![]() The buffer data makes its way to the SurfaceFlinger (or an OpenGL ES App, but that’s another topic entirely)Īnd ultimately to the HAL so that it can be rendered to the screen. In the above image, you can see that many different components can create bufferĭata. How does this all fit together?Ī great question! Fortunately Google has built a fantastic diagram that shows the flow of data from inception to render. The Binder is then returned to the WindowManager (and consequentially to the application) which can then start sending frames to SurfaceFlinger. The SurfaceFlinger then creates a new layer and a Binder object. When an app is summoned to the foreground, the WindowManager system-service asks the SurfaceFlinger system-service for a surface. Each SurfaceView will have it’s own buffer that is composited by the SurfaceFlinger and not your application! How does the SurfaceFlinger work? In this example, we’d only have two buffers.Ĭonsequentially, we can have 4 or more buffers by including a SurfaceView in our application. We know that we can hide the status bar by setting the appropriate WindowManager flags (or using a theme that omits the status bar). It’s even possible that you’ll have fewer than three buffers as well! However, it’s possible that you will actually have more than three buffers. In a vast majority of applications, you (and consequently the SurfaceFlinger) will only deal with three buffers. To render content to the screen! This is all taken care of for us, by the Operating Is created by us but we don’t have to new up a Buffer Object or anything like that Powered by their own buffer! If you’ve built apps before, you’ll know that we cantĬompletely control the status bar or the navigation bar, so we can assume that theseīuffers are provided by the operating system. The above image shows three different sections of our Android device’s screen, each You can see each of these regions in the diagram below. A buffer for the Status Bar, a buffer for the Navigation Bar, and a Buffer for the application content. In most Android applications, the SurfaceFlinger has access to three different buffers. Where does the SurfaceFlinger get it's buffers? It’s the same idea as the regular buffers that I just mentioned, except that all the data contained in them is used to inform something how the screen should be displayed. ![]() However, the SurfaceFlinger works specifically with buffers that contain graphics and display data. This layer allows Android toĮffectively run on thousands of different devices!Ī buffer is simply a region of memory allocated for storing something temporarily while it’s moved to another place. Responsible for running the operating system. ![]() The gap between the software that runs on Android and the actual hardware The HAL is an acronym for the Hardware Abstraction Layer. In layman’s terms - The SurfaceFlinger takes in buffers of display data, composites them into a single buffer, and then passes that on to the hardware abstraction layer. In fact, all it does is merely composite buffers of data before handing them off to the HAL. It’s important to note that the SurfaceFlinger doesn’t directly render anything to the screen. Actually, the SurfaceFlinger is a service that plays a critical part in determining what is rendered on the screen on any Android device. Now that that is out of the way… What does it actually do? If you’ve worked with scrolling, you’ll know that “flinging” is an action that a user can do, but it’s not related to that. Android’s SurfaceFlinger is a system service provided on the Android Operating System.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |