[AboutFragment / LicenseFragment] Fix license restore after rotation

Do not restore last opened license after a rotation change when the license was closed earlier.

This commit adds onCancelListener and onDismissListener to the AlertDialogs which are used to display the licenses.

app/src/main/java/org/schabi/newpipe/about/LicenseFragment.kt

@@ -1,15 +1,24 @@
 package org.schabi.newpipe.about
 
 import android.os.Bundle
+import android.util.Base64
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.webkit.WebView
+import androidx.appcompat.app.AlertDialog
 import androidx.core.os.bundleOf
 import androidx.fragment.app.Fragment
+import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers
+import io.reactivex.rxjava3.core.Observable
 import io.reactivex.rxjava3.disposables.CompositeDisposable
+import io.reactivex.rxjava3.disposables.Disposable
+import io.reactivex.rxjava3.schedulers.Schedulers
 import org.schabi.newpipe.R
 import org.schabi.newpipe.databinding.FragmentLicensesBinding
 import org.schabi.newpipe.databinding.ItemSoftwareComponentBinding
+import org.schabi.newpipe.util.Localization
+import org.schabi.newpipe.util.external_communication.ShareUtils
 
 /**
  * Fragment containing the software licenses.
@@ -41,7 +50,7 @@ class LicenseFragment : Fragment() {
         binding.licensesAppReadLicense.setOnClickListener {
             activeLicense = StandardLicenses.GPL3
             compositeDisposable.add(
-                showLicense(activity, StandardLicenses.GPL3)
+                showLicense(StandardLicenses.GPL3)
             )
         }
         for (component in softwareComponents) {
@@ -59,13 +68,13 @@ class LicenseFragment : Fragment() {
             root.setOnClickListener {
                 activeLicense = component.license
                 compositeDisposable.add(
-                    showLicense(activity, component)
+                    showLicense(component)
                 )
             }
             binding.licensesSoftwareComponents.addView(root)
             registerForContextMenu(root)
         }
-        activeLicense?.let { compositeDisposable.add(showLicense(activity, it)) }
+        activeLicense?.let { compositeDisposable.add(showLicense(it)) }
         return binding.root
     }
 
@@ -74,6 +83,51 @@ class LicenseFragment : Fragment() {
         activeLicense?.let { savedInstanceState.putSerializable(LICENSE_KEY, it) }
     }
 
+    private fun showLicense(component: SoftwareComponent): Disposable {
+        return showLicense(component.license) {
+            setPositiveButton(R.string.dismiss) { dialog, _ ->
+                dialog.dismiss()
+            }
+            setNeutralButton(R.string.open_website_license) { _, _ ->
+                ShareUtils.openUrlInApp(requireContext(), component.link)
+            }
+        }
+    }
+
+    private fun showLicense(license: License) = showLicense(license) {
+        setPositiveButton(R.string.ok) { dialog, _ -> dialog.dismiss() }
+    }
+
+    private fun showLicense(
+        license: License,
+        block: AlertDialog.Builder.() -> AlertDialog.Builder
+    ): Disposable {
+        return if (context == null) {
+            Disposable.empty()
+        } else {
+            val context = requireContext()
+            Observable.fromCallable { getFormattedLicense(context, license) }
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe { formattedLicense ->
+                    val webViewData = Base64.encodeToString(
+                        formattedLicense.toByteArray(), Base64.NO_PADDING
+                    )
+                    val webView = WebView(context)
+                    webView.loadData(webViewData, "text/html; charset=UTF-8", "base64")
+
+                    Localization.assureCorrectAppLanguage(context)
+                    AlertDialog.Builder(requireContext())
+                        .setTitle(license.name)
+                        .setView(webView)
+                        .setOnCancelListener { activeLicense = null }
+                        .setOnDismissListener { activeLicense = null }
+                        .block()
+                        .show()
+                }
+        }
+    }
+
     companion object {
         private const val ARG_COMPONENTS = "components"
         private const val LICENSE_KEY = "ACTIVE_LICENSE"

app/src/main/java/org/schabi/newpipe/about/LicenseFragmentHelper.kt

@@ -1,17 +1,8 @@
 package org.schabi.newpipe.about
 
 import android.content.Context
-import android.util.Base64
-import android.webkit.WebView
-import androidx.appcompat.app.AlertDialog
-import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers
-import io.reactivex.rxjava3.core.Observable
-import io.reactivex.rxjava3.disposables.Disposable
-import io.reactivex.rxjava3.schedulers.Schedulers
 import org.schabi.newpipe.R
-import org.schabi.newpipe.util.Localization
 import org.schabi.newpipe.util.ThemeHelper
-import org.schabi.newpipe.util.external_communication.ShareUtils
 import java.io.IOException
 
 /**
@@ -20,7 +11,7 @@ import java.io.IOException
  * @return String which contains a HTML formatted license page
  * styled according to the context's theme
  */
-private fun getFormattedLicense(context: Context, license: License): String {
+fun getFormattedLicense(context: Context, license: License): String {
     try {
         return context.assets.open(license.filename).bufferedReader().use { it.readText() }
             // split the HTML file and insert the stylesheet into the HEAD of the file
@@ -34,7 +25,7 @@ private fun getFormattedLicense(context: Context, license: License): String {
  * @param context the Android context
  * @return String which is a CSS stylesheet according to the context's theme
  */
-private fun getLicenseStylesheet(context: Context): String {
+fun getLicenseStylesheet(context: Context): String {
     val isLightTheme = ThemeHelper.isLightThemeSelected(context)
     val licenseBackgroundColor = getHexRGBColor(
         context, if (isLightTheme) R.color.light_license_background_color else R.color.dark_license_background_color
@@ -56,48 +47,6 @@ private fun getLicenseStylesheet(context: Context): String {
  * @param color   the color number from R.color
  * @return a six characters long String with hexadecimal RGB values
  */
-private fun getHexRGBColor(context: Context, color: Int): String {
+fun getHexRGBColor(context: Context, color: Int): String {
     return context.getString(color).substring(3)
 }
-
-fun showLicense(context: Context?, component: SoftwareComponent): Disposable {
-    return showLicense(context, component.license) {
-        setPositiveButton(R.string.dismiss) { dialog, _ ->
-            dialog.dismiss()
-        }
-        setNeutralButton(R.string.open_website_license) { _, _ ->
-            ShareUtils.openUrlInApp(context!!, component.link)
-        }
-    }
-}
-
-fun showLicense(context: Context?, license: License) = showLicense(context, license) {
-    setPositiveButton(R.string.ok) { dialog, _ -> dialog.dismiss() }
-}
-
-private fun showLicense(
-    context: Context?,
-    license: License,
-    block: AlertDialog.Builder.() -> AlertDialog.Builder
-): Disposable {
-    return if (context == null) {
-        Disposable.empty()
-    } else {
-        Observable.fromCallable { getFormattedLicense(context, license) }
-            .subscribeOn(Schedulers.io())
-            .observeOn(AndroidSchedulers.mainThread())
-            .subscribe { formattedLicense ->
-                val webViewData =
-                    Base64.encodeToString(formattedLicense.toByteArray(), Base64.NO_PADDING)
-                val webView = WebView(context)
-                webView.loadData(webViewData, "text/html; charset=UTF-8", "base64")
-
-                Localization.assureCorrectAppLanguage(context)
-                AlertDialog.Builder(context)
-                    .setTitle(license.name)
-                    .setView(webView)
-                    .block()
-                    .show()
-            }
-    }
-}