Use your phone for just about any length of time, and you'll notice that little icons pop up and sit on the top-most gray bar on your phone. This is known as the Notification Bar, though it's sometimes referred to as the "Status Bar" or "System Status Bar" in Android developer documents. For the purposes of this book, we'll call it the Notification Bar, because it's where you get notified of things.
What kind of things? The bar is divided into two basic sections. The left-hand side is where your applications and message services can drop you a note that there's something new to look at. The right-hand section, which is given more space, is where Android gives you the basic status information you'd expect from any cellphone. Let's start there.
Note: The look, and perhaps arrangement, of the notifications and status bar icons described in this chapter may look different on your phone, especially if it's made by HTC. The functionality of the Notification Bar, and the meaning of the icons, stays the same across all phones.
Starting at the right and heading left, you'll see what time it is, then an alarm-style clock icon if you've got an upcoming alarm set. To the left, you'll always see a battery icon, which fills up from right to left and changes from red to yellow to green as your phone gets juiced, and shows a power symbol if your phone is being charged. Next up on the left is the familiar cellular signal strength indicator. To the left you'll find another icon that appears if you've got your phone set to vibrate, or make no noise at all, for incoming calls. Finally, to the right of that vibrate icon, or on the far left of the right-hand icons (confusingly enough), you'll see possibly the most important indicator for an Android addict: the data connection icon.
When you've set your phone to connect to a wireless (Wi-Fi) signal, you'll see a recognizable circle and waves icon, with more waves lit up to indicate a stronger signal. We'll cover how to connect your phone to Wi-Fi networks in your home, your office, coffee shops, and other spots in just a bit. For now, we should point out that seeing the Wi-Fi icon simply indicates that your phone has been permitted to connect to a Wi-Fi network, and that usually means you've got web access—but not always, depending on the network setup.
If you've turned Wi-Fi off, or there's no valid network in range, you'll see a cellular data connection indicator, assuming you've purchased a data plan from your carrier. If you're a T-Mobile or AT&T wireless customer, or in Europe or on another GSM network, and you're in range of a data connection, you'll see different icons depending on your signal speed and strength. "G" indicates you've got only a very basic GPRS connection, which is a kind of last resort in this day and age. "E" shows that you're connected to an EDGE network—decent enough at browsing text-heavy web pages and managing email, but not so hot at multimedia. "3G" refers, as you might guess, to the heavily advertised 3G, a kind of catch-all term for a connection package that delivers a decent web experience—slightly better than you'd get at home with a DSL connection, speed-wise, but with a bit more latency between requesting something and getting it back. Verizon, Sprint, and other CDMA networks provide a more simple scale: 1x for basic, slower data service, and "3G" to indicate a full-strength connection. Speeds will vary across locations, and technologies like "4G" and WiMax are developing, so expect to see different icons in newer areas.
Your cellular connection icon has two arrows, up and down, that light up when your phone is passing information "up" to the network and making requests for web sites and services, and "down" when it's pulling data. These arrows can tell you a good bit about what's happening with your phone. When it's busy grabbing data and checking what's next, both arrows will be lit up. If you notice that only the "up" arrow is steadily lit up, and your web-connected apps don't seem to be responding, you might need to close that app or restart your phone to get it unstuck, so to speak. If you're wondering why your phone is so warm, see if the arrows are staying lit continuously, which indicates a big download or sync you might want to stop if you're trying to conserve batteries.
The left-hand side of your Notification Bar is where you see updates, messages, sync announcements, reminders—anything any app on your phone wants to tell you about, and that you probably want to be kept aware of.
Depending on your screen, you'll have a certain maximum number of icons that can stack up on the left-hand side of the Notification Bar. When you reach that limit and more notifications are coming in, the Notification Bar will show a generic left-pointing arrow and the number of notifications beyond what sits to the right of it. If you find this happening too often for your tastes, you can set up certain applications to stop putting up notification badges in the bar, covered just a bit further down.
