|
|
|
|
Pocket Smalltalk
FAQ 1.1
Table of Contents
1.
Questions
1.1.
Versions and Documentation
| Q1. What is the
latest PST version? |
|
There are 2
different latest versions: one built with Dolphin Smalltalk
(Dolphin v4.0), and one built with Squeak Smalltalk (Squeak
v2.7).
Development
of the Dolphin version of the IDE is more up-to-date than
that of the Squeak version. Both versions can be found
at: www.pocketsmalltalk.com/pst-download.html.
New users are encouraged to begin with the Dolphin version
of the IDE.
The latest
Dolphin-PST version is 1.6a4. It runs only on Windows.
The latest Squeak-PST version is 2.0a. It runs on all
platforms supported by Squeak (Windows, Mac, Linux).
Note that GEOS
port for Nokia is broken from v1.6. It still works for
v1.5 and v2.0a.
The next release,
probably called something like 2.0w (2.0 on Windows) will
include small improvements and a LOT of changes to the
VM. The VM is expected to be about 35% faster. [EA]
|
| Q3. Where do
I get documentation for PST? |
|
Documentation is
availble both at www.pocketsmalltalk.com
and in the PST distribution.
|
| Q4. Which Palm
OS versions are supported? |
|
PST 1.6a4 supports
all systraps through Palm OS version 3.5. Palm OS v4.1
systraps are not yet available. However, PST will run
on Palm OS 4 if your application does not call any specific
4.1 systraps.
A check-program
could be written to verify the minimum and maximum versions
a certain project requires. Going through all methods of "save
in project" packages, looking for the systraps they call and
listing what version the traps are implemented in would tell
what Palm OS versions this application can run on. These stamps
could even be included upon saving a package with a special
menu option.
The file pockectstug>>files>>PRJ,
osVersion-v1-and-v2.zip contains code to check at launch
time what version the device runs.
|
| Q5. Is there
a port of PST for WinCE? |
| Stefan Matthias
Aust is developing one. |
| Q7. Where do
I get technical information about Palm Systraps? |
| Q8. Where do
I find an update of Joey's version 1.5 tutorial (ManHourCalculator)? |
An update of the
PST tutorial for 1.6a4 can be found at pocketstug>>FAQ
+ tutorial.
A new chapter was added to show the debugger. |
| Q9. What was
Eric's nickname at school? |
| System Child ;) |
1.2 IDE
| Q10. Why can't
I find senders of systraps? |
|
For example, the
method SYSTRAP>>DmOpenDatabase: arg1 with: arg2 with: arg3
does not return any senders though Database>>openID:mode:
calls it this way:
SYSTRAP DmOpenDatabase: 0 localID: aLocalID mode: aMode
Ben Hultink:
The name of the SYSTRAP parameters does not matter (with:
or index: or fool: or...) it's only the number position and
type that does count. The parameters are pushed on the stack
and, in that way, passed to the VM machine where the systrap
is executed.
|
1.3 Development
| Q11. How can
I add more systraps? |
|
What is the procedure
to add more systraps in systrap.st?
Palm OS 4.1 systraps
are not available yet. In the palmos/ folder
of the PST installation, a SysTraps.txt file lists all
supported systraps. It might be the starting point for
generating systraps.st. See the file CoreTraps.h from
the Palm OS SDK for a list of all official traps per OS
version.
Look at the class
named SYSTRAP. All the methods that implement traps for Palm
OS are available as class-side protocol. If you would like
to add new entries, follow the same pattern used in each of
the class methods there. There are MANY examples of how to
define an OS call there. [EA]
|
| Q12. How are
C enums supported by PST for systrap calls? |
To illustrate,
consider the SYSTRAP specified for getting preferences (see
the Palm OS reference guide for details):
UInt32 PrefGetPreference (SystemPreferenceChoice choice)
where choice is a constant like prefVersion, prefCountry, prefShowPrivateRecords
from SystemPreferenceChoice enum (see preferences.h in SDK).
The question is, how to pass these enums as SYSTRAP parameters
in PST?
C expects the relevant bits to be in the first byte. Enums indeed
start at 0. So if you use (x bitShift: 8) where x is the element
you need counted from zero, things work fine. This is presumably
a big / little endian thing. What happens if there are more
than 255 elements? For enums bigger than 255 the first and last
byte of the word needs to be swapped but I have not tested this.
[BH]
So, the SYSTRAP call would look like:
SYSTRAP PrefGetPreference: (##prefCountry bitShift: 8).
where ##prefCountry is a constant defined to be 2 since it is
the second enum item in SystemPreferenceChoice enum. A more
readable version of this call would be:
SYSTRAP PrefGetPreference: ##prefCountry asBigEndian
where asBigEndian is implemented as follows:
Integer>>asBigEndian
^self bitShit: 8
Likewise, if you want to interpret a value returned from a systrap,
you need to bit-shit it; e.g.:
code := SYSTRAP MemPtrResize: (CPointer new) size: 10.
“code is 257, bit-shifted is 1”
(code bitShift: -8) = 1 ifTrue: [self error: ‘Could not resize’].
