PeterBelow
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Everything posted by PeterBelow
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SudokuHelper - Example for uncoupled design via interfaces
PeterBelow replied to PeterBelow's topic in I made this
Well, interface references are pointers, so the problem is just how to make sure the reference count stays correct, which the code does. The singleton template the code was created from is quite old, however, predating the appearance of TMonitor by several years. There may be a cleaner way to implement this these days, but I don't like to change working code if there's no pressing reason to do so.- 38 replies
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SudokuHelper - Example for uncoupled design via interfaces
PeterBelow replied to PeterBelow's topic in I made this
That code comes from the forin template that comes with newer versions of Delphi. Sorry for the inconvenience, but since I program mostly for my own use i'm not much concerned with compatibilty with older Delphi versions and simply did not notice this as a potential problem.- 38 replies
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Pointers... loops...
PeterBelow replied to Sonjli's topic in Algorithms, Data Structures and Class Design
http://rvelthuis.de/articles/articles-pointers.html -
That sounds as if the form is no longer the foreground window after the ActiveX control hasloaded the file. Try to add a BringToFront; after the LoadFile line.
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Just a guess: check the value of self.handle in both methods to verify they are the same. VCL forms are prone to recreate their window handle at the drop of a hat...
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Did you remember to set the PopupMode property of your modal forms to pmAuto? What you describe sounds like a Z-order problem. But I see from the newer messages that the problem spontaneously resolved itself. It always makes me nervous when that happens in my projects...
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Look at the Format function, it can be used to compose a string from values/variables using a template string with placeholders, taking the values to insert via an open array parameter. That covers all standard simple datatypes, but complex types like objects, arrays, dictionaries usually have no default method to convert their content to a string (although some have a ToString method, natively or through class or record helpers). For your own classes you can override the ToString method inherited from TObject, for instance.
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Maake sure you set the form borderstyle to bsNone, so it has no caption bar. Windows does not like controls with the WS_Caption window style (and that is what the form becomes when you embed it), they have focus issues likr the one you observed.
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Windows messages are lost when using SetTimer
PeterBelow replied to Clément's topic in Algorithms, Data Structures and Class Design
Timer messages have low priority. If your DoProcessMessages call takes longer than the message interval then a timer tick will not add a new wm_timer message to the queue but increment an internal count for the message already in the queue. Use a waitable timer and one of the MsgWait API functions instead of SetTimer, -
Well, there is a FileSearch function in Sysutils that will search for a file in semicolon-separated list of directory names, but of course you still have to extract the library path from the IDE settings (= registry key, specific for an IDE version), the search path from the current project, if relevant, replace any macros ($(name)) in the pathes etc. to get the list of folders. I'm not aware of a ready-made function for this exposed in the RTL or Open Tools API.
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The Embarcadero GetIt server could not be reached...
PeterBelow replied to PeterPanettone's topic in Delphi IDE and APIs
https://community.idera.com/developer-tools/b/blog/posts/temporary-10-3-2-getit-server-for-installing-10-3-2-add-on-packages?fbclid=IwAR1bV79CCoutmAyH6slVbima_F9QMX29QX1nnwuCl5COCdmXU86BJJNhN9Y -
Conceptual - callbacks that are called from background thread
PeterBelow replied to Fr0sT.Brutal's topic in Algorithms, Data Structures and Class Design
Yes, it is far from easy to switch processing to a specific secondary thread. Basically it is only possible savely if that thread has been written for this. So i can only concur with your previous reply: the responsibility of handling the synchronizing should fall to the code providing the callback. -
handling predicate conditions
PeterBelow replied to David Schwartz's topic in Algorithms, Data Structures and Class Design
Yes, but the error you get then will not immediately indicate what the problem is. The way I do it its clear that the problem is a contract violation, and one can write unit tests that check whether the method correctly detects a contract violation. -
handling predicate conditions
PeterBelow replied to David Schwartz's topic in Algorithms, Data Structures and Class Design
I usually test for pre and postconditions like this: procedure TBlobDB.CreateNewDatabase(aDBStream, aIndexStream: TStream; aTakeStreamOwnership: boolean); const Procname = 'TBlobDB.CreateNewDatabase'; begin if not Assigned(aDBStream) then raise EParameterCannotBeNil.Create(Procname,'aDBStream'); if not Assigned(aIndexStream) then raise EParameterCannotBeNil.Create(Procname,'aIndexStream'); This is for errors that are supposed to be found and fixed during the testing phase or (for library code) in unit tests. For user input the input is validated before it is used by the program, if this is at all feasable. The end user should never see an exception coming from parameter validation at a lower level, in my opinion, since the UI context may not be evident at that point and it may be unclear to the user what he did wrong. -
Well, the cure is simple: do not use inline variables 😉. They are alien to the language anyway and serve no real purpose IMNSHO...
