initialstart: Use DBus api to set brightness

Port away from deprecated P5Support.DataSource, doesn't seem to work anyway in this case

initialstart/modules/prepare/CMakeLists.txt

@@ -1,9 +1,12 @@
 # SPDX-FileCopyrightText: 2023 Devin Lin <devin@kde.org>
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+qt_add_dbus_interfaces(DBUS_SRCS dbus/org.kde.Solid.PowerManagement.Actions.BrightnessControl.xml)
+
 set(prepareplugin_SRCS
     prepareplugin.cpp
     prepareutil.cpp
+    ${DBUS_SRCS}
 )
 
 add_library(prepareplugin ${prepareplugin_SRCS})

initialstart/modules/prepare/dbus/org.kde.Solid.PowerManagement.Actions.BrightnessControl.xml

@@ -0,0 +1,33 @@
+<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN" "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
+<!--
+- SPDX-FileCopyrightText: 2015 Kai Uwe Broulik <kbroulik@kde.org>
+- SPDX-License-Identifier: GPL-2.0-or-later
+-->
+<node>
+  <interface name="org.kde.Solid.PowerManagement.Actions.BrightnessControl">
+    <method name="setBrightness">
+      <arg type="i" direction="in" />
+    </method>
+    <method name="setBrightnessSilent">
+      <arg type="i" direction="in" />
+    </method>
+    <method name="brightness">
+      <arg type="i" direction="out" />
+    </method>
+    <method name="brightnessMax">
+      <arg type="i" direction="out" />
+    </method>
+
+    <signal name="brightnessChanged">
+      <arg type="i" direction="out" />
+    </signal>
+    <signal name="brightnessMaxChanged">
+      <arg type="i" direction="out" />
+    </signal>
+
+    <method name="brightnessSteps">
+      <arg type="i" direction="out" />
+    </method>
+
+  </interface>
+</node>

initialstart/modules/prepare/package/contents/ui/main.qml

@@ -8,7 +8,6 @@ import QtQuick.Layouts 1.15
 import org.kde.kirigami 2.20 as Kirigami
 import org.kde.kirigamiaddons.formcard 1.0 as FormCard
 import org.kde.plasma.mobileinitialstart.prepare 1.0 as Prepare
-import org.kde.plasma.plasma5support 2.0 as P5Support
 
 Item {
     id: root
@@ -16,48 +15,6 @@ Item {
 
     readonly property real cardWidth: Math.min(Kirigami.Units.gridUnit * 30, root.width - Kirigami.Units.gridUnit * 2)
 
-    // brightness controls
-    property int screenBrightness: 0
-    property bool disableBrightnessUpdate: true
-    readonly property int maximumScreenBrightness: pmSource.data["PowerDevil"] ? pmSource.data["PowerDevil"]["Maximum Screen Brightness"] || 0 : 0
-    property QtObject updateScreenBrightnessJob
-
-    function updateBrightnessUI() {
-        if (updateScreenBrightnessJob)
-            return;
-
-        root.disableBrightnessUpdate = true;
-        root.screenBrightness = pmSource.data["PowerDevil"]["Screen Brightness"];
-        root.disableBrightnessUpdate = false;
-    }
-
-    onScreenBrightnessChanged: {
-        brightnessSlider.value = root.screenBrightness
-
-        if (!disableBrightnessUpdate) {
-            const service = pmSource.serviceForSource("PowerDevil");
-            const operation = service.operationDescription("setBrightness");
-            operation.brightness = screenBrightness;
-            operation.silent = true; // don't show OSD
-
-            updateScreenBrightnessJob = service.startOperationCall(operation);
-            updateScreenBrightnessJob.finished.connect(function (job) {
-                root.updateBrightnessUI();
-            });
-        }
-    }
-
-    P5Support.DataSource {
-        id: pmSource
-        engine: "powermanagement"
-        connectedSources: ["PowerDevil"]
-        onSourceAdded: if (source === "PowerDevil") {
-            disconnectSource(source);
-            connectSource(source);
-        }
-        onDataChanged: root.updateBrightnessUI()
-    }
-
     ScrollView {
         anchors {
             fill: parent
@@ -77,12 +34,15 @@ Item {
                 Layout.alignment: Qt.AlignTop
                 Layout.fillWidth: true
 
