AWT Interview Questions and Answers Guide
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Comparative Studies of 10 Programming Languages Within 10 Diverse Criteria
Department of Computer Science and Software Engineering Comparative Studies of 10 Programming Languages within 10 Diverse Criteria Jiang Li Sleiman Rabah Concordia University Concordia University Montreal, Quebec, Concordia Montreal, Quebec, Concordia [email protected] [email protected] Mingzhi Liu Yuanwei Lai Concordia University Concordia University Montreal, Quebec, Concordia Montreal, Quebec, Concordia [email protected] [email protected] COMP 6411 - A Comparative studies of programming languages 1/139 Sleiman Rabah, Jiang Li, Mingzhi Liu, Yuanwei Lai This page was intentionally left blank COMP 6411 - A Comparative studies of programming languages 2/139 Sleiman Rabah, Jiang Li, Mingzhi Liu, Yuanwei Lai Abstract There are many programming languages in the world today.Each language has their advantage and disavantage. In this paper, we will discuss ten programming languages: C++, C#, Java, Groovy, JavaScript, PHP, Schalar, Scheme, Haskell and AspectJ. We summarize and compare these ten languages on ten different criterion. For example, Default more secure programming practices, Web applications development, OO-based abstraction and etc. At the end, we will give our conclusion that which languages are suitable and which are not for using in some cases. We will also provide evidence and our analysis on why some language are better than other or have advantages over the other on some criterion. 1 Introduction Since there are hundreds of programming languages existing nowadays, it is impossible and inefficient -
Graphical User Interfaces Java Programming (Languages in Depth Series)
Graphical User Interfaces Java Programming (Languages in Depth Series) Christoph Angerer March 13th 2008 Why Java UI Programming is Special Platform independence (“write once runs anywhere”): Windows, Linux, Mac OS But user interfaces are highly platform dependent Look; e.g., sizes, colors, layout of UI elements Feel; e.g., their click- and selection behavior Question: how to write one UI that works on all platforms equally well? (not necessarily: “is on all platforms equal”!) 2 Outline Graphical User Interfaces with Java: Basics Abstract Window Toolkit (AWT) Java SWING (Standard Widget Toolkit (SWT)): not today... Advanced SWING Topics Pluggable Look And Feel (PLAF) Event Dispatching Thread SWING Animation 3 AWT ... heavyweight components History AWT was the first Java GUI API Released in 1995 by Sun Microsystems Now part of the Java Foundation Classes (JFC) AWT was “superseded” by SWING, but it is still important: AWT provides the core services for SWING: interface to the OS, event dispatching, drag&drop support... AWT is the GUI toolkit for several mobile java profiles 5 Features of AWT Limited set of basic widgets: Frame, Button, TextField, ... Event handling model Keyboard, Mouse, ... Graphics and imaging APIs Classes for fonts, colors, shapes LayoutManager mechanism Data Transfer from/to native platform clipboard 6 A Small AWT Applet //imports public class BeepButton extends Applet { public void init() { // Compose the GUI Button beepButton = new Button("Beep"); this.add(beepButton); // Setup Event handlers beepButton.addActionListener(new -
SSC - Communication and Networking
SSC - Communication and Networking SSC - Concurrency and Multi-threading Concurrency in Swing Shan He School for Computational Science University of Birmingham Module 06-19321: SSC SSC - Communication and Networking Outline Outline of Topics Concurrency in Swing SSC - Communication and Networking Concurrency in Swing Responsive or Unresponsive UI? I Screen liveliness: users expect a program is always responsive, no matter what it's doing I But let's take a look at a BAD example I Swing is a single-threaded programming model I Event-dispatch thread: handles all interaction events. I How the Swing works: I Step 1: Swing generates event objects that contain relevant event information, e.g. event source and event ID. I Step 2: placed