Digital Mars - D - about dig

↑ ↓ ← → Burton Radons <loth users.sourceforge.net> writes:
Lloyd Dupont wrote:
 I just beging to read dig code... (and soon use..)
 well it's huge and I think a bit of help might be needed.
 
 could one explain me the grid fitting / resizing behavior of control...
 it's unclear to me.


Sorry about the long delay.  I'd been meaning to make an example with a 
screenshot to show it, but then forgot about the message, and now I 
can't make the example very clear.

What you're doing with grid fitting is defining controls to be part of a 
table.  column (the first argument to grid) is the horizontal cell, row 
the vertical.  If a control needs to span across a number of other 
controls, then you supply third and fourth arguments to grid that 
indicate how large the control is in cells.  For example, if a and b are 
side-by-side and c should be below them but cover their range, then 
you'd do:

     a.grid (0, 0);
     b.grid (1, 0);
     c.grid (0, 1, 2, 1);

Which will create something like:

     +---+---+
     | A | B |
     +---+---+
     |   C   |
     +-------+

There's also the gridAddRow methods, which increment the row by the 
rowspan, and is handy for setting up large tables.

The sticky method determines the placement of the control within its 
grid space, if the grid space is larger than the control itself.  For 
example, c above might have a sticky of "|", meaning horizontal center. 
  It would then be:

     +---+---+
     | A | B |
     +-+-+-+-+
       | C |
       +---+

The way I have it in the first diagram, it has a stickiness of "<>", 
which means to stretch it to fill its full horizontal potential.  "<" is:

     +---+---+
     | A | B |
     +---+---+
     | C |
     +---+

">" is:

     +---+---+
     | A | B |
     +---+---+
         | C |
         +---+

For vertical placement, there is "^" for top, "-" for vertical center, 
"v" for bottom, and "^v" for vertical stretch.  So to make a control 
take its complete possible space, you would use "<>^v", although "^>v<" 
would also work.

Past that, there's border and pad.  border (x, y) is the number of 
pixels to indent children controls.  It adds x and y on both the 
top/left and the bottom/right.  pad (x, y) is the number of pixels to 
put around a control to separate it from other controls in this table.

Grid-fitting by itself can become limiting when there's complex layouts, 
either in making them impossible or in making them needlessly complex. 
You can use the "Pane" control to define a sub-table.  For example, the 
first diagram's controls could be setup with:

    Pane pane;

    with (pane = new Pane (control))
    {
        grid (0, 0);
        with (new MyClass (pane)) caption ("A"), grid (0, 0);
        with (new MyClass (pane)) caption ("B"), grid (1, 0);
    }

    with (new MyClass ())
    {
        caption ("C");
        grid (0, 1);
        sticky ("<>");
    }

The advantage is that C has no knowledge about how A and B are setup, 
which allows you to move the controls around.  Another important parent 
control is the GroupBox.
Dec 01 2002