Note: This repository contains tasks in slovak language.
Observer pattern uses three actor classes. Subject, Observer and Client. Subject is an object having methods to attach and detach observers to a client object. This pattern is used when there is one-to-many relationship between objects such as if one object is modified, its depenedent objects are to be notified automatically. Observer pattern falls under behavioral pattern category.
This repository contains two assignments done in Observer design pattern:
- Weather station - using class
java.util.Observableand interfacejava.util.Observer - Listeners
We have three variables at the input: temperature, pressure and humidity.
The CurrentConditionsDisplay display shows current values:
- temperature
- humidity
- pressure
The StatisticsDisplay display shows:
- minimum temperature
- maximum temperature
- average temperature
The ForecastDisplay display shows simple weather forecasting by rule:
- If the pressure rises =>
"The weather gets better" - If the pressure drops =>
"It will cool down, maybe it will rain." - If the pressure has not changed =>
"No change in future..."
Solved using
- class
java.util.Observable - interface
java.util.Observer
Here it is necessary to complete the project and ensure that the "click" statement always appears in the text area after clicking on the canvas. Also, we have to get the coordinates of the point on the canvas. See on the picture below:
