Layer Explorer

The Layer Explorer area of the Main Window shows all layers previously added to the project. To draw one or more  layer at the Map Display, check its box and click on draw  or on Recompose

The Spatial Reference System (SRS )of the Map Display showed at the status bar is the first valid SRID among the layers checked.  It is also possible to set a specific Map Display SRID by right-clicking over the Map Display area as explained here.

To find out the layer-SRID, right-click over a layer name and choose
Properties... or just move the mouse over the layer name (at the Layer Explorer tree) and wait a bit to see its metadata.

HINT: A layer without SRID (defined as 0 or -1) will not be draw with other layers with valid SRID, however it can the draw alone.

Each layer can be in one of the these status:
HINTS: it is quite common to take a project (*.tview) to another PC. In this case all local layers will appear as disconnected (layer disconnected). The user must copy all datasets referenced by the project to the other PC, open the project  and adjust the path of each of them.
Some actions at the Layer and at the Map Display depends on the layer status. Keep this in mind from now on and see how to select one or more layers at the Layer Explorer.

Layer Explorer - Selecting one or more layers

    Clicking over a layer name makes it selected and the actions available from the context menu can be executed. 

    Right-clicking over a layer name makes it selected and shows a context menu of actions that can be executed over a layer. Those actions are also accessible through the Layer Menu.

    Shift+clicking allows to select a consecutive set of layers by clicking over the first and the last  layer names in the tree.  A highlighted area appear in the tree and right-clicking over this area shows a context menu of actions that can be executed over more than one layer, for example Remove Layer(s).

    Ctrl+clicking allows to select a non-consecutive set of layers by clicking over layer names in the tree.  All layer names will became highlighted and right-clicking over one of them shows a context menu of actions that can be executed over all selected layer.

Note that the box-checked status is not necessary for some actions. For example, to execute 
Remove Layer, Show Table  or  Edit Legend,  it is enough to select a layer.