A simpler version of this call would be:
code asLittleEndian = 1 ifTrue: [self error: ‘Could not resize’].
where asLittleEndian is implemented as follows:
Integer>> asLittleEndian
^self bitShit: -8 |
| Q13. What is
class PopupApplication for? |
|
Make a subclass
of PopupApplication if you need a modal windows to popup.
Such a window often asks a question or asks for confirmation.
Call #popupFor: to start it and call #leave to exit it.
Note that in the default 1.6a4 installation there is not
support for the calling application to receive any return
value from child popup-applications. Install returningFromApplication.zip
from pockectstug>>files>>PRJ to add this
feature. This modification enables your application to
receive the exit state by looking at the value returned
by #popupFor:.
|
| Q14. Graphics:
how to avoid flickering while refreshing? |
|
“I wrote a
small program displaying a clock with an update of the hands
every second. The display is built as a bitmap showing the
dial and figures (3-6-9-12), and lines for the hands. Nothing
special, the program works. But: every second both bitmap
and hands are redisplayed, but there is a noticeable flickering
of the hours- and minutes- hands.
Two questions:
1. Is there any way to "freeze" the form, and to
unfreeze when the update is done?
2. The reason why I redisplay the bitmap is that I move the
hands by "erasing" the last position before redrawing
in a new position. Doing so also removes parts of the bitmap.
Is there a way to put the bitmap on the screen once, and to
move the hands only, without damaging the bitmap?”
There are some pointers on 3com's site for how to do games,
moving graphics. It has to do with off-screen buffers and
such. I don't have an exact url, but do a search on the palm
developer's area and you should find it. It'll be specific
to programming in c, but you should be able to extrapolate
to Smalltalk. [JD]
|
| Q15. How can
I store objects in Palm databases with PST? |
|
A persistency framework
is under development by TR.
The C equivalent
can be found at pocketstug>>files>>prj
|
| Q16. What are
"no name" and "" packages for? |
|
Joey:
The problem has to do with the 'new way' of handling packages,
uncommitted code, and not losing changes when quitting. Before
1.6a4, any code that you did not assign to a package was lost
when you shut down PST. The current version creates a 'no
name' package to hold this code, which is then inspected on
shutdown to force you to move it to your own package. Unfortunately,
the save logic seems to be a bit pear shaped here. To 'fix'
this problem: before trying to save the project, create a
new package, set it as the default and then remove the 'no
name' package. (If you've already created code and it is in
the 'no name' package, move it to your package first.) Then
save the project. I just recreated your problem, and this
is what worked for me to get around it. I will fix that logic
for the next release.
Thierry:
My wild guess at the beginning was that uncommitted would
be the package were my not-assigned-to-package code would
be saved and that no-name was just there at start to force
one to create an own package.
Joey:
Maybe that's what it was. Eric put that code in earlier this
year because people were complaining about losing their changes
(it's happened to me, I can tell you). I wasn't involved with
this change so I can't address it fully (I could if I dug
into the code...). Anyway, perhaps I stated the problem/fix
incorrectly, but if you do what I said in that message, then
you will be able to save your code with no worries.
Eric:
Oops, I'll fix that [error upon saving when ‘no name’
package is still present]. The problem is the “no name”
project as you so correctly guessed. I do not need to have
that when a developer loads a project. The “no name”
project is where things go now when you create a brand new
project. The intent is for you to save it when you are ready.
Thierry:
This was never corrected. See workaround later.
|
| Q17. How do I
set a custom font? |
|
I tried to do this
and it seems all to be right. It works, no error messages
and seems to set the font. But when I try to switch to my
new font, I still get a font with ID 0.
What I do first is to define font in .rcp:
FONT ID 1000 FONTID 128 "font.txt"
and then I reference it in my code.
| newFont handle temp |
newFont := SYSTRAP MemHandleLock: (SYSTRAP
DmGetResource: (Integer fromBytes: 'NFNT')
fntID: 1000).
SYSTRAP FntDefineFont: 128 resID: newFont.
"Seems like we defined the font"
"Now set it current"
Window font: 128.
"Try to draw string"
Window
drawString: ('ABCDEFGH', (SYSTRAP FntGetFont) printString)
x: 5
y: 45.
The string is output with font 0, but FntGetFont returns 128.
Ben Hultink:
(from an old issue, message 985)
font: fontID
"Answers the old font ID."
^SYSTRAP FntSetFont: (fontID bitShift: 8).
Works for me! Don’t forget bitShift.
Thierry:
Palm OS reference says that: your font ID “has to be greater
than fntAppFontCustomBase (currently 128). Values less than
or equals to 128 are reserved for system use. Note that the
font IDs are 8-bit unsigned value, and so must be less than
256.”
|
| Q18. How can
I handle real Palm buttons? |
|
In a regular Palm
OS application, this is done by adding a handler for the keyDownEvent,
which handles both graffiti characters and hard-keys (you
need to do a test to see which applies).
In PST, override
the method #Application>>onKeyDownEvent in your application
class, and examine the "key" and "modifiers"
arguments to see what you've been passed. [VPutz]
|
| Q19. Does PST
support video pages? |
|
This functionality
is handled by the Palm OS window manager functions.
