Viewing rules after pressing rules button in PostXXXActivity is available. Extend MarkwonView to support opening reddit subreddit and user links.

app/src/main/java/CustomView/CustomMarkwonView.java

@@ -0,0 +1,49 @@
+package CustomView;
+
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import android.util.AttributeSet;
+
+import androidx.annotation.Nullable;
+import androidx.browser.customtabs.CustomTabsIntent;
+
+import ml.docilealligator.infinityforreddit.R;
+import ml.docilealligator.infinityforreddit.ViewSubredditDetailActivity;
+import ml.docilealligator.infinityforreddit.ViewUserDetailActivity;
+import ru.noties.markwon.SpannableConfiguration;
+import ru.noties.markwon.view.MarkwonView;
+
+public class CustomMarkwonView extends MarkwonView {
+
+    public CustomMarkwonView(Context context) {
+        super(context);
+    }
+
+    public CustomMarkwonView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public void setMarkdown(@Nullable String markdown, Context conte) {
+        SpannableConfiguration configuration = SpannableConfiguration.builder(conte).linkResolver((view, link) -> {
+            if(link.startsWith("/u/") || link.startsWith("u/")) {
+                Intent intent = new Intent(conte, ViewUserDetailActivity.class);
+                intent.putExtra(ViewUserDetailActivity.EXTRA_USER_NAME_KEY, link.substring(3));
+                conte.startActivity(intent);
+            } else if(link.startsWith("/r/") || link.startsWith("r/")) {
+                Intent intent = new Intent(conte, ViewSubredditDetailActivity.class);
+                intent.putExtra(ViewSubredditDetailActivity.EXTRA_SUBREDDIT_NAME_KEY, link.substring(3));
+                conte.startActivity(intent);
+            } else {
+                CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder();
+                // add share action to menu list
+                builder.addDefaultShareMenuItem();
+                builder.setToolbarColor(conte.getResources().getColor(R.color.colorPrimary));
+                CustomTabsIntent customTabsIntent = builder.build();
+                customTabsIntent.launchUrl(conte, Uri.parse(link));
+            }
+        }).build();
+
+        super.setMarkdown(configuration, markdown);
+    }
+}