Fix crashes

app/src/main/kotlin/org/koitharu/kotatsu/core/nav/AppRouter.kt

@@ -52,6 +52,7 @@ import org.koitharu.kotatsu.core.ui.dialog.buildAlertDialog
 import org.koitharu.kotatsu.core.util.ext.connectivityManager
 import org.koitharu.kotatsu.core.util.ext.findActivity
 import org.koitharu.kotatsu.core.util.ext.getThemeDrawable
+import org.koitharu.kotatsu.core.util.ext.printStackTraceDebug
 import org.koitharu.kotatsu.core.util.ext.toFileOrNull
 import org.koitharu.kotatsu.core.util.ext.toUriOrNull
 import org.koitharu.kotatsu.core.util.ext.withArgs
@@ -614,9 +615,11 @@ class AppRouter private constructor(
 		startActivity(Intent(contextOrNull() ?: return, activityClass))
 	}
 
-	private fun getFragmentManager(): FragmentManager? {
-		return fragment?.childFragmentManager ?: activity?.supportFragmentManager
-	}
+	private fun getFragmentManager(): FragmentManager? = runCatching {
+		fragment?.childFragmentManager ?: activity?.supportFragmentManager
+	}.onFailure { exception ->
+		exception.printStackTraceDebug()
+	}.getOrNull()
 
 	private fun shareLink(link: String, title: String) {
 		val context = contextOrNull() ?: return

app/src/main/kotlin/org/koitharu/kotatsu/core/nav/NavUtil.kt

@@ -7,6 +7,7 @@ import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentActivity
 import org.koitharu.kotatsu.core.util.ext.isAnimationsEnabled
+import org.koitharu.kotatsu.core.util.ext.isOnScreen
 
 inline val FragmentActivity.router: AppRouter
 	get() = AppRouter(this)
@@ -26,14 +27,15 @@ tailrec fun Fragment.dismissParentDialog(): Boolean {
 	}
 }
 
-fun scaleUpActivityOptionsOf(view: View): Bundle? = if (view.context.isAnimationsEnabled) {
-	ActivityOptions.makeScaleUpAnimation(
-		view,
-		0,
-		0,
-		view.width,
-		view.height,
+fun scaleUpActivityOptionsOf(view: View): Bundle? {
+	if (!view.context.isAnimationsEnabled || !view.isOnScreen()) {
+		return null
+	}
+	return ActivityOptions.makeScaleUpAnimation(
+		/* source = */ view,
+		/* startX = */ 0,
+		/* startY = */ 0,
+		/* width = */ view.width,
+		/* height = */ view.height,
 	).toBundle()
-} else {
-	null
 }

app/src/main/kotlin/org/koitharu/kotatsu/core/util/ext/View.kt

@@ -1,10 +1,13 @@
 package org.koitharu.kotatsu.core.util.ext
 
+import android.content.Context
+import android.graphics.Point
 import android.graphics.Rect
 import android.os.Build
 import android.view.View
 import android.view.View.MeasureSpec
 import android.view.ViewGroup
+import android.view.WindowManager
 import android.widget.Checkable
 import androidx.annotation.StringRes
 import androidx.appcompat.widget.ActionMenuView
@@ -200,3 +203,24 @@ fun View.setContentDescriptionAndTooltip(@StringRes resId: Int) {
 	contentDescription = text
 	TooltipCompat.setTooltipText(this, text)
 }
+
+fun View.getWindowBounds(): Rect {
+	val wm = context.getSystemService(Context.WINDOW_SERVICE) as WindowManager
+	return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+		wm.currentWindowMetrics.bounds
+	} else {
+		val size = Point()
+		@Suppress("DEPRECATION")
+		display.getSize(size)
+		Rect(0, 0, size.x, size.y)
+	}
+}
+
+fun View.isOnScreen(): Boolean {
+	if (!isShown) {
+		return false
+	}
+	val actualPosition = Rect()
+	getGlobalVisibleRect(actualPosition)
+	return actualPosition.intersect(getWindowBounds())
+}