event objects to a single event queue ordered by their entry time. I Step 3: event-dispatch thread, regularly checks and takes event objects from the queue one by one and sends them to the interested parties I Step 4: the interested parties react to the event notification SSC - Communication and Networking Concurrency in Swing How the Swing works: Event queue Event n Queue up events Event n-1 Event n-2 … Update UI Event 2 Event 1 Event listener List Selection Listener Event dispatch thread Paint Others Notifies interested parties SSC - Communication and Networking Concurrency in Swing Let's trace the threads I We can tracing the threads executed in a Swing application I Five thread involved: I Main thread by the main() method I \AWT-Windows" (daemon thread): listen to UI events from AWT windows I \AWT-Shutdown": -
Bluebottle: a Thread-Safe Multimedia and GUI Framework for Active Oberon
Research Collection Doctoral Thesis Bluebottle: A Thread-safe Multimedia and GUI Framework for Active Oberon Author(s): Frey, Thomas M. Publication Date: 2005 Permanent Link: https://doi.org/10.3929/ethz-a-004999723 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library Diss. ETH No. 16074 Bluebottle : A Thread-safe Multimedia and GUI Framework for Active Oberon A dissertation submitted to the Swiss Federal Institute of Technology Zurich (ETH Zürich) for the degree of Doctor of Technical Sciences presented by Thomas Martin Frey Dipl. Informatik-Ing. ETH born February 01, 1975 citizen of Gontenschwil AG, Switzerland accepted on the recommendation of Prof. Dr. Jürg Gutknecht, examiner Prof. Dr. Moira Norrie, co-examiner 2005 11 © Thomas M. Frey, 2005. All rights reserved Acknowledgments First of all, I would like to thank Prof. J. Gutknecht for the opportunity to work in his group and for his liberal supervision of the thesis. Prof. M. Norrie kindly accepted to be co-examiner and provided much-appreciated feedback. I would like to thank P. Müller and P. Reali for writing the Aos kernel and Active Oberon compiler respectively and for their encouragement when I started the Bluebottle framework five years ago. I would also like to thank the previous developers and contributors of Oberon. Especially the work and comments of E. Oswald and E. Zeller had great influence on the project. I am also very grateful to B. Kirk for reading an early version of this thesis and providing valuable suggestions which helped to enhance its structure and reduce the number of mistakes. -
Graphical User Interfaces with Java: Basics Abstract Window Toolkit (AWT) Java SWING (Standard Widget Toolkit (SWT)): Not Today
Graphical User Interfaces Java Programming (Languages in Depth Series) Christoph Angerer April 26th 2007 Why Java UI Programming is Special Platform independence (“write once runs anywhere”): Windows, Linux, Mac OS But user interfaces are highly platform dependent Look; e.g., sizes, colors, layout of UI elements Feel; e.g., their click- and selection behavior Question: how to write one UI that works on all platforms equally well? (not necessarily: “is on all platforms equal”!) 2 Outline Graphical User Interfaces with Java: Basics Abstract Window Toolkit (AWT) Java SWING (Standard Widget Toolkit (SWT)): not today... Advanced SWING Topics Pluggable Look And Feel (PLAF) Event Dispatching Thread SWING Animation 3 AWT ... heavyweight components History AWT was the first Java GUI API Released in 1995 by Sun Microsystems Now part of the Java Foundation Classes (JFC) AWT was “superseded” by SWING, but it is still important: AWT provides the core services for SWING: interface to the OS, event dispatching, drag&drop support... AWT is the GUI toolkit for several mobile java profiles 5 Features of AWT Limited set of basic widgets: Frame, Button, TextField, ... Event handling model Keyboard, Mouse, ... Graphics and imaging APIs Classes for fonts, colors, shapes LayoutManager mechanism Data Transfer from/to native platform clipboard 6 A Small AWT Applet //imports public class BeepButton extends Applet { public void init() { // Compose the GUI Button beepButton = new Button("Beep"); this.add(beepButton); // Setup Event handlers beepButton.addActionListener(new -
