Known limitations and differences between Swing and Web Direct 2.0

This chapter lists the features that are currently not supported by Web Direct 2.0 as well as behaviors that are different between running as standard COBOL application and running as web application.

The list is updated to the date this document has been written.

Please consider that the number of unsupported features decreases as the product becomes more mature.

Most of the unsupported features will just be ignored and the application will behave like they were not specified in the source code. In some rare cases, an unsupported feature may cause an error.

For easiest reading, controls are listed in alphabetical order.

BAR

In control BAR the following styles are not supported: DOTTED, DASHED and DOT-DASH.

BITMAP

In control BITMAP BITMAP-START, BITMAP-END and BITMAP-TIMER properties are not supported andthe following mouse events are not returned: MSG-MOUSE-ENTERED, MSG-MOUSE-EXITED, MSG-MOUSE-CLICKED, MSG-MOUSE-DBLCLICK.

CHECK-BOX

In control CHECK-BOX the following styles are not supported: LEFT-TEXT, VTOP, MULTILINE, FLAT, FRAMED, UNFRAMED, SQUARE.

Check-boxes have a default layout that cannot be altered.

The TITLE-POSITION and BITMAP-DISABLED properties are not supported.

COMBO-BOX

The 3-D style is not supported.

It’s not possible to load items under MASS-UPDATE.

The NOTIFY-DBLCLICK style is not supported and the CMD-DBLCLICK event is not returned.

The list of Combo-Box items is never horizontally truncated. If the item text is too long, then the list width will be greater than the Combo-Box width to ensure that items text is displayed entirely.

The configuration properties iscobol.gui.curr_bcolor and iscobol.gui.curr_fcolor have no effect.

You can type something when the focus is on a DROP-LIST Combo-Box in order to change the selection. The Combo-Box selects the first item whose value begins with the digit that you typed. In WD2 only the first letter is evaluated, there’s no buffering of digits typed quickly.

DATE-ENTRY

In DATE-ENTRY control the following styles are not supported: NO-F4, RIGHT-ALIGN, SHORT-DATE, NO-UPDOWN, SHOW-NONE, SPINNER (that is default for ZK), DECORATION-BACKGROUND-VISIBLE, DECORATION-BORDERS-VISIBLE and WEEK-OF-YEAR-VISIBLE.

The following properties are not supported: CALENDAR-FONT, BITMAP-HANDLE, BITMAP-WIDTH, BITMAP-NUMBER, DECORATION-BACKGROUND, SUNDAY-FOREGROUND, WEEKDAY-FOREGROUND and MAXDAY-CHARACTERS.

ENTRY-FIELD

The following styles are not supported: AUTO, EMPTY-CHECK, NO-BOX, NO-WRAP, SPINNER, USE-RETURN, USET-TAB and VSCROLL.

The following properties are not supported: ACTION, AUTO-DECIMAL, CURSOR, CURSOR-COL, CURSOR-ROW, MAX-LINES, SELECTION-TEXT, SELECTION-START, SELECTION-START-ROW, SELECTION-START-COL, FORMAT-STRING and FORMAT-TYPE.

The PLACEHOLDER implementation is a little different than the Swing implementation. In Swing the placeholder text disappears at the first digit from the user, while in WD2 it disappears as soon as the field gets the focus.

FRAME

In FRAME control FILL-COLOR, FILL-COLOR2 and FILL-PERCENT properties are not supported as well as the ALTERNATE and FULL-HEIGHT styles.

GRID

In GRID control the following events are not fired: MSG-BEGIN-ENTRY produced by the Enter key (the user must double click with the mouse in order to produce such event), MSG-BEGIN-ENTRY produced by typing text while the cell is not in edit mode (note that, if you wish to provide direct editing, without the need of double clicking on the cell, you can display ENTRY-FIELDs within GRID cells as shown in the installed example), MSG-BEGIN-DRAG, MSG-BEGIN-HEADING-DRAG, MSG-COL-WIDTH-CHANGED, MSG-END-DRAG, MSG-END-HEADING-DRAG, MSG-GOTO-CELL, MSG-GOTO-CELL-DRAG, MSG-GOTO-CELL-MOUSE on the current cell (clicking on the current cell doesn’t fire the event; the event is fired when you click on another cell) and MSG-HEADING-DRAGGED.

