feat: 删除欢迎界面图片

app/src/main/java/io/legado/app/ui/welcome/WelcomeActivity.kt

@@ -1,5 +1,7 @@
 package io.legado.app.ui.welcome
 
+import android.animation.Animator
+import android.animation.ValueAnimator
 import android.content.Intent
 import android.os.Bundle
 import com.github.houbb.opencc4j.util.ZhConverterUtil
@@ -16,7 +18,7 @@ import kotlinx.android.synthetic.main.activity_welcome.*
 import org.jetbrains.anko.startActivity
 import java.util.concurrent.TimeUnit
 
-open class WelcomeActivity : BaseActivity(R.layout.activity_welcome) {
+open class WelcomeActivity : BaseActivity(R.layout.activity_welcome), Animator.AnimatorListener {
 
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         iv_book.setColorFilter(accentColor)
@@ -40,15 +42,33 @@ open class WelcomeActivity : BaseActivity(R.layout.activity_welcome) {
                 else -> null
             }
         }
-        root_view.postDelayed({
-            startActivity<MainActivity>()
-            if (getPrefBoolean(getString(R.string.pk_default_read))) {
-                startActivity<ReadBookActivity>()
-            }
-            finish()
-        }, 200)
+        val welAnimator = ValueAnimator.ofFloat(1f, 0.3f).setDuration(300)
+        welAnimator.addUpdateListener { animation ->
+            root_view.alpha = animation.animatedValue as Float
+        }
+        welAnimator.addListener(this)
+        welAnimator.start()
+    }
+
+    private fun startMainActivity() {
+        startActivity<MainActivity>()
+        if (getPrefBoolean(getString(R.string.pk_default_read))) {
+            startActivity<ReadBookActivity>()
+        }
+        finish()
     }
 
+    override fun onAnimationStart(animation: Animator) {
+
+    }
+
+    override fun onAnimationEnd(animation: Animator) {
+        startMainActivity()
+    }
+
+    override fun onAnimationCancel(animation: Animator) = Unit
+
+    override fun onAnimationRepeat(animation: Animator) = Unit
 }
 
 class Launcher1 : WelcomeActivity()