Last time we saw the LineChart view (in part 3) it looked like this: What I want you to notice now is not the appearance of the line chart view itself, but the size and position of it. As you can see, the line chart view has a specific size. How is that size determined? In this case there is a vertical LinearLayout and the LineChartView and the TextView below it share the available height equally using weights on the…

I recently held a presentation at Droidcon London about “Dynamic Animation using Custom Views” and got quite a lot of question about the source for the Dynamics class and the other sample applications I showed.  You can find the sources here: https://github.com/andersericsson/droidconSources A small disclaimer might be appropriate as well: The above sample views are small, quickly implemented views and are not really fully implemented. For example, none of the views handle padding correctly (except for the view tutorial views)….

In part 2 of this series we started doing a line chart view. This post assumes you’ve read part 2 so if you haven’t I’d recommend reading that first. Now, let’s continue working on the line chart view. What I have in mind is three buttons on top of the graph where the user can toggle the line chart to display data for different categories, in this case different training categories: walking, running and cycling. When the user presses a…

New views Sometimes, extending a standard Android View is not enough. For many purposes, you will need to actually draw the view yourself to accomplish a task. In this tutorial, we’ll make a view that draws a line chart using the Canvas class and also learn a bit about how the view dimensions and padding works. By the way, if you haven’t already, you might want to read the previous part as well. Drawing the first pixels If you plan…

Some introduction This will be a series of posts on the subject of making custom views in android. I’ll cover, among other things, how to draw the content, how layouting and measuring works, how to implement view groups and how to animate the content. This first post will start with how to extend views, how to use them and how to create your own xml attributes. Specific tasks, specific views Most standard views that android supplies are very general, that…