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Undo
Undo is an interaction technique which is implemented in many computer programs. It erases the last change done to the document, reverting it to an older state. In some more advanced programs, such as graphic processing, undo will negate the last command done to the file being edited. With the possibility of undo, users can explore and work without fear of making mistakes, because they can easily be undone. The expectations for undo are easy to understand: to have a predictable functionality, and to include all "undoable" commands. Usually undo is available until the user undoes all executed operations. But there are some actions which are not stored in the undo list, and thus they cannot be undone. For example, ''save file'' is not undoable, but is queued in the list to show that it was executed. Another action which is usually not stored, and thus not undoable, is ''scrolling'' or ''selection''. The opposite of undo is ''redo''. The redo command reverses the undo or advances t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Key
In computing, a Control key is a modifier key which, when pressed in conjunction with another key, performs a special operation (for example, ); similar to the Shift key, the Control key rarely performs any function when pressed by itself. The Control key is located on or near the bottom left side of most keyboards (in accordance with the international standard ISO/IEC 9995-2), with many featuring an additional one at the bottom right. On keyboards that use English abbreviations for key labeling, it is usually labeled (rarely, or is seen). Abbreviations in the language of the keyboard layout also are in use, e.g., the German keyboard layout uses as required by the German standard DIN 2137:2012-06. Also, there is a standardized keyboard symbol (to be used when Latin lettering is not preferred), given in ISO/IEC 9995-7 as symbol 26, and in ISO 7000 "Graphical symbols for use on equipment" as symbol ISO-7000-2028. This symbol is encoded in Unicode as U+2388 (⎈). His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warren Teitelman
Warren Teitelman (1941 – August 12, 2013) was an American computer scientist known for his work on programming environments and the invention and first implementation of concepts including Undo / Redo, spelling correction, advising, online help, and DWIM ''(Do What I Mean)''. Early career and ARPANET Warren Teitelman presented a novel scheme for real time character recognition in his master's thesis submitted in 1966 at MIT. A rectangle, in which a character is to be drawn, is divided into two parts, one shaded and the other unshaded. Using this division a computer converts characters into ternary vectors (a list composed of 3 values: 0, 1, or −) in the following way. If a pen enters the shaded region, a 1 is added to the vector. When the unshaded region is entered, a 0 is appended. The thesis continued to be cited for several decades after its submission. He started as ARPA Principal Investigator from 1968 to 1978, and was responsible for the design and development of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control-Y
Control-Y is a common computer command. It is generated by holding and pressing the key on most Computer Keyboards. In most Windows applications this keyboard shortcut functions as Redo, reversing a previous Undo. In some programs such as Microsoft Office it repeats the previous action if it was something other than Undo. Apple Macintosh systems use for Redo. In general a shortcut on Macintosh using matches up with a shortcut on Windows using , this is one of the most noticeable conflicts. Many programs (on all systems including Linux) support ''both'' and for Redo to resolve this conflict. But quite a few remain where only one or the other shortcut works. Other uses The OpenVMS operating system command-line uses as its "abort" character, stronger in effect than the ordinary "interrupt" character. deleted the current line in the ''WordStar'' word processor for CP/M and MS-DOS. In the 1980s, many text editors and word processors mimicked the ''WordStar'' command set, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown University
Brown University is a private research university in Providence, Rhode Island. Brown is the seventh-oldest institution of higher education in the United States, founded in 1764 as the College in the English Colony of Rhode Island and Providence Plantations. Brown is one of nine colonial colleges chartered before the American Revolution. Admissions at Brown is among the most selective in the United States. In 2022, the university reported a first year acceptance rate of 5%. It is a member of the Ivy League. Brown was the first college in the United States to codify in its charter that admission and instruction of students was to be equal regardless of their religious affiliation. The university is home to the oldest applied mathematics program in the United States, the oldest engineering program in the Ivy League, and the third-oldest medical program in New England. The university was one of the early doctoral-granting U.S. institutions in the late 19th century, adding masters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memento Pattern
The memento pattern is a software design pattern that exposes the private internal state of an object. One example of how this can be used is to restore an object to its previous state (undo via rollback), another is versioning, another is custom serialization. The memento pattern is implemented with three objects: the ''originator'', a ''caretaker'' and a ''memento''. The originator is some object that has an internal state. The caretaker is going to do something to the originator, but wants to be able to undo the change. The caretaker first asks the originator for a memento object. Then it does whatever operation (or sequence of operations) it was going to do. To roll back to the state before the operations, it returns the memento object to the originator. The memento object itself is an opaque object (one which the caretaker cannot, or should not, change). When using this pattern, care should be taken if the originator may change other objects or resources—the memento pattern o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command Key
The Command key (sometimes abbreviated as Cmd key), , formerly also known as the Apple key or open Apple key, is a modifier key present on Apple keyboards. The Command key's purpose is to allow the user to enter keyboard commands in applications and in the system. An "extended" Macintosh keyboard—the most common type—has two command keys, one on each side of the space bar; some compact keyboards have one only on the left. The symbol (the "looped square") was chosen by Susan Kare after Steve Jobs decided that the use of the Apple logo in the menu system (where the keyboard shortcuts are displayed) would be an over-use of the logo. Apple's adaptation of the symbol—encoded in Unicode at U+2318—was derived in part from its use in Nordic countries as an indicator of cultural locations and places of interest. The symbol is known by various other names, including "Saint John's Arms" and "Bowen knot". History Apple's computers up through the 1979 Apple II Plus did not h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adobe Photoshop
Adobe Photoshop is a raster graphics editor developed and published by Adobe Inc. for Microsoft Windows, Windows and macOS. It was originally created in 1988 by Thomas Knoll, Thomas and John Knoll. Since then, the software has become the industry standard not only in raster graphics editing, but in digital art as a whole. The software's name is often colloquially used as a verb (e.g. "to photoshop an image", "photoshopping", and "photoshop contest") although Adobe discourages such use. Photoshop can edit and compose raster images in multiple layers and supports Mask (computing), masks, alpha compositing and several color models including RGB color model, RGB, CMYK color model, CMYK, CIELAB, spot color, and duotone. Photoshop uses its own PSD and PSB file formats to support these features. In addition to raster graphics, Photoshop has limited abilities to edit or render text and vector graphics (especially through clipping path for the latter), as well as 3D graphics and video. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command Pattern
In object-oriented programming, the command pattern is a behavioral design pattern in which an object is used to encapsulate all information needed to perform an action or trigger an event at a later time. This information includes the method name, the object that owns the method and values for the method parameters. Four terms always associated with the command pattern are ''command'', ''receiver'', ''invoker'' and ''client''. A ''command'' object knows about ''receiver'' and invokes a method of the receiver. Values for parameters of the receiver method are stored in the command. The receiver object to execute these methods is also stored in the command object by aggregation. The ''receiver'' then does the work when the execute() method in ''command'' is called. An ''invoker'' object knows how to execute a command, and optionally does bookkeeping about the command execution. The invoker does not know anything about a concrete command, it knows only about the command ''interface' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control-Z
In computer data, a substitute character (␚) is a control character that is used to pad transmitted data in order to send it in blocks of fixed size, or to stand in place of a character that is recognized to be invalid, erroneous or unrepresentable on a given device. It is also used as an escape sequence in some programming languages. In the ASCII character set, this character is encoded by the number 26 ( hex). Standard keyboards transmit this code when the and keys are pressed simultaneously (, often documented by convention as '')''. Unicode inherits this character from ASCII, but recommends that the replacement character (�, U+FFFD) be used instead to represent un-decodable inputs, when the output encoding is compatible with it. Uses End of file Historically, under PDP-6 monitor, RT-11, VMS, and TOPS-10, and in early PC CP/M 1 and 2 operating systems (and derivatives like MP/M) it was necessary to explicitly mark the end of a file (EOF) because the native filesys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keyboard Shortcut
computing, a keyboard shortcut also known as hotkey is a series of one or several keys to quickly invoke a software program or perform a preprogrammed action. This action may be part of the standard functionality of the operating system or application program, or it may have been written by the user in a scripting language. Some integrated keyboards also include pointing devices; the definition of exactly what counts as a "key" sometimes differs. The meaning of term "keyboard shortcut" can vary depending on software manufacturer. In Windows, hotkeys consists of a specific key combination used to trigger an action (these are usually system-wide shortcuts that are available in all contexts so long as receiving program is active); mnemonics represent a designated letter in a menu command or toolbar button that when pressed together with the Alt key, activates such command. The term is generally associated with computer keyboards, but many electronic musical instruments now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft Paint
Microsoft Paint is a simple raster graphics editor that has been included with all versions of Microsoft Windows. The program opens and saves files in Windows bitmap (BMP), JPEG, GIF, PNG, and single-page TIFF formats. The program can be in color mode or two-color black-and-white, but there is no grayscale mode. For its simplicity and wide availability, it rapidly became one of the most used Windows applications, introducing many to painting on a computer for the first time. It is still widely used for simple image manipulation tasks. In July 2017, Microsoft added Paint to the list of deprecated features of Windows 10 and announced that it would become a free standalone application in Microsoft Store. Microsoft had envisioned Paint 3D as a replacement. However, Paint continued to be included with Windows 10. Microsoft eventually reversed course and announced an updated version of Paint in Windows 11. Instead, Microsoft deprecated Paint 3D. History The first version of Pain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Lisa
Lisa is a desktop computer developed by Apple, released on January 19, 1983. It is one of the first personal computers to present a graphical user interface (GUI) in a machine aimed at individual business users. Its development began in 1978. It underwent many changes before shipping at with a five-megabyte hard drive. It was affected by its high price, insufficient software, unreliable Apple FileWare floppy disks, and the immediate release of the cheaper and faster Macintosh. Only 10,000 were sold in two years. Considered a commercial failure (albeit one with technical acclaim), Lisa introduced a number of advanced features that reappeared on the Macintosh and eventually IBM PC compatibles. Among them is an operating system with protected memory and a document-oriented workflow. The hardware was more advanced overall than the forthcoming Macintosh 128K; the Lisa included hard disk drive support, capacity for up to 2 megabytes (MB) of random-access memory (RAM), expansion slo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
