add cancelling and constraints

Author: solygambas

11-blur-o-matic/README.md

@@ -2,19 +2,21 @@
 
 An app that blurs photos and saves the result to a file, using WorkManager.
 
-<!-- <p align="center">
+<p align="center">
 <img src="screenshot.png" style="width:528px;max-width: 100%;">
-</p> -->
+</p>
 
 ## Features
 
 - adding WorkManager to a project.
 - scheduling a simple task.
 - handling input and output parameters.
 - chaining work.
-- ensuring unique work.
+- naming unique work.
+- tagging work.
 - displaying work status in the UI.
 - showing final output.
 - cancelling work.
+- adding constraints.
 
 Based on [Background work with WorkManager - Kotlin](https://developer.android.com/codelabs/android-workmanager) by Google Codelabs (2022).

11-blur-o-matic/app/src/main/java/com/example/background/BlurActivity.kt

@@ -16,6 +16,7 @@
 
 package com.example.background
 
+import android.content.Intent
 import android.os.Bundle
 import android.view.View
 import androidx.activity.viewModels
@@ -39,8 +40,22 @@ class BlurActivity : AppCompatActivity() {
         setContentView(binding.root)
 
         binding.goButton.setOnClickListener { viewModel.applyBlur(blurLevel) }
+
         // observe work status
         viewModel.outputWorkInfos.observe(this, workInfosObserver())
+
+        // setup view output image file button
+        binding.seeFileButton.setOnClickListener {
+            viewModel.outputUri?.let { currentUri ->
+                val actionView = Intent(Intent.ACTION_VIEW, currentUri)
+                actionView.resolveActivity(packageManager)?.run {
+                    startActivity(actionView)
+                }
+            }
+        }
+
+        // hookup the cancel button
+        binding.cancelButton.setOnClickListener { viewModel.cancelWork() }
     }
 
     /**
@@ -84,6 +99,11 @@ class BlurActivity : AppCompatActivity() {
             val workInfo = listOfWorkInfo[0]
             if (workInfo.state.isFinished) {
                 showWorkFinished()
+                val outputImageUri = workInfo.outputData.getString(KEY_IMAGE_URI)
+                if (!outputImageUri.isNullOrEmpty()) {
+                    viewModel.setOutputUri(outputImageUri)
+                    binding.seeFileButton.visibility = View.VISIBLE
+                }
             } else {
                 showWorkInProgress()
             }

11-blur-o-matic/app/src/main/java/com/example/background/BlurViewModel.kt

@@ -76,8 +76,17 @@ class BlurViewModel(application: Application) : ViewModel() {
             }
             continuation = continuation.then(blurBuilder.build())
         }
+
+        // create charging constraint
+        val constraints = Constraints.Builder()
+            .setRequiresCharging(true)
+            //.setRequiresStorageNotLow(true)
+            //.setRequiredNetworkType(NetworkType.CONNECTED)
+            .build()
+
         // add work request to save the image to the filesystem
         val save = OneTimeWorkRequest.Builder(SaveImageToFileWorker::class.java)
+            .setConstraints(constraints)
             .addTag(TAG_OUTPUT)
             .build()
         continuation = continuation.then(save)
@@ -119,6 +128,10 @@ class BlurViewModel(application: Application) : ViewModel() {
         outputUri = uriOrNull(outputImageUri)
     }
 
+    internal fun cancelWork() {
+        workManager.cancelUniqueWork(IMAGE_MANIPULATION_WORK_NAME)
+    }
+
     class BlurViewModelFactory(private val application: Application) : ViewModelProvider.Factory {
 
         override fun <T : ViewModel?> create(modelClass: Class<T>): T {