HP 3000 Manuals HP 3000 Manuals
overlay, overwrite
The overlay and overwrite routines are used to overlap or overwrite
windows.
Syntax
#include <curses.h>
int overlay(WINDOW *srcwin, WINDOW *dstwin);
int overwrite(WINDOW *srcwin, WINDOW *dstwin);
Parameters
srcwin A pointer to the source window to be copied.
dstwin A pointer to the destination window to be overlayed
or overwritten.
Return Values
OK Successful completion.
ERR An error occurred.
Description
The overwrite() and overlay() routines copy srcwin to destwin. The
source window (srcwin) and destination window (dstwin) do not have to be
the same size.
The overwrite() routine copies all characters to dstwin; thus, destroying
all previous contents of the window. The overlay() routine copies only
nonblank characters, leaving blank characters intact. Thus, if the
background character of the original window was set to something other
than a blank, this original background could be preserved.
The example shown on the following pages illustrates how to use
overwrite() to implement a pop-up dialog box.
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| |
| |
| #include <curses.h> |
| |
| /* |
| * Pop-up a window on top of curscr. If row and/or col |
| * are -1 then that dimension will be centered within |
| * curscr. Return 0 for success or -1 if malloc() failed. |
| * Pass back the working window and the saved window for the |
| * pop-up. The saved window should not be modified. |
| */ |
| int |
| popup(work, save, nrows, ncols, row, col) |
| WINDOW **work, **save; |
| int nrows, ncols, row, col; |
| { |
| int mr, mc; |
| getmaxyx(curscr, mr, mc); |
| /* Windows are limited to the size of curscr. */ |
| if (mr < nrows) |
| nrows = mr; |
| if (mc < ncols) |
| ncols = mc; |
| /* Center dimensions. */ |
| if (row == -1) |
| row = (mr-nrows)/2; |
| if (col == -1) |
| col = (mc-ncols)/2; |
| /* The window must fit entirely in curscr. */ |
| if (mr < row+nrows) |
| row = 0; |
| if (mc < col+ncols) |
| col = 0; |
| *work = newwin(nrows, ncols, row, col); |
| if (*work == NULL) |
| return (-1); |
| if ((*save = dupwin(*work)) == NULL) { |
| delwin(*work); |
| return (-1); |
| |
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| |
| |
| } |
| overwrite(curscr, *save); |
| return (0); |
| } |
| |
| /* |
| * Restore the region covered by a popup window. |
| * Delete the working window and the saved window. |
| |
| |
| * This function is the complement to popup(). Return |
| * 0 for success or -1 for an error. |
| */ |
| int |
| popdown(work, save) |
| WINDOW *work, *save; |
| { |
| (void) overwrite(save, curscr); |
| (void) delwin(save); |
| (void) delwin(work); |
| return (0); |
| } |
| |
| /* |
| * Compute the size of a dialog box that would fit around |
| * the string. |
| */ |
| void |
| dialsize(str, nrows, ncols) |
| char *str; |
| int *nrows, *ncols; |
| |
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______________________________________________________________________
| |
| |
| { |
| int rows, cols, col; |
| for (rows = 1, cols = col = 0; *str != ' '; ++str) { |
| if (*str == '0) { |
| if (cols < col) |
| cols = col; |
| col = 0; |
| ++rows; |
| } else { |
| ++col; |
| } |
| } |
| if (cols < col) |
| cols = col; |
| *nrows = rows; |
| *ncols = cols; |
| } |
| |
| /* |
| * Write a string into a dialog box. |
| */ |
| void |
| dialfill(w, s) |
| WINDOW *w; |
| char *s; |
| { |
| int row; |
| (void) wmove(w, 1, 1); |
| for (row = 1; *s != ' '; ++s) { |
| (void) waddch(w, *((unsigned char*) s)); |
| if (*s == '0) |
| wmove(w, ++row, 1); |
| } |
| box(w, 0, 0); |
| |
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| |
| |
| } |
| |
| void |
| dialog(str) |
| char *str; |
| { |
| WINDOW *work, *save; |
| int nrows, ncols, row, col; |
| |
| /* Figure out size of window. */ |
| dialsize(str, &nrows, &ncols); |
| |
| /* Create a centered working window with extra */ |
| /* room for a border. */ |
| (void) popup(&work, &save, nrows+2, ncols+2, -1, -1); |
| |
| /* Write text into the working window. */ |
| dialfill(work, str); |
| |
| /* Pause. Remember that wgetch() will do a wrefresh() */ |
| /* for us. */ |
| (void) wgetch(work); |
| |
| /* Restore curscr and free windows. */ |
| (void) popdown(work, save); |
| |
| /* Redraw curscr to remove window from physical screen. */ |
| (void) doupdate(); |
| } |
| |
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Implementation Considerations
Identical to XPG/3
See Also
copywin()
Portability
HP-UX, UNIX System V, XPG/3