Thursday, May 24, 2007

Pocket GTViewer on Smartphones - Part 2

What does the Smartphone platform mean to Pocket GTViewer? The biggest impact to Pocket GTViewer is the loss of the touch screen. Many features in Pocket GTViewer depended on a touch screen such as Zoom In and Zoom out, Panning, Attribute Info, and Redlining. However, there are ways to overcome some of these limitations and thinking “phone” and not “device” help overcome the others.

Obviously, view navigation is a requirement in a Pocket GTViewer application. Locate queries do provide a non-touch screen way to navigate the data, but if you cannot freely navigate the view with panning and zooming, usefulness as a GIS viewer is greatly impaired. Fortunately, standards requires a set of controls to be present on all Smartphones: two soft buttons under the screen and a joypad which provides Left, Right, Up, Down, and Enter operations.

The available key inputs provide adequate controls for navigating the GIS data. Pocket GTViewer for Smartphone has 2 modes of navigation: Zoom and Pan. Pressing the Enter button (pressing the joypad button) toggles between these two modes and a small icon in the upper left corner of the screen indicates the mode you are in. In Pan mode, the joypad will move the view in the direction you indicate. In Zoom mode, the Left and Down actions will zoom in and the Right and Up actions will zoom out. All navigation can be easily done with one thumb.

A beefed up Overview mode is also provided to give another method of navigating the view. While viewing an overview map of the data an indicator can be quickly moved around the view with the joypad to find an area of interest.

Since there is no touch screen available on the Smartphone, the tap-and-hold method of reviewing a feature’s attributes is not possible, but the PGTV Control provides a special mode called Capture Point with Keys for selecting a point in the view without a touch screen. By showing a crosshair cursor in the view, the user can move the cursor around the view with the joypad until it is at desired point; then the user selects the Enter button to find all features at the point. If only one feature is found, the attribute information is displayed; if more than one feature is found, a picklist is presented so the user can refine his or her selection.

The Attribute Info dialog has been redesigned for Smartphone to make better use of screen space and key controls. The right soft button indicates which record is currently displayed and can be used to change the view to any of the available records associated with the feature.

Performing locate queries is not much different from that on a Window Mobile device running Pocket GTViewer. Fill out the prompts, perform the query, and select the feature you wish to locate.

GPS support is also provided by the PGTV Control and can be used with a Bluetooth GPS receiver or a built in GPS receiver.

ECW Raster files are supported as well and are ideal for backdrop imagery.

Redlining is really the only set of functionality provided by the Windows Mobile version of Pocket GTViewer that gets sacrificed in the Smartphone version. Without the touch screen, the traditional style of redlining (line, shape, circle, ellipse, rectangle, and freehand) is not practical. However, this limitation does not preclude redlines from future versions of the Smartphone version of the app. This type of functionality is where the thinking needs to be “phone” instead of “device” and needs to take advantage of features like the built in camera. Even with the Smartphone key interface, photos could be associated with links and provide a very usable capture tool.

This posting shows a quick glance at what Pocket GTViewer for Smartphone can accomplish. GTI plans to leverage the Smartphone (Windows Mobile 6 Standard) platform as much as we can to provide the best GIS tools on the market. If you have a Windows Mobile 5.0 Smartphone or Window Mobile 6 Standard device, please let us know if you want to give Pocket GTViewer for Smartphone a try.

No comments: