Oct 93 Tips, Tidbits
Volume Number: 9
Issue Number: 10
Column Tag: Tips & Tidbits
Tips & Tidbits 
By Neil Ticktin, Editor-in-Chief
This column is your opportunity to spread the word about little bits of
information that you find out about. These tidbits can be programming related or they
can be user tips that are particularly useful to programmers.
MacTech Magazine will pay $25 for every tip used, and $50 for the Tip of the
Month. Or you can take your award in orders or subscriptions.
To submit a tip, send in a letter to the magazine. E-mail is our preferred
method, but feel free to send something via the US Mail. See page two for all addresses.
If you do send snail mail, enclose a printed copy and a disk copy of the letter so that it
does not have to be retyped.
Tip of the MonthSometimes there are times that you will want to hide the menu bar. You
shouldn’t plan on doing this often, but in the proper situation (i.e., a presentation
package displaying a slide on the screen), here’s an example of how it might be done.
/* 1 */
int saveMBarHeight;
RgnHandle saveGrayRgn;
HideMenuBar (void)
{
RgnHandle mBarRgn;
RgnHandle theGrayRgn;
theGrayRgn = GetGrayRgn ();
saveMBarHeight = MBarHeight;
saveGrayRgn = NewRgn ();
CopyRgn (theGrayRgn, saveGrayRgn);
mBarRgn = NewRgn ();
SetRectRgn (mBarRgn, screenBits.bounds.left,
screenBits.bounds.top,
screenBits.bounds.right, screenBits.bounds.top +
saveMBarHeight);
MBarHeight = 0;
UnionRgn (theGrayRgn, mBarRgn, theGrayRgn);
PaintBehind (FrontWindow (), mBarRgn);
CalcVisBehind (FrontWindow (), mBarRgn);
DisposeRgn (mBarRgn);
}
ShowMenuBar (void)
{
MBarHeight = saveMBarHeight;
CopyRgn (saveGrayRgn, GetGrayRgn ());
DisposeRgn (saveGrayRgn);
DrawMenuBar ();
}
- Steve Wagy, Spring, Texas
Compile options in THINK Pascal - saving Time
If you are using Think Pascal you may set your compiler variables using the
Compile Options in the Project menu. Compile Options serve as directives for the
compiler. For example, if qCompileOption = FALSE the expressions within the $IFC -
$ENDC statement don't get compiled into your code.
{2}
{$IFC qCompileOption}
expression1; expression2; .........
{$ENDC}
Suppose you have several units in your project and only one of the units uses
qCompileOption. At the time, qCompileOption = TRUE in the Compile Options. You are
about to run your code and want to set qCompileOption = FALSE. Do you find yourself
going to the Compile Options in the Project menu and setting qCompileOption = FALSE?
If you do, you know the unpleasant side effect - every unit in the project, whether it
uses qCompileOption or not, gets recompiled. What a time waster! There is an easier
way to reset qCompileOption for a particular unit. In the unit where you want
qCompileOption reset, write this statement at the top of the unit following the
IMPLEMENTATION keyword:
{$SETC qCompileOption = FALSE}
This resets qCompileOption for this unit only and only this unit gets recompiled.
- Marek Hajek, Reno, Nevada
Assembler Editing through Hex Editor
I picked up a copy of MacTech at the Developer's Conference. I meant to respond to
an article entitled "The Secrets of the Machine" earlier, but didn't until now. The
article mentioned ResEdit's CODE resource extension. In paragraph three of pg 53 it
stated that the extension doesn't allow editing of Assembler. This is not strictly true. I
use the extension in conjunction with the Hex Editor (under the Resource menu) all
the time.
The strategy is to have both the extension and the hex editor open and in sync with
one another (an option under the Hex Editor menu). Then select what you would like to
edit in the far right hand side of the CODE extension window. With the selection
enforced, bring the hex editor to the forefront, make your modification, then return to
the CODE extension window for an up-to-date disassembly of the hex you've just
entered. I've found this approach to be very viable indeed. The instantaneous feedback
has allowed me to make small patches on-the-fly quickly and effectively.
At work I spend a great amount of time translating software via Echo Logic's
FlashPort. The code extension simplifies this process by allowing patches as mentioned
above, and by making it easier to distinguish between CODE and data, a common
necessity in FlashPort. Sometimes disassemblies become out of sync around embedded
data. Using the hex editor and CODE extension, one can make a fake CODE resource {just
needs a segment loader header and to end with an RTS}, paste the questionable data into
the new CODE resource's hex window, and suffix the listing with 4E75 {RTS}. Then, by
removing a word at a time from the beginning of the listing in the hex window and
switching to the corresponding CODE extension window to see the effect, one can gain
valuable insight by noting when the remaining instructions make sense. This approach
is great for finding embedded jump table information.
I hope you find this information useful. In summary, use the hex editor for all
editing, and the CODE extension for all viewing.
- Marisano James, Sent via AppleLink
Double Click in THINK Pascal
In the Think Pascal environment, hold down the option key and double click on a
function name anywhere in your project and Think Pascal will take you to the function
definition.
- Lillian Thompson, Reno, Nevada
Mousepositioning
The user should be the only one to wield the mouse. The position of the mouse
should not change by program control. In some cases however, it is might be necessary
to do so. A user-interface macro program, for example, or for a practical joke
The code snippet below does the trick. It is a macro that sets the position of the
mouse to a given point (the argument to SETMOUSE, is of type Point).
/* 3 */
extern Point MTemp : 0x0828 ; /* some Low Memory Globals */
extern Point RawMouse : 0x082C ;
extern Byte CrsrNew : 0x08CE ;
#define SETMOUSE(_pt) {
MTemp = _pt ;
RawMouse = _pt ;
CrsrNew = 0xFF ;}
- Jan Bruyndonckx, Wave Re search, Belgium