fix. Stylus button press changes tool to Eraser but do not erase.

lib/data/prefs.dart

@@ -105,6 +105,7 @@ abstract class Prefs {
   static late final PlainPref<bool> autoClearWhiteboardOnExit;
 
   static late final PlainPref<bool> disableEraserAfterUse;
+  static late final PlainPref<bool> eraserOnStylusButtonPressAndRelease;
   static late final PlainPref<bool> hideFingerDrawingToggle;
 
   static late final PlainPref<List<String>> recentColorsChronological;
@@ -217,6 +218,7 @@ abstract class Prefs {
     autoClearWhiteboardOnExit = PlainPref('autoClearWhiteboardOnExit', false);
 
     disableEraserAfterUse = PlainPref('disableEraserAfterUse', false);
+    eraserOnStylusButtonPressAndRelease = PlainPref('eraserOnStylusButtonPressAndRelease', false);
     hideFingerDrawingToggle = PlainPref('hideFingerDrawingToggle', false);
 
     recentColorsChronological = PlainPref('recentColorsChronological', []);

lib/i18n/strings_en.g.dart

@@ -374,6 +374,7 @@ class TranslationsSettingsPrefLabelsEn {
 	String get maxImageSize => 'Maximum image size';
 	String get autoClearWhiteboardOnExit => 'Auto-clear the whiteboard';
 	String get disableEraserAfterUse => 'Auto-disable the eraser';
+	String get eraserOnStylusButtonPressAndRelease => 'Eraser on stylus button press and release';
 	String get hideFingerDrawingToggle => 'Hide the finger drawing toggle';
 	String get editorPromptRename => 'Prompt you to rename new notes';
 	String get hideHomeBackgrounds => 'Hide backgrounds on the home screen';
@@ -400,6 +401,7 @@ class TranslationsSettingsPrefDescriptionsEn {
 	String get preferGreyscale => 'For e-ink displays';
 	String get autoClearWhiteboardOnExit => 'Clears the whiteboard after you exit the app';
 	String get disableEraserAfterUse => 'Automatically switches back to the pen after using the eraser';
+	String get eraserOnStylusButtonPressAndRelease => 'Switch to eraser pressing stylus button and releasing it';
 	String get maxImageSize => 'Larger images will be compressed';
 	late final TranslationsSettingsPrefDescriptionsHideFingerDrawingEn hideFingerDrawing = TranslationsSettingsPrefDescriptionsHideFingerDrawingEn.internal(_root);
 	String get editorPromptRename => 'You can always rename notes later';

lib/pages/editor/editor.dart

@@ -731,20 +731,49 @@ class EditorState extends State<Editor> {
     // whether the stylus button is or was pressed
     stylusButtonPressed = stylusButtonPressed || buttonPressed;
 
-    if (isHovering) {
-      if (buttonPressed) {
-        if (currentTool is Eraser) return;
-        tmpTool = currentTool;
-        currentTool = Eraser();
-        setState(() {});
-      } else {
-        if (tmpTool != null) {
-          currentTool = tmpTool!;
-          tmpTool = null;
+    if (!Prefs.eraserOnStylusButtonPressAndRelease.value) {
+      // standard behavior of stylus button, while holding is erasing
+      if (isHovering) {
+        if (buttonPressed) {
+          if (currentTool is Eraser) return;
+          tmpTool = currentTool;
+          currentTool = Eraser();
           setState(() {});
+        } else {
+          if (tmpTool != null) {
+            currentTool = tmpTool!;
+            tmpTool = null;
+            setState(() {});
+          }
+        }
+      }
+    }
+    else {
+      // some pens do not send moving events when stylus button is pressed
+      // so switch to eraser when button is pressed and back on next press
+      if (isHovering) {
+        if (buttonPressed) {
+          // switch to Eraser
+          if (currentTool is Eraser) {
+            if (tmpTool != null) {
+              // change back original tool
+              currentTool = tmpTool!;
+              tmpTool = null;
+              setState(() {});
+            }
+            else {
+              return; // when I am on eraser and previous tool is not set, it means that Eraser is main tool
+            }
+          }
+          else {
+            tmpTool = currentTool;
+            currentTool = Eraser();
+            setState(() {});
+          }
         }
       }
     }
+
   }
 
   void onMoveImage(EditorImage image, Rect offset) {

lib/pages/home/settings.dart

@@ -352,6 +352,12 @@
                 icon: FontAwesomeIcons.eraser,
                 pref: Prefs.disableEraserAfterUse,
               ),
+              SettingsSwitch(
+                title: t.settings.prefLabels.eraserOnStylusButtonPressAndRelease,
+                subtitle: t.settings.prefDescriptions.eraserOnStylusButtonPressAndRelease,
+                icon: FontAwesomeIcons.eraser,
+                pref: Prefs.eraserOnStylusButtonPressAndRelease,
+              ),
               SettingsSwitch(
                 title: t.settings.prefLabels.hideFingerDrawingToggle,
                 subtitle: () {
@@ -587,4 +593,5 @@
     UpdateManager.status.removeListener(onChanged);
     super.dispose();
   }
 }
+