How do you act on notifications? By "pulling down" the bar from the top of your screen. Place your thumb or finger at the top of your screen, on the gray bar or slightly above it on the black buffer around your screen. Slide your finger at least halfway down the screen, and you'll see a gray "window shade" pull down with it. You can let go when you're halfway down, and the screen will fall all the way down. If you pull down fast and let go, you can also flick the screen down without having to follow it with your finger. Trust me—over time, your subconscious will start connecting the "New thing on my phone" sound or buzz with the "Flick down the screen" motion, and it will feel pretty natural.
What's on the Notification Bar? That depends on what apps and processes you have running on your phone, but they work mostly the same. In the example above, I have my phone connected to my laptop via a USB cable, and I've enabled USB debugging in the settings in order to take screenshots of my phone. Those are "Ongoing" things that I shouldn't be able to dismiss, but that I can access by clicking on either of those items. When you have music running in the background, or if you run software that tracks your exercise with GPS, for example, those will show up in the same "Ongoing" area. In many situations, this area won't show up at all.
"Notifications" is what you'll usually see when you pull down the window shade. In the example at left, I've got three items that have arrived since I last looked. The little critter icon next to the "New Reply" notice indicates that Seesmic, the Twitter client on my phone, has a new reply for me, and shows a small part of the message. Under that, there's a text message from my wife, and an email to myself at the bottom, with the subject line highlighted. If I tapped any of these rows with my thumb, the application they came from—Seesmic, Messaging, or Gmail—would launch and show that message.
If you're not in the mood to see them, or plan to get to them later, hit the "Clear" button in the upper-right corner. Those messages won't be deleted or marked as read, but will be dismissed from the "Notifications" section.
To a newcomer, the icons that appear in the Notification Bar aren't exactly apparent, even after rolling down the window shade to see what's happening. As you install new applications from the Market, they'll add their own notification icons, but every Android phone has a standard set it uses. Here's a look at those default notifications (which, as noted above, are pulled from an Android 2.2 phone running the stock interface; yours may vary).
There is, at the moment, no one central spot on your phone to control which notifications show up on your phone—and that's a pity. Instead, you'll need to open up each application and tweak how and when it notifies you about new messages or happenings.
I'll use the Voice (a.k.a. Google Voice) application as an example. Hit the app button at the bottom of your home screen to launch the application list, and choose Voice. Hit the Menu button on your phone when the app launches, and you'll see a Settings icon, which looks the same on just about every Android app.
Sometimes, though, an app's Settings—sometimes dubbed Preferences—are tucked away under the More button. Hit the button and a sub-menu of options will pop up, with Settings often among them.
In most Android app's settings, you'll find a category for "Notification," "Alerts," or something akin. In the Voice app, it's "Refresh and notification," as if to cover all bases. Click it!
From this screen, you can usually change when and how an app notifies you of whatever it monitors. In the Voice example, I can un-check "Inbox notifications" entirely to remove Voice's pinging from the Notification Bar. In less drastic fashion, I can un-check Vibrate and Light to turn off phone vibrations and blinking of the LED light on my phone. "Select ringtone" seems to imply that I can only select a different sound for Voice notifications, but click it and take a look:
You can keep Voice using the same ringtone your phone normally uses, or select "Silent" to have Voice not actually make a sound. You can also choose a different ringtone or sound, so that your brain eventually learns what each sound means when it issues forth from your pocket or purse.
The notification system in Android 2.3 "Gingerbread" is pretty much the same as with previous versions, but it is a different color, and some of the icons have changed a bit. Icons for Wi-Fi and cellular internet connections appear whenever the connection is available, then light up green whenever they're being used. The battery indicator has flipped into a vertical bar, and you'll notice the indicator of GPS being active is now a crosshair with a center sphere that blinks. Other than that, it's the same pull-down bar you've come to know (or just learned about, like, a few paragraphs ago).
Now you've got a pretty good handle on how your phone keeps you aware of everything coming in, and how to calmly filter or ignore those notifications if you don't want to be chained to your phone. Let's dig in a bit deeper now into becoming a producer of messages, not just a diligent receiver.