panel: Backlight control widget

meson.build

@@ -22,6 +22,7 @@ epoxy = dependency('epoxy')
 gtklayershell = dependency('gtk4-layer-shell-0', fallback: ['gtk4-layer-shell'])
 libpulse = dependency('libpulse', required: get_option('pulse'))
 wireplumber = dependency('wireplumber-0.5', required: get_option('wireplumber'))
+ddcutil = dependency('ddcutil', required: get_option('ddcutil'))
 dbusmenu_gtk = dependency('dbusmenu-glib-0.4')
 libgvc = subproject('gvc', default_options: ['static=true'], required: get_option('pulse'))
 xkbregistry = dependency('xkbregistry')
@@ -40,6 +41,10 @@ if wireplumber.found()
 	add_project_arguments('-DHAVE_WIREPLUMBER=1', language: 'cpp')
 endif
 
+if ddcutil.found()
+	add_project_arguments('-DHAVE_DDCUTIL=1', language: 'cpp')
+endif
+
 needs_libinotify = ['freebsd', 'dragonfly'].contains(host_machine.system())
 libinotify = dependency('libinotify', required: needs_libinotify)
 

meson_options.txt

@@ -10,6 +10,12 @@ option(
     value: 'auto',
     description: 'Build wireplumber and mixer widget',
 )
+option(
+    'ddcutil',
+    type: 'feature',
+    value: 'auto',
+    description: 'Build external monitor support for backlight widget'
+)
 option(
     'wayland-logout',
     type: 'boolean',

metadata/panel.xml

@@ -467,5 +467,38 @@ Set to -1 to only run it by clicking the button.
 		<min>1</min>
 	</option>
 	</group>
+	<group>
+	<_short>Light</_short>
+	<option name="light_popup_on_change" type="bool">
+		<_short>Popup on change</_short>
+		<default>true</default>
+	</option>
+	<option name="light_popup_timeout" type="double">
+		<_short>Popup timeout</_short>
+		<default>2.5</default>
+		<min>0</min>
+	</option>
+	<option name="light_slider_length" type="int">
+		<_short>Slider length</_short>
+		<default>300</default>
+		<min>1</min>
+	</option>
+	<option name="light_scroll_sensitivity" type="double">
+		<_short>Scroll sensitivity</_short>
+		<default>1</default>
+	</option>
+	<option name="light_invert_scroll" type="bool">
+		<_short>Invert scroll</_short>
+		<_long>
+			Inverts which scroll direction raises and lowers display brightness
+		</_long>
+		<default>false</default>
+	</option>
+	<option name="light_icon_size" type="int">
+		<_short>Light icon size</_short>
+		<default>0</default>
+		<min>0</min>
+	</option>
+	</group>
 	</plugin>
 </wf-shell>

src/panel/meson.build

@@ -20,6 +20,8 @@ widget_sources = [
   'widgets/tray/item.cpp',
   'widgets/tray/host.cpp',
   'widgets/tray/dbusmenu.cpp',
+  'widgets/light/light.cpp',
+  'widgets/light/sysfs.cpp',
 ]
 
 deps = [
@@ -56,6 +58,13 @@ else
   message('Wireplumber not found, mixer widget will not be available.')
 endif
 
+if ddcutil.found()
+  widget_sources += 'widgets/light/ddcutil.cpp'
+  deps += ddcutil
+else
+  message('Libddcutil not found, light widget will not support external monitors.')
+endif
+
 executable(
   'wf-panel',
   ['panel.cpp'] + widget_sources,

src/panel/panel.cpp

@@ -29,6 +29,7 @@
 #ifdef HAVE_WIREPLUMBER
     #include "widgets/wp-mixer/wp-mixer.hpp"
 #endif
+#include "widgets/light/light.hpp"
 #include "widgets/window-list/window-list.hpp"
 #include "widgets/notifications/notification-center.hpp"
 #include "widgets/tray/tray.hpp"
@@ -178,6 +179,15 @@ class WayfirePanel::impl
 #endif
         }
 
