+MODULE_ID("$Id: resizeterm.c,v 1.14 2002/07/13 21:32:57 tom Exp $")
+
+#define stolen_lines (screen_lines - SP->_lines_avail)
+
+NCURSES_EXPORT(bool)
+is_term_resized(int ToLines, int ToCols)
+{
+ return (ToLines != screen_lines
+ || ToCols != screen_columns);
+}
+
+/*
+ * Return the number of levels of child-windows under the current window.
+ */
+static int
+child_depth(WINDOW *cmp)
+{
+ int depth = 0;
+
+ if (cmp != 0) {
+ WINDOWLIST *wp;
+
+ for (wp = _nc_windows; wp != 0; wp = wp->next) {
+ WINDOW *tst = &(wp->win);
+ if (tst->_parent == cmp) {
+ depth = 1 + child_depth(tst);
+ break;
+ }
+ }
+ }
+ return depth;
+}
+
+/*
+ * Return the number of levels of parent-windows above the current window.
+ */
+static int
+parent_depth(WINDOW *cmp)
+{
+ int depth = 0;
+
+ if (cmp != 0) {
+ WINDOW *tst;
+ while ((tst = cmp->_parent) != 0) {
+ ++depth;
+ cmp = tst;
+ }
+ }
+ return depth;
+}
+
+/*
+ * FIXME: must adjust position so it's within the parent!
+ */
+static int
+adjust_window(WINDOW *win, int ToLines, int ToCols, int stolen)
+{
+ int result;
+ int bottom = screen_lines + SP->_topstolen - stolen;
+ int myLines = win->_maxy + 1;
+ int myCols = win->_maxx + 1;
+
+ T((T_CALLED("adjust_window(%p,%d,%d) currently %dx%d at %d,%d"),
+ win, ToLines, ToCols,
+ getmaxy(win), getmaxx(win),
+ getbegy(win), getbegx(win)));
+
+ if (win->_begy >= bottom) {
+ win->_begy += (ToLines - screen_lines);
+ } else {
+ if (myLines == screen_lines - stolen
+ && ToLines != screen_lines)
+ myLines = ToLines - stolen;
+ else if (myLines == screen_lines
+ && ToLines != screen_lines)
+ myLines = ToLines;
+ }
+
+ if (myLines > ToLines)
+ myLines = ToLines;
+
+ if (myCols > ToCols)
+ myCols = ToCols;
+
+ if (myLines == screen_lines
+ && ToLines != screen_lines)
+ myCols = ToLines;
+
+ if (myCols == screen_columns
+ && ToCols != screen_columns)
+ myCols = ToCols;
+
+ result = wresize(win, myLines, myCols);
+ returnCode(result);
+}
+
+/*
+ * If we're decreasing size, recursively search for windows that have no
+ * children, decrease those to fit, then decrease the containing window, etc.
+ */
+static int
+decrease_size(int ToLines, int ToCols, int stolen)
+{
+ bool found;
+ int depth = 0;
+ WINDOWLIST *wp;
+
+ T((T_CALLED("decrease_size(%d, %d)"), ToLines, ToCols));
+
+ do {
+ found = FALSE;
+ TR(TRACE_UPDATE, ("decreasing size of windows to %dx%d, depth=%d",
+ ToLines, ToCols, depth));
+ for (wp = _nc_windows; wp != 0; wp = wp->next) {
+ WINDOW *win = &(wp->win);
+
+ if (!(win->_flags & _ISPAD)) {
+ if (child_depth(win) == depth) {
+ if (adjust_window(win, ToLines, ToCols, stolen) != OK)
+ returnCode(ERR);
+ }
+ }
+ }
+ ++depth;
+ } while (found);
+ returnCode(OK);
+}
+
+/*
+ * If we're increasing size, recursively search for windows that have no
+ * parent, increase those to fit, then increase the contained window, etc.
+ */
+static int
+increase_size(int ToLines, int ToCols, int stolen)
+{
+ bool found;
+ int depth = 0;
+ WINDOWLIST *wp;
+
+ T((T_CALLED("increase_size(%d, %d)"), ToLines, ToCols));
+
+ do {
+ found = FALSE;
+ TR(TRACE_UPDATE, ("increasing size of windows to %dx%d, depth=%d",
+ ToLines, ToCols, depth));
+ for (wp = _nc_windows; wp != 0; wp = wp->next) {
+ WINDOW *win = &(wp->win);
+
+ if (!(win->_flags & _ISPAD)) {
+ if (parent_depth(win) == depth) {
+ if (adjust_window(win, ToLines, ToCols, stolen) != OK)
+ returnCode(ERR);
+ }
+ }
+ }
+ ++depth;
+ } while (found);
+ returnCode(OK);
+}
+
+/*
+ * This function reallocates NCURSES window structures, with no side-effects
+ * such as ungetch().
+ */
+NCURSES_EXPORT(int)
+resize_term(int ToLines, int ToCols)
+{
+ int result = OK;
+ int was_stolen = (screen_lines - SP->_lines_avail);
+
+ T((T_CALLED("resize_term(%d,%d) old(%d,%d)"),
+ ToLines, ToCols,
+ screen_lines, screen_columns));
+
+ if (is_term_resized(ToLines, ToCols)) {
+ int myLines = screen_lines;
+ int myCols = screen_columns;
+
+ if (ToLines > screen_lines) {
+ increase_size(myLines = ToLines, myCols, was_stolen);
+ }
+
+ if (ToCols > screen_columns) {
+ increase_size(myLines, myCols = ToCols, was_stolen);
+ }
+
+ if (ToLines < myLines ||
+ ToCols < myCols) {
+ decrease_size(ToLines, ToCols, was_stolen);
+ }
+
+ screen_lines = lines = ToLines;
+ screen_columns = columns = ToCols;
+
+ SP->_lines_avail = lines - was_stolen;
+
+ if (SP->oldhash) {
+ FreeAndNull(SP->oldhash);
+ }
+ if (SP->newhash) {
+ FreeAndNull(SP->newhash);
+ }
+ }
+
+ /*
+ * Always update LINES, to allow for call from lib_doupdate.c which
+ * needs to have the count adjusted by the stolen (ripped off) lines.
+ */
+ LINES = ToLines - was_stolen;
+ COLS = ToCols;
+
+ returnCode(result);
+}