| 1 | Window handle | Input | Binary(4) |
| 2 | Save screen | Input | Char(1) |
| 3 | Error code | I/O | Char(*) |
| Return code | Output | Binary(4) |
The Start a Window (QsnStrWin) API starts a window created with the Create a Window (QsnCrtWin) API. This causes the window to be displayed on the screen and added to the active window list. If specified, the Draw Window exit routine is called immediately before the window is drawn.
None
A handle for the window to be started.
Indicates if the underlying display image should be saved prior to drawing the window. This option should be used only if the window will not be moved or resized over an existing display image. Performance can be improved by not saving the display image. However, doing this limits the overlapping nature of the window. If an attempt is made to move or resize a window for which the display image was not saved, the screen is cleared and all windows are redrawn prior to moving the window.
The possible values for this parameter are:
| 0 | Do not save the underlying display image when the window is started. |
| 1 | Save the underlying display image when the window is started. This is the default. |
The structure in which to return error information. For the format of the structure, see Error code parameter. If this parameter is omitted, diagnostic and escape messages are issued to the application.
A return code indicating the result of the operation. The value returned will be 0 if the operation was successful, or -1 otherwise.
| Message ID | Error Message Text |
|---|---|
| CPF24B4 E | Severe error while addressing parameter list. |
| CPF3CF1 E | Error code parameter not valid. |
| CPF3CF2 E | Error(s) occurred during running of &1 API. |
| CPFA318 E | Error calling exit routine. |
| CPFA31E E | Required parameter &1 omitted. |
| CPFA343 E | Output operation not done. |
| CPFA344 E | The file &2 in library &3 is not valid. |
| CPFA345 E | The invite active flag is not valid. |
| CPFA3AA E | Window handle incorrect. |
| CPFA3AB E | The value for &1 must be '0' or '1'. |
You can improve the performance of window operations by doing the following:
The sample program in Creating and Manipulating Windows shows how to create and manipulate several windows with exit routines. The program creates three windows- Window 1, Window 2, and Window 3. Each time Enter is pressed, the next window is made current; in which case, the Draw Window exit routine for that window is called. If the user presses F4=Move or F5=Resize, the current window is moved or resized and the Draw Window exit routine is called again. The resulting screen output is shown in Display Screen.
Note: By using the code examples, you agree to the terms of the Code license and disclaimer information.
Creating and Manipulating Windows
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "qsnapi.h"
void GenericDraw(const Qsn_Cmd_Buf_T *cbuf, const Qsn_Win_T *win)
{
char *msg1 = "F3: quit F4: move F5: resize";
char *msg2 = "text no attribute";
QsnWrtDta(msg2, strlen(msg2), 0, 2, 1, QSN_NO_SA, QSN_NO_SA,
QSN_NO_SA, QSN_NO_SA, *cbuf, *win, NULL);
QsnWrtDta(msg1, strlen(msg1), 0, -1, 1, QSN_SA_HI, QSN_SA_NORM,
QSN_SA_RED, QSN_SA_NORM, *cbuf, *win, NULL);
}
void Draw1(const Qsn_Win_T *win, const Qsn_Cmd_Buf_T *cbuf)
{
char *txt = "window 1 (ul/blue)";
GenericDraw(cbuf, win);
QsnWrtDta(txt, strlen(txt), 0, 5, 5, QSN_SA_UL, QSN_SA_NORM,
QSN_SA_BLU, QSN_SA_NORM, *cbuf, *win, NULL);
}
void Draw2(const Qsn_Win_T *win, const Qsn_Cmd_Buf_T *cbuf)
{
char *txt = "window 2 (ul/red)";
GenericDraw(cbuf, win);
QsnWrtDta(txt, strlen(txt), 0, 5, 5, QSN_SA_UL, QSN_SA_NORM,
QSN_SA_RED, QSN_SA_NORM, *cbuf, *win, NULL);
}
void Draw3(const Qsn_Win_T *win, const Qsn_Cmd_Buf_T *cbuf)
{
char *txt = "window 3 (ul/pink)";
GenericDraw(cbuf, win);
QsnWrtDta(txt, strlen(txt), 0, 5, 5, QSN_SA_UL, QSN_SA_NORM,
QSN_SA_PNK, QSN_SA_NORM, *cbuf, *win, NULL);
}
int main (void) {
int i;
char text[100];
Qsn_Win_T win1, win2, win3, cur;
Qsn_Win_Desc_T win_desc;
Qsn_Win_Ext_Inf_T ext = { NULL, NULL, NULL, NULL, NULL, NULL };
Q_Bin4 win_desc_length = sizeof(win_desc);
char aid;
QsnInzWinD(&win_desc, win_desc_length, NULL);
win_desc.GUI_support = '0';
/* define and start window 1 */
win_desc.top_row = 3;
win_desc.left_col = 5;
win_desc.num_rows = 13;
win_desc.num_cols = 40;
ext.draw_fp = Draw1;
win1 = QsnCrtWin(&win_desc, win_desc_length, &ext, sizeof(ext),
'1', NULL, 0, NULL, NULL);
QsnGetAID(NULL, 0, NULL);
/* define and start window 2 */
win_desc.top_row = 10;
win_desc.left_col = 10;
win_desc.num_rows = 10;
win_desc.num_cols = 30;
ext.draw_fp = Draw2;
win2 = QsnCrtWin(&win_desc, win_desc_length, &ext, sizeof(ext),
'1', NULL, 0, NULL, NULL);
QsnGetAID(NULL, 0, NULL);
/* define and start window 3 */
win_desc.top_row = 5;
win_desc.left_col = 20;
win_desc.num_rows = 15;
win_desc.num_cols = 50;
ext.draw_fp = Draw3;
win3 = QsnCrtWin(&win_desc, win_desc_length, &ext, sizeof(ext),
'1', NULL, 0, NULL, NULL);
cur = win3;
for ( ;; ) {
if (( (aid=QsnGetAID(NULL, 0, NULL)) == QSN_F3))
break;
else if (aid == QSN_F4)
QsnMovWinUsr(cur, NULL);
else if (aid == QSN_F5)
QsnRszWinUsr(cur, NULL);
else {
/* switch current window to next window */
if (cur == win1) {
QsnSetCurWin(win2, NULL);
cur = win2;
} else if (cur == win2) {
QsnSetCurWin(win3, NULL);
cur = win3;
} else {
QsnSetCurWin(win1, NULL);
cur = win1;
}
}
}
}
+--------------------------------------------------------------------------------+
Command Entry RCHASD0I
Request level: 1
Pr ............................................
: :
: text no attr ......................................................
: : :
: : text no attribute :
: window 1 : :
: : :
: ......... : window 3 (ul/pink) :
: : : :
: : text no : :
: : : :
: : : :
: F3 : win : :
: : : : ottom
Ty :... : : :
===> ca : : :
: F3: qui : F3: quit F4: move F5: resize :
: : :
:........ :....................................................:
F3=Exit F4=Prompt F9=Retrieve F10=Include detailed messages
F11=Display full F12=Cancel F13=Information Assistant F24=More keys
+--------------------------------------------------------------------------------+
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