QGIS GUI¶

Layers Panel¶

The layers panel lists all the layers in the project. The checkbox in each legend entry can be used to show or hide the layer. The toolbar in the layers panel allows you to:

• Add new group
• ^{Manage Visibility}: control visibility of layers and preset layers combination
• ^{Filter Legend by Map Content}: only the layers that are set visible and whose features intersect the current map canvas have their style rendered in the layers panel. Otherwise, a generic NULL symbol is applied to the layer. Based on the layer symbology, this is a convenient way to identify which kind of features from which layers cover your area of interest.
• ^{Filter Legend by Expression}: helps you apply an expression to remove from the selected layer tree styles that have no feature satisfying the condition. This can be used for example to highlight features that are within a given area/feature of another layer. From the drop-down list, you can edit and clear the expression set.
• ^{Expand All} or ^{Collapse All} layers and groups in the layers panel.
• and ^{Remove Layer/Group} currently selected.

Figure Layer tools Bar:

Layer Toolbar in Layers Panel

The button allows you to add Presets views in the legend. Presets are a way to save and easily restore a combination of layers with their current style. To add a preset view, just set visible the layers you want, with their desired symbology, and click on button. Choose Add Preset... from the drop-down menu and give a name to the preset. The added preset is listed at the bottom of the drop-down menu and is recalled by clicking on it.

The Replace Preset ‣ option helps you overwrite a preset content with the current map view while the Remove Current Preset button deletes the active preset.

Tutte le viste predefinite aggiunte sono presenti anche nel compositore di stampe in modo di permetterti di creare stampe impostate sulle suddette viste (vedi: ref: composer_main_properties).

Puoi selezionare un layer e trascinarlo in modo da modificarne la visibilità (Z-ordering). Z-ordering significa che i layer in cima alla legenda coprono nella mappa quelli sottostanti.

Layers in the legend window can be organized into groups. There are two ways to do this:

1. Press the icon to add a new group. Type in a name for the group and press Enter. Now click on an existing layer and drag it onto the group.

2. Seleziona alcuni layer, clicca con il tasto destro e scegli Gruppo selezionato. I layer selezionati saranno automaticamente spostati nel nuovo gruppo.

Per rimuovere un layer da un gruppo puoi selezionare e trascinare il layer al di fuori dello stesso o in alternativa puoi cliccare con il tasto destro del mouse sul layer e selezionare Muovi fuori dal gruppo –>. I gruppi possono essere nidificati all’interno di altri gruppi.

Puoi usare la casella di controllo di un gruppo per mostrare/nascondere tutti i layer del gruppo con un singolo click.

The content of the right mouse button context menu depends on whether the selected legend item is a raster or a vector layer. For GRASS vector layers, ^{Toggle editing} is not available. See section Digitalizzare e modificare layer vettoriali GRASS for information on editing GRASS vector layers.

Below are listed available options in context menu depending on the selected item.

Option	Vector Layer	Raster Layer	Group
Zoom to Layer/Group
Show in Overview
Zoom to Native Resolution (100%)
Stretch Using Current Extent
Remove
Duplicate
Imposta la scala di visibilità del layer
Set Layer/Group CRS
Imposta SR progetto dal layer
Stili ‣
Copy Style
Paste Style
Open Attribute Table
Toggle Editing
Current Edits ‣	(in Edit mode)
Save As...
Save As Layer Definition File...
Filtro
Show Feature Count
Proprietà
:menuselection:` Muovi al livello più alto`
Rinomina ‣
Gruppo selezionato
Proprietà
Set Group WMS Data
Mutually Exclusive Group
Add Group

Enabling the Mutually Exclusive Group option you can make a group have only one layer visible at the same time. Whenever a layer within the group is set visible the others will be toggled not visible.

Puoi selezionare più di un layer o di un gruppo allo stesso tempo tenendo premuto il tasto Ctrl e cliccando il tasto sinistro del mouse sui vari layer. Potrai cosi spostare contemporaneamente tutti i layer selezionati in un nuovo gruppo.

You may also delete more than one layer or group at once by selecting several items with the Ctrl key and pressing Ctrl+D afterwards. This way, all selected layers or groups will be removed from the layers list.

Lavorare con la legenda indipendentemente dall’ordine dei layer¶

There is a panel that allows you to define an independent drawing order for the layers panel. You can activate it in the menu Settings ‣ Panels ‣ Layer Order Panel. This feature allows you to, for instance, order your layers in order of importance, but still display them in the correct order (see figure_layer_order). Checking the Control rendering order box underneath the list of layers will cause a revert to default behavior.

Figure Layer Order:

Define a legend independent layer order

Statistical Summary Panel¶

This panel can show some statistics on a specific vector layers. The panel allows users to choose:

• the vector layer;
• the column or the expression;
• filter statistics to selected features;
• refresh the informations;
• the statistics information to display with the bottom right button;

QGIS Overview Panel¶

In QGIS, you can use an overview panel that provides a full extent view of layers added to it. Within the view is a rectangle showing the current map extent. This allows you to quickly determine which area of the map you are currently viewing. Note that labels are not rendered to the map overview even if the layers in the map overview have been set up for labelling. If you click and drag the red rectangle in the overview that shows your current extent, the main map view will update accordingly.

Log Messages Panel¶

When loading or processing some operations, you can track and follow messages that appear in different tabs using the Log Messages Panel. It can be activated using the most right icon in the bottom status bar.

Undo/Redo Panel¶

For each layer being edited, this panel shows the list of actions done, allowing to quickly undo a set of actions by simply selecting the action listed above.