This allows to declare data dependencies between layers. A data
dependency occurs when a data modification in a layer, not by direct
user manipulation may modify data of other layers.
This is the case for instance when geometry of a layer is updated by a
database trigger after modification of another layer's geometry.
When enabled, repeating locks are not automatically cleared when
a new point is added. They are handy when the same constraint
must be repeated for multiple points (eg adding vertices
which are always 50 meters apart)
(fix#12605)
A new "legend" tab has been added to diagram properties, allowing
both the existing attribute legend and a new size legend to be
enabled/disabled. The size legend has a configurable marker
symbol.
Also includes unit tests for both diagram attribute and size
legends.
Sponsored by ADUGA
This change allows the attributes of multiple features to be edited
simultaneously. It is enabled when the attribute table dialog is in
"form mode", via a new "multi edit" button on the toolbar.
In this mode, attribute value changes will apply to all selected
features. New widgets appear next to each editor widget allowing for
display of the current multi-edit state and for rolling back changes
on a field-by-field basis.
Changes are made as a single edit command, so pressing undo will
rollback the attribute changes for all selected features at once.
Multiedit mode is only available for auto generated and drag and
drop forms - it is not supported by custom ui forms.
Sponsored by Kanton Basel Stadt
Using this renderer no symbol will be drawn for features, but labeling,
diagrams and other non-symbol parts will still be shown.
Selections can still be made on the layer in the canvas and selected
features will be rendered with a default symbol. Features being edited
will also be shown.
This is intended as a handy shortcut for layers which you only want
to show labels or diagrams for, and avoids the need to render
symbols with totally transparent fill/border to achieve this.
(fix#12131)
[FEATURE] Tracing of features (digitizing)
Tracing can be now used in various capturing map tools (add feature, add part, ...) including reshape and split tools.
Tracing is simply a new mode for these tools - when tracing is not enabled, the tools work as usual. When tracing is enabled (by clicking the new magnet icon or pressing T key), tools switch to tracing behavior:
- first click on a vertex/edge (must be snapped!) will start tracing - moving mouse on top of the map continuously updates the trace
- next click will confirm the trace and mark start of a new trace Tracing can be enabled/disabled anytime even while digitizing one feature, so it is possible to digitize some parts of the feature with tracing enabled and other parts with tracing disabled.
Tracing respects snapping configuration for the list of traceable layers.
If there are too many features in map display, tracing is disabled to avoid potentially long tracing structure preparation and large memory overhead. After zooming in or disabling some layers the tracing is enabled again.
Internally, things work like this:
- when tracing is requested, linestrings are extracted from vector layers, then noded (using GEOSNode to resolve all intersections) and finally a simple planar graph is built (vertices + edges)
- when tracing, endpoints are temporarily added to the graph (if not equal to one of existing vertices already) and Dijkstra's algorithm is run to get shortest path
Original specs for the curious ones (the interaction with QGIS is slightly improved from what has been specified): http://www.lutraconsulting.co.uk/crowdfunding/autotrace-phase-2/specification.pdf
