panel: Backlight control widget

[AKArien]

Add backlight widget to control display brightness.
Handles devices exposed in sysfs and external external monitors that implement MCCS.
MCCS depends on libddcutil, and is not built if it is not detected.

[trigg]

So I start with this message
Cannot read/write brightness for "/sys/class/backlight/amdgpu_bl1", ignoring.

And then find I can cause a segfault by scrolling on the widget ;)

[AKArien]

@trigg latest commits fix this segfault and add a fallback to use the systemd-logind dbus method as a fallback

[trigg]

diff --git a/src/panel/widgets/backlight/sysfs.cpp b/src/panel/widgets/backlight/sysfs.cpp
index 2db42c2..5dcddac 100644
--- a/src/panel/widgets/backlight/sysfs.cpp
+++ b/src/panel/widgets/backlight/sysfs.cpp
@@ -133,6 +133,7 @@ class WfLightSysfsDbusSystemdControl : public WfLightSysfsControl
 
     void set_brightness(double brightness) override
     {
+        brightness = std::clamp(brightness, 0.0, 1.0);
         auto params = Glib::VariantContainerBase::create_tuple({
             Glib::Variant<Glib::ustring>::create("backlight"),
             Glib::Variant<Glib::ustring>::create(name),

A fix for the out-of-range GDBUS errors

[AKArien]

don’t take it as rebelling against authority, but i just changed the scrolling itself ;)

i’m actually quite confused as to why it wasn’t doing errors with others, but… oh well, now should be safe.

[soreau]

Why are there changes to 18 files here? I see changes to all of the wp-mixer files and some addition of icons.cpp in until with a header, amongst other changes not related to the title of this PR.

[AKArien]

Why are there changes to 18 files here? I see changes to all of the wp-mixer files and some addition of icons.cpp in until with a header, amongst other changes not related to the title of this PR.

Because to not copypaste code, the way icons that scale with a numeric value (so, volumes and brightness) is handled was changed. for now this new way was carelessly thrown together to get working, please read them and make suggestions.

[trigg]

@soreau makes a good point here.

Can you split the icon-from-ranges work to a different PR which we will take first?

[AKArien]

Can you split the icon-from-ranges work to a different PR which we will take first?

sure, seemed a bit pointless to me given there’s no other thing using it, but if you want