21.2 Manual XML vs. Visual Layout Design
When to write XML manually as opposed to using the Layout Editor tool in design mode is a matter of personal preference. There are, however, advantages to using design mode.
First, design mode will generally be quicker given that it avoids the necessity to type lines of XML. Additionally, design mode avoids the need to learn the intricacies of the various property values of the Android SDK view classes. Rather than continually refer to the Android documentation to find the correct keywords and values, most properties can be located by referring to the Attributes panel.
All the advantages of design mode aside, it is important to keep in mind that the two approaches to user interface design are in no way mutually exclusive. As an application developer, it is quite likely that you will end up creating user interfaces within design mode while performing fine-tuning and layout tweaks of the design by directly editing the generated XML resources...