor.scale))
                         monitor.scale = mode.preferred_scale;
                     emit_changed();
                 }
@@ -326,7 +324,7 @@ namespace TunerDisplays {
         }
 
         private void add_mirror_row(Adw.PreferencesGroup group) {
-            if (backend_id != "hyprland")
+            if (!backend.supports_output_mirroring)
                 return;
 
             if (all_monitors.size <= 1)
@@ -364,66 +362,79 @@ namespace TunerDisplays {
         }
 
         private void add_hyprland_rows() {
-            var use_description = new Adw.SwitchRow() {
-                title = _("Use description"),
-                active = monitor.use_description
-            };
-            use_description.notify["active"].connect(() => {
-                monitor.use_description = use_description.active;
-                emit_changed();
-            });
-            hyprland_group.add(use_description);
-
-            add_int_combo(hyprland_group, _("Bit depth"), new string[] { "8", "10" }, new int[] { 8, 10 }, monitor.bitdepth, value => monitor.bitdepth = value);
-            add_int_combo(hyprland_group, _("VRR"), new string[] { _("Off"), _("On"), _("Fullscreen"), _("Fullscreen video/game") }, new int[] { 0, 1, 2, 3 }, monitor.vrr, value => monitor.vrr = value);
-            add_string_combo(hyprland_group, _("Color management"), new string[] { "auto", "srgb", "dcip3", "dp3", "adobe", "wide", "edid", "hdr", "hdredid" }, monitor.color_management_preset, value => monitor.color_management_preset = value);
-            add_string_combo(hyprland_group, _("SDR EOTF"), new string[] { "default", "gamma22", "srgb" }, monitor.sdr_eotf, value => monitor.sdr_eotf = value);
-            hyprland_group.add(create_spin_row(_("SDR brightness"), monitor.sdr_brightness, 0.1, 4.0, 0.05, 2, value => monitor.sdr_brightness = value));
-            hyprland_group.add(create_spin_row(_("SDR saturation"), monitor.sdr_saturation, 0.1, 4.0, 0.05, 2, value => monitor.sdr_saturation = value));
-
-            add_int_combo(hdr_group, _("Force wide color"), new string[] { _("Auto"), _("Off"), _("On") }, new int[] { 0, -1, 1 }, monitor.supports_wide_color, value => monitor.supports_wide_color = value);
-            add_int_combo(hdr_group, _("Force HDR"), new string[] { _("Auto"), _("Off"), _("On") }, new int[] { 0, -1, 1 }, monitor.supports_hdr, value => monitor.supports_hdr = value);
-            hdr_group.add(create_spin_row(_("SDR min luminance"), monitor.sdr_min_luminance, 0.0, 10.0, 0.01, 2, value => monitor.sdr_min_luminance = value));
-            hdr_group.add(create_spin_row(_("SDR max luminance"), monitor.sdr_max_luminance, 1, 1000, 1, 0, value => monitor.sdr_max_luminance = (int) value));
-            hdr_group.add(create_spin_row(_("Min luminance"), monitor.min_luminance, -1, 10.0, 0.01, 2, value => monitor.min_luminance = value));
-            hdr_group.add(create_spin_row(_("Max luminance"), monitor.max_luminance, -1, 10000, 1, 0, value => monitor.max_luminance = (int) value));
-            hdr_group.add(create_spin_row(_("Max average luminance"), monitor.max_avg_luminance, -1, 10000, 1, 0, value => monitor.max_avg_luminance = (int) value));
-
-            var icc = new Adw.EntryRow() {
-                title = _("ICC profile")
-            };
-            icc.text = monitor.icc;
-            icc.notify["text"].connect(() => {
-                monitor.icc = icc.text;
-                emit_changed();
-            });
-            hdr_group.add(icc);
+            if (backend.supports_description_identifier) {
+                var use_description = new Adw.SwitchRow() {
+                    title = _("Use description"),
+                    active = monitor.use_description
+                };
+                use_description.notify["active"].connect(() => {
+                    monitor.use_description = use_description.active;
+                    emit_changed();
+                });
+                hyprland_group.add(use_description);
+            }
+
+            if (backend.supports_bit_depth)
+                add_int_combo(hyprland_group, _("Bit depth"), new string[] { "8", "10" }, new int[] { 8, 10 }, monitor.bitdepth, value => monitor.bitdepth = value);
+            if (backend.supports_vrr_modes)
+                add_int_combo(hyprland_group, _("VRR"), new string[] { _("Off"), _("On"), _("Fullscreen"), _("Fullscreen video/game") }, new int[] { 0, 1, 2, 3 }, monitor.vrr, value => monitor.vrr = value);
+            if (backend.supports_color_management) {
+                add_string_combo(hyprland_group, _("Color management"), new string[] { "auto", "srgb", "dcip3", "dp3", "adobe", "wide", "edid", "hdr", "hdredid" }, monitor.color_management_preset, value => monitor.color_management_preset = value);
+                add_string_combo(hyprland_group, _("SDR EOTF"), new string[] { "default", "gamma22", "srgb" }, monitor.sdr_eotf, value => monitor.sdr_eotf = value);
+                hyprland_group.add(create_spin_row(_("SDR brightness"), monitor.sdr_brightness, 0.1, 4.0, 0.05, 2, value => monitor.sdr_brightness = value));
+                hyprland_group.add(create_spin_row(_("SDR saturation"), monitor.sdr_saturation, 0.1, 4.0, 0.05, 2, value => monitor.sdr_saturation = value));
+            }
+
+            if (backend.supports_hdr_metadata) {
+                add_int_combo(hdr_group, _("Force wide color"), new string[] { _("Auto"), _("Off"), _("On") }, new int[] { 0, -1, 1 }, monitor.supports_wide_color, value => monitor.supports_wide_color = value);
+                add_int_combo(hdr_group, _("Force HDR"), new string[] { _("Auto"), _("Off"), _("On") }, new int[] { 0, -1, 1 }, monitor.supports_hdr, value => monitor.supports_hdr = value);
+                hdr_group.add(create_spin_row(_("SDR min luminance"), monitor.sdr_min_luminance, 0.0, 10.0, 0.01, 2, value => monitor.sdr_min_luminance = value));
+                hdr_group.add(create_spin_row(_("SDR max luminance"), monitor.sdr_max_luminance, 1, 1000, 1, 0, value => monitor.sdr_max_luminance = (int) value));
+                hdr_group.add(create_spin_row(_("Min luminance"), monitor.min_luminance, -1, 10.0, 0.01, 2, value => monitor.min_luminance = value));
+                hdr_group.add(create_spin_row(_("Max luminance"), monitor.max_luminance, -1, 10000, 1, 0, value => monitor.max_luminance = (int) value));
+                hdr_group.add(create_spin_row(_("Max average luminance"), monitor.max_avg_luminance, -1, 10000, 1, 0, value => monitor.max_avg_luminance = (int) value));
+
+                var icc = new Adw.EntryRow() {
+                    title = _("ICC profile")
+                };
+                icc.text = monitor.icc;
+                icc.notify["text"].connect(() => {
+                    monitor.icc = icc.text;
+                    emit_changed();
+                });
+                hdr_group.add(icc);
+            }
         }
 
