Lesson: An Overview of the Interface
===============================================================================

We will explore the QGIS user interface so that you are familiar with the
menus, toolbars, map canvas and layers list that form the basic structure of
the interface.

**The goal for this lesson:** To understand the basics of the QGIS user
interface.

:abbr:`â˜…â˜†â˜† (Basic level)` Try Yourself: The Basics
-------------------------------------------------------------------------------

.. _figure_gui_numbered:

.. figure:: img/gui_numbered.png
   :align: center

The elements identified in the figure above are:

#. Layers List / Browser Panel
#. Toolbars
#. Map canvas
#. Status bar
#. Side Toolbar
#. Locator bar

.. Don't reorder these list items! They refer to elements as numbered on an
   image.

:abbr:`â˜…â˜†â˜† (Basic level)` The Layers List
...............................................................................

In the Layers list, you can see a list, at any time, of all the layers
available to you.

Expanding collapsed items (by clicking the arrow or plus symbol beside them)
will provide you with more information on the layer's current appearance.

Hovering over the layer will give you some basic information: layer name, type
of geometry, coordinate reference system and the complete path of the location
on your device.

Right-clicking on a layer will give you a menu with lots of extra options. You
will be using some of them before long, so take a look around!

.. note::  A vector layer is a dataset, usually of a specific kind of object,
   such as roads, trees, etc. A vector layer can consist of either points,
   lines or polygons.

.. _browser_panel_tm:

:abbr:`â˜…â˜†â˜† (Basic level)` The Browser Panel
...............................................................................

The QGIS Browser is a panel in QGIS that lets you easily navigate in your
database. You can have access to common vector files (e.g. ESRI Shapefile
or MapInfo files), databases (e.g. PostGIS, Oracle, SpatiaLite, GeoPackage or
MS SQL Server) and WMS/WFS connections. You can also view your GRASS data.

If you have saved a project, the Browser Panel will also give you quick access to
all the layers stored in the same path of the project file under in the
|qgsProjectFile| :guilabel:`Project Home` item.

Moreover, you can set one or more folder as **Favorites**: search under your path
and once you have found the folder, right click on it and click on ``Add as a
Favorite``. You should then be able to see your folder in the |favourites|
:guilabel:`Favorites` item.

.. tip:: It can happen that the folders added to Favorite item have a really
  long name: don't worry right-click on the path and choose ``Rename Favorite...``
  to set another name.

:abbr:`â˜…â˜†â˜† (Basic level)` Toolbars
...............................................................................

Your most often used sets of tools can be turned into toolbars for basic access.
For example, the :guilabel:`Project` toolbar allows you to save, load, print, and start a new
project. You can easily customize the interface to see only the tools you use
most often, adding or removing toolbars as necessary via the
:menuselection:`View --> Toolbars` menu.

Even if they are not visible in a toolbar, all of your tools will remain
accessible via the menus. For example, if you remove the :guilabel:`Project`
toolbar (which contains the :guilabel:`Save` button), you can still save your
map by clicking on the :guilabel:`Project` menu and then clicking on
:guilabel:`Save`.

:abbr:`â˜…â˜†â˜† (Basic level)` The Map Canvas
...............................................................................

This is where the map itself is displayed and where layers are loaded. In the map
canvas you can interact with the visible layers: zoom in/out, move the map,
select features and many other operations that we will deeply see in the next
sections.

:abbr:`â˜…â˜†â˜† (Basic level)` The Status Bar
...............................................................................

Shows you information about the current map. Also allows you to adjust the map
scale, the map rotation and see the mouse cursor's coordinates on the map.

:abbr:`â˜…â˜†â˜† (Basic level)` The Side Toolbar
...............................................................................

By default the Side toolbar contains the buttons to load the layer and all the
buttons to create a new layer. But remember that you can move all the toolbars
wherever it is more comfortable for you.

:abbr:`â˜…â˜†â˜† (Basic level)` The Locator Bar
...............................................................................

Within this bar you can access to almost all the objects of QGIS: layers, layer
features, algorithms, spatial bookmarks, etc. Check all the different options in
the :ref:`locator_options` section of the QGIS User Manual.

.. tip:: With the shortcut :kbd:`Ctrl+K` you can easily access the bar.


:abbr:`â˜…â˜†â˜† (Basic level)` Try Yourself: 1
-------------------------------------------------------------------------------

Try to identify the four elements listed above on your own screen, without
referring to the diagram above. See if you can identify their names and
functions. You will become more familiar with these elements as you use them in
the coming days.

.. admonition:: Answer
   :class: dropdown

   Refer back to the image showing the interface layout and check that you
   remember the names and functions of the screen elements.


:abbr:`â˜…â˜†â˜† (Basic level)` Try Yourself: 2
-------------------------------------------------------------------------------

Try to find each of these tools on your screen. What is their purpose?

1. |fileSaveAs|
2. |zoomToLayer|
3. |invertSelection|
4. |checkbox|:guilabel:`Render`
5. |measure|

.. note:: If any of these tools is not visible on the screen, try enabling
   some toolbars that are currently hidden. Also keep in mind that if there
   isn't enough space on the screen, a toolbar may be shortened by hiding some
   of its tools. You can see the hidden tools by clicking on the double right
   arrow button in any such collapsed toolbar. You can see a tooltip with the
   name of any tool by holding your mouse over the tool for a while.

.. admonition:: Answer
   :class: dropdown

   #. :guilabel:`Save as`
   #. :guilabel:`Zoom to layer(s)`
   #. :guilabel:`Invert selection`
   #. :guilabel:`Rendering on/off`
   #. :guilabel:`Measure line`


What's Next?
-------------------------------------------------------------------------------

Now that you are familiar with the basics of the QGIS interface, in the next 
lesson we will see how to load some common data types.


.. Substitutions definitions - AVOID EDITING PAST THIS LINE
   This will be automatically updated by the find_set_subst.py script.
   If you need to create a new substitution manually,
   please add it also to the substitutions.txt file in the
   source folder.

.. |checkbox| image:: /static/common/checkbox.png
   :width: 1.3em
.. |favourites| image:: /static/common/mIconFavourites.png
   :width: 1.5em
.. |fileSaveAs| image:: /static/common/mActionFileSaveAs.png
   :width: 1.5em
.. |invertSelection| image:: /static/common/mActionInvertSelection.png
   :width: 1.5em
.. |measure| image:: /static/common/mActionMeasure.png
   :width: 1.5em
.. |qgsProjectFile| image:: /static/common/mIconQgsProjectFile.png
   :width: 1.5em
.. |zoomToLayer| image:: /static/common/mActionZoomToLayer.png
   :width: 1.5em