Overview of the Print Composer¶

Sessão de Amostra¶

Before you start to work with the Print Composer, you need to load some raster or vector layers in the QGIS map canvas and adapt their properties to suit your own convenience. After everything is rendered and symbolized to your liking, click the ^{New Print Composer} icon in the toolbar or choose File ‣ New Print Composer. You will be prompted to choose a title for the new Composer.

To demonstrate how to create a map please follow the next instructions.

1. On the left side, select the ^{Add new map} toolbar button and draw a rectangle on the canvas holding down the left mouse button. Inside the drawn rectangle the QGIS map view to the canvas.
2. Select the ^{Add new scalebar} toolbar button and click with the left mouse button on the Print Composer canvas. A scalebar will be added to the canvas.
3. Select the ^{Add new legend} toolbar button and draw a rectangle on the canvas holding down the left mouse button. Inside the drawn rectangle the legend will be drawn.
4. Select the ^{Select/Move item} icon to select the map on the canvas and move it a bit.
5. While the map item is still selected you can also change the size of the map item. Click while holding down the left mouse button, in a white little rectangle in one of the corners of the map item and drag it to a new location to change its size.
6. Click the Item Properties panel on the left down side and find the setting for the orientation. Change the value of the setting Map orientation to ‘15.00° ‘. You should see the orientation of the map item change.
7. Now, you can print or export your print composition to image formats, PDF or to SVG with the export tools in Composer menu.
8. Finally, you can save your print composition within the project file with the ^{Save Project} button.

You can add multiple elements to the Composer. It is also possible to have more than one map view or legend or scale bar in the Print Composer canvas, on one or several pages. Each element has its own properties and, in the case of the map, its own extent. If you want to remove any elements from the Composer canvas you can do that with the Delete or the Backspace key.

The Composer Manager¶

The Composer Manager is the main window to manage print composers in the project. It helps you add new print composer, duplicate an existing one, rename or delete it. To open the composer manager dialog, click on the ^{Composer Manager} button in the toolbar or choose Composer ‣ Composer Manager. It can also be reached from the main window of QGIS with Project ‣ Composer Manager.

The Print Composer Manager

The composer manager lists in its upper part all the available print composers in the project. The bottom part shows tools that help to:

• show the selected composer(s): you can open multiple print composers in one-click
• duplicate the selected composer (available only if one print composer is selected): it creates a new composer using the selected composer as template. You’ll be prompted to choose a new title for the new composer
• rename the composer (also available only if one print composer is selected): You’ll be prompted to choose a new title for the composer. Note that you can also rename the composer by double-clicking on its title in the upper part
• remove the composer: the selected print composer(s) will be deleted from the project.

With the Composer Manager, it’s also possible to create new print composers as an empty composer or from a saved template. By default, QGIS will look for templates in user directory (~/.qgis2/composer_templates) or application’s one (ApplicationFolder/composer_templates). QGIS will retrieve all the available templates and propose them in the combobox. The selected template will be used to create a new composer when clicking Add button. You can also save composer templates in another folder. Choosing specific in the template list offers the ability to select such template and use it to create a new print composer.

Menus, tools and panels of the print composer¶

Opening the Print Composer provides you with a blank canvas that represents the paper surface when using the print option. Initially you find buttons on the left beside the canvas to add map composer items: the current QGIS map canvas, text labels, images, legends, scale bars, basic shapes, arrows, attribute tables and HTML frames. In this toolbar you also find toolbar buttons to navigate, zoom in on an area and pan the view on the composer and toolbar buttons to select a map composer item and to move the contents of the map item.

Figure_composer_overview shows the initial view of the Print Composer before any elements are added.

Print Composer

On the right beside the canvas you find two set of panels. The upper one holds the panels Items and Command History and the lower holds the panels Composition, Item properties and Atlas generation.

• The Items panel provides a list of all map composer items added to the canvas.
• The Command history panel displays a history of all changes applied to the Print Composer layout. With a mouse click, it is possible to undo and redo layout steps back and forth to a certain status.
• The Composition panel allows you to set paper size, orientation, the page background, number of pages and print quality for the output file in dpi. Furthermore, you can also activate the Print as raster checkbox. This means all items will be converted to raster before printing or saving as PostScript or PDF. In this panel, you can also customize settings for grid and smart guides.
• The Item Properties panel displays the properties for the selected item. Click the ^{Select/Move item} icon to select an item (e.g., legend, scale bar or label) on the canvas. Then click the Item Properties panel and customize the settings for the selected item (see Composer Items for detailed information on each item settings).
• The Atlas generation panel allows you to enable the generation of an atlas for the current Composer and gives access to its parameters (see Generate an Atlas for detailed information on atlas generation usage).

