X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/532372a31c2786eef1c84c0c17c031fa02105d1e..c6b65b76a196e1aa2313f89f6fc609d497c388a0:/docs/latex/wx/tdelwin.tex diff --git a/docs/latex/wx/tdelwin.tex b/docs/latex/wx/tdelwin.tex index f9df4e54f0..ff8b02df27 100644 --- a/docs/latex/wx/tdelwin.tex +++ b/docs/latex/wx/tdelwin.tex @@ -9,22 +9,22 @@ to close windows. \wxheading{What is the sequence of events in a window deletion?} When the user clicks on the system close button or system close command, -in a frame or a dialog, wxWindows calls \helpref{wxWindow::Close}{wxwindowclose}. This -in turn generates an EVT\_CLOSE event: see \helpref{wxWindow::OnCloseWindow}{wxwindowonclosewindow}. +in a frame or a dialog, wxWidgets calls \helpref{wxWindow::Close}{wxwindowclose}. This +in turn generates an EVT\_CLOSE event: see \helpref{wxCloseEvent}{wxcloseevent}. It is the duty of the application to define a suitable event handler, and decide whether or not to destroy the window. If the application is for some reason forcing the application to close -(\helpref{wxCloseEvent::CanVeto}{wxcloseeventcanveto} returns FALSE), the window should always be destroyed, otherwise there is the option to +(\helpref{wxCloseEvent::CanVeto}{wxcloseeventcanveto} returns false), the window should always be destroyed, otherwise there is the option to ignore the request, or maybe wait until the user has answered a question -before deciding whether it's safe to close. The handler for EVT\_CLOSE should +before deciding whether it is safe to close. The handler for EVT\_CLOSE should signal to the calling code if it does not destroy the window, by calling \helpref{wxCloseEvent::Veto}{wxcloseeventveto}. Calling this provides useful information to the calling code. The wxCloseEvent handler should only call \helpref{wxWindow::Destroy}{wxwindowdestroy} to delete the window, and not use the {\bf delete} operator. This is because -for some window classes, wxWindows delays actual deletion of the window until all events have been processed, +for some window classes, wxWidgets delays actual deletion of the window until all events have been processed, since otherwise there is the danger that events will be sent to a non-existent window. As reinforced in the next section, calling Close does not guarantee that the window @@ -35,13 +35,13 @@ certain that the window is destroyed. Your application can either use \helpref{wxWindow::Close}{wxwindowclose} event just as the framework does, or it can call \helpref{wxWindow::Destroy}{wxwindowdestroy} directly. -If using Close(), you can pass a TRUE argument to this function to tell the event handler +If using Close(), you can pass a true argument to this function to tell the event handler that we definitely want to delete the frame and it cannot be vetoed. The advantage of using Close instead of Destroy is that it will call any clean-up code defined by the EVT\_CLOSE handler; for example it may close a document contained in a window after first asking the user whether the work should be saved. Close can be vetoed -by this process (return FALSE), whereas Destroy definitely destroys the window. +by this process (return false), whereas Destroy definitely destroys the window. \wxheading{What is the default behaviour?} @@ -54,9 +54,6 @@ on the stack, so the assumption of dynamic creation cannot be made). The default close event handler for wxFrame destroys the frame using Destroy(). -Under Windows, wxDialog defines a handler for \helpref{wxWindow::OnCharHook}{wxwindowoncharhook} that -generates a Cancel event if the Escape key has been pressed. - \wxheading{What should I do when the user calls up Exit from a menu?} You can simply call \helpref{wxWindow::Close}{wxwindowclose} on the frame. This @@ -70,8 +67,8 @@ the exit command altogether. \wxheading{What should I do to upgrade my 1.xx OnClose to 2.0?} -In wxWindows 1.xx, the {\bf OnClose} function did not actually delete 'this', but signalled -to the calling function (either {\bf Close}, or the wxWindows framework) to delete +In wxWidgets 1.xx, the {\bf OnClose} function did not actually delete 'this', but signaled +to the calling function (either {\bf Close}, or the wxWidgets framework) to delete or not delete the window. To update your code, you should provide an event table entry in your frame or @@ -113,7 +110,7 @@ dialog, using the EVT\_CLOSE macro. The event handler function might look like t \wxheading{How do I exit the application gracefully?} -A wxWindows application automatically exits when the designated top window, or the +A wxWidgets application automatically exits when the designated top window, or the last frame or dialog, is destroyed. Put any application-wide cleanup code in \helpref{wxApp::OnExit}{wxapponexit} (this is a virtual function, not an event handler).