In particular,
look at the Palm OS documentation for WinCreateOffscreenWindow,
WinSetDrawWindow, and the like (available in PST through the
class SYSTRAP>>WinCreateOffscreenWindow:with:with:with messages
and the like).
|
| Q20. Is it possible
to beam with PST? |
|
Q: I'm writing
an application and would like to be able to "beam"
information to another computer (using either the Exchange
Manager or raw IR). Do I need to use SYSTRAPs or add primitives
to the VM?
The key here is
that exchange manager will actually send in a launch code
notifying you that something has come in. The current VM does
not currently support this launch code. This launch code has
serious limitations like sub-launch (no globals and such).
You would need to add the stuff to the VM and recompile. The
new source [1.6a4] is coming out soon. [EA]
|
| Q21. How can
I add an item to a popupTrigger? |
|
Q: How should an
application add an item to the list of a popupTrigger, and
then get the new entry to become the selected item, and have
this reflected on the Form?
From a C perspective,
but the same should apply in Smalltalk, wait until you get
the event that's going to pop up the list before setting up
the list and the selection. This is a ctlSelectEvent for the
popup trigger. You can let the OS actually pop up the list,
and wait for the lstSelectEvent that tells you which item
was selected, if any. [PE]
|
| Q22. Are Delays
supported by PST? |
|
For implementing
a clock displaying time (and some other information) I need
a class which sends a callback every second (or whatever timeframe).
I havn't found anything in the standard packages. Is such
a class available?
If I have to implement it myself, which SYSTRAPS do I have
to use?
Hans Scholz:
I suggest you overwrite "eventTimeout" in your application
(should be msec). Also overwrite handleLastEvent, it will
call super handleLastEvent after the screen is refreshed.
This is not exactly "a class which sends a callback"
but might fit your requirements.
|
| Q23. Which method
actually starts my application? |
| Smalltalk>>start
is the method that calls and starts your application. Your application
should override it and it should be saved in one of your packages. |
| Q24. How does
my application exit PST? |
| To exit your application,
your exit method (preferably implemented as a subclass of class
Application) should send "self class eventuallyExitSmalltalk". |
| Q25. When do
I need mathLib.prc? |
| Before running on
your device or from the emulator you must ensure that mathLib.prc
is installed as soon as your application uses any Double or
Fraction objects. |
1.4 Testing
| Q26. Uploading
ROMs via USB connection |
I'm trying to use
the Palm Emulator (3.3). I have a Palm m505 and want to upload
the ROM to my PC (for the emulator), but I only have the USB
connection (No serial connection). I can only select COM1 or
COM3 to download. [TS]
The latest version of the Emulator (3.3) supports downloading
ROMs via USB.
Alternatively, you may use a MAC, if you have one lying around.
[JJM] |
| Q27. Is there
a debugger? |
PST includes a very
simple debugger to show the last smalltalk method that was executed.
The upper list of the debugger shows methods on the stack in
decreasing order. Press the arrow buttons to browse up and down
the stack. If you select a method you can then view its associated
parameters and local variables. |
1.5 Applications
| Q28. Have any
business applications been built with PocketSmalltalk? |
|
So far, PST
has been used primarily for games (See pocketstug>>files).
Ben Hultink
used PST to write a commercial application for registering
car usage, needed to satisfy the Dutch tax office. Ben
reports that after one year of free usage, users have
to register and they actually do! For details, see: www.becorora.com
or www.autorit.becorora.com for details (in Dutch).
Post a message
to list if you learn of details about other commercial
applications.
|
| Q29. Where can
I find code examples? |
|
In pocketstug>>files>>PRJ
you can find:
- BlackJack
- VolleyScore
- Sokodan (only prc)
- ClueTrain (change vm path and exit method if re-generate
with 1.6),
See message #1517 from Nathan Eaton for bug corrections
- NewFlippy (change vm path and exit method if re-generate
with1.6)
- SunitF101 (never completed because of PST limitations,
see readMe file)
In the standard PST release installation, you can find:
- PST demo
- ManHourCalculation (see Joey’s tutorial and Thierry’s
update for 1.6)
Other:
- PocketSet (Jason Dufair, ask for it)
Mail me (Thierry
Reignier) if you want your application be listed here.
|
1.6 Virtual Machine
| Q30. Why is there
a difference in number of vm invoke and return calls? |
Q: Counting
the number of invoke_method() and the number of local_return()
+ nonlocal_return() calls in the VM, I thought they would be
the same number but they're not : there are a few more invoke_method()
than return(). Is this normal ?
(I would like to make a Smalltalk profiler, so I need to know
exactly in which method I am)
A: The asymmetry between invoke_method and *_return is
normal. The Smalltalk stack is basically independent of the
C stack. If you are trying to build a profiler into the VM,
your best bet is to use the global variables 'instruction_ptr'
and 'receiver' along with the functions 'infer_selector' and
'infer_class' to find out where in the Smalltalk program execution
is taking place. [AB] |
1.7 Known Limitations
| Q31. Are PalmOS
launch flags supported? |
| No. |
| Q32. Are callbacks
supported? |
|
No.
Consequences: any special widgets that use callbacks (like
tables) cannot be used in PST.
|
| Q33. Are Smalltalk
exceptions supported? |
|
No.
