Allowing interaction using ChartProxy

Now that we know how to create charts, let’s discover more hidden tricks by adding user interaction capabilities. User interaction in charts, with its many uses, allows users to explore the chart’s data using touch. Here are some use cases for user interaction with charts:

• Drill down to a specific data mark: By touching a BarMark or SectorMark charts, the user can navigate to a new screen that shows additional information about the particular data point. For example, if the BarMark chart shows information about watermelon sales, we can navigate the user to a screen that details the watermelon sales deals.
• Exploring new data points: Enabling user interaction with LineMark charts, for example, provides insights to the user on data points not originally part of the dataset if our LinkMark chart includes information about the growing population in a specific city over time, touching a particular point the chart can display...