Tk_Grab, Tk_Ungrab − manipulate grab state in an application
Tk_Grab(interp, tkwin, grabGlobal)
Tcl_Interp *interp (in)
Interpreter to use for error reporting
Tk_Window tkwin (in)
Window on whose behalf the pointer is to be grabbed or released
int grabGlobal (in)
Boolean indicating whether the grab is global or application local
These functions are used to set or release a global or application local grab. When a grab is set on a particular window in a Tk application, mouse and keyboard events can only be received by that window and its descendants. Mouse and keyboard events for windows outside the tree rooted at tkwin will be redirected to tkwin. If the grab is global, then all mouse and keyboard events for windows outside the tree rooted at tkwin (even those intended for windows in other applications) will be redirected to tkwin. If the grab is application local, only mouse and keyboard events intended for a windows within the same application (but outside the tree rooted at tkwin) will be redirected.
Tk_Grab sets a grab on a particular window. Tkwin specifies the window on whose behalf the pointer is to be grabbed. GrabGlobal indicates whether the grab should be global or application local; if it is non-zero, it means the grab should be global. Normally, Tk_Grab returns TCL_OK; if an error occurs and the grab cannot be set, TCL_ERROR is returned and an error message is left if interp’s result. Once this call completes successfully, no window outside the tree rooted at tkwin will receive pointer- or keyboard-related events until the next call to Tk_Ungrab. If a previous grab was in effect within the application, then it is replaced with a new one.
Tcl_Ungrab releases a grab on the mouse pointer and keyboard, if there is one set on the window given by tkwin. Once a grab is released, pointer and keyboard events will start being delivered to other windows again.
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.