| Safe Haskell | None |
|---|---|
| Language | GHC2021 |
SDL3.Sys.Power
Contents
Description
SDL power management routines.
There is a single function in this category: getPowerInfo
This function is useful for games on the go. This allows an app to know if it's running on a draining battery, which can be useful if the app wants to reduce processing, or perhaps framerate, to extend the duration of the battery's charge. Perhaps the app just wants to show a battery meter when fullscreen, or alert the user when the power is getting extremely low, so they can save their game. The basic state for the system's power supply.
These are results returned by getPowerInfo
FFI conventions
Unsuffixed aliases are unsafe foreign imports; aliases suffixed Safe are safe. Functions whose callbacks fire during the call export only the Safe alias (the genuine unsafe import stays reachable under SDL3.Sys.Bindgen.Power.Unsafe); functions curated unsafe-only export only the unsuffixed one. Each alias's documentation records its flavor and rationale.
Full conventions: SDL3.Sys.
Since: 3.2.0
Synopsis
- module SDL3.Sys.Bindgen.Power
- getPowerInfo :: Ptr CInt -> Ptr CInt -> IO SDL_PowerState
- getPowerInfoSafe :: Ptr CInt -> Ptr CInt -> IO SDL_PowerState
Documentation
module SDL3.Sys.Bindgen.Power
Function aliases
Arguments
| :: Ptr CInt |
|
| -> Ptr CInt |
|
| -> IO SDL_PowerState |
Get the current power supply details.
You should never take a battery status as absolute truth. Batteries (especially failing batteries) are delicate hardware, and the values reported here are best estimates based on what that hardware reports. It's not uncommon for older batteries to lose stored power much faster than it reports, or completely drain when reporting it has 20 percent left, etc.
Battery status can change at any time; if you are concerned with power state, you should call this function frequently, and perhaps ignore changes until they seem to be stable for a few seconds.
It's possible a platform can only report battery percentage or time left but not both.
On some platforms, retrieving power supply details might be expensive. If you want to display continuous status you could call this function every minute or so.
- Returns
- the current battery state or
SDL_POWERSTATE_ERRORon failure; callgetErrorfor more information. - Thread safety
- This function is not thread safe.
sdl3-bindgen-sys notes
- FFI safety
- Unsafe foreign import of
SDL_GetPowerInfo. The safe flavor isgetPowerInfoSafe. - C declaration
SDL_GetPowerInfo, defined atSDL3/SDL_power.h 100:44
Since: 3.2.0
Arguments
| :: Ptr CInt |
|
| -> Ptr CInt |
|
| -> IO SDL_PowerState |
Get the current power supply details.
You should never take a battery status as absolute truth. Batteries (especially failing batteries) are delicate hardware, and the values reported here are best estimates based on what that hardware reports. It's not uncommon for older batteries to lose stored power much faster than it reports, or completely drain when reporting it has 20 percent left, etc.
Battery status can change at any time; if you are concerned with power state, you should call this function frequently, and perhaps ignore changes until they seem to be stable for a few seconds.
It's possible a platform can only report battery percentage or time left but not both.
On some platforms, retrieving power supply details might be expensive. If you want to display continuous status you could call this function every minute or so.
- Returns
- the current battery state or
SDL_POWERSTATE_ERRORon failure; callgetErrorfor more information. - Thread safety
- This function is not thread safe.
sdl3-bindgen-sys notes
- FFI safety
- Safe foreign import of
SDL_GetPowerInfo. The unsafe flavor isgetPowerInfo. - C declaration
SDL_GetPowerInfo, defined atSDL3/SDL_power.h 100:44
Since: 3.2.0