CHAPTER 7: Making Apps Interactive: Intents, Event Handling, and Menus 237Fortunately, these RelativeLayout UI alignment and positioning parameters all evaluate quite
well in the Eclipse Graphical Layout Editor (GLE) tab, located at the bottom of the central
editing pane, and so we will use this to save time previewing the UI design as we built it. Using a
Run As ➤ Android Application menu sequence and launching the Nexus One AVD emulator every
time you want to preview a UI design parameter will take about ten times longer (or more than ten
times longer if you have a slow system) than simply clicking back and forth between the XML editing
tab and the GLE tab!
Using the Eclipse Graphical Layout Editor (GLE)
As you can see in Figure 7-19, where I show the XML editing tab and the GLE tab output in the
same screen shot, I have copied the required layout_width and layout_height parameters into the