Modes for Create Geometry Tools

Modes for Create Geometry Tools (under development)

Applying temporary constrains to vertex editing while creating a geometry

Warning

This is work in progress. There are a couple known issues to be solved yet. So, while you're welcome and encouraged to try this out, be aware that this functionality is not based on production code and feel free to send us your comments and bug reports to the uDig devel mailing list.

Intro

uDig is getting better for digitizing purposes, by expanding the editing possibilities while maintaining simple and consistent interactions.
Edit Modes are a mean to apply temporary constraints to the allowable location of a vertex while creating a Geometry.

This means that, while you're creating a LineString or a Polygon, you can modify the standard behaviour of the Create Line Tool or the Create Polygon Tool so uDig can assist you, for example, to allow only orthogonal line segments, to snap the vertex to be added up to the closest point on another line segment, to draw segments parallel to another one, etc.

As this is work in progress, two new create tools have been incorporated to the create geometries drop down button on the uDig toolbar, as shown in Figure 1 and Figure 2. They might well end up being merged on the standard Create Line Tool and Create Polygon Tool. But by now you just have to select the Advanced Line Tool or Advanced Polygon Tool to use this new functionality.

Figure 1 Select Advanced Line Tool to create LineStrings Figure 2 Select Advanced Polygon Tool to create Polygons

Modes

Once you selected one of the available geometry creation tools as shown above, you can start digitizing as usual.
At any time, you can choose to select a mode from the Modes Toolbar (Figure 3). The Modes Toolbar contains a series of buttons. A single button may be active at a time. While active, this button will apply a constraint or an extra behaviour to the creation tool in use.


Figure 3 Edit Modes Toolbar

Edit Modes and Snapping Behaviour

Some Edit Modes use the snapping behaviour for different purposes. Depending on the mode chosen, whether it is for snapping the next vertex to another vertex, or for selecting a reference geometry to apply a constraint upon, the lookup of the Snap Behaviour will follow the preference set on the Edit Tool preference page accessible through the Window->Preferences menu option, as shown in Figure 4.


Figure 4 setting the snap behaviour preference

Available Modes

The following edit modes are available while creating a new Geometry:

Caveats

So you were warned at the top of the page that there were a couple known issues to be solved yet, and still got to this point, thanks. So these are those couple things that still need to be fixed:

All this stuff is planned to be fixed in a later iteration so keep tuned.

(c) Copyright (c) 2004-2008 Refractions Research Inc. and others.