Prevent crashes when dismissing dialogs

src/main/java/com/nutomic/syncthingandroid/activities/DeviceActivity.java

@@ -235,20 +235,14 @@ public class DeviceActivity extends SyncthingActivity implements View.OnClickLis
         outState.putString("device", new Gson().toJson(mDevice));
         if (mIsCreateMode){
             outState.putBoolean(IS_SHOWING_DISCARD_DIALOG, mDiscardDialog != null && mDiscardDialog.isShowing());
-            if(mDiscardDialog != null){
+            Util.dismissDialogSafe(mDiscardDialog, this);
-                mDiscardDialog.cancel();
-            }
         }
 
         outState.putBoolean(IS_SHOWING_COMPRESSION_DIALOG, mCompressionDialog != null && mCompressionDialog.isShowing());
-        if(mCompressionDialog != null){
+        Util.dismissDialogSafe(mCompressionDialog, this);
-            mCompressionDialog.cancel();
-        }
 
         outState.putBoolean(IS_SHOWING_DELETE_DIALOG, mDeleteDialog != null && mDeleteDialog.isShowing());
-        if (mDeleteDialog != null) {
+        Util.dismissDialogSafe(mDeleteDialog, this);
-            mDeleteDialog.cancel();
-        }
     }
 
     private void onServiceConnected() {

src/main/java/com/nutomic/syncthingandroid/activities/FolderActivity.java

@@ -31,6 +31,7 @@ import com.nutomic.syncthingandroid.model.Device;
 import com.nutomic.syncthingandroid.model.Folder;
 import com.nutomic.syncthingandroid.service.SyncthingService;
 import com.nutomic.syncthingandroid.util.TextWatcherAdapter;
+import com.nutomic.syncthingandroid.util.Util;
 
 import java.io.File;
 import java.io.IOException;
@@ -242,15 +243,11 @@ public class FolderActivity extends SyncthingActivity
     protected void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);
         outState.putBoolean(IS_SHOWING_DELETE_DIALOG, mDeleteDialog != null && mDeleteDialog.isShowing());
-        if (mDeleteDialog != null) {
+        Util.dismissDialogSafe(mDeleteDialog, this);
-            mDeleteDialog.cancel();
-        }
 
         if (mIsCreateMode){
             outState.putBoolean(IS_SHOW_DISCARD_DIALOG, mDiscardDialog != null && mDiscardDialog.isShowing());
-            if(mDiscardDialog != null){
+            Util.dismissDialogSafe(mDiscardDialog, this);
-                mDiscardDialog.cancel();
-            }
         }
     }
 

src/main/java/com/nutomic/syncthingandroid/activities/MainActivity.java

@@ -288,9 +288,7 @@ public class MainActivity extends StateDialogActivity
                 outState.putParcelable(QRCODE_BITMAP_KEY, ((BitmapDrawable) qrCode.getDrawable()).getBitmap());
                 outState.putString(DEVICEID_KEY, deviceID.getText().toString());
             }
-            if (mRestartDialog != null){
+            Util.dismissDialogSafe(mRestartDialog, this);
-                mRestartDialog.cancel();
-            }
         }
     }
 

src/main/java/com/nutomic/syncthingandroid/activities/ShareActivity.java

@@ -22,6 +22,7 @@ import com.google.common.io.Files;
 import com.nutomic.syncthingandroid.R;
 import com.nutomic.syncthingandroid.model.Folder;
 import com.nutomic.syncthingandroid.service.SyncthingService;
+import com.nutomic.syncthingandroid.util.Util;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -258,7 +259,7 @@ public class ShareActivity extends StateDialogActivity
         }
 
         protected void onPostExecute(Boolean isError) {
-            mProgress.dismiss();
+            Util.dismissDialogSafe(mProgress, ShareActivity.this);
             Toast.makeText(ShareActivity.this, mIgnored > 0 ?
                     getResources().getQuantityString(R.plurals.copy_success_partially, mCopied,
                             mCopied, mFolder.label, mIgnored) :

src/main/java/com/nutomic/syncthingandroid/activities/StateDialogActivity.java

@@ -13,6 +13,7 @@ import android.widget.TextView;
 
 import com.nutomic.syncthingandroid.R;
 import com.nutomic.syncthingandroid.service.SyncthingService;
+import com.nutomic.syncthingandroid.util.Util;
 
 /**
  * Handles loading/disabled dialogs.
@@ -78,11 +79,9 @@ public abstract class StateDialogActivity extends SyncthingActivity {
     }
 
     private void dismissDisabledDialog() {
-        if (mDisabledDialog != null && mDisabledDialog.isShowing()) {
+        Util.dismissDialogSafe(mDisabledDialog, this);
-            mDisabledDialog.dismiss();
         mDisabledDialog = null;
     }
-    }
 
     /**
      * Shows the loading dialog with the correct text ("creating keys" or "loading").
@@ -111,9 +110,7 @@ public abstract class StateDialogActivity extends SyncthingActivity {
     }
 
     private void dismissLoadingDialog() {
-        if (mLoadingDialog != null && mLoadingDialog.isShowing()) {
+        Util.dismissDialogSafe(mLoadingDialog, this);
-            mLoadingDialog.dismiss();
         mLoadingDialog = null;
     }
-    }
 }

src/main/java/com/nutomic/syncthingandroid/activities/SyncthingActivity.java

@@ -10,6 +10,7 @@ import com.annimon.stream.Stream;
 import com.nutomic.syncthingandroid.service.RestApi;
 import com.nutomic.syncthingandroid.service.SyncthingService;
 import com.nutomic.syncthingandroid.service.SyncthingServiceBinder;
+import com.nutomic.syncthingandroid.util.Util;
 
 import java.util.LinkedList;
 

src/main/java/com/nutomic/syncthingandroid/util/Util.java

@@ -1,19 +1,22 @@
 package com.nutomic.syncthingandroid.util;
 
+import android.app.Activity;
+import android.app.Dialog;
 import android.content.ClipData;
 import android.content.ClipboardManager;
-import android.widget.Toast;
-import android.util.Log;
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager.NameNotFoundException;
-
+import android.os.Build;
-import java.io.IOException;
+import android.util.Log;
-import java.io.DataOutputStream;
+import android.widget.Toast;
 
 import com.nutomic.syncthingandroid.R;
 
+import java.io.DataOutputStream;
+import java.io.IOException;
 import java.text.DecimalFormat;
+
 import eu.chainfire.libsuperuser.Shell;
 
 public class Util {
@@ -116,4 +119,21 @@ public class Util {
         }
         return false;
     }
+
+    /**
+     * Make sure that dialog is showing and activity is valid before dismissing dialog, to prevent
+     * various crashes.
+     */
+    public static void dismissDialogSafe(Dialog dialog, Activity activity) {
+        if (dialog == null || !dialog.isShowing())
+            return;
+
+        if (activity.isFinishing())
+            return;
+
+        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN && activity.isDestroyed())
+            return;
+
+        dialog.dismiss();
+    }
 }