Fix various crashes of v2.13.1, by @gsantner

app/src/main/java/net/gsantner/markor/activity/DocumentEditAndViewFragment.java

@@ -286,7 +286,7 @@ public void onPause() {
         _appSettings.setDocumentPreviewState(_document.path, _isPreviewVisible);
         _appSettings.setLastEditPosition(_document.path, TextViewUtils.getSelection(_hlEditor)[0]);
 
-        if(_document.path.equals(_appSettings.getTodoFile().getAbsolutePath())){
+        if (_document.path.equals(_appSettings.getTodoFile().getAbsolutePath())) {
             TodoWidgetProvider.updateTodoWidgets();
         }
         super.onPause();
@@ -862,7 +862,12 @@ private boolean isDisplayedAtMainActivity() {
     }
 
     public void updateViewModeText() {
-        _format.getConverter().convertMarkupShowInWebView(_document, getTextString(), getActivity(), _webView, _nextConvertToPrintMode, _hlEditor.isLineNumbersEnabled());
+        // Don't let text to view mode crash app
+        try {
+            _format.getConverter().convertMarkupShowInWebView(_document, getTextString(), getActivity(), _webView, _nextConvertToPrintMode, _hlEditor.isLineNumbersEnabled());
+        } catch (OutOfMemoryError e) {
+            _format.getConverter().convertMarkupShowInWebView(_document, "updateViewModeText getTextString(): OutOfMemory  " + e, getActivity(), _webView, _nextConvertToPrintMode, _hlEditor.isLineNumbersEnabled());
+        }
     }
 
     public void setViewModeVisibility(final boolean show) {

app/src/main/java/net/gsantner/markor/activity/DocumentShareIntoFragment.java

@@ -17,6 +17,7 @@
 import android.os.Build;
 import android.os.Bundle;
 import android.text.TextUtils;
+import android.util.Log;
 import android.util.Pair;
 import android.util.Patterns;
 import android.util.TypedValue;
@@ -433,7 +434,9 @@ public void onFsViewerConfig(GsFileBrowserOptions.Options dopt) {
 
                 @Override
                 public void onFsViewerSelected(final String request, final File sel, final Integer lineNumber) {
-                    if (sel.isDirectory()) {
+                    if (sel == null) {
+                        Log.e(getClass().getName(), "onFsViewerSelected: selected file is null");
+                    } else if (sel.isDirectory()) {
                         NewFileDialog.newInstance(sel, false, f -> {
                             if (f.isFile()) {
                                 appendToExistingDocumentAndClose(f, true);

app/src/main/java/net/gsantner/markor/frontend/textview/HighlightingEditor.java

@@ -119,7 +119,11 @@ public void afterTextChanged(final Editable s) {
     @Override
     public boolean onPreDraw() {
         _lineNumbersDrawer.setTextSize(getTextSize());
-        return super.onPreDraw();
+        try {
+            return super.onPreDraw();
+        } catch (OutOfMemoryError ignored) {
+            return false; // return false to cancel current drawing pass/round
+        }
     }
 
     @Override

app/src/main/java/net/gsantner/markor/frontend/textview/SyntaxHighlighterBase.java

@@ -62,9 +62,9 @@
  * Spans are further divided into two categories: dynamic and static.
  * - Dynamic spans are updated as one scrolls, as described above
  * - Static spans are applied once and never updated. These are typically used for
- *   spans which affect the text layout.
- *   - For example, a span which makes text bigger.
- *   - Updating these dynamically would make the text jump around as one scrolls
+ * spans which affect the text layout.
+ * - For example, a span which makes text bigger.
+ * - Updating these dynamically would make the text jump around as one scrolls
  * <p>
  * Fixup:
  * - As the user types we shift all spans to accomodate the changed text.
@@ -75,19 +75,19 @@
  * - Derived classes should override generateSpans() to generate all spans
  * - New spans are added by calling addSpanGroup()
  * - The HighlightingEditor will trigger the generation of spans when the text changes.
- *   - This is debounced so that changes are batched
- *   - Span generation is done on a background thread
+ * - This is debounced so that changes are batched
+ * - Span generation is done on a background thread
  * <p>
  * Other performance tips:
  * - Performance is heavily dependent on the number of spans applied to the text.
  * - Combine related spans into a single span if possible
- *   - HighlightSpan is a helper class which can be used to create a span with multiple attributes
- *   - For example, a span which makes text bold and italic
+ * - HighlightSpan is a helper class which can be used to create a span with multiple attributes
+ * - For example, a span which makes text bold and italic
  * - Absolutely minimize the number of spans implementing `UpdateLayout`
- *   - These spans trigger a text layout update when changed in any way
- *   - Instead consider using a span implementing `StaticSpan`
- *     - If StaticSpans are present, the text is reflowed after applying them
- *     - This happens once, and not for each span, which is much more efficient
+ * - These spans trigger a text layout update when changed in any way
+ * - Instead consider using a span implementing `StaticSpan`
+ * - If StaticSpans are present, the text is reflowed after applying them
+ * - This happens once, and not for each span, which is much more efficient
  */
 public abstract class SyntaxHighlighterBase {
 
@@ -230,7 +230,7 @@ public SyntaxHighlighterBase clearStatic() {
         boolean hasStatic = false;
         for (int i = _groups.size() - 1; i >= 0; i--) {
             final SpanGroup group = _groups.get(i);
-            if (group.isStatic) {
+            if (group != null && group.isStatic) {
                 hasStatic = true;
                 _spannable.removeSpan(group.span);
             }
@@ -348,7 +348,7 @@ public SyntaxHighlighterBase applyDynamic(final int[] range) {
             for (int i = 0; i < _groups.size(); i++) {
                 final SpanGroup group = _groups.get(i);
 
-                if (group.isStatic) {
+                if (group == null || group.isStatic) {
                     continue;
                 }
 
@@ -368,7 +368,6 @@ public SyntaxHighlighterBase applyDynamic(final int[] range) {
     }
 
 
-
     public SyntaxHighlighterBase applyStatic() {
         if (_spannable != null && !_staticApplied) {
             applyFixup();

app/src/main/java/net/gsantner/opoc/frontend/filebrowser/GsFileBrowserListAdapter.java

@@ -56,6 +56,7 @@
 import java.util.Set;
 import java.util.Stack;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
@@ -687,7 +688,10 @@ private void loadFolder(final File folder, final File show) {
         final File toShow = show == null ? _fileToShowAfterNextLoad : show;
         _fileToShowAfterNextLoad = null;
 
-        executorService.execute(() -> _loadFolder(toLoad, toShow));
+        try {
+            executorService.execute(() -> _loadFolder(toLoad, toShow));
+        } catch (RejectedExecutionException ignored) { // during exit
+        }
     }
 
     // This function is not called on the main thread, so post to the UI thread