Direct registration button

app/src/main/java/com/keylesspalace/tusky/LoginActivity.kt

@@ -80,6 +80,7 @@ class LoginActivity : BaseActivity(), Injectable {
                 getString(R.string.preferences_file_key), Context.MODE_PRIVATE)
 
         loginButton.setOnClickListener { onButtonClick() }
+        registerButton.setOnClickListener { onRegisterClick() }
 
         whatsAnInstanceTextView.setOnClickListener {
             val dialog = AlertDialog.Builder(this)
@@ -119,6 +120,21 @@ class LoginActivity : BaseActivity(), Injectable {
         return super.onOptionsItemSelected(item)
     }
 
+    private fun onRegisterClick() {
+        registerButton.isEnabled = false
+
+        val uri = Uri.parse(BuildConfig.REGISTER_ACCOUNT_URL)
+        if (!openInCustomTab(uri, this)) {
+            val viewIntent = Intent(Intent.ACTION_VIEW, uri)
+            if (viewIntent.resolveActivity(packageManager) != null) {
+                startActivity(viewIntent)
+            } else {
+                domainEditText.error = getString(R.string.error_no_web_browser_found)
+                setLoading(false)
+            }
+        }
+    }
+
     /**
      * Obtain the oauth client credentials for this app. This is only necessary the first time the
      * app is run on a given server instance. So, after the first authentication, they are