There are three types of dragging gestures. ScreenX,screenY - relative to origin of the screen that Origin of the Scene that contains the node, MouseEvent's node, sceneX,sceneY - relative to to the The mouse (pointer's) location is available relative to severalĬoordinate systems: x,y - relative to the origin of the The event is delivered to it through capturing and bubbling phases The Processing variables mouseX and mouseY (note the capital X and Y) store the x-coordinate and y-coordinate of the cursor relative to the origin in the upper-left corner of the display window.When mouse event occurs, the top-most node under cursor is picked and This more than one-hundred-year-old mechanical legacy still affects how we write software today. This layout is called QWERTY because of the order of the top row of letter keys. The position of the keys on an English-language keyboard is inherited from early typewriters. The modern computer keyboard is a direct descendant of the typewriter. It's also possible to ignore the characters printed on the keyboard itself and use the location of each key relative to the keyboard grid as a numeric position. This information could control the speed of an event or the quality of motion. For example, basic information such as the speed and rhythm of the fingers can be determined by the rate at which keys are pressed. When writing your own software, you have the freedom to use the keyboard data any way you wish. The migration of the keyboard from typewriter to computer expanded its function to enable launching software, moving through the menus of software applications, and navigating 3D environments in games. Keyboards are typically used to input characters for composing documents, email, and instant messages, but the keyboard has potential for use beyond its original intent. This data can in turn be used for gesture and pattern recognition. If these coordinates are collected and analyzed, they can be used to extract higher-level information such as the speed and direction of the mouse. These numbers can be used to control attributes of elements on screen. The cursor position is read by computer programs as two numbers, the x-coordinate and the y-coordinate. The physical mouse object is used to control the position of the cursor on screen and to select interface elements. In Engelbart's original patent application in 1970 he referred to the mouse as an “X-Y position indicator,” and this still accurately, but dryly, defines its contemporary use. The design of the mouse has gone through many revisions in the last forty years, but its function has remained the same. The mouse concept was further developed at the Xerox Palo Alto Research Center (PARC), but its introduction with the Apple Macintosh in 1984 was the catalyst for its current ubiquity. The computer mouse dates back to the late 1960s, when Douglas Engelbart presented the device as an element of the oN-Line System (NLS), one of the first computer systems with a video display. We control elements on screen through a variety of devices such as touch pads, trackballs, and joysticks, but the keyboard and mouse remain the most common input devices for desktop computers. The screen forms a bridge between our bodies and the realm of circuits and electricity inside computers. If you see any errors or have comments, please let us know. This tutorial is the Interactivity chapter from Processing: A Programming Handbook for Visual Designers and Artists, Second Edition, published by MIT Press.
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