7. QGIS GUI

The QGIS graphical user interface (GUI) is shown in the figure below (the numbers 1 through 5 in yellow circles indicate important elements of the QGIS GUI, and are discussed below).

../../../_images/startup.png

Рис. 7.1 QGIS GUI with Alaska sample data

Примечание

Внешний вид элементов интерфейса (заголовки окон и т.п.) может отличаться, в зависисмости от операционной системы и менеджера окон.

The main QGIS GUI (Рис. 7.1) consists of five components / component types:

  1. Menu Bar

  2. Toolbars

  3. Panels

  4. Map View

  5. Status Bar

Scroll down for detailed explanations of these.

7.2. Panels and Toolbars

From the View menu (or kde Settings), you can switch QGIS widgets (Panels ►) and toolbars (Toolbars ►) on and off. To (de)activate any of them, right-click the menu bar or toolbar and choose the item you want. Panels and toolbars can be moved and placed wherever you like within the QGIS interface. The list can also be extended with the activation of Core or external plugins.

7.2.1. Панели инструментов

The toolbars provide access to most of the functions in the menus, plus additional tools for interacting with the map. Each toolbar item has pop-up help available. Hover your mouse over the item and a short description of the tool’s purpose will be displayed.

Available toolbars are:

Таблица 7.16 QGIS Toolbars

Toolbar name

Main Reference for tools

Advanced Digitizing

Дополнительные функции оцифровки

Annotations

Инструменты аннотации

Атрибуты

Working with the Attribute Table, Основные инструменты

Data Source Manager

Managing Data Source

Database

DB Manager Plugin

Оцифровка

Редактирование существующего слоя

GRASS

Интеграция с GRASS GIS

Справка

Label

The Label Toolbar

Manage Layers

Opening Data

Map Navigation

Exploring the map view

Mesh Digitizing

Editing a mesh layer

Plugins

Модули

Проект

Working with Project Files, Laying out the maps, The Style Library

Processing Algorithms

Configuring the Processing Framework

Raster

Модули

Selection

Selecting features

Shape digitizing

Shape digitizing

Snapping

Setting the snapping tolerance and search radius

Vector

Модули

Web

Модули, MetaSearch Catalog Client

Примечание

Third-party plugins can extend the default toolbar with their own tools or provide their own toolbar.

Совет

Восстановление панелей инструментов

If you have accidentally hidden a toolbar, you can get it back using View ► Toolbars ► (or kde Settings ► Toolbars ►). If, for some reason, a toolbar (or any other widget) totally disappears from the interface, you’ll find tips to get it back at restoring initial GUI.

7.2.2. Panels

QGIS provides many panels. Panels are special widgets that you can interact with (selecting options, checking boxes, filling values…) to perform more complex tasks.

Below is a list of the default panels provided by QGIS:

Таблица 7.17 QGIS Panels

Panel name

Комбинация клавиш

Справка

Advanced Digitizing

Ctrl+4

The Advanced Digitizing panel

Browser

Ctrl+2

The Browser Panel

Browser (2)

The Browser Panel

Debugging/Development Tools

F12

Debugging/Development Tools Panel

Elevation Profile

Geometry Validation

Digitizing Properties

GPS Information

Ctrl+0

GPS-слежение

GRASS Tools

Интеграция с GRASS GIS

Layer Order

Ctrl+9

Layer Order Panel

Layer Styling

Ctrl+3

Layer Styling Panel

Layers

Ctrl+1

Layers Panel

Log Messages

Log Messages Panel

Overview

Ctrl+8

Overview Panel

Processing Toolbox

The Toolbox

Results Viewer

The Toolbox

Snapping and Digitizing Options

Setting the snapping tolerance and search radius

Spatial Bookmark Manager

Ctrl+7

Bookmarking extents on the map

Statistics

Ctrl+6

Statistical Summary Panel

Temporal Controller

The temporal controller panel

Tile Scale

Мозаики

Undo/Redo

Ctrl+5

Undo/Redo Panel

Vertex Editor

The Vertex Editor Panel

7.3. Строка состояния

The status bar provides you with general information about the map view and processed or available actions, and offers you tools to manage the map view.

