See a full list under “Standard Action Activities” 21. The Action says what the target should do with the intent (a Command), and the Data gives more detail about what to run that action on.Īctions can be things like ACTION_VIEW to view some data, or ACTION_PICK to choose an item from a list.

“For that guy at the end of the block with the red mailbox.”Īn Implicit Intent includes an Action and some Data. This is a little bit like letters that have weird addresses, but still get delivered.When calling on other apps, we usually use an Implicit Intent.

We can send Intents to our own Activities, but we can also address them to other applications. Note that there are couple of different kinds of Intents we’ll go through examples of each. When the envelope arrives, the recipient can get that data out and do something with it… and possibly send a response back. But to reiterate: you can think of Intents as like letters you’d send through the mail: they are addressed to a particular target (e.g., another Activity-more properly a Context), and have room for some data called extras to go inside (held in a Bundle). Intents were previously introduced in Lecture 3. This is similar to an event callback, but working at a slightly higher system level. Intents work a bit differently: they allow us to create an object that can be “given” to another component (read: Activity), who can then respond upon receiving it. We’ve also seen event callbacks, where on an event one of our callbacks gets executed by the system-but this is really just a wrapper around direct method call via the Observer pattern. Most object communication we do is via direct method call you have a reference to an Object and then you call a method on it. Confirm that it is enabled by launching the Camera app.Īn Intent is a message that is sent between app components, allowing them to communicate! To enable the camera in the emulator, use the Tools > Android > AVD menu to modify the emulator, and select “webcam” for the front camera option. Note that you will need to have a working camera on your device for this demo.

The Intent system allows Activities to communicate, even though they don’t have references to each other (and thus we can’t just call a method on them). This lecture discusses how to use Intents to communicate between different Activities and Applications.

7.1 Intents for Another Activity (Explicit).

Android studio kotlin intent