ESPHome 2026.4.0: MediaPlayer callback signature changed

[bdraco]

Summary

ESPHome 2026.4.0 changes MediaPlayer::add_on_state_callback to pass state as an argument (PR #15200). The callback signature changed from void() to void(MediaPlayerState).

Current usage

components/homeassistant_media_player/HomeAssistantMediaPlayerGroup.cpp registers a zero-argument lambda on add_on_state_callback.

Recommended migration

// Before
player->add_on_state_callback([this, player]() {
  this->state_updated(player);
});

// After
player->add_on_state_callback([this, player](MediaPlayerState state) {
  this->state_updated(player);
});

References

• ESPHome PR: [media_player] Migrate triggers to callback automation esphome/esphome#15200
• Developer blog post: Add blog post: Trigger trampolines eliminated (#15174, #15198, #15199, #15200) esphome/developers.esphome.io#122