Book Image

Android Studio 4.2 Development Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.2 Development Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Android Studio is an Integrated Development Environment that is based on the JetBrains IntelliJ IDEA. It provides developers with a unique platform to design and develop Android apps using various developer tools. The new Android Studio 4.2 has an upgraded IntelliJ platform and a variety of new features designed to improve the productivity of Android app developers. Fully updated for Android Studio 4.2, the objective of this book is to help you master the skills necessary to develop Android applications using Kotlin as the programming language. This book begins by outlining the steps necessary to set up an Android development and testing environment and introduces programming in Kotlin, addressing data types, flow control, functions, lambdas, and object-oriented programming. It includes an overview of Android Studio, covering areas such as tool windows, the code editor, and the Layout Editor tool. An introduction to Android architecture is followed by an in-depth explanation of the design of Android applications and user interfaces using the Android Studio environment. Early chapters detail Android Architecture components like view models, lifecycle management, Room database access, the Database Inspector, app navigation, live data, and data binding. Advanced topics such as intents are also covered, as are touch screen handling, gesture recognition, and the recording and playback of audio. You will also explore printing, transitions, cloud-based file storage, and foldable device support. Detailed descriptions of material design concepts are provided, including the use of floating action buttons, Snackbars, tabbed interfaces, card views, navigation drawers, and collapsing toolbars. Some key features of Android Studio 4.2 and Android discussed in-depth include the Layout Editor, the ConstraintLayout and ConstraintSet classes, MotionLayout Editor, view binding, constraint chains, barriers, and direct reply notifications. Later chapters cover advanced features of Android Studio such as App links, Dynamic Delivery, the Android Studio Profiler, Gradle build configuration, and submitting apps to the Google Play Developer Console.
Table of Contents (94 chapters)
94
Index

88.5 The CPU Profiler

When displayed, the CPU Profiler window will appear as shown in Figure 88-8. As with the main window, the data is displayed in realtime including the event time-line (A) and a scrolling graph showing CPU usage (B) in realtime for both the current app and a combined total for all other processes on the device:

Figure 88-8

Located beneath the graph is a list of all of the threads associated with the current app (C). Referred to as the thread activity timeline, this also takes the form of a scrolling time-line displaying the status of each thread as represented by colored blocks (green for active, yellow for active but waiting for a disk or network I/O operation to complete or gray if the thread is currently sleeping).

The CPU Profiler supports two types of method tracing (in other words profiling individual methods within the running app). The current tracing type, either sampled or instrumented, is selected using the menu marked D. The tracing types...