X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/75b31b23fd0930eb7f002bc6da4fa55064ebc789..e18e78a7cc106a75e5228c51edd982436682633d:/docs/doxygen/overviews/windowids.h diff --git a/docs/doxygen/overviews/windowids.h b/docs/doxygen/overviews/windowids.h index ae71d5d173..989f6002ee 100644 --- a/docs/doxygen/overviews/windowids.h +++ b/docs/doxygen/overviews/windowids.h @@ -1,75 +1,88 @@ ///////////////////////////////////////////////////////////////////////////// -// Name: windowids +// Name: windowids.h // Purpose: topic overview // Author: wxWidgets team // RCS-ID: $Id$ // Licence: wxWindows license ///////////////////////////////////////////////////////////////////////////// -/*! - - @page overview_windowids Window IDs overview - - @b See Also - #wxIdManager - wxWindow::NewControlId - wxWindow::UnreserveControlId - #Introduction - @ref windowidstypes_overview - @ref windowidsusing_overview - - - @section windowidsoverviewintro Introduction - - Various contols and other parts of wxWidgets need an ID. Sometimes the - ID may be directly provided by the use or have a predefined value, such as - @c wxID_OPEN. Often, however, the value of the ID is unimportant and is - created automatically by calling wxWindow::NewControlId - or by passing @c wxID_ANY as the ID of an object. - There are two ways to generate an ID. One way, is to start at a negative number, - and for each new ID, return the next smallest number. This is fine for systems - that can used the full range of negative numbers for an ID, as this provides - more than enough IDs and it would take a very very long time to run out and - wrap around. However, some systems can not use the full range of the ID value. - Windows, for example, can only use 16 bit IDs, and only has about 32000 possible - automatic IDs that can be generated by wxWindow::NewControlId. - If the program runs long enough, depending on the program itself, using this first - method would cause the IDs to wrap around into the positive ID range and cause possible - clashes with any directly specified ID values. - The other way is to keep track of the IDs returned by wxWindow::NewControlId - and don't return them again until the ID is completely free and not being used by - any other objects. This will make sure that the ID values do not clash with one - another. This is accomplished by keeping a reference count for each of the IDs - that can possibly be returned by wxWindow::NewControlId. - Other IDs are not reference counted. - - @section windowidsoverviewtypes Data types - - A wxWindowID is just the integer type for a window ID. It should be used almost - everywhere. To help keep track of the count for the automatically generated IDs, - a new type, wxWindowIDRef exists, that can take the place of wxWindowID where needed. - When an ID is first created, it is marked as reserved. When assigning it to a - wxWindowIDRef, the usage count of the ID is increased, or set to 1 if it is currently - reserved. Assigning the same ID to several wxWindowIDRefs will keep track of the count. - As the wxWindowIDRef gets destroyed or its value changes, it will decrease the count - of the used ID. When there are no more wxWindowIDRef types with the created ID, the - ID is considered free and can then be used again by wxWindow::NewControlId. - If a created ID is not assigned to a wxWindowIDRef, then it remains reserved until it - is unreserved manually with wxWindow::UnreserveControlId. - However, if it is assigned to a wxWindowIDRef, then it will be unreserved automatically - and will be considered free when the count is 0, and should NOT be manually unreserved. - wxWindowIDRef can store both automatic IDs from wxWindow::NewControlId - as well as normal IDs. Reference counting is only done for the automatic IDs. Also, - wxWindowIDRef has conversion operators that allow it to be treated just like a wxWindowID. - - @section windowidsoverviewusing Using wxWindowIDRef - - A wxWindowIDRef should be used in place of a wxWindowID where you want to make sure the - ID is not created again by wxWindow::NewControlId - at least until the wxWindowIDRef is destroyed, usually when the associated object is destroyed. - This is done already for windows, menu items, and tool bar items. - It should only be used in the main thread, as it is not thread safe. - - */ +/** +@page overview_windowids Window IDs + +@li @ref overview_windowids_intro +@li @ref overview_windowids_type +@li @ref overview_windowids_using + +@see + +@li wxIdManager +@li wxWindow::NewControlId +@li wxWindow::UnreserveControlId + + +
+ + +@section overview_windowids_intro Introduction + +Various contols and other parts of wxWidgets need an ID. Sometimes the ID may +be directly provided by the use or have a predefined value, such as +@c wxID_OPEN. Often, however, the value of the ID is unimportant and is created +automatically by calling wxWindow::NewControlId or by passing @c wxID_ANY as +the ID of an object. + +There are two ways to generate an ID. One way, is to start at a negative +number, and for each new ID, return the next smallest number. This is fine for +systems that can used the full range of negative numbers for an ID, as this +provides more than enough IDs and it would take a very very long time to run +out and wrap around. However, some systems can not use the full range of the +ID value. Windows, for example, can only use 16 bit IDs, and only has about +32000 possible automatic IDs that can be generated by wxWindow::NewControlId. +If the program runs long enough, depending on the program itself, using this +first method would cause the IDs to wrap around into the positive ID range and +cause possible clashes with any directly specified ID values. + +The other way is to keep track of the IDs returned by wxWindow::NewControlId +and don't return them again until the ID is completely free and not being used +by any other objects. This will make sure that the ID values do not clash with +one another. This is accomplished by keeping a reference count for each of the +IDs that can possibly be returned by wxWindow::NewControlId. Other IDs are not +reference counted. + + +@section overview_windowids_type Data Types + +A wxWindowID is just the integer type for a window ID. It should be used +almost everywhere. To help keep track of the count for the automatically +generated IDs, a new type, wxWindowIDRef exists, that can take the place of +wxWindowID where needed. When an ID is first created, it is marked as reserved. +When assigning it to a wxWindowIDRef, the usage count of the ID is increased, +or set to 1 if it is currently reserved. Assigning the same ID to several +wxWindowIDRefs will keep track of the count. As the wxWindowIDRef gets +destroyed or its value changes, it will decrease the count of the used ID. When +there are no more wxWindowIDRef types with the created ID, the ID is considered +free and can then be used again by wxWindow::NewControlId. + +If a created ID is not assigned to a wxWindowIDRef, then it remains reserved +until it is unreserved manually with wxWindow::UnreserveControlId. However, if +it is assigned to a wxWindowIDRef, then it will be unreserved automatically and +will be considered free when the count is 0, and should NOT be manually +unreserved. + +wxWindowIDRef can store both automatic IDs from wxWindow::NewControlId as well +as normal IDs. Reference counting is only done for the automatic IDs. Also, +wxWindowIDRef has conversion operators that allow it to be treated just like a +wxWindowID. + + +@section overview_windowids_using Using wxWindowIDRef + +A wxWindowIDRef should be used in place of a wxWindowID where you want to make +sure the ID is not created again by wxWindow::NewControlId at least until the +wxWindowIDRef is destroyed, usually when the associated object is destroyed. +This is done already for windows, menu items, and tool bar items. It should +only be used in the main thread, as it is not thread safe. + +*/