After starting the application and loading a map the main window of the OpenLR MapViewer will be shown. Figure 2.1 shows this main window after startup. The map being loaded and shown in the main area of the window in this example is the map of Utrecht (version 2007.07, provided by TomTom).
Figure 2.1: The main window
The main window divides into four rows. The menu bar at the very top, the toolbar below, the main area in the middle and the status bar at the bottom.
The menu bar provides drop down menus regarding general functionality and settings.
The user is able to exit the application from menu "File".
In section "Edit" it is possible to customize several settings. Option "Preferences" defines the general application settings. The user is able to specify colors and stroke sizes regarding the map graphics. Some of the color settings relate to the functionality to filter network links, please see section Filtering for details. Changing a color is possible by clicking the colored box in front of the label. A dialog for choosing a desired color will open.
Figure 2.2: The preferences dialog
Tab "General" provides to specify some general properties.
It is possible there to define a dedicated path to a web browser executable. This property is used for the feature that visualizes the currently active location in Google Maps. The property is optional. Clearing the value removes this setting.
Furthermore the section provides settings that activate the feature of displaying the log after OpenLR encoder or decoder runs.
Figure 2.3: General properties
The toolbar holds action buttons for all important actions and modes. Table 1 summarizes the available buttons and gives a short explanation.
The toolbar splits into two blocks. The first one, containing the buttons "Filter lines", "Search", "Load locations", "Reset map" and "Screenshot" provides general functionality that is available in every state of the application. The second block holding "Map info", "Measure" and "Select location" provides map-related mouse features that are mutually exclusive.
| Icon | Action | Icon | Action |
 |
Filtering the road network |  |
Searching for coordinates, nodes and lines |
 |
Load locations from file |  |
Reset the map view |
 |
Make screenshot of map |  |
Show map information (standard mode) |
 |
Measuring distances in the map |  |
Selecting a location |
Table 1: Explanation of the toolbar buttons
Feature "Screenshot" creates an image of the current state of the map graphics and allows to save it to a file.
Button "Reset map" resets the map graphics to its default display area.
"Map info" activates the output of information about map elements when hovering with the mouse pointer over it. It can be used to disable the other map related modes "Measure" and "Select location".
The remaining buttons comprise a more complex functionality. Please see the specific sections for details.
The status bar at the bottom of the main window presents additional information to the user. On the right it displays the copyright information. The space in the left displays information provided by the current functionality like measuring. When moving the mouse over the map graphics it shows the geo-coordinate that corresponds to the position of the mouse pointer. The coordinates are presented in the format [longitude/latitude].
The main area of the MapViewer graphical user interface resides between the toolbar and the status bar. The map panel is located on the right side and shows the current viewport of the map. At the bottom of the map panel the scale shows the actual zoom level and scale (red bar).
On the left side several information panels are located. The location panel is at the top and shows all the attributes of the currently active location. This part also provides all available input options when a location is selected by the user. In the lower part of the location panel the "Encode" button, allowing to encode the selected location, and the clear button to delete the current location can be found.
The location reference panel is placed at the bottom of the main area and shows the encoded location reference as a Base64-encoded string. The location reference data can also be viewed in other formats by pressing the "Other formats" button. The decoding process will be started by pressing the "Decode" button. This will open another dialog where the location reference to be decoded can be chosen.
While moving the mouse pointer over a line in the map panel an information panel with all relevant information about that line will be shown. Figure 2.4 shows an example where the mouse is close to a line. The related line is highlighted in red in the map panel and the corresponding line information is shown in the info panel. The blue point indicates the start point of the highlighted line. Moving the mouse pointer to the other side of the line will highlight the line with the counter direction (if available). The information panel will be removed automatically after some seconds.
Figure 2.4: Line information at mouse pointer
While the line information panel is shown the user may press the "i" key. This will open a persistent dialog with the line information (see figure 2.5). This enables the user to access the information for a longer period of time and allows to mark and copy it.
Figure 2.5: Line information in a persistent dialog
