Androidで部分的なViewをぼかす

build.gradle

defaultConfig {
  // for blurview
  renderscriptTargetApi 25
  renderscriptSupportModeEnabled true
}

dependencies {
  compile 'com.eightbitlab:blurview:1.3.0'
}

activity_main.xml

<eightbitlab.com.blurview.BlurView
  android:id="@+id/blurview"
  android:layout_width="match_parent"
  app:blurOverlayColor="@android:color/transparent">
</eightbitlab.com.blurview.BlurView>

blurOverlayColor は標準の transparent を指定。

MainActivity.java

final float radius = 16;
final View decorView = getWindow().getDecorView();
final ViewGroup rootView = (ViewGroup) decorView.findViewById(R.id.activity_main);
final Drawable windowBackground = decorView.getBackground();

BlurView blurView = (BlurView) findViewById(R.id.blurview);
blurView.setupWith(rootView)
        .windowBackground(windowBackground)
        .blurAlgorithm(new RenderScriptBlur(this, true))
        .blurRadius(radius);

検討したもの

• android - dim/blur a parent layout background - Stack Overflow
• GitHub - Dimezis/BlurView: Dynamic iOS-like blur of underlying Views for Android
• GitHub - wl9739/BlurredView: Dynamic blur of image views for Android
• GitHub - wonderkiln/blurkit-android: The missing Android blurring library. Fast blur-behind layout that parallels iOS.