In the bottom part of the Print Composer window, you can find a status bar with mouse position, current page number, a combo box to set the zoom level, the number of selected items if applicable and, in the case of atlas generation, the number of features.

In the upper part of the Print composer window, you can find menus and other toolbars. All Print Composer tools are available in menus and as icons in a toolbar. See a list of tools in table_composer_tools.

The toolbars and the panels can be switched off and on using the right mouse button over any toolbar or through View ‣ Toolbars or View ‣ Panels.

Tools¶

Icon	Purpose	Icon	Purpose
	Save Project		New Composer
	Duplicate Composer		Composer Manager
	Load from template		Save as template
	Print or export as PostScript		Export to an image format
	Export print composition to SVG		Export as PDF
	Revert last change		Restore last change
	Zoom to full extent		Zoom to 100%
	Zoom in		Zoom out
	Refresh View
	Pan		Zoom to specific region
	Select/Move item in print composition		Move content within an item
	Add new map from QGIS map canvas		Add image to print composition
	Add label to print composition		Add new legend to print composition
	Add scale bar to print composition		Add basic shape to print composition
	Add arrow to print composition		Add attribute table to print composition
	Add an HTML frame		Add nodes shape to print composition
	Edit a nodes shape
	Group items of print composition		Ungroup items of print composition
	Lock Selected Items		Unlock All items
	Raise selected items		Lower selected items
	Move selected items to top		Move selected items to bottom
	Align selected items left		Align selected items right
	Align selected items center		Align selected items center vertical
	Align selected items top		Align selected items bottom
	Preview Atlas		First Feature
	Previous Feature		Next Feature
	Last feature		Print Atlas
	Export Atlas as Image		Atlas Settings

Table Composer 1: Print Composer Tools

Composition Panel¶

Page size and settings¶

In the Composition panel, you can define the global settings of the current composition.

Composition settings in the Print Composer

You can choose one of the Presets formats for your paper sheet, or enter your custom width, height and units. You can also choose the page Orientation to use.

Composition can be divided into several pages. For instance, a first page can show a map canvas, and a second page can show the attribute table associated with a layer, while a third one shows an HTML frame linking to your organization website. Set the Number of pages to the desired value. you can also custom the Page Background with the color or the symbol you want.

The Page size options apply to all the pages in the composition. However, you can modify the values using the data defined override options (see Data Defined Override Buttons).

A custom page size can also be set, using the Resize page tool. This creates an unique page composition, resizes the page to fit the current contents of the composition (with optional margins).

Export settings¶

You can define a resolution to use for all exported maps in Export resolution. This setting can, however, be overridden each time you are exporting a map. When checked, print as raster means all elements will be rasterized before printing or saving as PostScript or PDF.

While exporting to an image file format, you can choose to generate a world file by checking Save world file and select a map item in Reference map. The world file is created beside the exported map, has the same name and contains information to georeference it easily.

Export Settings in the Print Composer

Grid and guides¶

You can put some reference marks on your composition paper sheet to help you place some items. These marks can be:

• simple lines (called Guides) put at the position you want. To do that, ensure that Show Rulers and Show Guides in View menu are checked. Then, click and drag from within the ruler to the paper sheet. A vertical or horizontal line is added to the paper and you can set its position following the coordinates displayed at the left bottom of the composer dialog.
• or regular Grid.

Whether grids or guides should be shown is set in View menu. There, you can also decide if they might be used to snap composer items. The Grid and guides section lets you customize grid settings like Grid spacing, Grid offset and Snap tolerance to your need. The tolerance is the maximum distance below which an item is snapped to a grid or a guide.

Snapping to grids in the Print Composer

In the Options ‣ Composer menu in QGIS main canvas, you can also set the spacing, offset and snap tolerance of the grid as much as its style and color. These options are applied by default to any new print composer.

Variables¶

The Variables lists all the variables available at the composition’s level (which includes all global and project’s variables).

It also allows the user to manage composition-level variables. Click the button to add a new custom composition-level variable. Likewise, select a custom composition-level variable from the list and click the button to remove it.

More information on variables usage in the General Tools Variables section.

Variables editor in the Print Composer

Command History Panel: Revert and Restore actions¶

During the layout process, it is possible to revert and restore changes. This can be done with the revert and restore tools:

• ^{Revert last change}
• ^{Restore last change}

This can also be done by mouse click within the Command history panel (see figure_composer). The History panel lists the last actions done within the composer. Just select the point you want to revert to and once you do new action all the actions done after the selected one will be removed.

Command history in the Print Composer