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Message Loop In Microsoft Windows
The message loop is an obligatory section of code in every program that uses a graphical user interface under Microsoft Windows. Windows programs that have a GUI are event-driven. Windows maintains an individual message queue for each thread that has created a window. Usually only the first thread creates windows. Windows places messages into that queue whenever mouse activity occurs on that thread's window, whenever keyboard activity occurs while that window has focus, and at other times. A process can also add messages to its own queue. To accept user input, and for other reasons, each thread with a window must continuously retrieve messages from its queue, and act on them. A programmer makes the process do that by writing a loop that calls GetMessage (which blocks for a message and retrieves it), and then calls DispatchMessage (which dispatches the message), and repeats indefinitely. This is the message loop. There usually is a message loop in the main program, which runs o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source Code
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only understands machine code, source code must be Translator (computing), translated before a computer can Execution (computing), execute it. The translation process can be implemented three ways. Source code can be converted into machine code by a compiler or an assembler (computing), assembler. The resulting executable is machine code ready for the computer. Alternatively, source code can be executed without conversion via an interpreter (computing), interpreter. An interpreter loads the source code into memory. It simultaneously translates and executes each statement (computer science), statement. A method that combines compilation and interpretation is to first produce bytecode. Bytecode is an intermediate representation of source code tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Null-terminated String
In computer programming, a null-terminated string is a character string stored as an array containing the characters and terminated with a ''null character'' (a character with an internal value of zero, called "NUL" in this article, not same as the glyph zero). Alternative names are '' C string'', which refers to the C programming language and ASCIIZ (although C can use encodings other than ASCII). The length of a string is found by searching for the (first) NUL. This can be slow as it takes O(''n'') (linear time) with respect to the string length. It also means that a string cannot contain a NUL (there is a NUL in memory, but it is after the last character, not the string). History Null-terminated strings were produced by the .ASCIZ directive of the PDP-11 assembly languages and the ASCIZ directive of the MACRO-10 macro assembly language for the PDP-10. These predate the development of the C programming language, but other forms of strings were often used. At the time C ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Window System
The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at version 11 (hence "X11") since September 1987. The X.Org Foundation leads the X project, with the current reference implementation, X.Org Server, available as free and open-source software under the MIT License and similar permissive licenses. Purpose and abilities X is an architecture-independent system for remote graphical user interfaces and input device capabilities. Each person using a networked computer terminal, terminal has the ability to interact with the display with any type of user input device. In its standard distribution it is a complete, albeit simple, display and interface solution which delivers a standard widget toolkit, toolkit and protocol stack for building graphical user interfaces on most Unix-like operating syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xlib
Xlib (also known as libX11) is an X Window System protocol client library (computer science), library written in the C (programming language), C programming language. It contains subroutine, functions for interacting with an X Server (computing), server. These functions allow programmers to write programs without knowing the details of the X Window System protocols and architecture, X protocol. Few applications use Xlib directly; rather, they employ other libraries that use Xlib functions to provide widget toolkits: * X Toolkit Intrinsics (Xt) * X Athena Widgets, Athena widget set (Xaw) * Motif (software), Motif * FLTK * GTK * Qt (software), Qt (X11 version) * Tk (software), Tk * Simple DirectMedia Layer, SDL (Simple DirectMedia Layer) * Simple and Fast Multimedia Library, SFML (Simple and Fast Multimedia Library) Xlib, which was first publicly released in September 1985, is used in GUIs for many Unix-like operating systems. A re-implementation of Xlib was introduced in 2007 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qt (software)
Qt ( pronounced "cute") is a cross-platform application development framework for creating graphical user interfaces as well as Cross-platform software, cross-platform applications that run on various software and hardware platforms such as Linux, Windows, macOS, Android (operating system), Android or embedded systems with little or no change in the underlying codebase while still being a native application with native capabilities and speed. Qt is currently being developed by The Qt Company, a publicly listed company, and the Qt Project under open-source governance, involving individual developers and organizations working to advance Qt. Qt is available under both commercial licenses and open-source GNU General Public License, GPL 2.0, GPL 3.0, and GNU Lesser General Public License, LGPL 3.0 licenses. Purposes and abilities Qt is used for developing graphical user interfaces (GUIs) and multi-platform application software, applications that run on all major Desktop computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delphi (programming Language)
Delphi is a general-purpose programming language and a software product that uses the Delphi dialect of the Object Pascal programming language and provides an integrated development environment (IDE) for rapid application development of desktop, mobile application, mobile, web application, web, and console application, console software, currently developed and maintained by Embarcadero Technologies. Delphi's compilers generate native code for Microsoft Windows, macOS, iOS, Android (operating system), Android and Linux (X86-64, x64). Delphi includes a code editor, a visual designer, an integrated debugger, a Version control, source code control component, and support for third-party Plugin (computing), plugins. The code editor features Code Insight (code completion), Error Insight (real-time error-checking), and Code refactoring, refactoring. The visual forms designer has the option of using either the Visual Component Library (VCL) for pure Windows development or the FireMonkey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft Foundation Class Library