The original PST whitepaper (www.pocketsmalltalk.com/whitepaper.html#exceptions)
mentions support for exception handling (ExceptionHandler
class) but this class does not exist in the core package (1.6a4
and 2.0a).
|
2. Known Errors
2.1
IDE
| E1. Error #indexOfSubCollection:startingAt: |
As of 1.6a4, if
you receive this error: ”undefinedObject does not understand
#indexOfSubCollection:startingAt:”, browse packages, set
a package as default via the ”set as default” option
and remove the ”no name” project.
Eric:
Oops, I'll fix that. The problem is the “no name”
project as you so correctly guessed. I do not need to have that
when a developer loads a project. The “no name” project
is where things go now when you create a brand new project.
The intent is for you to save it when you are ready. |
| E2. A "no name"
package is still shown upon reloading an old project |
| As of version 1.6a4,
this package is always part of a PST project after a reload.
It should not be reintroduced if previously removed. To be able
to save your project, remove it first. |
| E3. "PstRuntimeSessionManager
does not understand #inspectItFor:" |
|
“Inspect it"
in a Workspace now produces the following error [1.6a4]:
"PstWorkspace does not understand #sourceCode"
followed by:
"PstRuntimeSessionManager does not understand #inspectItFor:"
Joey:
If you have the IDE source loaded, you can just change the #inspectIt
method of class PstShell to look like this:
self sourceCodePart inspectItFor: self receiverForEvaluations.
The problem was sourceCode should have been sourceCodePart.
If you don't have the IDE source loaded, you'll have to wait
for a patched version of 1.6a4
|
| E4. "PstMethodListBrowser
does not understand #classLibrary:" |
|
Loading the BlackJack
application (pocketstug), selecting ”Database” in
initialize method and choosing ”Browse it” returns
this error:
BlackJackMatch>>Initialize
database := nil.
(Database findDatabaseIDByName: 'BkJk' )
Pressing ok gives more errors. Should not be a ok, cancel warning,
just a ok one.
|
| E5. File location
error when generating an application |
| The error occurs
because the path to the VM is set incorrectly. Look at ##resourceDB1
in the Constants Browser and make sure it's valid. |
| E6. Path spelling
error when generating an application |
An extra back-slash in the string for resourceDB2 (##ResourceDB2*:
'\resources\*.bin') may give an error. |
| E7. Package error |
|
Symptom:
Add a method
(let’s say #organizer) to a superclass and then remove
it from 2 subclasses. Then, when saving the project from the
PST launcher window, the error "method not in any class"
is raised:
Going through the package browser, saving packages one by
one I could locate the error: an old reference to #organizer
was still filed under "methods", though I deleted
it from a ”browse implementers” browser. I could
find a workaround (re-implementing the method, seeing twice
the same row in package>>method tab and choosing remove
from package for both.
Note that removing from package gave the same error if I did
not re-implement the method in the first place.
If the error can’t be fixed, fine, but a more specific
error message would be better: ”method: #organizer not
in any category for class: Blabla, package: blabla”,
and maybe: "Do you want PST to remove it?"
(Sent to Joey, 29.08.2001)
|
| E8. Error when
saving a project |
Symptom:
Load a project, then save it. The IDE gives an error that the
"none" package still exists. If you press ok, the
project file is not corrupted but if you press cancel it gets
corrupted.
Saving a project should first make a back-up (or keep a backup
in memory). If E1 is corrected then this problem will be resolved. |
| E9. Error when
saving a method |
| I saved a method
to a package different than the one where the class is defined.
Modifying this method afterwards and then saving it, moves it
back to the default package. The method should stay in the given
package if this package is savable. |
| E10. Removing
packages |
| Removing a package
does not remove or unload classes. |
| E11. Hover help
for the save project icon says: "Save proiject" |
| 1.6a4 shows an incorrect
spelling. |
| E12. Error when
selecting code |
| Double-clicking
on a method ending with a semi-colon does not select that last
semi-colon character. |
2.2. Development
| E13. Trouble
with garbage collection |
Every time I call
the #collectGarbage manually I get a mark stack overflow error
(using the Palm Emulator). I seem to get the same problem when
Smalltalk calls it automatically, because after several button-clicks
in my application I get the same message.
I tried the vm16a4.prc but I still have the same problems. I
can only make a limited number of pen-clicks, before the mark
stack overflows.
The mark stack is used by the garbage collector to hold objects
that have been "marked" during the mark & sweep
collection. What it probably means is that you have too many
objects being referenced, but one would need to check the VM
source to confirm this. [JH] |
2.3 Testing
| E14. Error upon
exiting any application |
|
Symptom:
On hitting the Done button on the Demo app, you see an "application
accessed invalid chunk" or something like that, unless
the check was turned off in the Palm Emulator, and running the
application on a physical Palm device was fine.
Solution:
It turns out that the way we were exiting from a form was BAD.
The implementation of the Done button method handler called:
Smalltalk exit
If you are INSIDE a form, this is BAD.
Do not use Smalltalk
exit in a form event handler, UNLESS you are handling the appStopEvent.
