Feature info

What it does

Info shows the data at a point on the map: feature attributes, elevation where available, and Street View where configured.

It has two modes:

• Hover: move the pointer and the panel follows it, reading the vector features under the cursor. Nothing is committed. You are browsing.
• Pinned: click, and that location is held. The panel stops following the pointer, so you can read it, scroll it, and select the text. Clicking the same place again unpins and returns to hovering.

Hover works for vector layers only, because those features are already in the browser. Clicking also queries WMS layers with GetFeatureInfo.

The panel also shows elevation where the map has terrain data, and a Street View thumbnail where a Google API key is configured.

Layer metadata can make attributes readable: translate names, add units, and map coded values to labels. For example, pop_est can be shown as population.

Using it

1. Open the info tool from the toolbar.
2. Move over the map. The panel shows the features under the pointer, layer by layer.
3. Click to pin a location. The panel holds still so you can read and copy it.
4. Click the same spot again to release it, or move on and click elsewhere to pin that instead.

For tiled vector layers, only drawn features can be queried. A feature outside the current view or below its zoom range cannot appear in the panel.

In your own map

The tool needs no configuration to work: it queries whatever the map has.

One option is worth setting: googleApiKey, which turns on the Street View thumbnail. Without googleApiKey, the rest of the panel is unchanged. The Street View section simply does not appear.

Attribute display comes from the layer, not from this tool. Give a layer metadata.attributes.translations and every panel that shows those properties reads the same definitions.

Extending it

Hover and pinned mode use different query paths. Hover is throttled and hit-tests within a few pixels. A click uses a slightly wider tolerance. A second click close to the pinned point unpins it.

metadata.attributes may be a string naming a shared definition in layerData.attributeMetadata. Use that when many layers share the same columns.