When the GRID component has not the focus and the user clicks on a cell, the MSG-GOTO-CELL-MOUSE event may not be fired along with the CMD-GOTO event.

The ADJUSTABLE-ROWS and REORDERING-COLUMNS styles are not supported.

The following properties are not supported: ACTION-HIDE-DRAG, CURSOR-FRAME-WIDTH, DRAG-BACKGROUND-COLOR, DRAG-COLOR, DRAG-FOREGROUND-COLOR, END-COLOR, ENTRY-REASON, FINISH-REASON, HEADING-DIVIDER-COLOR, HSCROLL-POS, ROW-DIVIDERS, ROW-HIDING and VSCROLL-POS.

It’s not possible to move the cursor from a cell to another using the arrow keys.

The COLUMN-HIDING property is supported only along with the COLUMN-HEADINGS style, you cannot hide columns of a grid without headings. Setting the VIRTUAL-WIDTH property to a value that is less than the Grid size in order to hide the last column (or columns) has no effect in Web Direct 2.0.

Modifying CURSOR-X and CURSOR-Y changes the cursor position on video only when the Grid gets the focus.

A vertical cursor bar is always visible in the selected cell, even if you’re not editing the cell content. This behavior depends by the fact that a grid cell that is not in edit mode is emulated by a ZK read-only text field and this kind of field always shows the cursor.

For COLUMN-DIVIDERS and ROW-DIVIDERS it is considered only the first value for all columns; the default color is light gray.

If the GRID has SORTABLE-COLUMNS style or ADJUSTABLE-COLUMNS style and NUM-COL-HEADINGS is greater than 1, then all the cells whose row number is the value of NUM-ROW-HEADINGS must not be overridden by any value of CELL-ROWS-SPAN of the cells whose rows number is less than the value of NUM-COL-HEADINGS.

Scroll-bars are always shown when columns exceeds the Grid’s size. This is because in WD2 it is not possible to move among cells using the keyboard, so, without scroll-bars, the columns over the Grid’s size would not be reachable.

The HEADING-MENU-POPUP button is shown over each single column.

It’s not possible to copy Grid content to the clipboard.

JAVA-BEAN

In Web Direct 2.0 only the controls of the ZK Framework can be used as JAVA-BEAN; Swing controls are not supported.

In JAVA-BEAN control the following styles are not supported: HAS-BITMAP, HSCROLL, VSCROLL, NO-BOX, BOXED, 3-D, USE-RETURN and USE-ALT.

As a consequence of the lack of HAS-BITMAP, the BITMAP-HANDLE and BITMAP-WIDTH properties are not supported.

If you want to force the focus on the Java-Bean by invoking the setFocus() method, you have to invoke this method in the Java-Bean BEFORE PROCEDURE.

LABEL

In LABEL control the VERTICAL style is not supported.

LIST-BOX

In LIST-BOX control THUMB-POSITION is not supported.

PUSH-BUTTON

In PUSH-BUTTON control the following styles are not supported: DEFAULT-BUTTON, FRAMED, MULTILINE, SQUARE and UNFRAMED.

In Web Direct 2.0 Push-Button titles are always shown entirely. If the Push-Button SIZE is not sufficient to store the title text, then it’s automatically extended by the Framework.

RADIO-BUTTON

In RADIO-BUTTON control the following styles are not supported: 3-D, LEFT-TEXT, VTOP, MULTILINE, FLAT, FRAMED, UNFRAMED and SQUARE.

Radio-Buttons have a default layout that cannot be altered.

The TITLE-POSITION and BITMAP-DISABLED properties are not supported.

TAB-CONTROL

In TAB-CONTROL the following styles are not supported: MULTILINE, BUTTONS, FIXED-WIDTH, BOTTOM, HOT-TRACK, FLAT-BUTTONS and NO-DIVIDERS.

After Procedure and Before Procedure are not supported. The Tab-Control never gets the focus, so it’s not possible to change page by pressing TAB to activate the Tab-Control and then using left and right arrow keys. Use the mouse to change page in a Tab-Control.

TREE-VIEW

In TREE-VIEW control the SHOW-SEL-ALWAYS style is not supported. The following properties are not supported: ACTION, BITMAP-NUMBER, BITMAP-HANDLE, BITMAP-WIDTH, ACTION, MASS-UPDATE.

