Fix NPE when releasing camera

When tapping rapidly on the telegraph key, the camera is
released, either directly or delayed via a posted Runnable.
When tapping rapidly, the delayed runnable would run after
a synchronous release of the camera, in a state where the
camera would be null.

Extract open and release of the camera to two methods and
protect the release with a null check.

Also update the Gradle wrapper to 8.0 to be compatible
with the latest stable version of Android Studio (Giraffe).

app/src/main/java/rocks/poopjournal/morse/MainActivity.java

@@ -513,7 +513,7 @@ protected void onCreate(Bundle savedInstanceState) {
 
 
  if (!Build.MANUFACTURER.equals("HUAWEI")) {
- camera = Camera.open();
+ openCamera();
  }
 
 
@@ -528,10 +528,7 @@ protected void onCreate(Bundle savedInstanceState) {
  turnOff();
  }
  }
-
- camera.release();
- camera = null;
-
+ releaseCamera();
  }
  } else {
  if (!TextUtils.isEmpty(input.getText().toString())) {
@@ -561,8 +558,7 @@ protected void onCreate(Bundle savedInstanceState) {
  turnOff();
  }
  }
- camera.release();
- camera = null;
+ releaseCamera();
  }
  }
  });
@@ -997,7 +993,7 @@ public void onAutoFocus(boolean b, Camera camera) {
  public void turnOn() {
  try {
  if (android.os.Build.MANUFACTURER.equals("HUAWEI")) {
- camera = Camera.open();
+ openCamera();
  }
 
  Log.d("cameraMorseCheck","turning camera on at " + System.currentTimeMillis());
@@ -1234,7 +1230,7 @@ private boolean setKeySelectedForTelegraph(MotionEvent event) {
  telegraphPlayer.start();
  } else {
  time = System.currentTimeMillis();
- camera = Camera.open();
+ openCamera();
  turnOn();
  }
  return true;
@@ -1255,19 +1251,28 @@ private boolean setKeySelectedForTelegraph(MotionEvent event) {
 
  if (System.currentTimeMillis() - time >= 200) {
  turnOff();
- camera.release();
- camera = null;
+ releaseCamera();
  } else {
  final Handler handler = new Handler(Looper.getMainLooper());
  handler.postDelayed(() -> {
  turnOff();
- camera.release();
- camera = null;
+ releaseCamera();
  }, 100);
  }
  }
  return true;
  }
  return false;
  }
+
+ private void openCamera() {
+ camera = Camera.open();
+ }
+
+ private void releaseCamera() {
+ if (camera != null) {
+ camera.release();
+ camera = null;
+ }
+ }
 }

build.gradle

@@ -3,10 +3,10 @@
 buildscript {
  repositories {
  google()
- jcenter()
+ mavenCentral()
  }
  dependencies {
- classpath 'com.android.tools.build:gradle:8.1.1'
+ classpath 'com.android.tools.build:gradle:8.1.2'
 
  // NOTE: Do not place your application dependencies here; they belong
  // in the individual module build.gradle files
@@ -16,7 +16,7 @@ buildscript {
 allprojects {
  repositories {
  google()
- jcenter()
+ mavenCentral()
  }
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 #Wed Jun 09 15:32:18 PKT 2021
 distributionBase=GRADLE_USER_HOME
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.0-bin.zip
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME