ESRL Global Systems Division

Probabilistic Forecasting Exploratory Development

Legend Overlay and Management

Legend Focus and PopUp Controls Cheat Sheet

Within AWIPS, legends have been used quite successfully as a user interface device for manipulating the characteristics of overlays. However, anyone familiar with current D2D ensemble capabilities will realize that if several ensemble fields are loaded, legend management becomes very difficult. So one of the goals of this prototyping was to improve that.

The little circles "O" on the left side of the Legend show the overlay or overlays most recently acted on; we say these overlays have Legend focus. Some popup controls respond to Legend focus, some do not.

Step 1: Start D2D.
Step 2: From Volume->Browser..., load Sources Ensemble->SREF-21, Fields Basic->Height, and Planes Pres->700MB (see below, click on image for full resolution). Minimize the VB.

Step 3: Expand the Legend, by clicking Mouse Button-1 (MB1) on the + on the left side of the Legend.
Step 4: Click and hold Mouse Button-3 (MB3) on an item in the Legend, a popup window displays; select Unload to unload that item.
Step 5: Collapse the Legend, by clicking MB1 on the - on the left side of the Legend.
Step 6: Click and hold MB3 on the collapsed Legend (not on the +), a popup window displays; slect Unload to unload all items in the Legend.

The point here is that the Unload function does not respond to Legend focus, but does respond to the collapse state.

Step 7: From the Volume->Browser..., load Sources Ensemble->SREF-21, Fields Basic->Height, and Planes Pres->500MB (see below, click on image for full resolution). Minimize the VB.

Step 8: Expand the SREF 500MB Height overlay by clicking MB1 on the + on the left side of the Legend.
Step 9: Toggle all items in the SREF 500MB Height overlay off by clicking MB3 on an item in the Legend. Now toggle on one group by clicking Mouse Button-2 (MB2) on a single item in the Legend (see below, click on image for full resolution). Note that the focus marker "O" is now to the left of the items in the group.

Step 10: Click and hold MB3 on an item in the group, a popup window displays; select Line width to increase the thickness of the lines (see below, click on image for full resolution). Note that this action changed the thickness of the lines of all items in the group.

The point here is that the line thickness control does respond to Legend focus. Line Style, Magnification, and Density also do.

Step 11: Completely collapse the SREF 500MB Height overlay by clicking MB1 on a - on the left side of the Legend.
Step 12: Click and hold MB3 over the SREF 500MB Height overlay, a popup window displays; change the color of the overlay.
Step 13: Expand the SREF 500MB Height overlay by clicking MB1 on the + on the left side. Toggle on all items of the overlay, if not already, by clicking MB3 on a toggled off item. Note that all the colors were changed, but not to the same thing.
Step 14: Pick one of the items in the Legend and use the MB3 popup to change the color, note that just that color changed (see below, click on image for full resolution).

The point here is that the change color function has its own unique rules.

Step 15: Clear the screen.
Step 16: Exit D2D.