By Pavel Luzanov

Introduction

Implementing grid control for Oracle Forms blocks is a long time dream for many Forms developers. But what is easy in some others products is not so easy in Forms (and vise versa, of course). Some of us, developers, thinks that this is not possible, some thinks that it does not needed, but where is truth?

At first, we must to know why we need it.

Someone can say that "it's cooooool!". But this is not an argument, at least for me.

Personally, I want to be able to add grid control for multi record blocks for a simple practical reason. Sometime ago one of my users call to me and say that he replace his old monitor with 640x480 resolution with new one (17" and 1024x768 resolution). But multi record blocks in my application still small and can't use new space.

And what I must say to him? That many other users still has old monitors and I don't want to design forms for each possible screen resolution?

Grid control needed!
Period

What we have

So, we will try to implement it!

Bad news here, that we can't fully implement grid control in Oracle Forms. We can't resize multi record block vertically. To do this, we must have something like

   SET_ITEM_PROPERTY(..., NUMBER_OF_ITEMS_DISPLAYED, ...);
and/or
   SET_BLOCK_PROPERTY(..., NUMBER_OF_RECORDS_DISPLAYED, ...);
and
   SET_BLOCK_PROPERTY(..., SCROLLBAR_HEIGHT, ...);

Good news that we can do following:

• resize items with SET_ITEM_PROPERTY(..., WIDTH, ...)
• change column order(move items) with SET_ITEM_PROPERTY (..., POSITION & NEXT|PREVIOUS_NAVIGATION_ITEM, ...)
• move block scrollbar with SET_BLOCK_PROPERTY(..., BLOCKSCROLLBAR_X_POS, ...)
• for Web deployment, we can avoid using When-Mouse-Move|Enter|Leave triggers (which are no longer exists in a Web environment), using such triggers as When-Mouse-Up|Down|Click

Simple GRID utility

Now, I want to share my expirience on this subject, and present simple GRID utility. Zip archive contain grid.pll library with pl/sql code, grid.olb object library with requared form objects and simple_grid.fmb demo form.

All code was designed in Forms 6i, but also worked in Forms 10G without any changes.

Using simple_grid.fmb demo form

• Unpack grid.zip
• Open grid.pll library in Forms Builder and compile it
• Make sure that grid.plx in FORMSXX_PATH
• Open grid.olb object library in Forms Builder
• Open simple_grid.fmb form in Forms Builder and compile it
• Run simple_grid form
  • Press Configure button to resize and reorder items in a block
  • Resize individual items by mouse.
    To do this press mouse left button down near the rigth end of item, move mouse while holding mouse button, leave mouse button in desired place

Adding GRID utility to your forms

• Attach grid.pll to your form
• Subclass OG_GRID Object Group from grid.olb
• Make sure that BLK_GRID_ITEMS and BLK_GRID_CONTROL placed below your multi record block in the Object Navigator
• Add into starting trigger, for example When-New-Form-Instance:

     fp_grid.register_block ('_your_multi_record_block_name_');
     

• Add two block level triggers into multi record block:
  1. When-Mouse-Down with code

           fp_grid.when_mouse_down;
              

  2. When-Mouse-Up with code

           fp_grid.when_mouse_up;
              

• For all items in a multi record block set PM_GRID Popup Menu and/or add call to fp_grid.configure to any place - button, menu item, etc
• Make sure that grid block canvas has width large enough

Current Restrictions and Suggestions

• May work for only one block per form
• All block items in a grid must be on the same canvas and the same Y position as a first item in a block
• All items must have prompt text
• Tested only on text items, not checkboxes, radio groups, etc
• Not tested with multiple opened forms

What functionality may be added

• Automatically resize (width) grid items when window resized
• Ability to hide some items from the grid
• Permanently save user settings (in db table) and restore it on restart
• Allow to user to set and save ORDER BY and filter (WHERE) information for a grid block
• Allow to user to create and save different "views" on a same block

08 September 2004