kulkarni@umn-cs.CS.UMN.EDU (Srinivas R. Kulkarni) (08/19/89)
I am developing a small spreadsheet sort of application using
Xaw. I am using X11R3.
Since I want the spreadsheet to scroll both horizontally and
vertically, I have implemented the spreadsheet canvas as the child of a
viewport widget.
concise problem description:
^^^^^^^^^^^^^^^^^^^^^^^^^^
I want Column titles on the top row and Row titles in the
leftmost column of my spreadsheet. The Column titles scroll ONLY
horizontally and similarly the Row titles scroll ONLY vertically.
That is the problem. I am not quite sure if (and how) I can
achieve such 'partial' scrolling.
a few things I tried:
^^^^^^^^^^^^^^^^^^^^^
I thought of using label widgets for the Column titles and making
them the children of the Viewport's horizontall scroll bar using
XtNameToWidget(viewport, "horizontal") but that's out of question
since a scrollbar/viewport widget can have only child. So I created
a form widget as the child of my viewport widget and made the
canvas and the column/row label widgets the child of my form widget.
But now, as expected, the whole form widget i.e ALL its
children scroll. I somehow need to stop ( can i do this?) the vertical
scroll bar from scrolling Column label widgets and vice versa for
the Row label widgets.
Is there a better design? Would using two Scrollbar widgets
help? If so, how can I do that? Also, can I scroll in units
of CELL_HEIGHT(vertically) and CELL_WIDTH(horizontally) by
'intercepting' the values passed to ScrollUpDownProc?
Please help. Thanks in advance.
Please e-mail me directly.
Srinivas R. Kulkarni
kulkarni@umn-cs.cs.umn.edu
(612) 341-2921 (home)kulkarni@UMN-CS.CS.UMN.EDU ("Srinivas R. Kulkarni") (08/22/89)
I am having problems choosing the right sort of widgets for
a small spreadsheet sort of application (with Xaw, X11R3). I will
appreciate it very much if you could help me out.
Since I want the spreadsheet to scroll both horizontally and
vertically, I have implemented the spreadsheet canvas as the child of a
viewport widget.
concise problem description:
^^^^^^^^^^^^^^^^^^^^^^^^^^
I want Column titles on the top row and Row titles in the
leftmost column of my spreadsheet. The Column titles scroll ONLY
horizontally and similarly the Row titles scroll ONLY vertically.
That is the problem. I am not quite sure if (and how) I can
achieve such 'partial' scrolling.
a few things I tried:
^^^^^^^^^^^^^^^^^^^^^
I thought of using label widgets for the Column titles and making
them the children of the Viewport's horizontall scroll bar using
XtNameToWidget(viewport, "horizontal") but that's out of question
since a scrollbar/viewport widget can have only child. So I created
a form widget as the child of my viewport widget and made the
canvas and the column/row label widgets the child of my form widget.
But now, as expected, the whole form widget i.e ALL its
children scroll. I somehow need to stop ( can i do this?) the vertical
scroll bar from scrolling Column label widgets and vice versa for
the Row label widgets.
Is there a better design? Would using two Scrollbar widgets
help? If so, how can I do that? Also, can I scroll in units
of CELL_HEIGHT(vertically) and CELL_WIDTH(horizontally) by
'intercepting' the values passed to ScrollUpDownProc?
Please help. Thanks in advance.
Please e-mail me directly.