+                visible: Prepare.PrepareUtil.brightnessAvailable
                 wrapMode: Text.Wrap
                 horizontalAlignment: Text.AlignHCenter
                 text: i18n("Adjust the screen brightness to be comfortable for the installation process.")
             }
 
             FormCard.FormCard {
+                id: brightnessCard
+                visible: Prepare.PrepareUtil.brightnessAvailable
                 maximumWidth: root.cardWidth
 
                 Layout.alignment: Qt.AlignTop | Qt.AlignHCenter
@@ -103,9 +63,17 @@ Item {
                             id: brightnessSlider
                             Layout.fillWidth: true
                             from: 1
-                            to: root.maximumScreenBrightness
+                            to: Prepare.PrepareUtil.maxBrightness
-                            value: root.screenBrightness
+                            value: Prepare.PrepareUtil.brightness
-                            onMoved: root.screenBrightness = value;
+                            onMoved: Prepare.PrepareUtil.brightness = value;
+
+                            // HACK: for some reason, the slider initial value doesn't set without being done after the component completes loading
+                            Timer {
+                                interval: 0
+                                running: true
+                                repeat: false
+                                onTriggered: brightnessSlider.value = Qt.binding(() => Prepare.PrepareUtil.brightness)
+                            }
                         }
 
                         Kirigami.Icon {
@@ -129,6 +97,7 @@ Item {
             }
 
             FormCard.FormCard {
+                id: scalingCard
                 maximumWidth: root.cardWidth
 
                 Layout.alignment: Qt.AlignTop | Qt.AlignHCenter

initialstart/modules/prepare/prepareutil.cpp

@@ -8,9 +8,24 @@
 #include <kscreen/output.h>
 #include <kscreen/setconfigoperation.h>
 
+#include <QDBusPendingCallWatcher>
+#include <QDBusPendingReply>
+
 PrepareUtil::PrepareUtil(QObject *parent)
     : QObject{parent}
 {
+    m_brightnessInterface =
+        new org::kde::Solid::PowerManagement::Actions::BrightnessControl(QStringLiteral("org.kde.Solid.PowerManagement"),
+                                                                         QStringLiteral("/org/kde/Solid/PowerManagement/Actions/BrightnessControl"),
+                                                                         QDBusConnection::sessionBus(),
+                                                                         this);
+
+    fetchBrightness();
+    fetchMaxBrightness();
+
+    connect(m_brightnessInterface, &org::kde::Solid::PowerManagement::Actions::BrightnessControl::brightnessChanged, this, &PrepareUtil::fetchBrightness);
+    connect(m_brightnessInterface, &org::kde::Solid::PowerManagement::Actions::BrightnessControl::brightnessMaxChanged, this, &PrepareUtil::fetchMaxBrightness);
+
     connect(new KScreen::GetConfigOperation(), &KScreen::GetConfigOperation::finished, this, [this](auto *op) {
         m_config = qobject_cast<KScreen::GetConfigOperation *>(op)->config();
 
@@ -28,6 +43,20 @@ PrepareUtil::PrepareUtil(QObject *parent)
         m_scaling = scaling;
         Q_EMIT scalingChanged();
     });
+
+    // watch for brightness interface
+    m_brightnessInterfaceWatcher = new QDBusServiceWatcher(QStringLiteral("org.kde.Solid.PowerManagement.Actions.BrightnessControl"),
+                                                           QDBusConnection::sessionBus(),
+                                                           QDBusServiceWatcher::WatchForOwnerChange,
+                                                           this);
+
+    connect(m_brightnessInterfaceWatcher, &QDBusServiceWatcher::serviceRegistered, this, [this]() -> void {
+        Q_EMIT brightnessAvailableChanged();
+    });
+
+    connect(m_brightnessInterfaceWatcher, &QDBusServiceWatcher::serviceUnregistered, this, [this]() -> void {
+        Q_EMIT brightnessAvailableChanged();
+    });
 }
 
