Docs for ‘QGIS testing’. Visit http://docs.qgis.org/2.14 for QGIS 2.14 docs and translations.
The Style Manager is the place where users can manage and create generic symbols to be used in several QGIS projects. You can open it with the Settings ‣ Style Manager or from the Style tab in the vector layer’s Properties. It allows users to:
You can organize symbols into different categories. These categories, listed in the panel at the left, can be static (called Group) or dynamic (named Smart Group). A group is smart when its symbols are dynamically fetched according to conditions set. See figure_smart_group:
To create a group, right click on an existing group or on the main Groups directory in the left of the dialog. You can also select a group and click the Add Group button. The new group will be a sub-group of the selected one.
Create Smart Group is similar to creating group, but instead select Smart Groups. The dialog box allows user to choose the expression to select symbols in order to appear in the smart group (contains some tags, member of a group, have a string in its name, etc.). Any symbol that satisfies the entered condition(s) is automatically added to the smart group.
Unlike the smart groups that automatically fetch their belonged symbols, simple groups are filled by the user. To add a symbol into a group, you can either right click on a symbol, choose Apply Group and then the group name. There is a second way to add several symbols into a group: just select the group, click and choose Group Symbols. All symbols display a checkbox that allows you to add the symbol into the selected groups. When selection is finished, you can click the same button, and choose Finish Grouping.
All the symbols that are not placed under a custom group belong to a default group named Ungrouped.
Selecting a group returns in the right panel, if applicable, the list of symbols of the group (including its subgroups). These symbols are organized in four different tabs:
The symbol list can be modified by adding new symbols with Add item button or modifying existing ones with Edit item. See The Symbol Selector for further information.
The Color ramp tab in the Style Manager presents different types of color ramps you can use to style layers.
Easily custom the color stops of the gradient color ramp
Double-clicking the ramp preview or drag-and-drop a color from the color spot onto the ramp preview adds a new color stop. Each color stop can be tweaked using the Color Selector widgets or by plotting each of its parameters. You can also reposition it using the mouse, the arrow keys (combine with Shift key for a larger move) or the Relative position spinbox. Pressing Delete stop as well as DEL key removes the selected color stop.
You can use the Invert option while classifying the data with a color ramp. See figure_color_custom_ramp for an example of a custom color ramp and figure_color_cpt_city for the cpt-city Colors dialog.
The cpt-city option opens a new dialog with hundreds of themes included ‘out of the box’.
The Symbol selector is the main dialog to design a symbol. You can create or edit Marker, Line or Fill Symbols.
Two main components structure the symbol selector dialog:
A symbol can consist of several Symbol layers. The symbol tree shows the overlay of these symbol layers that are combined afterwards to shape a new global symbol. Besides, a dynamic symbol representation is updated as soon as symbol properties change.
A set of tools is available to manage the symbol tree items and according to the level selected, you’ll get enabled different tools at the bottom of the dialog to:
In QGIS, configuring a symbol is done in two steps: the symbol and then the symbol layer.
At the top level of the tree, it depends on the layer geometry and can be of Marker, Line or Fill type. Each symbol can embed one or more symbols (including, of any other type) or symbol layers.
You can setup some parameters that apply to the global symbol:
The Data-defined override button beside the last layer-related parameters is inactive when setting the symbol from the Style manager dialog. When the symbol is connected to a map layer, this button offers access to the size assistant dialog which helps to create proportional or multivariate analysis rendering.
The symbols used at this level are items you can pick from the symbols library. A list of available symbols of the same type from your symbol library is shown and can be filtered by selecting a group in the drop-down list just above. Click the Save button to add the designed symbol to your symbol library.
Note that once you have set the size in the lower levels of the Symbol layers dialog, the size of the whole symbol can be changed with the Size (for marker symbols) or the Width (for line symbols) menu in the first level again. The size of the lower levels changes accordingly, while the size ratio is maintained.
At a lower level of the tree, you can customize the symbol layers. The available symbol layer types depend on the upper symbol type. You can apply on the symbol layer paint effects to enhance its rendering.
Because describing all the options of all the symbol layer types would not be possible, only particular and significative ones are mentioned below.
Some common options and widgets are available to build a symbol layer, regardless it’s of marker, line or fill sub-type:
While the description below assumes that the symbol layer type is bound to the feature geometry, keep in mind that you can embed symbol layers in each others. In that case, the lower level symbol layer parameter (placement, offset...) might be bound to the upper-level symbol, and not to the feature geometry itself.
Appropriate for point geometry features, marker symbols have several Symbol layer types:
SVG marker: provides you with images from your SVG paths (set in Settings ‣ Options ‣ System menu) to render as marker symbol. Each SVG file colors and stroke can be adapted.
Requirements for a customizable SVG marker symbol
To have the possibility to change the colors of a SVG marker, you have to add the placeholders param(fill) for fill color, param(outline) for stroke color and param(outline-width) for stroke width. These placeholders can optionally be followed by a default value, e.g.:
<svg width="100%" height="100%"> <rect fill="param(fill) #ff0000" stroke="param(outline) #00ff00" stroke-width="param(stroke-width) 10" width="100" height="100"> </rect> </svg>
For each marker symbol layer type, you can set some of the following properties:
In most of the marker symbols dialog, you also have a frame with previews of predefined symbols you can choose from.
Appropriate for line geometry features, line marker symbols have following symbol layer types:
Appropriate for polygon geometry features, fill symbols have also several symbol layer types:
When geometry type is polygon, you can choose to disable the automatic clipping of lines/polygons to the canvas extent. In some cases this clipping results in unfavourable symbology (e.g. centroid fills where the centroid must always be the actual feature’s centroid).
Available with all types of symbols, the geometry generator symbol layer allows to use expression syntax to generate a geometry on the fly during the rendering process. The resulting geometry does not have to match with the original geometry type and you can add several differently modified symbol layers on top of each other.
-- render the centroid of a feature centroid( $geometry ) -- visually overlap features within a 100 map units distance from a point -- feature, i.e generate a 100m buffer around the point buffer( $geometry, 100 ) -- Given polygon layer1( id1, layer2_id, ...) and layer2( id2, fieldn...) -- render layer1 with a line joining centroids of both where layer2_id = id2 make_line( centroid( $geometry ), centroid( geometry( get_feature( 'layer2', 'id2', attribute( $currentfeature, 'layer2_id') ) ) )
The vector field marker is used to display vector field data such as earth deformation, tidal flows, and the like. It displays the vectors as lines (preferably arrows) that are scaled and oriented according to selected attributes of data points. It can only be used to render point data - line and polygon layers are not drawn by this symbology.
The vector field is defined by attributes in the data, which can represent the field either by:
The magnitude of field can be scaled up or down to an appropriate size for viewing the field.