Links in help and about are clickable. Also added scroll in about activity. Fixes #232.

src/main/java/de/dennisguse/opentracks/AboutActivity.java

@@ -2,11 +2,13 @@ package de.dennisguse.opentracks;
 
 import android.os.Bundle;
 import android.view.Menu;
+import android.view.ViewGroup;
 import android.widget.TextView;
 
 import androidx.annotation.Nullable;
 
 import de.dennisguse.opentracks.util.SystemUtils;
+import de.dennisguse.opentracks.util.ViewUtils;
 
 public class AboutActivity extends AbstractActivity {
 
@@ -27,6 +29,8 @@ public class AboutActivity extends AbstractActivity {
 
         TextView textURL = findViewById(R.id.about_app_url);
         textURL.setText(getString(R.string.about_url, getString(R.string.app_web_url)));
+
+        ViewUtils.makeClickableLinks((ViewGroup) findViewById(android.R.id.content));
     }
 
     protected int getLayoutResId() {

src/main/java/de/dennisguse/opentracks/HelpActivity.java

@@ -1,7 +1,20 @@
 package de.dennisguse.opentracks;
 
+import android.os.Bundle;
+import android.view.ViewGroup;
+
+import androidx.annotation.Nullable;
+
+import de.dennisguse.opentracks.util.ViewUtils;
+
 public class HelpActivity extends AbstractActivity {
 
+    @Override
+    public void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        ViewUtils.makeClickableLinks((ViewGroup) findViewById(android.R.id.content));
+    }
+
     @Override
     protected int getLayoutResId() {
         return R.layout.help;

src/main/java/de/dennisguse/opentracks/util/ViewUtils.java

@@ -0,0 +1,30 @@
+package de.dennisguse.opentracks.util;
+
+import android.text.method.LinkMovementMethod;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+public class ViewUtils {
+
+    private ViewUtils() {
+    }
+
+    /**
+     * Traverses all childs of {@link View} recursively and makes links within {@link TextView}s clickable.
+     */
+    public static void makeClickableLinks(ViewGroup view) {
+        if (view == null) {
+            return;
+        }
+
+        for (int i = 0; i < view.getChildCount(); i++) {
+            final View child = view.getChildAt(i);
+            if (child instanceof ViewGroup) {
+                makeClickableLinks((ViewGroup) child);
+            } else if (child instanceof TextView) {
+                ((TextView) child).setMovementMethod(LinkMovementMethod.getInstance());
+            }
+        }
+    }
+}