Android Developer Fundamentals V2 - Activities

The complete sequence of states an Activity can be in throughout its lifespan, from creation to destruction.

A visual representation of the various states an Activity can occupy, along with the corresponding callbacks triggered when transitioning between these states.

A state where the Activity is being created, but is not yet visible to the user.

A state where the Activity is visible to the user, but is not in the foreground.

This callback is called when the Activity is first created. It handles static setup like creating views or binding data to lists.

This callback is called when the Activity becomes visible to the user, indicating the start of its visual appearance on the screen.

This callback is triggered when the Activity is resumed after being stopped. It essentially restarts the Activity.

This callback is called when the Activity is fully active and ready to interact with the user.

This callback is called when the Activity is about to be paused, as another Activity takes focus. It's a chance for the Activity to save its state.

The state in which an activity is created but not yet visible to the user.

The state in which an Activity is becoming/is visible to the user.

The process of saving the state of an Activity. It is called when the Activity is destroyed.

A bundle containing data that represents the previous state of an activity. It is used to restore the state of an activity when it is recreated.

The method that restores the state of an activity from a saved instance state.

A method that is called when the Activity is no longer visible to the user.

This method is usually used to perform operations that are too heavy for the onPause() method, like releasing resources or saving data.

The Activity is being finished and removed from the system. It's the final step of the Activity's lifecycle.

When a user navigates back to an Activity, its Activity's life begins at the onRestart method and proceeds following the lifecycle callbacks from there.

onPause() should be as fast as possible so the Activity can be quickly resumed.

The Android system automatically saves the state of views with unique IDs, like text entered in an EditText, and the Intent that started the Activity, along with any data in its extras.

You are responsible for saving any other data related to the Activity or user progress, such as preferences or game scores.

A method that is called by the Android runtime when there is a possibility the Activity might be destroyed. It allows you to save data specific to the current instance of the Activity during the current session.

The method onSaveInstanceState() receives a Bundle object as an argument. You can use this Bundle to store data that needs to be saved, such as the state of UI elements.

You can save data to be restored later by putting it in the Bundle object provided by the onSaveInstanceState() method. This data can then be retrieved when the Activity is restored.

When the Activity is recreated, the Android runtime passes the saved data from the Bundle back to the Activity using the onRestoreInstanceState() method.

If an Activity is destroyed and later recreated, the system can restore its state by calling the onRestoreInstanceState() method with the saved data from the Bundle.

If an Activity is destroyed and recreated, the system uses the saved data from the Bundle to restore the Activity to its previous state, potentially using information from the saved Bundle.

The data that represents the state of an Activity instance, such as user inputs, counter values, or progress indicators, that gets stored and restored when an Activity transitions between different states (e.g., when transitioning to the background).

This method is used within the onDestroy() callback to check whether an activity is intentionally being finished by the user or system. It is useful for deciding how to handle specific cleanup tasks.

A UI state change, such as screen orientation change or multi-window mode activation, that can lead to the system destroying and recreating an activity.