Editing of the visual properties of map layers and the order of the layers in a map

A map window contains a subwindow with the map legend. The legend (see Figure 1) shows the layers the map consists of, the status (drawn or hidden) of each layer, the visual properties such as colour or line thickness, the order of the layers in the map, and the active layer. The active layer is the layer the objects of which react to mouse events, that is, pointing on an object with the mouse cursor or clicking on an object.

Figure 1. An example map legend.

For each map layer there is an item in the legend that consists of the following elements:

"Plus" or "minus" icon indicating whether the layer is drawn or not. The icon is sensitive to mouse clicks. Upon a mouse click the icon is changed to the opposite (that is, plus to minus and vice versa), and so does the drawing status of the layer.
An image representing the type of the objects in the layer (point, line, or area) and their current visual propeties. For example, in Figure 1 the layer "Cities" consists of point objects, the layer "Roads" - of linear objects, and the layer "Counties" - of areal objects.
The name of the layer.

When visualisation of thematic data is added to a map, the legend item of the corresponding map layer is extended to include the explanation of the symbols used for the visualisation.

Through the legend it is possible to do following interactive operations:

switch on/off drawing of a layer click on the "minus" or "plus" icon

change the active layer click on the legend item of the layer that should become active (but not on the "plus" icon)

change the order of drawing of the layers drag the legend items to the desired positions. Note that layers shown at the bottom of the legend are drawn first, and the layers at the top are drawn last

change the visual properties of a layer double-click on the corresponding legend item. A dialog for editing of the visual properties will appear on the screen.

switch on/off drawing of a layer	click on the "minus" or "plus" icon
change the active layer	click on the legend item of the layer that should become active (but not on the "plus" icon)
change the order of drawing of the layers	drag the legend items to the desired positions. Note that layers shown at the bottom of the legend are drawn first, and the layers at the top are drawn last
change the visual properties of a layer	double-click on the corresponding legend item. A dialog for editing of the visual properties will appear on the screen.