How to respect Battery Saving Mode?

nephros · 6 April 2023 07:47

I have some apps which to things like check for data updates online, or have systemd services packaged which to some background processing - some of which may be resource intensive or otherwise contradict the purposes of “battery saving mode”.

How can I detect (in a hopefully simple manner) that BSM is active, and that my services/apps shouldn’t do their thing?

I know about

mcetool -N | grep  'saving mode'
Power saving mode:                   enabled (inactive)
Forced power saving mode:            disabled

 busctl call  "com.nokia.mce" /com/nokia/mce/request "com.nokia.mce.request" get_psm_state

but are there other ways (e.g. ~~query a dbus service~~, check for presence of a file, read a dconf key)?

spiiroin · 6 April 2023 10:23

nephros:

 busctl call  "com.nokia.mce" /com/nokia/mce/request "com.nokia.mce.request" get_psm_state
but are there other ways (e.g. ~~query a dbus service~~ , check for presence of a file, read a dconf key)?

Well, mce is the dbus service from which the info is available:

github.com

sailfishos/mce-dev/blob/master/include/mce/dbus-names.h#L519

      
        
            *@{
            */
            
            
/** Query the automatic power saving mode
            *
            * @since mce 1.10.44
            *
            * @return boolean: TRUE if automatic power saving mode is active, or
            *                  FALSE if automatic power saving mode is inactive
            */
            # define MCE_PSM_STATE_GET                 "get_psm_state"
            
            
/** Notify everyone that the state of the automatic power saving mode changed
            *
            * @since mce 1.10.44
            *
            * @param active boolean: TRUE if automatic power saving mode is active, or
            *                        FALSE if automatic power saving mode is inactive
            */
            # define MCE_PSM_STATE_SIG                 "psm_state_ind"

But there is also libmce-qt and QMcePowerSaveMode class that makes things a bit simpler

github.com

sailfishos/libmce-qt/blob/master/lib/include/qmcepowersavemode.h#L42

      
        
            * The views and conclusions contained in the software and documentation
            * are those of the authors and should not be interpreted as representing
            * any official policies, either expressed or implied.
            */
            
            
#ifndef QMCE_POWERSAVEMODE_H_
            #define QMCE_POWERSAVEMODE_H_
            
            
#include "qmcetypes.h"
            
            
class QMCE_EXPORT QMcePowerSaveMode : public QObject
            {
               Q_OBJECT
               Q_PROPERTY(bool valid READ valid NOTIFY validChanged)
               Q_PROPERTY(bool active READ active NOTIFY activeChanged)
            public:
               QMcePowerSaveMode(QObject* aParent = NULL);
               bool valid() const;
               bool active() const;
            Q_SIGNALS:
               void validChanged();

There is also runnable qml example here:

github.com

sailfishos/libmce-qt/blob/master/examples/qml/mcebattery.qml#L89

      
        
            }
            Label {
                text: "PowerSaveMode"
            }
            Label {
                x: Theme.paddingLarge
                text: "Valid: " + mcePowerSaveMode.valid
            }
            Label {
                x: Theme.paddingLarge
                text: "Active: " + mcePowerSaveMode.active
            }
            Label {
                text: "BatteryStatus"
            }
            Label {
                x: Theme.paddingLarge
                text: "Valid: " + mceBatteryStatus.valid
            }
            Label {
                x: Theme.paddingLarge

nephros · 6 April 2023 10:39

Lovely! Thanks a lot!