REFERENCE GUIDE

The window-function name must be exported by including it inan EXPORTS statement in the application's module-definition file.Default windowfunctionTable 1.3Default actions for messagesThe DefWindowProc function is the default message processor forwindow functions that do not or cannot process some of themessages sent to them. For most window functions, theDefWindowProc function carries out most, if not all, processing ofnonclient-area messages. Those are the messages that signifyactions to be carried out on parts of the window other than theclient area. Table 1.3 lists the messages DefWindowProc processesand the default actions for each:MessageWM_ACTIV ATEWM_ CANCELMODEWM_CLOSEWM_CTLCOLORWM_ERASEBKGNDWM_GETTEXTWM_ GETTEXTLENGTHWM_ICONERASEBKGNDWM_NCACTIV ATEWM_NCCALCSIZEWM_NCCREATEWM_NCDESTROYWM_NCHITTESTWM_NCLBUTTONDBLCLKWM_NCLBUTTONDOWNDefault ActionSets or kills the input focus.Terminates internal processing ofstandard scroll bar input, terminatesinternal menu processing, and releasesmouse capture.Calls the DestroyWindow function.Sets the background and text color andreturns a handle to the brush used to fillthe control background.Fills the client area with the color andpattern specified by the class brush, ifany.Copies the window title into a specifiedbuffer.Returns the length (in characters) of thewindow title.Fills the icon client area with thebackground brush of the parent window.Activates or deactivates the window anddraws the icon or title bar to show thenew state.Computes the size of the client area.Initializes standard scroll bars, if any, andsets the default title for the window.Frees any space internally allocated forthe window title.Determines what part of the window themouse is in.Tests the given point to determine thelocation of the mouse and, if necessary,generates additional messages.Determines whether the left mousebutton was pressed while the mouse wasin the nonclient area of a window.Chapter 7, Window manager interface functions 33