set minimal brush size to 5

app/src/main/kotlin/com/simplemobiletools/draw/pro/activities/MainActivity.kt

@@ -644,7 +644,7 @@ class MainActivity : SimpleActivity(), CanvasListener {
 
     private var onStrokeWidthBarChangeListener: SeekBar.OnSeekBarChangeListener = object : SeekBar.OnSeekBarChangeListener {
         override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {
-            brushSize = progress.toFloat()
+            brushSize = Math.max(progress.toFloat(), 5f)
             updateBrushSize()
         }
 

app/src/main/kotlin/com/simplemobiletools/draw/pro/views/MyCanvas.kt

@@ -292,7 +292,7 @@ class MyCanvas(context: Context, attrs: AttributeSet) : View(context, attrs) {
 
     fun setBrushSize(newBrushSize: Float) {
         mCurrBrushSize = newBrushSize
-        mPaintOptions.strokeWidth = resources.getDimension(R.dimen.full_brush_size) * (newBrushSize / mScaleFactor / 100f)
+        mPaintOptions.strokeWidth = resources.getDimension(R.dimen.full_brush_size) * (mCurrBrushSize / mScaleFactor / 100f)
     }
 
     fun setAllowZooming(allowZooming: Boolean) {

app/src/main/res/layout/activity_main.xml

@@ -107,6 +107,7 @@
                 android:layout_centerHorizontal="true"
                 android:layout_marginBottom="12dp"
                 android:max="100"
+                android:min="5"
                 android:padding="@dimen/medium_margin"
                 android:progress="50" />