修复低版本 Android 无法正确显示二维码

fixed #281

Author: aaa1115910

app/shared/src/main/kotlin/dev/aaa1115910/m3qrcode/MaterialShapeRenderer.kt

@@ -5,9 +5,10 @@ import android.graphics.Paint
 import android.graphics.Rect
 import android.graphics.RectF
 import android.graphics.drawable.VectorDrawable
-import kotlin.math.cos
+import android.os.Build
 import androidx.core.graphics.withRotation
 import androidx.core.graphics.withSave
+import kotlin.math.cos
 
 class MaterialShapeRenderer {
     var animationStyle: EntryAnimationStyle
@@ -60,12 +61,15 @@ class MaterialShapeRenderer {
 
     private fun draw(canvas: Canvas, rectF: RectF, paint: Paint) {
         canvas.withRotation(initialRotation * 90.0f, rectF.centerX(), rectF.centerY()) {
-            val vectorDrawable = srcImgSvg
+            val vectorDrawable = if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
+                runCatching { srcImgSvg.constantState!!.newDrawable().mutate() }
+                    .getOrDefault(srcImgSvg)
+            } else srcImgSvg
             val rect = Rect()
             rectF.round(rect)
             vectorDrawable.bounds = rect
-            srcImgSvg.setColorFilter(paint.colorFilter)
-            srcImgSvg.draw(this)
+            vectorDrawable.colorFilter = paint.colorFilter
+            vectorDrawable.draw(this)
         }
     }