Don't act on Camera if it is in the middle of a stop (#50)

* Don't act on Camera if it is in the middle of a stop
* Ensure no issues if scheduled for stop

Author: natario1

cameraview/src/main/java/com/otaliastudios/cameraview/Camera1.java

@@ -191,7 +191,7 @@ void onStop() throws Exception {
         Exception error = null;
         LOG.i("onStop:", "About to clean up.");
         mHandler.get().removeCallbacks(mPostFocusResetRunnable);
-        if (isCameraAvailable()) {
+        if (mCamera != null) {
             LOG.i("onStop:", "Clean up.", "Ending video?", mIsCapturingVideo);
             if (mIsCapturingVideo) endVideo();
 
@@ -510,7 +510,20 @@ boolean shouldFlipSizes() {
     }
 
     private boolean isCameraAvailable() {
-        return mCamera != null;
+        switch (mState) {
+            // If we are stopped, don't.
+            case STATE_STOPPED: return false;
+            // If we are going to be closed, don't act on camera.
+            // Even if mCamera != null, it might have been released.
+            case STATE_STOPPING: return false;
+            // If we are started, act as long as there is no stop/restart scheduled.
+            // At this point mCamera should never be null.
+            case STATE_STARTED: return !mScheduledForStop && !mScheduledForRestart;
+            // If we are starting, theoretically we could act.
+            // Just check that camera is available.
+            case STATE_STARTING: return mCamera != null && !mScheduledForStop && !mScheduledForRestart;
+        }
+        return false;
     }
 
 

cameraview/src/main/java/com/otaliastudios/cameraview/CameraController.java

@@ -38,6 +38,10 @@ abstract class CameraController implements CameraPreview.SurfaceCallback {
 
     protected int mDisplayOffset;
     protected int mDeviceOrientation;
+
+    protected boolean mScheduledForStart = false;
+    protected boolean mScheduledForStop = false;
+    protected boolean mScheduledForRestart = false;
     protected int mState = STATE_STOPPED;
 
     protected WorkerHandler mHandler;
@@ -84,11 +88,13 @@ private String ss() {
     // Starts the preview asynchronously.
     final void start() {
         LOG.i("Start:", "posting runnable. State:", ss());
+        mScheduledForStart = true;
         mHandler.post(new Runnable() {
             @Override
             public void run() {
                 try {
                     LOG.i("Start:", "executing. State:", ss());
+                    mScheduledForStart = false;
                     if (mState >= STATE_STARTING) return;
                     mState = STATE_STARTING;
                     LOG.i("Start:", "about to call onStart()", ss());
@@ -108,11 +114,13 @@ public void run() {
     // Stops the preview asynchronously.
     final void stop() {
         LOG.i("Stop:", "posting runnable. State:", ss());
+        mScheduledForStop = true;
         mHandler.post(new Runnable() {
             @Override
             public void run() {
                 try {
                     LOG.i("Stop:", "executing. State:", ss());
+                    mScheduledForStop = false;
                     if (mState <= STATE_STOPPED) return;
                     mState = STATE_STOPPING;
                     LOG.i("Stop:", "about to call onStop()");
@@ -148,11 +156,13 @@ void stopImmediately() {
     // Forces a restart.
     protected final void restart() {
         LOG.i("Restart:", "posting runnable");
+        mScheduledForRestart = true;
         mHandler.post(new Runnable() {
             @Override
             public void run() {
                 try {
                     LOG.i("Restart:", "executing. Needs stopping:", mState > STATE_STOPPED, ss());
+                    mScheduledForRestart = false;
                     // Don't stop if stopped.
                     if (mState > STATE_STOPPED) {
                         mState = STATE_STOPPING;