Refactoring Existing Code

The destructors of the Page and Options structs use delete instead of XtFree() to deallocate all char* members. This is a necessary change since we are migrating away from Xt/Motif. We need to fix existing code that modifies the Page struct members to use new and delete ( instead of XtMalloc(), XtNewString() and XtFree() ).

The PageChange() function in todo.cpp simply saves the contents and cursor position of current page before calling SetPage(). We use new and delete when modifying members of the Page struct.

    PageChange(Widget, XtPointer, XmNotebookCallbackStruct *cs)
    {
      if (modified && pages[currentPage] != NULL) {
        delete [] pages[currentPage] -> page;

When storing the context of the XmText widget, we use qstrdup() to make a copy of the string returned by the XmTextGetString() function.

        char *p = XmTextGetString(textw);
        pages[currentPage] -> page = qstrdup( p );
        XtFree( p );

        pages[currentPage] -> lasttoppos = XmTextGetTopCharacter(textw);
        pages[currentPage] -> lastcursorpos = XmTextGetInsertionPosition(textw);
      }

      SetPage(cs -> page_number - 1);
    }

The ReadDB() function in io.cpp needs similar changes. We replace all use of XtMalloc() and XtNewString() with new and qstrdup(), respectively.

This needs to be done just after opening the file.

      if (input != NULL) {
        max = MAXINIT;
        buffer = new char[max];
        buffer[0] = 0; /* Reset page buffer */
        current = 0;
        pages[0] = new Page();

... when starting a new page ...

    ...

                    pages[number] -> page = buffer;
                    current = 0;
                    max = MAXINIT;
                    buffer = new char[max];
                    buffer[0] = 0; /* Reset page buffer */
                    number++;
                    pages[number] = new Page();

... and when reading in the label and tab texts/

    ...

                    pages[number] -> label = qstrdup( &line[2] );

    ...

                    pages[number] -> majorTab = qstrdup( &line[2] );

    ...

                    pages[number] -> minorTab = qstrdup( &line[2] );

The ReadDB() function uses XtRealloc() to expand the data storage buffer. Unfortunately, C++ does not provide a way to reallocate an existing block of data, so we have to do this ourselves.

                // C++ doesn't have 'renew', so we need to create a new
                // buffer, copy the existing data from old to new and then
                // delete the old

                int newmax = 2 * max;
                char *b = new char[newmax];
                memcpy( b, buffer, max );

                delete [] buffer;
                buffer = b;
                max = newmax;

There is also one occurence in ReadDB() where we call XtMalloc() with an argument of 2. This was done when a file could not be read. Creating an empty string is not necessary, so we remove this code instead of using new.

      if (input == NULL) {
        number = 0;
        pages[0] = new Page();
      } else {
        pages[number] -> page = buffer;
      }

The SaveDB() function in io.cpp also needs these changes. We change one occurence of XtFree() to delete.

      /* Make sure to grab current page */
      if (modified) {
        delete [] pages[currentPage] -> page;

Finally, We need to replace two occurences of XtNewString() in the main() function in todo.cpp.

      if (options.todoFile == NULL) {
        strcpy(temppath, user -> pw_dir);
        strcat(temppath, "/.todo");
        options.todoFile = qstrdup( temppath );
      } else {
        /* Copy the string for consistency */
        options.todoFile = qstrdup( options.todoFile );
      }

Moving Existing Code

    #include <Xm/Xm.h>
    #include <Xm/Notebook.h>
    #include <Xm/Text.h>

    #include "page.h"

    #include <qmessagebox.h>

    #include <unistd.h>

    #include <Xm/Xm.h>
    #include <Xm/Text.h>

    #include "page.h"

    extern "C" {
    #include <Exm/TabB.h>
    }

    #include "mainwindow.h"

    #include <qapplication.h>
    #include <qmotif.h>
    #include <qmotifwidget.h>

    #include <pwd.h>
    #include <unistd.h>
    #include <stdlib.h>

    #include <Xm/Xm.h>
    #include <Xm/Label.h>
    #include <Xm/Notebook.h>
    #include <Xm/Text.h>

    #include "page.h"

    #include "pageeditdialog.h"

    #include <qapplication.h>
    #include <qfiledialog.h>
    #include <qlineedit.h>
    #include <qmessagebox.h>
    #include <qstatusbar.h>

    #include <qmotifwidget.h>
    #include <qmotifdialog.h>

    #include <unistd.h>

    #include <X11/Intrinsic.h>
    #include <X11/StringDefs.h>
    #include <X11/Xatom.h>

    #include <Xm/Xm.h>
    #include <Xm/Text.h>

    #include "page-refactor.h"

    extern "C" {
    #include <Exm/TabB.h>
    #include <Xmd/Print.h>
    } // extern "C"