Fixed undo and redo crashing app when no paths are visible

robothaver · Jun 2, 2024 · 4b97e2a · 4b97e2a
1 parent 1b40005
commit 4b97e2a
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Showing 2 changed files with 20 additions and 5 deletions.
diff --git a/...src/main/java/com/robothaver/kandraw/dialogs/eraserSettingsDialog/EraserSettingsDialog.kt b/...src/main/java/com/robothaver/kandraw/dialogs/eraserSettingsDialog/EraserSettingsDialog.kt
@@ -17,6 +17,7 @@ import androidx.compose.runtime.MutableState
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.robothaver.kandraw.dialogs.penSettingsDialog.composables.Title
@@ -35,20 +36,28 @@ fun EraserSettingsDialog(
         Title(text = "Eraser width: ${eraserWidth.value.roundToInt()}")
         Slider(
             value = eraserWidth.value,
-            onValueChange = {eraserWidth.value = it},
+            onValueChange = { eraserWidth.value = it },
             valueRange = 10f..200f,
         )
         HorizontalDivider(
             modifier = Modifier.padding(vertical = 12.dp),
             color = MaterialTheme.colorScheme.surfaceVariant
         )
-        Button(onClick = { canvasController.clearCanvas() },
+        Button(
+            onClick = { canvasController.clearCanvas() },
             modifier = Modifier.fillMaxWidth()
         ) {
             Row(verticalAlignment = Alignment.CenterVertically) {
                 Icon(Icons.Rounded.Delete, null)
                 Text(text = "Clear canvas", fontSize = 18.sp, fontWeight = FontWeight.Bold)
             }
         }
+        Text(
+            text = "Clear canvas is experimental and it could break the app!",
+            fontSize = 10.sp,
+            textAlign = TextAlign.Center,
+            modifier = Modifier.fillMaxWidth(),
+            color = MaterialTheme.colorScheme.error
+        )
     }
 }
diff --git a/app/src/main/java/com/robothaver/kandraw/domain/canvasController/CanvasController.kt b/app/src/main/java/com/robothaver/kandraw/domain/canvasController/CanvasController.kt
@@ -151,10 +151,14 @@ class CanvasController(
                 }
             } else if (undoPaths.last().action == Actions.Erase) {
                 allPaths.add(undoPaths.last().index, undoPaths.last())
-                visiblePaths.add(undoPaths.last().index, undoPaths.last())
+                if (visiblePaths.isNotEmpty()) {
+                    visiblePaths.add(undoPaths.last().index, undoPaths.last())
+                }
             } else {
                 allPaths.removeLast()
-                visiblePaths.removeLast()
+                if (visiblePaths.isNotEmpty()) {
+                    visiblePaths.removeLast()
+                }
             }
             undoPaths.removeLast()
         }
@@ -174,7 +178,9 @@ class CanvasController(
 
             } else if (redoPaths.last().action == Actions.Erase) {
                 allPaths.removeAt(redoPaths.last().index)
-                visiblePaths.removeAt(redoPaths.last().index)
+                if (visiblePaths.isNotEmpty() || redoPaths.last().index != visiblePaths.lastIndex) {
+                    visiblePaths.removeAt(redoPaths.last().index)
+                }
             } else {
                 allPaths.add(redoPaths.last())
                 visiblePaths.add(redoPaths.last())