Booting up
When freimap starts, the first thing it will do, is to parse the config file config.yaml. Beware, for since YAML is not very picky with its syntax, some typing errors in the structure may not be detected, and freimap will not necessarily complain if you made a mistake there. From the YAML data found in the config file, freimap will try to identify the Background and DataSource? layers to load, and initialize them with the given parameters. Layers will first be loaded, and initialized in a second run. Hence, cross-references should work from any layer to any other.
Freimap will output status information and error messages on the console while loading the layers and initializing data sources. For example
fetching node data from URL: file:latlon.js This may take a while ... finished.
would be the output of successfully loading node coordinates using a LatLonJsDataSource?.
Messages and their meanings will be described here:
The Graphical User Interface
Once the freimap window appears, you should see a black-greenish screen, with some decorations and -if you have selected the OpenStreetMap? backdrop- a world map in the center.
Status Information
The second green bar on the top of the window displays your current location (longitude and latitude) and the map zoom factor. On the left side, where the URL of this site is displayed, at some point in the future, you might be able to see an actual place name.
The bottom bar displays the currently selected time, and the memory usage of the software. When the 'resource usage' runs towards 100%, you may experience some OutOfMemoryErrors?. This would usually happen when you work with larger quantities of data, which freimap currently seeks to keep in memory.
The Map / Navigation
The main portion of the screen is occupied by the map. At the beginning, you will find that it zoomed out to the maximum, so that you will have to zoom in to your preferred location first. If your data source has provided some node coordinates, you should be able to identify that location easily.
Mouse control:
- Left mouse button drag: Move the map
- Mouse wheel, or right button drag up/down: Zoom the map
- Double click: Print the current longitude/latitude to the console.
- Right click on a link or node: Begin fetching additional information (see section "Layers" below)
Keyboard control - Currently supported:
- '+' - Zoom in
- '-' - Zoom out
The Time Bar
The time bar at the bottom of the screen displays which data source has provided information for which time interval. A dark green bar represents the total interval where any data is available. Lighter green bars stacked on top represent the various data sources. You may directly click on the time bar to select a specific data set.
A red/green play button to the left of the bar allows you to replay the recorded data in order. Currently, the replay speed is a bit arbitrary.
Layers
On the top left of the screen is a list of layers. Clicking on an item in this list will select it as the active layer, which reacts on your mouse actions. You may drag and drop layers to change the order of drawing. The eye icon to the left of the layer allows you to cycle between different display types of this layer - usually "on", "off" and "semi-transparent". More or less display types may be supported.
Data Layers may react differently on your mouse actions. Their usage will be described in the following.
Node/Link Layers
When moving over the displayed nodes and links, you will discover that the closest node or link to your mouse cursor will be highlighted. Additionally, an information pane is displayed on the top right of the screen. This information will display an identifier of the node or link, as well as more or less information provided by the data source. This list is usually followed by the words "+ right click for more +".
If you do right click, the data source will try to fetch further information concerning the given element. Depending on the element, this may include some statistics, generated over the available data, or add further elements to the information pane. This process may take some time. During this time, the information pane will display the message "retrieving information". When the process is finished, the additional information will be displayed automatically when hovering over the link.
Another right click on the node or link may refresh the information, for example in the case of statistics and charts.
The Menus
A menu bar is on top of the application. Currently, the only useful menu entries are the following.
View
Hide unlocated nodes
Stops/Starts interpolation and display of unlocated nodes.
Display Filter
Selecting this menu will show a popup window which allows you to specify a display filter for nodes and links. To enable a filter, enter a string, select "enable display filter" and click on the "Apply" button. Now, only nodes containing (normal mode) or matching (regular expression mode) the specified string will be displayed.