Instead, use:
Application eventuallyExitSmalltalk
Here's why: calling #exit will exit the VM. Well, the OS is
not done sending events to the application. So what happens
is that the app disappears, and the OS sends events to someone
who is no longer there. The correct way to exit is to tell the
OS somehow you wish to exit, and to let it send an appStopEvent.
When your application receives this event, no more events will
come through. So this is the right time to exit. PST 1.6a4 includes
the method Application class>>#eventuallyExitSmalltalk
which does the trick. Keep in mind that the event loop must
run after this call is done in order for the exit to actually
occur. [EA]
|
| E15. Error upon
leaving any popup application |
Symptom:
Errors after using the #leave method in PopupApplication.
Ben Hultink:
This is an old problem, this weekend I tried the Handera emulator
so I changed it a little because it didn't work any more. Here
is the stuff for PopUpApplication:
Create an instanceVariable named finished and modify the following
two methods:
PopUpApplication>>leave
"BJH"
finished ifFalse: [finished := true].
PopUpApplication>>handleLastEvent
"BJH"
| event |
finished ifTrue: [
finished := false.
self release.
Form returnToForm: self owner class formID.
[event := CEvent waitForEvent: -1.
event eventType == ##winEnterEvent]
whileFalse.
^false].
^super handleLastEvent.
Explanation: it used to wait for the winExitEvent but I don't
get this for the Handera. Actually you should resend the winEnterEvent
again so the owner can pick it up.
Christian Schmidt-Setzwein:
PopupApplication>>leave. The Palm OS generates two more
events (CtlSelectevents) for the done button (from the Popup
form, which is already closed), which should be handled from
the main form (which is now the active one).
To bypass this problem and make all PST programs, even with
PopupApplication forms, run properly on the emulator, add the
following:
Application class>>consumeCtlSelectEvents
| event |
[event := CEvent waitForEvent: -1.
CEvent sysHandleEvent: event.
event eventType == ##ctlSelectEvent]
whileTrue.
PopupApplication>>leave
finished ifFalse: [
finished := true.
Form returnToForm: self owner class formID.
self class consumeCtlSelectEvents].
Thierry:
Christian’s solution is the one implemented in 1.6a4.
Ben: does it work for you on your Handera with Christian’s
solution? |
| E16. Listbox
error upon opening the debugger |
|
Symptom:
Using the latest Emulator (3.3) and a non-debug Palm OS 3.5
ROM, the following warning occurs four times whenever the
application enters the debugger:
It seems like the VM in primitive 100 is not following Palm
OS rules and accesses Palm resources directly.
Listbox>>primSetListChoices: choices
controlID: controlID freeVisibleItems: boolean
<primitive: 100>
^self primitiveFailed.
|
| E17. Memory Leak
upon exiting applications |
Running the latest
emulator and a Palm OS 3.5 debug ROM gives the following error:
The VM apparently does not release all memory it acquired. Solution:
do not use a debug ROM or try to fix the VM. |
| E18. MathLib
error |
|
Running the tutorial,
for example Ð or any application using Double or Fraction,
without having installed mathLib.prc, gives the following
error:
So next time, don't
forget MathLib.
|
| E19. Debugger |
|
Symptom:
- Every time my application shows the debugger, I always
get an empty upper pane with just 1 row: "Object>>error:"
- an empty lower pane with just 1 row of parameters
Pressing the arrow button at the right-hand side has no effect
for both panes.
What could be wrong with my app?
Have I set wrong System Properties settings? (In this case,
##debug is set to true).
|
| E20. Error with
##debug option set |
Symptom:
I went through the tutorial and wanted to see effects of turning
the Constant Browser>>System Properties>>##debug
to false. When running the newly generated tutorial, I get an
error:
"ManHour Calc (unknown version) called SysFatalAlter
with the message: "main.c, Line 40, unsued primitive"
Could the VM show what primitive number failed? What’s
wrong? |
3. Corrections
| C1. General:
Reporting Bugs or Corrections |
To report bugs,
send them to the pocketstug discussion group with subject starting
with the text "[Bug]" on the subject line, or else
send them to me (Thierry
Reignier). I will see that the FAQ is updated with known
bugs.
You might also want to publish them in the files directory:
pocketstup>>files>>bugs.
Known bugs were found in PST 1.6a4.
If you send a smalltalk package containing only your bug corrections,
please follow this naming convention:
correctedXxx.st
— where Xxx is the name of the original package. Example:
correctedCore.st. |
3.1 Packages
| C2. Bug missing
method: SortedCollection>>reallyExpandAtEndBy: |
SortedCollection>>reallyExpandAtEndBy: amount
"TREG: missing method"
| oldSort |
oldSort := sortBlock.
super reallyExpandAtEndBy: amount.
sortBlock := oldSort
|
| C3. Bug in ListModel>>selectionIndex: |
ListModel>>selectionIndex: newIndex
"TREG: added selection to changed method"
selectionIndex == newIndex ifFalse: [
selectionIndex := newIndex.
self changed: #selection with: self selection].
It provides the selected
object in the #update:with: method. |
| C4. Bug in Application>>showFor: |
|
TREG: This method
is unclear. Is it really needed? How is the next form opened?
Application>>showFor: instance
"TREG: replaced self by instance class in first line"
| temp |
Form gotoForm: instance class formID.
[instance isNil] whileFalse: [
self consumeExcessEvents.
instance create.
instance handleLastEvent.
instance eventLoop.
temp := instance nextToRun.
instance nextToRun: nil. "clear forward reference"
"Note: hard assignment is used here to avoid keeping
a perpetual reference to the first shown application...this
is one of the few places where ::= is actually required"
instance ::= temp].
|
| C5. Bug in Dictionary>>new: |
Jean-Jacques Moreau:
The class Dictionary currently allows dictionaries to be created
with a size of 0 which later on causes hashing problems (division
by zero). A brief look at Set>>new: suggests the following
fix:
Dictionary>>new: capacity
^(self basicNew: (capacity max: 1) * 2) initialize.
|
| C6. Bug in Integer>>readFrom:radix: |
Integer>>readFrom: stream radix: radix
" ^ nil or Integer
TREG: if the stream has no digit return nil"
| value char position |
position := stream position.
[(char := stream peek) notNil and: [char isDigit]]
whileTrue: [
value := 0.
stream next].
value ifNil: [^nil].
stream position: position.
value := 0.
[(char := stream peek) notNil and: [char isDigit]]
whileTrue: [
char digitValue >= radix
ifTrue: [^value].
value := value * radix + char digitValue.
stream next].
^value.
|
| C7. Bug in TextField>>grabFocus |
TextField>>grabFocus
"1.6a4 implementation: SYSTRAP FldGrabFocus: self getPointer
Palm: you rarely need to call this function directly.
Instead use FrmSetFocus which calls FldGrabFocus for you.
One instance you need to call it direclty is to set the focus in
a field contained in table cell.
TREG: if you only call FldGrabFocus, copy, paste, cut won't work"
Better to call this method from your application via widgetName:
rather than directly calling Form>setFocus:"
| formPtr index |
formPtr := SYSTRAP FrmGetActiveForm.
index := SYSTRAP FrmGetObjectIndex: formPtr id: id.
SYSTRAP FrmSetFocus: formPtr index: index
|
| C8. Bug in Database>>recordCount |
Database>>recordCount
"Return the number of records in the database.
Deleted records are also included.
See recordCountInCategory: aCategory to get only active records.
Record indexes are 0..recordCount-1"
"TREG: If the database has just been created, systrap
fails so return 0"
dmOpenRef fNil: [^0].
^SYSTRAP DmNumRecords: dmOpenRef.
|
| C9. Bug in Database>>
recordCountInCategory: aCategory |
Database>>recordCountInCategory: aCategory
" ^ <Integer>aCategory <Integer>
Return the number of records in the database for a specific category
Use ##dmAllCategories to excluded deleted records"
"TREG: If the database has just been created, systrap fails so return 0"
dmOpenRef ifNil: [^0].
^SYSTRAP DmNumRecordsInCategory: dmOpenRef category: aCategory
|
| C10. Bug in String>>trimBlanks |
Jean-Jacques Moreau:
"The current version of String>>trimBlanks does
not work with either empty of blank strings. Appended is a suggested
fix, which reverses the order of the tests."
String>>trimBlanks
| first last |
first := 1.
last := self size.
[first < last and: [(self at: first) isWhitespace]]
whileTrue: [first := first + 1].
[first <= last and: [(self at: last) isWhitespace]]
whileTrue: [last := last - 1].
^self copyFrom: first to: last
|
| C11. Possible
bug in Transcript >>nextPutAll: |
Jean-Jacques Moreau:
"Currently, the Transcript does not scroll when displaying
long strings. Even worse, it crashes when displaying strings
>= 100 characters. Here is a suggested fix."
Transcript >>nextPutAll: string
| window stream line |
window := Window.
stream := string readStream.
[stream atEnd] whileFalse:
[line := stream upTo: Character cr.
window
drawString: line
x: x
y: 150 - window fontHeight.
x := x + (window widthOfString: line).
self cr].
|
| C12. Possible
bug in Integer>>~= |
Jean-Jacques Moreau:
I believe there is a bug in the ~= comparison method for
integers. I have two collections, of identical sizes. The following
expression generates an error (but it shouldn't):
coll1 size ~= coll2 size ifTrue: [self error: 'different sizes']
The following expression works as expected, and does not generate an error:
coll1 size = coll2 size ifFalse: [self error: 'different sizes']
|
3.2 Virtual
Machine
| C13. Bug in vm.c>>infer_selector() |
Jean-Jacques Moreau:
The method infer_selector(class, ip) in vm.c can fail to
return the corresponding selector. This is due to an improper
test:
if (ip > ip_start)
The correct test is:
if (ip >= ip_start)
|
3.3 Upgrading
from PST 1.5 to PST 1.6
| C14. To make
old 1.5 projects work: |
|
Don’t forget
these 2 changes:
Otherwise you might get this error message:
|
4. Improvements
| I. How should
I submit suggested improvements to Pocket Smalltalk? |
If you are proud
of a some functionality that you've built, don't hesitate to
post the packages. Send them to the pocketstug discussion
group or to me. I will make sure the FAQ is updated. You might
also want to publish them in: pocketstup>>files>>prj
If you send a smalltalk package adding functionality to original
packages, please follow this naming convention:
ExtendedXxx.st
where Xxx is the name of the original package. Example: extendedCore.st.