The NEXT-ITEM property doesn’t support TVNI-FIRST-VISIBLE, TVNI-NEXT-VISIBLE and TVNI-PREVIOUS-VISIBLE.

No editing is allowed and the following events are not returned: MSG-TV-EXPANDING, MSG-TV-SELCHANGING, MSG-BEGIN-ENTRY, MSG-CANCEL-ENTRY and MSG-FINISH-ENTRY.

WINDOW

Windowss must be Initial/Standard, Independent or Floating.

Subwindows are not supported.

SHADOW, SCROLL and POP-UP AREA are not supported.

AT LINE / COL syntax is not supported. Windows appear at the center of the web page. AUTO-RESIZE, MIN-SIZE, MIN-LINES, MAX-SIZE, MAX-LINES and LAYOUT-MANAGER are not supported.

Windows can have the RESIZABLE style, but you cannot configure resizing boundaries and rules. The CONTROLS-UNCROPPED style is not supported.

The CMD-ACTIVATE and NTF-RESIZED events are not fired by windows in Web Direct 2.0.

The UNDECORATED style just reduces the border, but the title bar is still visible.

Unsupported Controls

The RIBBON, the SCROLL-BAR, the SLIDER, the STATUS-BAR and the WEB-BROWSER controls are not supported at all in Web Direct 2.0.

Other Differences with Desktop Applications

All keyboard input is trapped by the web-browser and therefore keystrokes mapped to exception or termination values will not work. The key that allows the user to move between controls is TAB (use SHIFT+TAB to move to the previous control). Only function keys from F1 to F12 that are not trapped by the web-browser will cause an ACCEPT to terminate with an exception. The other function keys and other keys will not, so it is strongly suggested to provide a graphical push-button for each mapped keystroke that the COBOL program expects.

An ACCEPT can be terminated by pressing ENTER unless the focus is on a Push-Button, on a multiline Entry-Field, on a Grid or on a Tab-Control.

An ACCEPT can be terminated by pressing ESC unless the focus is on a Grid or on a Tab-Control.

Relative columns in Screen Section are not supported by Web Direct 2.0 because the Framework doesn’t know the real font size that the browser will use to paint the field. When working on Desktop with Java Swing controls, isCOBOL first puts the control in the window and then inquires its actual size. A similar operation would be very slow if executed by AJAX in the browser, and therefore is better for the user to specify the size and the column of the control using fixed values.

HTML rendering is supported only in the TITLE of Label, Check-Box, Push-Button and Radio-Button as well as in Grid cells when they’re not editable.

Unsupported Library Routines and functions

In Web Direct 2.0 all the library routines and functions work on the server machine. Generally speaking all the functions that need to show a dialog on the client machine or to manage files on the client machine are not supported. The following table lists in detail the routines that are partially or totally not supported.

Routine	Notes
A$CURRENT-USER A$GET-USER A$GETTHREAD A$LIST-LOCKS A$LIST-USERS A$USERINFO AS$COPY	Not supported at all
C$COPY C$DELETE	Not supported "@[DISPLAY]:" in the file name
C$EASYOPEN C$GETCGI C$GUICFG C$OPENSAVEBOX	Not supported at all
C$SYSTEM	Not supported the flag CSYS-DESKTOP
CBL_READ_SCR_CHARS CBL_READ_SCR_CHATTRS CBL_WRITE_SCR_CHARS CBL_WRITE_SCR_CHATTRS J$GETFROMLAF KEISEN KEISEN1 KEISEN2 KEISEN_SELECT P$CLEARDIALOG P$DISPLAYDIALOG P$ENABLEDIALOG P$SETDIALOG W$CAPTURE W$CENTER_WINDOW	Not supported at all
W$FONT	Not supported the WFONT-CHOOSE-FONT function
W$HINT W$KEYBUF	Not supported at all
W$MENU	Not supported the WMENU-NEW-TRAY function
W$MOUSE	Supported the SET-MOUSE-SHAPE function, but it’s not possible to use a custom mouse pointer
W$PALETTE	Not supported the WPALETTE-CHOOSE-COLOR function
W$PROGRESSDIALOG WIN$PLAYSOUND	Not supported at all
WIN$PRINTER	Not supported the WINPRINT-SETUP function

Note - when a routine that is not supported is called, the effect are unpredictable.

The CALL CLIENT statement is not supported in Web Direct 2.0.