         private void add_niri_rows(Adw.PreferencesGroup group) {
-            if (monitor.supports_variable_refresh_rate) {
+            if (backend.supports_adaptive_sync && monitor.supports_variable_refresh_rate) {
                 add_int_combo(group, _("Variable Refresh Rate"), new string[] {
                     _("Off"), _("On"), _("On demand")
                 }, new int[] { 0, 1, 2 }, monitor.vrr, value => monitor.vrr = value);
             }
 
-            var focus = new Adw.SwitchRow() {
-                title = _("Focus at startup"),
-                active = monitor.niri_focus_at_startup
-            };
-            focus.notify["active"].connect(() => {
-                monitor.niri_focus_at_startup = focus.active;
-                emit_changed();
-            });
-            group.add(focus);
+            if (backend.supports_focus_at_startup) {
+                var focus = new Adw.SwitchRow() {
+                    title = _("Focus at startup"),
+                    active = monitor.niri_focus_at_startup
+                };
+                focus.notify["active"].connect(() => {
+                    monitor.niri_focus_at_startup = focus.active;
+                    emit_changed();
+                });
+                group.add(focus);
+            }
 
-            add_niri_backdrop_color_row(group);
+            if (backend.supports_backdrop_color)
+                add_niri_backdrop_color_row(group);
 
-            add_string_combo_with_labels(group, _("Hot corners"), new string[] {
-                _("Default"), _("Off"), _("All"), _("Top left"), _("Top right"), _("Bottom left"), _("Bottom right")
-            }, new string[] {
-                "", "off", "all", "top-left", "top-right", "bottom-left", "bottom-right"
-            }, monitor.niri_hot_corners, value => monitor.niri_hot_corners = value);
+            if (backend.supports_hot_corners) {
+                add_string_combo_with_labels(group, _("Hot corners"), new string[] {
+                    _("Default"), _("Off"), _("All"), _("Top left"), _("Top right"), _("Bottom left"), _("Bottom right")
+                }, new string[] {
+                    "", "off", "all", "top-left", "top-right", "bottom-left", "bottom-right"
+                }, monitor.niri_hot_corners, value => monitor.niri_hot_corners = value);
+            }
         }
 
         private void add_niri_backdrop_color_row(Adw.PreferencesGroup group) {
@@ -467,17 +478,22 @@ namespace TunerDisplays {
         }
 
         private void add_gnome_rows(Adw.PreferencesGroup group) {
-            var underscanning = new Adw.SwitchRow() {
-                title = _("Underscanning"),
-                active = monitor.underscanning
-            };
-            underscanning.notify["active"].connect(() => {
-                monitor.underscanning = underscanning.active;
-                emit_changed();
-            });
-            group.add(underscanning);
+            if (!backend.supports_underscanning && !backend.supports_hdr_toggle)
+                return;
+
+            if (backend.supports_underscanning) {
+                var underscanning = new Adw.SwitchRow() {
+                    title = _("Underscanning"),
+                    active = monitor.underscanning
+                };
+                underscanning.notify["active"].connect(() => {
+                    monitor.underscanning = underscanning.active;
+                    emit_changed();
+                });
+                group.add(underscanning);
+            }
 
-            if (monitor.supported_color_modes.contains(1)) {
+            if (backend.supports_hdr_toggle && monitor.supported_color_modes.contains(1)) {
                 var hdr = new Adw.SwitchRow() {
                     title = _("HDR"),
                     active = monitor.color_mode == 1