If you send a totally new packages or set of packages, please
also include a simple demo to ease understanding. |
4.1 Suggested
Improvements to the IDE
| I1. List of 4
last projects in File menu |
| A request was made
to have a list in the File menu showing the 4 last projects
as in MS-Excel or Word. |
| I2. Is it possible
to automatically launch a project? |
| Is it possible to
pass a project file as parameter to PST? Add a pocketSt /? e.g.,
to see all parameters in Windows? |
| I3. When exiting,
could PST offer more options for saving the project? |
| PST could offer
the choice: ”Do you want to save before exiting?: Yes,
No, Cancel" |
| I4. Remembering
categories? |
| Quick categorize
should show all categories, even those entered manually. |
| I5. Categorize
SYSTRAPs? |
| Add categories per
Palm OS Manager and version. |
| I6. Add a "project
properties" window? |
|
From the File menu
a "Properties" option could display a new window with
major properties:
- Project name (human readable)
- Pilrc path
- Start directory (give the whole path from the top)
- System directory (local to start directory)
- Working directory (local to start directory)
- Some items from the "System Properties" constant
categories
Display project name without path in title bar or PST.
|
| I7. Add a version
number to packages? — a date is not enough |
| To ease manipulation
of packages, a version number could be added as it was done
for the vm (alias vm16a4.prc). |
| I8. Subclass
CPointer into Pointer and Handle (HeapAllocater is super class)? |
| Ask for my handleRedo.zip,
though changes are required in the VM that I haven't been able
to do yet. |
| I9. Sort by class
(and method names) all new methods of a package? |
| Sorting could be
done upon saving from special save menu |
| I10. Add "Copy
to another class" in class browser? |
| |
| I11. Reloading
packages? |
| Reload a large project
without having sorted packages causes problems because classes
are in wrong package. Pressing ”Continue” goes fine.
Could get a list of errors? |
| I12. Add Find
and Replace in method code? |
| Add these menu picks
to the Browser. |
| I13. Why do windows
still have the "sun" icon, not the balloon? |
| While the dialog
windows have a baloon icons? |
| I14. How can
a PST application be assigned to a category on the PalmOS? |
| |
| I15. Renaming
resources? |
| Why does PST have
names like ##ResourceDB1 and ##ResourceDB2? Why not GuiResources
and WmResource? and also PilrcResource if it's possible to generate
.rcp files from PST. |
| I16. Save chosen
font? |
| Chosen font is not
saved and restored. |
| I17. Cancelling
loading project? |
| Changing paths manually
in a PST file and reloading the project can give an understandable
error "The system cannot find the path specified" but pressing
"No" should really stop the loading process and maybe
revert to the previous fully-loaded image. This should also
be the case upon errors when loading single packages from the
Package Browser. |
| I18. Path definition
of packages? |
Changing paths manually
in the PST file and reloading the project can give an understandable
error: ”The system cannot find the path specified”.
I edited it to specify the right local paths given the working
directory. I had 3 local packages (Black jack.pst). I updated
all 3 but got errors on loading the second one:
PST adds the local path. Suggestion: define the system and working
directories.
I.e., it could look like:
PstSystem systemDirectory: ’palmos\’!
PstSystem workingDirectory: ’demos\black jack’!
PstSystem addSystemPackage: 'core.st' dontSave: true!
PstSystem addSystemPackage: 'forms.st' dontSave: true!
PstSystem addSystemPackage: 'database.st' dontSave: true!
PstSystem addWorkingPackage: 'Emulated UI.st' dontSave: true!
PstSystem addWorkingPackage: ' CardFramework.st' dontSave: true!
|
| I19. Palm OS
Constants? |
| PST could be able
to read Palm OS header files from SDK and automatically generate
constants from C constants and enums. If this is too complex
there could be constant packages created. |
| I20. Determining
minimum and maximum required OS versions? |
| A check-program
could be written to verify the minimum and maximumOS versions
a certain project requires. Going through all methods of "save
in project" packages, looking for SYSTRAP they call and listing
what version the traps are implemented in would tell what Palm
OS versions this application can run on. These stamps could
even be included upon saving a package with a special menu option. |
4.2 New
Packages and VM features
| I21. Ben's C
calls and VM optimisation |
| Ben Hultink has
released a distribution-2001-07-25.zip (in the discussion
group file area pocketstug>>files) that includes changes
to the virtual machine to support C calls and vm as GLIB. This
could be part of a later PST release. |
| I22. Ben's table
package |
| Ben Hultink has
released a distribution-2001-07-25.zip (in the discussion
group file area pocketstug>>files). This files contains
a table.st. This could be part of a later PST release and there
could be a demo. |
| I23. Ben's augment
package |
| It can be found
in pocketstug>>files. |
| I24. BlackJack's
EmulatedUi.st |
| It can be found
in pocketstug>>files. Should it be part of standard
packages? |
| I25. SerialTest.st |
| It can be found
in pocketstug>>files. Should it be part of standard
"communication" package? |
| I26. SerialPort.zip |
| It can be found
in pocketstug>>files. Should it be part of standard
"communication" demo? |
| I27. Palm OS
Version package |
| It can be found
in pocketstug>>files>>prj. The file osVersion-v1-and-v2.zip
contains 2 ways of retrieving the OS version your devide runs
on. It also shows how to test the version at laucnh time. The
3 methods of OsVersion-v2.st are worth considering for core.st. |
| I28. Returning
for Application package |
It can be found
in pocketstug>>files>>prj. ReturningFromApplication.st
implements return values that your application can receive upon
closing popup as well as other non-popup applications. This
value can then be used by the calling application to take the
appropriate action.
