WEBVTT

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Welcome back.

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In this application we're going to use a simple user interface because the main purpose is to use the

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pre-trained model to detect objects for this purpose, create a new package, create call it screens,

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and inside this screens create a new Kotlin file.

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Name it as camera permission wrapper.

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First of all, let's start with the main screen that requests from the user the permission of camera.

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And for this, let me add in the manifest the camera permissions.

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So here uses permission camera.

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It's very simple.

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And there is a note that we need to add uses feature as we did in the previous videos.

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So here uses feature camera required and set it to false always.

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When you use camera in your app, add the uses feature and the user's permission back to the camera

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permission wrapper file.

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Let me create a new composable and name it the same as the file.

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This function takes two parameters the modifier modifier and on granted, which is a composable lambda

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expression.

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Alt+ enter to import the modifier.

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And here let's start building this composable function.

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Start with val context.

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Get the context from the local context and var has permission by.

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Remember start as mutable state of context compat Alt+.

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Enter to import it and mutable state of the by operator and get value local context the manifest and

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package.

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Here I imported the wrong manifest, So make sure you import the manifest of Android okay.

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This code creates a reactive permission state in jetpack.

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Compose has permission a boolean state variable that tracks camera permission status if the user granted

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or doesn't grant it.

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Remember, preserve the state across Recompositions and the mutable state of makes the value observable

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for compose UI updates.

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Context compact self permission checks if the camera permission is granted.

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So here let me write this note down and comparing it with the package manager.

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Package manager permission granted to get a boolean result.

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Okay, so here we are getting this and compare it with the package manager.

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Permission granted boolean.

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If it is the same so it is granted.

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If not, the That permission is not granted initially sets the has permission based on current permission

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status.

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When permission changes, the UI automatically Recomposes.

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Used to conditionally show and hide UI elements based on UI and the permission state.

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Then you create another variable called launcher equals to remember launcher for activity result.

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Then add the contract.

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Pass the contract parameter as activity result context and the second parameter is on result.

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So we need to pass two parameters the contract and on result.

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The on result is passed like this.

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Okay so let me remove this and pass it like this.

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It's better.

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Close.

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This code launches the permission request.

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The remember launcher for activity result remembers a launcher across Recompositions and activity result

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contracts that request permissions contract for requesting a single permission for.

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So this is requesting a single permission.

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The second parameter is on results callback that updates the state when permission result is received.

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What we need to do is receiving a boolean value and updating the has permission variable that we just

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created before.

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Okay.

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So on uh requesting the single permission and on result, what we need to do go and update the has permission

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and set it to granted.

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So this is a callback that updates the state when permission result is received okay.

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So this is very important.

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In this way we handle the permission and we ask the user for the permission.

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In the next video we'll continue with the UI.

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We're going to create the box and the button.