Symbian characteristics

Display

The Symbian platform supports the following common display resolutions:

• 176 x 208 (discontinued after S60 3rd Edition)

• 240 x 320

• 352 x 416 (discontinued after S60 3rd Edition)

• 360 x 640 (since S60 5th Edition)

Even though there is some variation between devices, in the majority of cases, you can rely on the resolution of the target device to be either 176 x 208 / 352 x 416, if the platform version is earlier than S60 3rd Edition, or 240 x 320, if the platform version is newer than that. The supported color depth ranges from the minimum 12-bit (4096) colors of the early devices to the current 24-bit colors.

There are some irregular devices, such as Nokia 5500, which has a 208 x 208 pixel resolution.

The Symbian UI is scalable between landscape and portrait modes, in which the height and width of the display are switched. In landscape mode, some UI elements, such as softkeys, may change places. MIDlets designed for a certain resolution can be scaled to other resolutions supported by the device. For more information, see section Scalability.

Input

The following figure shows the required input keys in a non-touch Symbian device.

Figure: Keypad example

The required input keys for non-touch devices are:

• Two softkeys (SK1 and SK2)

• Five-way navigation keypad (four arrows and a selection key)

  Note: From S60 5th Edition onwards, some devices may include a 9-way navigation keypad.

• Call handling keys (Call and End keys)

• Applications key

• Alphanumeric keypad with digits from 0 to 9 and symbols * and #

• Clear key

On devices with no Edit key, a short press of the Star (*) key opens the editing menu and a long press opens the special characters table.

The Symbian platform also supports the following extra keys:

• Camera key

• Power key

• Volume keys

Depending on the device, there may also be support for QWERTY-keyboards, 9-way navigation mechanisms, and other more advanced keys.

From S60 5th Edition onwards, touch UI replaces many physical keys on touch-enabled devices. On these devices, the amount of required input keys is diminished and additional commands are handled with custom input methods, such as handwriting recognition (HWR) and virtual keyboard (VKB). The custom input methods are generally optimized for stylus usage.

The required input keys for touch devices are:

• Call handling keys (Call and End keys)

• Applications key

Touch-enabled devices based on the Symbian platform also often feature the following extra keys:

• Camera key

• Keyguard switch

• Power key

• Volume keys

For more information about the touch UI, see section Touch UI.

Memory

Nokia devices based on the Symbian platform use dynamic memory allocation, which allows the reuse of memory space once reserved and released. The shared heap size starts from 1MB on S60 1st Edition devices, whereas for example S60 3rd Edition FP 2 devices include up to 128MB SDRAM and 16GB. When you are developing MIDlets for S60 2nd Edition and later releases, memory limitations are very rarely a problem as there are no limitations for the maximum heap size.

Devices based on the Symbian platform also support unlimited JAR size. For detailed information about each device, see the Forum Nokia Device Specifications.