CS 230 01 - Threading Introduction
Res Overview Threads Custom Daemons Termination Joins Interrupts API Interference Consistency Swing-and-Threads CS 230 01 - Threading Introduction Radu Nicolescu Department of Computer Science University of Auckland 15 May 2013 1 / 56 Res Overview Threads Custom Daemons Termination Joins Interrupts API Interference Consistency Swing-and-Threads 1 Resources 2 Overview 3 Concurrency with Threads 4 Simple Custom Threads 5 Daemon Threads 6 Threads Termination 7 Thread Joins 8 Thread Interruptions 9 Thread API 10 Thread Interference 11 Memory Consistency 12 Swing and Threads 2 / 56 Res Overview Threads Custom Daemons Termination Joins Interrupts API Interference Consistency Swing-and-Threads Resources For a complementary view: • The Java Tutorial Trail: Essential Classes • Lesson: Concurrency • The Java Tutorial Trail: Creating a GUI With JFC/Swing • Lesson: Concurrency in Swing • Initial Threads, The Event Dispatch Thread • MultiThreaded toolkits: A failed dream?, Graham Hamilton http://weblogs.java.net/blog/kgh/archive/2004/10/ multithreaded_t.html • The Java API (J2SE7 Documentation) 4 / 56 Res Overview Threads Custom Daemons Termination Joins Interrupts API Interference Consistency Swing-and-Threads Quiz: How many threads does your program have? • Briefly, a thread is a single sequential flow of control within a program. • To find out (1) the number of logical cores and (2) which thread runs a particular method, use 1 i n t Runtime.getRuntime(). availableProcessors() 2 long Thread.currentThread (). getId() • Command-line • Initial thread: -
Overview of Java Introduction
Content [Real-Time Control System: Chapter 6.4] Overview of Java Real-Time Systems, Lecture X 1. Introduction 2. The Java Language Karl-Erik Arz´en˚ 18 January 2021 2.1 Java Statements Lund University, Department of Automatic Control 2.2 Object-Oriented Programming 1 Aim of the Lecture Introduction • Present the basic ideas and concepts behind Java. • Show how a simple Graphical User Interface (GUI) can be implemented. 2 Further Sources Overview • Developed at Sun Microsystems (by Gosling et al.); • Sun acquired Oracle in 2009; • Essentials of the Java programming language Part I1 and II2. • Syntax from C and C++, semantics from Simula • Per Holm, Objektorienterad programmering och Java, Studentlitteratur, 1998. • General object-oriented language; • Arnold and Gosling, The Java Programming language, • First release in May 1995, Latest release Java 8 in 2014; 4th edition3, 2005. • Java 9 scheduled for March 2017; • Java links and material on the course home page. • Originally intended for consumer electronics; • Later remarkted as a WWW-language; • Programs are compiled into bytecode and interpreted by the Java Virtual Machine (JVM), platform independent. 1http://www.oracle.com/technetwork/java/index-138747.html 2http://www.oracle.com/technetwork/java/basicjava2-138746.html 3Online from http://www-public.tem-tsp.eu/˜gibson/Teaching/CSC7322/ 3 4 Applications, Applets and Servlets The Java Language • Simple: easy to learn, based on today’s practice (borrow C++ syntax), small size, automatic garbage collection; • Network-oriented: full support for networked applications, TCP/IP protocols (FTP, HTTP), open, access objects across the net; • Java applications are stand-alone programs; • Portable: architecture-netural, byte code interpreter; • Java applets run within Java-enabled browsers; • (more) Strongly typed (than C): compile-time checks, safe • Java servlets run within network servers. -
Finding Errors in Multithreaded GUI Applications
