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

88.6 Memory Profiler

The memory profiler is displayed when the memory time-line is clicked within the main Android Profiler Tool window and appears as shown in Figure 88-14:

Figure 88-14

The memory time-line shows memory allocations relative to the scale on the right-hand side of the time-line for a range of different categories as indicated by the color key. The dashed line (A) represents the number of objects allocated for the app relative to the scale on the left-hand side of the time-line graph.

The trash can icons (B) indicate garbage collection events. A garbage collection event occurs when the Android runtime decides that an object residing in memory is no longer needed and automatically removes it to free memory.

In addition to the usual timelines, the window includes buttons (C) to force garbage collection events and to capture a heap dump.

A heap dump (Figure 88-15) lists all of the objects within the app that were using memory at the time the dump was...