7.3.1. Панель локатора

On the left side of the status bar, the locator bar, a quick search widget, helps you find and run any feature or options in QGIS:

  1. Click in the text widget to activate the locator search bar or press Ctrl+K.

  2. Type a text associated with the item you are looking for (name, tag, keyword, …). By default, results are returned for the enabled locator filters, but you can limit the search to a certain scope by prefixing your text with the locator filters prefix, ie. typing l cad will return only the layers whose name contains cad.

    The filter can also be selected with a double-click in the menu that shows when accessing the locator widget.

  3. Click on a result to execute the corresponding action, depending on the type of item.

Совет

Limit the lookup to particular field(s) of the active layer

By default, a search with the «active layer features» filter (f) runs through the whole attribute table of the layer. You can limit the search to a particular field using the @ prefix. E.g., f @name sal or @name sal returns only the features whose «name» attribute contains „sal“. Text autocompletion is active when writing and the suggestion can be applied using Tab key.

A more advanced control on the queried fields is possible from the layer Fields tab. Read Fields Properties for details.

Searching is handled using threads, so that results always become available as quickly as possible, even if slow search filters are installed. They also appear as soon as they are encountered by a filter, which means that e.g. a file search filter will show results one by one as the file tree is scanned. This ensures that the UI is always responsive, even if a very slow search filter is present (e.g. one which uses an online service).

Примечание

The Nominatim locator tool may behave differently (no autocompletion search, delay of fetching results, …) with respect to the OpenStreetMap Nominatim usage policy.

Совет

Quick access to the locator’s configurations

Click on the search icon inside the locator widget on the status bar to display the list of filters you can use and a Configure entry that opens the Locator tab of the Settings ► Options… menu.

7.3.2. Reporting actions

In the area next to the locator bar, a summary of actions you’ve carried out will be shown when needed (such as selecting features in a layer, removing layer, pan distance and direction) or a long description of the tool you are hovering over (not available for all tools).

In case of lengthy operations, such as gathering of statistics in raster layers, executing Processing algorithms or rendering several layers in the map view, a progress bar is displayed in the status bar.

7.3.3. Control the map canvas

The tracking Coordinate option shows the current position of the mouse, following it while moving across the map view. You can set the units (and precision) in the Project ► Properties… ► General tab. Click on the small button at the left of the textbox to toggle between the Coordinate option and the extents Extents option that displays the coordinates of the current bottom-left and top-right corners of the map view in map units.

Next to the coordinate display you will find the Scale display. It shows the scale of the map view. There is a scale selector, which allows you to choose between predefined and custom scales.

On the right side of the scale display, press the lockedGray button to lock the scale to use the magnifier to zoom in or out. The magnifier allows you to zoom in to a map without altering the map scale, making it easier to tweak the positions of labels and symbols accurately. The magnification level is expressed as a percentage. If the Magnifier has a level of 100%, then the current map is not magnified, i.e. is rendered at accurate scale relative to the monitor’s resolution (DPI). A default magnification value can be defined within Settings ► Options ► Rendering ► Rendering Behavior, which is very useful for high-resolution screens to enlarge small symbols. In addition, a setting in Settings ► Options ► Canvas & Legend ► DPI controls whether QGIS respects each monitor’s physical DPI or uses the overall system logical DPI.

To the right of the magnifier tool you can define a current clockwise rotation for your map view in degrees.

On the right side of the status bar, the checkbox Render checkbox can be used to temporarily suspend the map view rendering (see section Controlling map rendering).

To the right of the checkbox Render function, you find the projectionEnabled EPSG:code button showing the current project CRS. Clicking on this opens the Project Properties dialog and lets you reproject the map view or adjust any other project property.

Совет

Calculating the Correct Scale of Your Map Canvas

When you start QGIS, the default CRS is WGS 84 (EPSG 4326) and units are degrees. This means that QGIS will interpret any coordinate in your layer as specified in degrees. To get correct scale values, you can either manually change this setting in the General tab under Project ► Properties… (e.g. to meters), or you can use the projectionEnabled EPSG:code icon seen above. In the latter case, the units are set to what the project projection specifies (e.g., +units=us-ft).

Note that CRS choice on startup can be set in Settings ► Options ► CRS Handling.

7.3.4. Messaging

The messageLog Messages button next to it opens the Log Messages Panel which has information on underlying processes (QGIS startup, plugins loading, processing tools…)