- 9 replies
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- debug
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Lots of errors when trying to compile an old project
PeterBelow replied to ertank's topic in General Help
Did you just open the old D7 project in Rio to start the migration? That is not a good idea for such a massive version jump. After you have extracted the complete old project from version control, close all files and the RIO IDE and go to the project folder on disk and move all files not having one of the following extensions to a zip folder: dpr, pas, res, rc, ico If the project contains other resources you may keep them as well. The important part is to delete the old project file (do not remember what extension it used in D7, perhaps bdsproj, and the old cfg file as well. Then open the IDE and open the project's dpr file. This will create a new project file. The project will show up in the project manager view and should have the Win32 target assigned automatically. It will also have a default build configuration assigned, but the settings used for that will not all be suitable for your project. So the next step is to open the project options dialog (from the Project menu or the project manager view's context menu) and adjust the settings, especially the search and output pathes. Beware! The settings dialog is completely different from the one you may know from D7! Since you can have multiple build configurations for multiple target platforms the settings are organized as a kind of hierarchy, and you have to first select the correct hierarchy level for the settings you want to modify. You do this using the combo box at the top of the right-side pane, pick "32 bit windows platform" under "all configurations". In the left-hand treeview you should have the top node (Delphi compiler) selected, that shows the page with the project-specific path settings on the right. The most important things here to get your project to compile are the unit scope names and the search path. Delphi uses namespace-like scope names on the run-time and framework units and has done so since many versions. But D7 did not use unit scope names. To make migration easier the IDE and the compiler will automatically search for units named in Uses clauses within the scopes listed in the unit scope names field if the unit is not found by the given name (the System scope is always searched, though). The default list contains the most frequently used scopes, but you have to make sure that VCL and VCL.Win are in the list as well. The search path becomes important if your project uses custom units not located in the project folder (where the dpr file and the generated dproj file reside). You have to add all pathes for units there that are not found on the IDE library path (as dcu or pas). I don't know how you organize your project files on disk. I usually use something like projectname (dpr, dproj, cfg) source (pas, inc) bin (dcus) exe (exe) doc (documentation) resources (rc and res files, files embedded in them) test (unit tests and other test programs) So the output folder path set in the dialog would be (without the quotes, of course) ".\exe". The unit output path would be ".\bin\$(platform)\$(config)" The search path would be ".\bin\$(platform)\$(config);.\source;$(common);$(include)" "common" and "include" are environment variables defined in the IDE Options dialog that contain the pathes to my code library (not project specific units). The resource compiler node on the left also has a search path setting, these are for rc and res files, but in my experience this has been a bit unreliable in recent versions; i often have to add rc files explicitely to a project to get them compiled and linked in. -
As far as I remember from older discussions you have to merge (mix) the sound files into one before you can play it. Windows has an API for that, see Audio mixers If you google for mixer audio sound delphi you may find something useful.
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Mh, not very enlightening. Looks like setting up a exception handling frame.
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I'm surprised that you can even set a breakpoint on a variable declaration. Makes no sense in my opinion. Could you please run to the breakpoint and switch to the CPU disassembly view to see what statement the breakpoint is actually on? I have not been able to install 10.3.2 myself yet due to trouble with the licence, so cannot test that myself.
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Component Compatibility 10.3.2 vs. 10.3.1?
PeterBelow replied to Steve Maughan's topic in General Help
Generally the minor releases of Delphi (e.g. 10.3.1 10.3.2) are binary compatible, which means there are no changes to the interface part of run-time library or frame work units, so dcus and packages build for one release can be used with other. The same applies to the open tools API, so components you bought for 10.3.1 should work in 10.3.2, even if you cannot recompile them since you don't have the source. This only applies if said components play by the rules, of course. If they rely on undocumented features or dig around in the IDE's innards all bets are off. -
Is the project perhaps Win64 or FMX?
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WinAPI to query if a form is ready to Rock.
PeterBelow replied to Tommi Prami's topic in Windows API
Some of the form properties (e.g. border and bordericons) are implemented via window styles on the API level, and Windows only honors some of the styles when the window is first created. Changes to these properties recreate the window handle for this reason. Another reason are modal forms with popupmode pmauto or pmexplicit; their window handle has to be recreated when they are shown to tie them to their popup parent in Z-order. Changing the formstyle also recreates the handle. -
WinAPI to query if a form is ready to Rock.
PeterBelow replied to Tommi Prami's topic in Windows API
There is no panacea for this kind of problem, too much depends on how the form in question has been set up. What you can do from "outside" the process is check if the window is visible (IsWindowVisible) check whether it is the current foreground window (GetForegroundWindow) check whether its message loop is running (WaitForInputIdle, or use SendMessageTimeout to send a do-nothing message to the form, e.g. wm_null, the call will not return until the loop is running) Nothing will help you if the form does some kind of delayed initialization, e.g. using a timer started when the form is created. Also keep in mind that a Delphi form may recreate its window handle at the drop of a (virtual) hat during the initialization phase. -
The <projectname>.res file is the one the IDE builds for the form resources, it also contains versioninfo if you enabled that in the project options. The verinfo.res has to be something you added yourself to the project, or some add-in you use added. Look for a {$R verinfo.rc verinfo.res} line in the project dpr file and delete it. The confllict arises since both resources have the same ID.
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Refer to Form Control without using the Form unit?
PeterBelow replied to Mike Torrettinni's topic in VCL
You cannot do it this way without using the form units. It is not a good way to translate an application anyway. Have you looked at the IDE Translation Manager?