What Problem Does This Solve?
A user wants to see points of interest within a given area as visually represented through the current map extent. Typically the available options (results) update when the user changes the map extent through panning or zooming.
When to Use This Pattern
Sometimes called a ‘short list’ this pattern is used to show a list of points of interest (e.g. restaurants, sights, hotels) side-by-side with a map showing the corresponding features. This allows users to navigate the desired geographical area while always displaying the correct results.
What’s the Solution?
Show content in the context of the current extent, i.e. limit the available content options by binding them to the current extent of the map. This works best when it can be anticipated that the user prefers to use the map to navigate and see content updating (search results, legend, charts, etc.).
Why Use This Pattern?
Out of the multitude of results it is important to only show content that is relevant and meaningful. Tying that selection to the user-specified map extent can provide a spatial filter that is updated as the map extent changes.
This pattern works best when the content is presented side by side with the map. Removing either element (content or map) would invalidate this pattern which is a special challenge for devices with small screen resolutions.
Explicit opt-in in the form of a checkbox labeled ‘Redo search when map moved’ or similar can be considered to avoid performance issues or confusion by the user. One may argue that it’s the job of the application designer to anticipate the need for such a control versus making the assumption that the behavior is on by default.