Kbase 18558: Code for overstrike mode in editor object ( widget )
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
2/4/1999 |
|
Code for overstrike mode in editor object ( widget )
By default the editor widget / object in PROGRESS does not include
support for overstrike mode. When typing into the widget, only insert
mode is available.
This is due to the fact that the editor is Windows compliant. (For
comparison, one can see that the Windows Notepad utility also does
not include overstrike mode support.)
Programmers can write trigger code for the editor that creates this
overstrike capability. Example code is shown below. Please note that
running this code will result in a subtle flashing effect on the
editor when text is typed into it. This is unavoidable due to the
way the trigger code refreshes the editor's SCREEN-VALUE.
Step 1: Write a trigger for when the user toggles the INSERT key
while in the editor.
DEFINE VAR in-mode AS LOGICAL.
ON INSERT-MODE OF EDITOR-1 IN FRAME DEFAULT-FRAME
DO:
IF in-mode THEN in-mode = NO.
ELSE in-mode = yes.
END.
Step 2: Write a trigger for ANY-PRINTABLE in the editor that handles
keystrokes depending on whether insert mode is enabled.
Note that the trigger code must take into account whether
text has been highlighted in the editor. In both insert and
overstrike mode, typing into the editor when text is
highlighted will result in the typed key replacing the
entire block of highlighted text.
ON ANY-PRINTABLE OF EDITOR-1 IN FRAME DEFAULT-FRAME
DO:
if editor-1:selection-end <> ? then do:
/* text is highlighted -- remove all highlighted text and
replace it with the last key that was entered */
x = editor-1:selection-start.
editor-1:screen-value =
substring(editor-1:screen-value,1,
editor-1:selection-start - 1) +
keylabel(lastkey) +
substring(editor-1:screen-value,editor-1:selection-end,
(length(editor-1:screen-value) -
editor-1:cursor-offset) + 1).
editor-1:cursor-offset = x + 1.
return no-apply.
end.
else do:
if in-mode = NO then do:
/* save cursor's current position in editor */
x = editor-1:cursor-offset.
/* overstrike mode */
editor-1:screen-value =
substring(editor-1:screen-value,1,
(editor-1:cursor-offset - 1)) +
keylabel(lastkey) +
substring(editor-1:screen-value,
(editor-1:cursor-offset + 1),
(length(editor-1:screen-value)) -
editor-1:cursor-offset).
editor-1:cursor-offset = x + 1.
return no-apply.
end.
else do:
/* insert mode - just use editor default behavior */
apply lastkey.
return no-apply.
end.
end.
END.
DISCLAIMER: This example code is provided for informational purposes
only. Its inclusion in the Progress Support Knowledgebase does not
constitute endorsement of it or support for it, nor does it
guarantee that it has been tested to the extent recommended for
application deployment. Programmers are advised that they use it at
their own risk.