Microsoft Foundation Class Library (MFC) is a C++ object-oriented library for developing desktop applications for Windows. MFC was introduced by Microsoft in 1992 and quickly gained widespread use. While Microsoft has introduced alternative application frameworks since then, MFC remains widely used. History MFC was introduced in 1992 with Microsoft's ''C/C++ 7.0'' compiler for use with 16-bit versions of Windows as an extremely thin object-oriented C++ wrapper for the Windows API. C++ was just beginning to replace C for development of commercial application software at the time. In an MFC program, direct Windows API calls are rarely needed. Instead, programs create objects from Microsoft Foundation Class classes and call member functions belonging to those objects. Many of those functions share their names with corresponding API functions. One quirk of MFC is the use of "Afx" as the prefix for many functions, macros and the standard precompiled header name "stdafx.h". Du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows Presentation Foundation
Windows Presentation Foundation (WPF) is a free and open-source user interface framework for Windows-based desktop applications. WPF applications are based in .NET, and are primarily developed using C# and XAML. Originally developed by Microsoft, WPF was initially released as part of .NET Framework 3.0 in 2006. In 2018, Microsoft released WPF as open source under the MIT License. WPF's design and its layout language XAML have been adopted by multiple other UI frameworks, such as UWP, .NET MAUI, and Avalonia. Overview WPF employs XAML, an XML-based language, to define and link various interface elements, and uses C# to define program behavior. WPF applications are deployed as standalone desktop programs. WPF supports a number of common user interface elements, such as 2D/3D rendering, fixed and adaptive documents, typography, vector graphics, runtime animation, and pre-rendered media. These elements can then be linked and manipulated based on various events, user interact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows Forms
Windows Forms, also known as WinForms, is a free, open-source graphical user interface (GUI) class library for building Windows desktop applications, included as a part of Microsoft .NET, .NET Framework or Mono, providing a platform to write client applications for desktop, laptop, and tablet PCs. While it is seen as a replacement for the earlier and more complex C++ based Microsoft Foundation Class Library, it does not offer a comparable paradigm and only acts as a platform for the user interface tier in a multi-tier solution. At the Microsoft Connect event on December 4, 2018, Microsoft announced releasing Windows Forms as an open source project on GitHub. It is released under the MIT License. With this release, Windows Forms has become available for projects targeting the .NET Core framework. However, the framework is still available only on the Windows platform, and Mono's incomplete implementation of Windows Forms remains the only cross-platform implementation. Arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application Framework
In computer programming, an application framework consists of a software framework used by software developers to implement the standard structure of application software. Application frameworks became popular with the rise of graphical user interfaces (GUIs), since these tended to promote a standard structure for applications. Programmers find it much simpler to create automatic GUI creation tools when using a standard framework, since this defines the underlying code structure of the application in advance. Developers usually use object-oriented programming (OOP) techniques to implement frameworks such that the unique parts of an application can simply inherit from classes extant in the framework. Examples Apple Inc., Apple Computer developed one of the first commercial application frameworks, MacApp (first release 1985), for the Mac (computer), Macintosh. Originally written in an extended (object-oriented) version of Pascal (programming language), Pascal termed Object Pascal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callback (computer Programming)
In computer programming, a callback is a function that is stored as data (a reference) and designed to be called by another function often ''back'' to the original abstraction layer. A function that accepts a callback parameter may be designed to call back before returning to its caller which is known as '' synchronous'' or ''blocking''. The function that accepts a callback may be designed to store the callback so that it can be called back after returning which is known as ''asynchronous'', '' non-blocking'' or ''deferred''. Programming languages support callbacks in different ways such as function pointers, lambda expressions and blocks. A callback can be likened to leaving instructions with a tailor for what to do when a suit is ready, such as calling a specific phone number or delivering it to a given address. These instructions represent a callback: a function provided in advance to be executed later, often by a different part of the system and not necessarily by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Event Loop
In computer science, the event loop (also known as message dispatcher, message loop, message pump, or run loop) is a programming construct or design pattern that waits for and dispatches events or messages in a program. The event loop works by making a request to some internal or external "event provider" (that generally blocks the request until an event has arrived), then calls the relevant event handler ("dispatches the event"). It is also commonly implemented in servers such as web servers. The event loop may be used in conjunction with a reactor, if the event provider follows the file interface, which can be selected or 'polled' (the Unix system call, not actual polling). The event loop almost always operates asynchronously with the message originator. When the event loop forms the central control flow construct of a program, as it often does, it may be termed the main loop or main event loop. This title is appropriate, because such an event loop is at the highest leve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