The code uses predefined constants but it could more general
and could return instead the button or menu option value that
was pressed. |
| I29. Daniel Enting's
SUnit |
|
It can be found
in pocketstug>>files. However, as long as PST
has no exceptions, it is not possible to do ordinary unit
testing. After a failure it is not possible to continue testing
within the running application.
|
| I30. Add AddOnsVW
package |
| It can be found
in a message to the pocketstug discussion group. Search for
that package name. |
4.3 New
Methods
| I31. Useful method:
ReadStream>>upToSeparator |
|
Jean-Jacques Moreau:
ReadStream >>upToSeparator
"Answer a subcollection from position to the occurrence
(if any, exclusive) of a separator. The stream is left positioned
after the separator. If no separator is found answer everything."
| index start end |
start := index := position + 1.
[index <= limit] whileTrue: [
(collection at: index) isWhitespace ifTrue: [
position := index.
^collection copyFrom: start to: index - 1].
index := index + 1].
position := limit.
^collection copyFrom: start to: limit
|
| I32. Useful method:
ReadStream>>space and tab |
|
Jean-Jacques Moreau:
Here are two utility methods for class Transcript.
Transcript>>space
^self current nextPut: $\space.
Transcript>>tab
^self current nextPut: $\tab.
|
| I33. Useful method:
Integer>>asBigEndian / asLittleEndian |
When a parameter
has to be a value within a C enum, a bitshit 8 in PST is needed.
To make code more understandable than just adding "bitshift:
0", use:
Integer>>asBigEndian
"Convert myself into a 8 bit-left-shifted integer.
To be used as input parameter for SYSTRAP when referring to
C enum values and some C constants"
^self bitShift: 8
Integer>>asLittleEndian
"Convert myself into a 8 bit-right-shifted integer.
To be used on SYSTRAP return values when retrieving
C enum values and some C constants"
^self bitShift: -8
The method name
was suggested by Sunir Shah.
[Note from N.C.: Isn't it the case that big-endian / little-endian
should swap bytes, not just shift them?
Note: Behavior to be tested — is the bitshift or byte
reversal needed at all? |
| I34. Storing
in and reading from the Clipboard |
|
Eric:
Here is the C function used to do it, it’s a systrap:
void ClipboardAddItem (const ClipboardFormatType format,
const VoidPtr ptr, Word length)
enum clipboardFormats {
clipboardText,
clipboardInk,
clipboardBitmap };
typedef enum clipboardFormats ClipboardFormatType;
Daniel Enting:
I worked one day to make the clipboard function and the result
is well worth it. I don’t think there are simpler ways
to implement this. Why not add it to the Forms package?
PalmOS class>>getClipboardString
| handle length string |
handle := SYSTRAP ClipboardGetItem: 0 with: PadBuffer.
length := PadBuffer wordAt: 0.
string := String new: length.
SYSTRAP
MemMove: string
from: handle lock
bytes: length.
handle unlock.
^string
PalmOS class>>putClipboardString: aStringOrByteArray
SYSTRAP
ClipboardAddItem: 0
with: aStringOrByteArray
with: aStringOrByteArray size
Thierry:
ClipboardFormatType
enum values could be defined as constants in category: "PalmOS:
Clipboard Format Type":
| Constant
Name |
Enum
Position |
| ##clipboardText |
0 |
| ##clipboardInk |
1 |
| ##clipboardBitmap |
2 |
In Daniel's code 0s can now be replaced by "##clipboardText
asBigEndian".
|
5. Contributors
Thanks to the
following persons for their supportive replies and contributions:
Joey Gibson
Eric Arseneau
Ben Hultink
Andrew Brault
Jason Dufair
Nathan Eaton
Daniel Enting
Peter Epstein
Jean-Jacques Moreau
Christian Schmidt-Setzwein
Hans Scholz
Sunir Shah
VPutz
N. Chamfort
Send any comments, additions,
corrections, questions, or answers to:
thierry_reignier@hotmail.com
6. Document History
| Version |
Editor |
Comments |
| 1.1 |
N.
Chamfort |
December
19, 2001 — Converted to HTML; set in new page layout;
extensive editing to make the text more readable by newbies.
|
| 1.0 |
Thierry
Reignier |
September
10, 2001 — Created document; messages 1250 through
1612
October 6, 2001 — Published document at pocketstug |
|
Last updated:
Jan 20, 2002
Palm
Powered is a trademark of Palm Inc. Pocket Smalltalk is trademark
of Pocket Smalltalk Group. Copyright (c) 1998 - 2001 Pocket Smalltalk
Group.
|
|
