The Map Item

The map item is the main frame that displays the map you’ve designed in the map canvas. Use the addMap Add Map tool following items creation instructions to add a new map item that you can later manipulate the same way as exposed in Interacting with layout items.

By default, a new map item shows the current status of the map canvas with its extent and visible layers. You can customize it thanks to the Item Properties panel. Other than the items common properties, this feature has the following functionalities:

../../../../_images/map_mainproperties.png

Map Item Properties Panel

Main properties

In the Main properties group (see figure_layout_map) of the map Item Properties panel, available options are:

  • The Update Preview button to refresh the map item rendering if the view in map canvas has been modified. Note that most of the time, the map item refresh is automatically triggered by the changes;

  • The Scale to manually set the map item scale;

  • The Map rotation allows you to rotate the map item content clockwise in degrees. The rotation of the map canvas can be imitated here;

  • The CRS allows you to display the map item content in any CRS. It defaults to Use project CRS;

  • checkbox Draw map canvas items lets you show in the print layout annotations that are placed on the main map canvas.

Layers

By default, map item appearance is synced with the map canvas rendering meaning that toggling visibility of the layers or modifying their style in the Layers Panel is automatically applied to the map item. Because, like any other item, you may want to add multiple map items to a print layout, there’s a need to break this synchronization in order to allow showing different areas, layer combinations, at different scales… The Layers properties group (see figure_layout_map_layers) helps you do that.

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Map Layers group

If you want to keep the map item consistent with an existing map theme, check checkbox Follow map theme and select the desired theme in the drop-down list. Any changes applied to the theme in QGIS’ main window (using the replace theme function) will automatically affect the map item. If a map theme is selected, the Lock styles for layers option is disabled because Follow map theme also updates the style (symbology, labels, diagrams) of the layers.

To lock the layers shown in a map item to the current map canvas visibility, check checkbox Lock layers. When this option is enabled, any changes on the layers’ visibility in QGIS’ main window will not affect the layout’s map item. Nevertheless, style and labels of locked layers are still refreshed according to QGIS’ main window. You can prevent this by using Lock styles for layers.

Instead of using the current map canvas, you can also lock the layers of the map item to those of an existing map theme: select a map theme from the showMapTheme Set layer list from a map theme drop-down button, and the checkbox Lock layers is activated. The set of visible layers in the map theme is from now on used for the map item until you select another map theme or uncheck the checkbox Lock layers option. You then may need to refresh the view using the draw Refresh view button of the Navigation toolbar or the Update Preview button seen above.

Note that, unlike the Follow map theme option, if the Lock layers option is enabled and set to a map theme, the layers in the map item will not be refreshed even if the map theme is updated (using the replace theme function) in QGIS’ main window.

Locked layers in the map item can also be data-defined, using the dataDefined icon beside the option. When used, this overrides the selection set in the drop-down list. You need to pass a list of layers separated by | character. The following example locks the map item to use only layers layer 1 and layer 2:

concat ('layer 1', '|', 'layer 2')

Extents

The Extents group of the map item properties panel provides the following functionalities (see figure_layout_map_extents):

../../../../_images/map_extents.png

Map Extents group

The Extents area displays X and Y coordinates of the area shown in the map item. Each of these values can be manually replaced, modifying the map canvas area displayed and/or map item size. Clicking the Set to Map Canvas Extent button sets the extent of the layout map item to the extent of the main map canvas. The button View Extent in Map Canvas does exactly the opposite; it updates the extent of the main map canvas to the extent of the layout map item.

You can also alter a map item extent using the moveItemContent Move item content tool: click-and-drag within the map item to modify its current view, keeping the same scale. With the moveItemContent tool enabled, use the mouse wheel to zoom in or out, modifying the scale of the shown map. Combine the movement with Ctrl key pressed to have a smaller zoom.

Controlled by atlas

The checkbox Controlled by atlas group properties is available only if an atlas is active in the print layout. Check this option if you want the map item being ruled by the atlas; when iterating over the coverage layer, the map item extent is panned/zoomed to the atlas feature following:

  • radioButtonOn Margin around features: zooms to the feature at the best scale, keeping around each a margin representing a percentage of the map item width or height. The margin can be the same for all features or set variable, e.g., depending on map scale;

  • radioButtonOff Predefined scale (best fit): zooms to the feature at the project predefined scale where the atlas feature best fits;

  • radioButtonOff Fixed scale: atlas features are panned from one to another, keeping the same scale of the map item. Ideal when working with features of same size (e.g., a grid) or willing to highlight size differences among atlas features.