Finding Errors in Multithreaded GUI Applications Sai Zhang Hao Lü Michael D. Ernst Department of Computer Science & Engineering University of Washington, USA {szhang, hlv, mernst}@cs.washington.edu ABSTRACT All GUI objects, including visual components and data models, To keep a Graphical User Interface (GUI) responsive and active, must be accessed exclusively from the event dispatching thread. a GUI application often has a main UI thread (or event dispatching The event dispatching thread, also called the UI thread, is a single thread) and spawns separate threads to handle lengthy operations special thread initialized by the GUI framework, where all event- in the background, such as expensive computation, I/O tasks, and handling code is executed. All code that interacts with GUI objects network requests. Many GUI frameworks require all GUI objects to must also execute on that thread. There are several advantages to be accessed exclusively by the UI thread. If a GUI object is accessed the single-GUI-thread rule: from a non-UI thread, an invalid thread access error occurs and the whole application may abort. • Concurrency errors, such as races and deadlocks, never occur This paper presents a general technique to find such invalid thread on GUI objects. GUI developers need not become experts at access errors in multithreaded GUI applications. We formulate find- concurrent programming. Programming the framework itself is ing invalid thread access errors as a call graph reachability problem also simpler and less error-prone. with thread spawning as the sources and GUI object accessing as • The single-GUI-thread rule incurs less overhead. -
Event Based Programming
Event Based Programming S. Hansen T.V. Fossum UW - Parkside SUNY - Potsdam Kenosha WI, May 23, 2010 2 Contents 1 Event Based Systems 1 1.1 Events . .1 1.1.1 Responding to events . .1 1.1.2 Event sources . .2 1.2 Event based systems . .2 1.2.1 Request-response . .2 1.2.2 Message passing . .2 1.2.3 Publish-subscribe . .3 1.2.4 Events in Systems . .3 1.2.5 System state . .3 1.2.6 Event based systems defined . .4 1.2.7 Discrete systems and events . .4 1.2.8 Examples of events . .5 1.3 Attributes of Event Based Systems . .6 1.3.1 State Based . .7 1.3.2 Nondeterminism . .7 1.3.3 Loose Coupling . .8 1.3.4 Decentralized Control . .8 1.4 The Event Based Programming Paradigm . .8 1.4.1 The Event Model . .8 1.4.2 Events versus Method Invocations . .9 1.4.3 Writing Event Based Programs . 10 1.5 Goals of the Text . 10 2 Event Based Programming Basics 13 2.1 Introduction . 13 2.1.1 Integrated Development Environments . 13 2.2 The Object{Oriented Event Model . 14 2.2.1 A Simple Example . 14 2.3 Java Language Features to Support Event Based Programming . 17 2.3.1 Anonymous Classes . 17 2.3.2 Inner Classes . 19 2.3.3 List Example using Inner Classes . 19 2.4 Inheritance . 23 2.4.1 Model{View{Controller . 23 2.4.2 The Drawing Application . 33 2.5 List of Doubles . 36 2.5.1 Double List Model . -
SSC - Communication and Networking
SSC - Communication and Networking SSC - Concurrency and Multi-threading Concurrency in Swing Shan He School for Computational Science University of Birmingham Module 06-19321: SSC SSC - Communication and Networking Outline Outline of Topics Concurrency in Swing SSC - Communication and Networking Concurrency in Swing Responsive or Unresponsive UI? I Screen liveliness: users expect a program is always responsive, no matter what it's doing I Let's take a look at an example I Swing is a single-threaded programming model I Event-dispatch thread: handles all interaction events. I How the Swing works: I Step 1: Swing generates event objects that contain relevant event information, e.g. event source and event ID. I Step 2: placed event objects to a single event queue ordered by their entry time. I Step 3: event-dispatch thread, regularly checks and takes event objects from the queue one by one and sends them to the interested parties I Step 4: the interested parties react to the event notification SSC - Communication and Networking Concurrency in Swing How the Swing works: Event queue Event n Queue up events Event n-1 Event n-2 … Update UI Event 2 Event 1 Event listener List Selection Listener Event dispatch thread Paint Others Notifies interested parties SSC - Communication and Networking Concurrency in Swing Let's trace the threads I We can tracing the threads executed in a Swing application I Five thread involved: I Main thread by the main() method I \AWT-Windows" (daemon thread): listen to UI events from AWT windows I \AWT-Shutdown": Handling