+        if (name == "light")
+        {
+            return Widget(new WayfireLight(output));
+#ifndef HAVE_DDCUTIL
+            std::cout << "Built without DDC/CI support, light widget "
+                         " doesn’t support external monitors." << std::endl;
+#endif
+        }
+
         if (name == "window-list")
         {
             return Widget(new WayfireWindowList(output));
@@ -381,7 +391,8 @@ void WayfirePanelApp::on_activate()
         {"panel/volume_icon_size", ".volume"},
         {"panel/wp_icon_size", ".wireplumber"},
         {"panel/notifications_icon_size", ".notification-center "},
-        {"panel/tray_icon_size", ".tray-button"}
+        {"panel/tray_icon_size", ".tray-button"},
+        {"panel/light_icon_size", ".light"}
     };
     for (auto pair : icon_sizes_args)
     {

src/panel/widgets/light/ddcutil.cpp

@@ -0,0 +1,103 @@
+#include <iostream>
+extern "C"{
+	#include <ddcutil_c_api.h>
+	#include <ddcutil_status_codes.h>
+}
+
+#include "light.hpp"
+
+#define VCP_BRIGHTNESS_CODE 0x10
+
+void show_err(std::string location, DDCA_Status status){
+	// if (!status)
+		std::cerr << location << " :" << ddca_rc_name(status) << " : " << ddca_rc_desc(status) << "\n";
+}
+
+
+class WfLightDdcaControl : public WfLightControl
+{
+	private:
+		DDCA_Display_Ref ref;
+		int max;
+
+		int get_max(){
+			return max;
+		}
+
+	public:
+		WfLightDdcaControl(WayfireLight *parent, DDCA_Display_Ref _ref) : WfLightControl(parent){
+			ref = _ref;
+
+			DDCA_Display_Handle handle;
+			DDCA_Status status = ddca_open_display2(ref, false, &handle);
+			show_err("open display", status);
+
+			DDCA_Non_Table_Vcp_Value value;
+			status = ddca_get_non_table_vcp_value(handle, VCP_BRIGHTNESS_CODE, &value);
+			max = value.mh << 8 | value.ml;
+
+			ddca_close_display(handle);
+		}
+
+		std::string get_name(){
+			std::string name;
+			name = "display";
+			return name;
+		}
+
+        void set_brightness(double brightness){
+			DDCA_Display_Handle handle;
+			DDCA_Status status = ddca_open_display2(ref, false, &handle);
+			show_err("open display", status);
+
+			uint16_t value = (uint16_t)(get_max() * brightness);
+			uint8_t sh = value >> 8;
+			uint8_t sl = value & 0xFF;
+			status = ddca_set_non_table_vcp_value(handle, VCP_BRIGHTNESS_CODE, sh, sl);
+			show_err("set brigthness", status);
+			ddca_close_display(handle);
+        }
+
+        double get_brightness(){
+			DDCA_Display_Handle handle;
+			DDCA_Status status = ddca_open_display2(ref, false, &handle);
+			show_err("open display", status);
+
+			DDCA_Non_Table_Vcp_Value value;
+			status = ddca_get_non_table_vcp_value(handle, VCP_BRIGHTNESS_CODE, &value);
+			show_err("get brightness", status);
+			ddca_close_display(handle);
+			return value.sh << 8 | value.sl;
+	    }
+};
+
+DdcaSurveillor::DdcaSurveillor(){
+	ddca_enable_verify(true);
+	DDCA_Display_Info_List *display_list = NULL;
+	ddca_get_display_info_list2(false, &display_list);
+
+	for (int i = 0 ; i < display_list->ct ; i++){
+		displays_info.push_back(&display_list->info[i]);
+	}
+}
+
+void DdcaSurveillor::catch_up_widget(WayfireLight *widget){
+    for (auto info : displays_info){
+        auto control = std::make_shared<WfLightDdcaControl>(widget, info->dref);
+        // it.second.second.push_back(std::shared_ptr<WfLightSysfsControl>(control));
+        widget->add_control((std::shared_ptr<WfLightControl>)control);
+    }
+
+}
+
+void DdcaSurveillor::strip_widget(WayfireLight *widget){
+
+}
+
+DdcaSurveillor& DdcaSurveillor::get(){
+    if (!instance)
+    {
+        instance = std::unique_ptr<DdcaSurveillor>(new DdcaSurveillor());
+    }
+    return *instance;
+}