Dark mode

[orontee]

Context

Firmware 6.8.x introduces "dark mode". @neilswann80 suggested to implement "dark mode" and to link that mode to the system state (cf. #71 (comment)).

Analysis

1. Build with last SDK, cf. https://github.com/pocketbook/SDK_6.3.0/releases/download/6.8/SDK-B288-6.8.7z
2. If firmware >=6.8, set application capability and device will handle everything!:

enum iv_app_capability_e {
    APP_CAPABILITY_SUPPORT_SCREEN_INVERSION = 1 << 0,
    APP_CAPABILITY_USER                     = 1 << 1 // The first role that can be used for application-specific purposes.
} typedef iv_app_capability;

/*
 * Set/Get app capability bitfield mask defined by enum iv_app_capability_e
 */
void IvSetAppCapability(int caps);
int IvGetAppCapability(void);

⚠️ Application must be tested with old firmware!

[orontee]

Looks nice!