This project is an MPP version of kfsm-android-compose-traffic. It will be extended over time to test the extent of support for various UI mechanisms of Compose across Android, Desktop and Web.
This application demonstrates using 2 state machines to provide a solution. The traffic light state machine operates the light and only has a stop and go event. The stop event will switch to amber and after a timeout switch to red and generate a stopped notification.
The intersection state machine cycles through controlling the lights in order, sending go to current light and then waiting after stopped before switching to next light sending the go event.
The TrafficIntersectionService can be created by providing a different number of lights.
The application illustrates how to create a view models that uses Channel and StateFlow and SharedFlow to represent the changing values and states so that compose can update the UI efficiently. Using channels from the service means the ViewModel can decide which coroutine context to when updating the state flow after receiving from the channel.
We are using to completely separate finite state machines to manage the intersection. The intersection knows about the traffic lights and subscribes to a stop event in order to know when the cycle ends. It can also be achieved with a timeout based on the knowledge of the amber timeout and wait time. However, we wanted to experiment with events.
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The traffic light can be turned on and off, it can be configured with amber timeout and flashing timeoutes.
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The traffic light can be started and stopped or turned to flashing.
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When it is turned on all lights are read.
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When it is started it will switch the active light to green.
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When it is stopped it will switch to amber and after timeout to red.
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Then it will generate a stopped event.
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The traffic intersection can be configured with a cycle time that determines how long the light is green and a wait time that determines how long the light is red before switching to the next light.
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The traffic intersection will switch between lights.
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Starting a light which turns it to green. Then after a timeout it will stop the light which turns it to amber and after timeout to red and then the light sends a stop event.
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The intersection will receive the stopped event and then wait for a period before switching to next light and then starting that light.