Grids

With grids, you can add, over your map, information relative to its extent or coordinates, either in the map item projection or a different one. The Grids group provides the possibility to add several grids to a map item.

  • With the signPlus and signMinus buttons you can add or remove a selected grid;

  • With the arrowUp and arrowDown buttons you can move up and down a grid in the list, hence move it on top or bottom of another one, over the map item.

Double-click the added grid to rename it.

../../../../_images/map_grids.png

Map Grids Dialog

After you add a grid, you can activate the checkbox checkbox Draw grid to allow overlaying the grid onto the map item. Press the Modify Grid… button to access configuration options.

Grid Appearance

As grid type, you can specify to use a:

  • Solid: shows a line across the grid frame. The Line style can be customized using color and symbol selector widget;

  • Cross: displays segment at the grid lines intersection for which you can set the Line style and the Cross width;

  • Markers: only displays customizable markers symbol at grid lines intersection;

  • or Frame and annotations only.

Other than the grid type, you can define:

  • the CRS which could not be the same as the map item’s;

  • the Interval between two consecutive grid references in X and Y directions;

  • the Interval Units to use for the grid references, in Map units, Millimeters or Centimeters;

  • an Offset from the map item edges, in X and Y directions;

  • and the Blend mode of the grid (see Blending Modes) when compatible.

../../../../_images/map_draw_grid.png

Draw Grid Dialog

Grid Frame

There are different options to style the frame that holds the map. Following options are available: No Frame, Zebra, Interior ticks, Exterior ticks, Interior and Exterior ticks and Line border. Also you can choose to set visible or not each side of the grid frame.

When compatible, it’s possible to set the Frame size, Frame line thickness, Frame fill colors. With Latitude/Y only and Longitude/X only settings in the divisions section you have the possibility to prevent a mix of latitude/Y and longitude/X coordinates showing on a side when working with rotated maps or reprojected grids.

../../../../_images/map_grid_frame.png

Grid Frame Dialog

Coordinates

The checkbox Draw coordinates checkbox allows you to add coordinates to the map frame. You can choose the annotation numeric format, the options range from decimal to degrees, minute and seconds, with or without suffix, aligned or not and a custom format using the expression dialog.

You can choose which annotation to show. The options are: show all, latitude only, longitude only, or disable(none). This is useful when the map is rotated. The annotation can be drawn inside or outside the map frame. The annotation direction can be defined as horizontal, vertical ascending or vertical descending.

Finally, you can define the annotation font, font color, distance from the map frame and the precision of the drawn coordinates.

../../../../_images/map_grid_draw_coordinates.png

Grid Draw Coordinates dialog

Overviews

Sometimes you may have more than one map in the print layout and would like to locate the study area of one map item on another one. This could be for example to help map readers identify the area in relation with its larger geographic context shown in the second map.

The Overviews group of the map panel helps you create the link between two different maps extent and provides the following functionalities:

../../../../_images/map_overview.png

Map Overviews group

To create an overview, select the map item on which you want to show the other map item’s extent and expand the Overviews option in the Item Properties panel. Then press the signPlus button to add an overview.

Initially this overview is named ‘Overview 1’ (see Figure_layout_map_overview). You can:

  • Rename it with a double-click;

  • With the signPlus and signMinus buttons, add or remove overviews;

  • With the arrowUp and arrowDown buttons, move up and down an overview in the list, hence move it on top or bottom of another one, over the map item.

Then select the overview item in the list and check the checkbox Draw “<name_overview>” overview to enable the overview drawing over the selected map frame. You can customize it with:

  • The Map frame combo list can be used to select the map item whose extents will be drawn on the present map item.

  • The Frame Style allows you to change the style of the overview frame.

  • The Blending mode allows you to set different transparency blend modes.

  • The checkbox Invert overview creates a mask around the extents when activated: the referenced map extents are shown clearly, whereas everything else is blended with the frame color.

  • The checkbox Center on overview puts the extent of the overview frame in the center of the overview map. You can only activate one overview item to center, when you have added several overviews.