Srinivas R. Kulkarni
kulkarni@umn-cs.CS.UMN.EDU
(612) 341-2921 (home)bob@odi.COM (Bob Miner) (08/22/89)
> I am developing a small spreadsheet sort of application using > Xaw. I am using X11R3. > > [...stuff deleted...] > > I want Column titles on the top row and Row titles in the > leftmost column of my spreadsheet. The Column titles scroll ONLY > horizontally and similarly the Row titles scroll ONLY vertically. > That is the problem. I am quite sure if (and how) I can > achieve such 'partial' scrolling. > > [...stuff deleted...] I'd recommend you do one of two things, depending on how you want your spreadsheet to look. If you want the scrollbars to extend the full width and height of the window, including to the right of the column titles and below the row titles, #1 is the way to go. If you want the scrollbars to only extend to the boundaries of the cell area, leaving the space to the right of the column titles and below the row titles empty, #2 is the way to go. 1. Create a form widget with 6 child widgets - 2 scrollbar widgets (one horizontal and and another vertical) and 4 core widgets (one for the column titles, another for the row titles, a third for the cells and a fourth for that little square area where the row titles and cell titles intersect). You'll need to do scrolling in the core widgets yourself when you receive callbacks from the scrollbars. 2. Create a form widget with 4 children - 3 core widgets (one for the column titles, another for the row titles and the third for that little square area again) and 1 viewport widget with scrollbars. Again, though, when the person scrolls the cell area in the viewport widget, you'll have to have set up a callback such that you know to scroll either the column or row area. The answer you're really looking for is a way to synchronize the scrolling of one widget's contents with the scrolling of another widget's contents. I know of no way to do that with the Athena widgets (or any other toolkit). Another possibility, one which I've implemented but which takes more effort, is to forget about making the column, row and cell areas separate widgets and draw them all in one core widget. You'll then need to do clipping to each area yourself. There are advantages to this approach in that you'll be able to draw to all three areas simultaneously (with one Xlib call) which looks smoother during scrolling and dynamic cell selection than first drawing in the cell area with one Xlib call and then drawing in either the row or column area with another Xlib call. I haven't used the Athena widget set much myself, so I could be off slightly on the exact capabilities of the Athena widgets. Most form and scrollbar widgets in the various toolkits provide similar capabilities, however. Good luck, Bob Miner Object Design, Inc. 1 New England Executive Park Burlington, MA 01803 (617) 270-9797 Email: bob@odi.com
meo@stiatl.UUCP (Miles O'Neal) (08/25/89)
In article <15318@umn-cs.CS.UMN.EDU> kulkarni@umn-cs.CS.UMN.EDU (Srinivas R. Kulkarni) writes: | | I am developing a small spreadsheet sort of application using |Xaw. I am using X11R3. | | Since I want the spreadsheet to scroll both horizontally and |vertically, I have implemented the spreadsheet canvas as the child of a |viewport widget. | |concise problem description: |^^^^^^^^^^^^^^^^^^^^^^^^^^ | I want Column titles on the top row and Row titles in the |leftmost column of my spreadsheet. The Column titles scroll ONLY |horizontally and similarly the Row titles scroll ONLY vertically. | That is the problem. I am not quite sure if (and how) I can |achieve such 'partial' scrolling. | |a few things I tried: |^^^^^^^^^^^^^^^^^^^^^ |I thought of using label widgets for the Column titles and making |them the children of the Viewport's horizontall scroll bar using |XtNameToWidget(viewport, "horizontal") but that's out of question |since a scrollbar/viewport widget can have only child. So I created |a form widget as the child of my viewport widget and made the |canvas and the column/row label widgets the child of my form widget. In addition to the suggestions someone else made, there is another solution. It involves a bit more work, but has some advantages. Don't use a viwport widget. Use a form widget with something like the following layout. +----------------------------------------------------------------------+ | sub-form widget containing labels containing column titles | +----------------------------------------------------------------------+ | sub-form | | | widget | | | containing | | | labels | | | containing | This are contains the cell widgets (label, | | row titles | or whatever) | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +----------------------------------------------------------------------+ Only create enough cell widgets to fill your screen. I didn't draw the scrollbars above, but attach them wherever you want them. The scrollbar action routines would change internal spreadsheet cell pointers to point to the "active" cells. These would then be mapped into the cell widgets on the screen. For large spreadsheets, this is MUCH less memory-intensive than having lots and lots of widgets. For any size spreadsheet, this should give you much faster scrolling than having the viewport tell a whole bunch of widgets to move/unmap/map themselves. We did a srcolling menu based on this. We originally tried the classic approaches, and discarded them one by one for memory and/or speed reasons. This was not an academic excersize; this was a real-world solution to real- world problems. It works VERY well. -Miles (if I disappear from the net, it is because I was shot for giving away trade secrets...)