 int PrepareUtil::scaling() const
@@ -59,3 +88,57 @@ QStringList PrepareUtil::scalingOptions()
 {
     return {"50%", "100%", "150%", "200%", "250%", "300%"};
 }
+
+int PrepareUtil::brightness() const
+{
+    return m_brightness;
+}
+
+void PrepareUtil::setBrightness(int brightness)
+{
+    m_brightnessInterface->setBrightness(brightness);
+}
+
+int PrepareUtil::maxBrightness() const
+{
+    return m_maxBrightness;
+}
+
+bool PrepareUtil::brightnessAvailable() const
+{
+    return m_brightnessInterface->isValid();
+}
+
+void PrepareUtil::fetchBrightness()
+{
+    QDBusPendingReply<int> reply = m_brightnessInterface->brightness();
+    QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(reply, this);
+
+    connect(watcher, &QDBusPendingCallWatcher::finished, this, [this](QDBusPendingCallWatcher *watcher) {
+        QDBusPendingReply<int> reply = *watcher;
+        if (reply.isError()) {
+            qWarning() << "Getting brightness failed:" << reply.error().name() << reply.error().message();
+        } else if (m_brightness != reply.value()) {
+            m_brightness = reply.value();
+            Q_EMIT brightnessChanged();
+        }
+        watcher->deleteLater();
+    });
+}
+
+void PrepareUtil::fetchMaxBrightness()
+{
+    QDBusPendingReply<int> reply = m_brightnessInterface->brightnessMax();
+    QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(reply, this);
+
+    connect(watcher, &QDBusPendingCallWatcher::finished, this, [this](QDBusPendingCallWatcher *watcher) {
+        QDBusPendingReply<int> reply = *watcher;
+        if (reply.isError()) {
+            qWarning() << "Getting max brightness failed:" << reply.error().name() << reply.error().message();
+        } else if (m_maxBrightness != reply.value()) {
+            m_maxBrightness = reply.value();
+            Q_EMIT maxBrightnessChanged();
+        }
+        watcher->deleteLater();
+    });
+}

initialstart/modules/prepare/prepareutil.h

@@ -3,16 +3,21 @@
 
 #pragma once
 
+#include <QDBusServiceWatcher>
 #include <QObject>
-#include <QProcess>
 
 #include <kscreen/config.h>
 
+#include "brightnesscontrolinterface.h"
+
 class PrepareUtil : public QObject
 {
     Q_OBJECT
     Q_PROPERTY(int scaling READ scaling WRITE setScaling NOTIFY scalingChanged);
     Q_PROPERTY(QStringList scalingOptions READ scalingOptions CONSTANT);
+    Q_PROPERTY(int brightness READ brightness WRITE setBrightness NOTIFY brightnessChanged);
+    Q_PROPERTY(int maxBrightness READ maxBrightness NOTIFY maxBrightnessChanged)
+    Q_PROPERTY(bool brightnessAvailable READ brightnessAvailable NOTIFY brightnessAvailableChanged)
 
 public:
     PrepareUtil(QObject *parent = nullptr);
@@ -22,10 +27,29 @@ public:
 
     QStringList scalingOptions();
 
+    int brightness() const;
+    void setBrightness(int brightness);
+
+    int maxBrightness() const;
+
+    bool brightnessAvailable() const;
+
 Q_SIGNALS:
     void scalingChanged();
+    void brightnessChanged();
+    void maxBrightnessChanged();
+    void brightnessAvailableChanged();
+
+private Q_SLOTS:
+    void fetchBrightness();
+    void fetchMaxBrightness();
 
 private:
     int m_scaling;
+    int m_brightness;
+    int m_maxBrightness;
+
     KScreen::ConfigPtr m_config;
+    org::kde::Solid::PowerManagement::Actions::BrightnessControl *m_brightnessInterface;
+    QDBusServiceWatcher *m_brightnessInterfaceWatcher;
 };