adding extension for checking if charsequence is a matrix id

vector/src/main/java/im/vector/app/core/extensions/BasicExtensions.kt

@@ -19,6 +19,7 @@ package im.vector.app.core.extensions
 import android.util.Patterns
 import com.google.i18n.phonenumbers.NumberParseException
 import com.google.i18n.phonenumbers.PhoneNumberUtil
+import org.matrix.android.sdk.api.MatrixPatterns
 import org.matrix.android.sdk.api.extensions.ensurePrefix
 
 fun Boolean.toOnOff() = if (this) "ON" else "OFF"
@@ -30,6 +31,8 @@ inline fun <T> T.ooi(block: (T) -> Unit): T = also(block)
  */
 fun CharSequence.isEmail() = Patterns.EMAIL_ADDRESS.matcher(this).matches()
 
+fun CharSequence.isMatrixId() = MatrixPatterns.isUserId(this.toString())
+
 /**
  * Return empty CharSequence if the CharSequence is null.
  */