Merge pull request #90 from Fbada006/emmanuelmuturia/task/disable-erase-button-without-drawing

Toggle Eraser Button Based On Drawing Presence

Author: emmanuelmuturia

artmaker/src/main/java/io/artmaker/ArtMaker.kt

@@ -80,6 +80,12 @@ fun ArtMaker(
         finishedImage?.let { onFinishDrawing(it) }
     }
 
+    LaunchedEffect(key1 = state.canErase) {
+        if (!state.canErase) {
+            isEraserActive = false
+        }
+    }
+
     Scaffold(
         floatingActionButton = {
             AnimatedVisibility(

artmaker/src/main/java/io/artmaker/ArtMakerUIState.kt

@@ -28,6 +28,7 @@ data class ArtMakerUIState(
     val canRedo: Boolean = false,
     val canUndo: Boolean = false,
     val canClear: Boolean = false,
+    val canErase: Boolean = false,
     val shouldUseStylusOnly: Boolean = false,
     val shouldDetectPressure: Boolean = false,
     val canShowEnableStylusDialog: Boolean = true,

artmaker/src/main/java/io/artmaker/ArtMakerViewModel.kt

@@ -104,6 +104,7 @@ internal class ArtMakerViewModel(
                         canRedo = state.canRedo,
                         canUndo = state.canUndo,
                         canClear = state.canClear,
+                        canErase = state.canErase,
                     )
                 }
             }

artmaker/src/main/java/io/artmaker/composables/ArtMakerControlMenu.kt

@@ -150,6 +150,7 @@ internal fun ArtMakerControlMenu(
                         )
                     },
                     onItemClicked = onActivateEraser,
+                    enabled = state.canErase,
                 )
                 MenuItem(
                     imageVector = ImageVector.vectorResource(id = R.drawable.ic_undo),

artmaker/src/main/java/io/artmaker/drawing/DrawingManager.kt

@@ -72,9 +72,11 @@ internal class DrawingManager {
     }
 
     private fun updateCurrentShape(offset: Offset, pressure: Float) {
-        val idx = _pathList.lastIndex
-        _pathList[idx].points.add(offset)
-        _pathList[idx].alphas.add(pressure)
+        if (pathList.isNotEmpty()) {
+            val idx = _pathList.lastIndex
+            _pathList[idx].points.add(offset)
+            _pathList[idx].alphas.add(pressure)
+        }
     }
 
     private fun undoLastShapePoint() {