Kryvich

@Alexander Elagin Just in case you need the icons because of change indicators, you can try https://sites.google.com/site/kryvich/kryvichs-editor-status-bars. Works without IDE theming too.

@Attila Kovacs if typeData.MaxValue > 30 then "change me to UInt64".

Have you measured how users work with your program? It's possible that an average user use 5-10 reports (tabs) in one session. Then all controls on other tabs just sit in memory, grab GDI resources without need. It's OK to create the form layouts manually, Delphi has all instruments to make this work easier. But after rising HTML and CSS it has become fashionable to entrust the program with the placement and adjustment of the size of controls on a form. For ex. https://www.delphihtmlcomponents.com/comp.html https://www.delphihtmlcomponents.com/reports.html https://www.devexpress.com/products/vcl/layout/ http://docwiki.embarcadero.com/Libraries/Tokyo/en/FMX.Layouts

I presume you didn't put all that controls to the form manually. It's a lot of work. I would use some sort of automation, and create the appropriate controls on the fly when the tab was selected. Then you'll get 3000/50 = 60 controls at a moment.

I never see such forms. Is it for flight control center?

@Stefan Glienke Interesting... Do modern processors can not predict the branch that will be executed in the common case?

You're right. A better solution would be to create and initialize a form by request, and then Show(ShowModal)/Close it as needed. The reference to the created form can be saved as a class variable and freed when an application to finish. It makes sense for forms that need to maintain their state. Or for modal dialogs. And you need to ensure that two or more identical forms are not opened at the same time.

There is option in the project options (Application | Forms) to select what forms to create when an application starts.

@Erik@Grijjy The checks can be regulated by the RangeChecks option {R+}.

A list not allocated in the heap? How is it even possible? Start reading... Good idea! I know where I can try it in my code.

Hi, I try to adopt outstanding and free Pas2js transpiler to Delphi language. My main development IDE is Delphi CE Rio, so I decided to try a new Delphi syntax: generic collections and inline variables. And stumbled upon a runtime error. The code (simplified): program TestInlineVarForDictionary; {$APPTYPE CONSOLE} {$R *.res} uses SysUtils, Generics.Collections; procedure TestDictErr; var Dict: TDictionary<string,TObject>; begin Dict := TDictionary<string,TObject>.Create; for var item in Dict do Writeln('Key = ', item.Key, 'Name = ', item.Value.ClassName); end; procedure TestDictOK; var Dict: TDictionary<string,TObject>; item: TPair<string,TObject>; begin Dict := TDictionary<string,TObject>.Create; for item in Dict do Writeln('Key = ', item.Key, 'Name = ', item.Value.ClassName); end; begin try //!!TestDictOK; TestDictErr; except on E: Exception do begin Writeln(E.ClassName, ': ', E.Message); Write('Press Enter to continue...'); Readln; end; end; end. This program causes Exception class $C0000005 with message 'access violation at 0x0040a86e: write of address 0x0040a29e'. Can you confirm it? Is it a bug in the compiler or/and RTL, or am I misusing the new syntax? It's interesting: if you uncomment TestDictOK that does enumeration in old-style, the exception will disappear!

OK I have a workaround for this issue. Try to specify a type of the inline variable. procedure TestDictErr_WorkAround; var Dict: TDictionary<string,TObject>; begin Dict := TDictionary<string,TObject>.Create; for var item: TPair<string,TObject> in Dict do Writeln('Key = ', item.Key, ' Name = ', item.Value.ClassName); end; I cannot guarantee that this code will be correctly compiled. But at least there is no the runtime error anymore.

Another observation. The exception occurs only if the dictionary has the key and/or value of the string type. If I change it to Integer - the exception disappears. procedure TestDictErr_IntegerKey_OK; var Dict: TDictionary<Integer,TObject>; begin Dict := TDictionary<Integer,TObject>.Create; for var item in Dict do Writeln('Key = ', item.Key, 'Name = ', item.Value.ClassName); end; Well, I just found it. For procedure TestDictOK the compiler generates a pair of calls: call @InitializeRecord call @FinalizeRecord But for procedure TestDictErr it generates only call @FinalizeRecord Program tries to finalize not initialized record and falls. P.S. Is there a bug bounty program for Delphi? :) https://quality.embarcadero.com/browse/RSP-23417

@haentschman It's always better to have named constants instead of numbers. Say you want to swap 2nd and 6th bits in some structure's field. Then you need to scan all your program and check all places where these bits are used. But if you used an enumeration from the start, you just swap these bits in the declaration: type TMyEnum = (mb0, mb5, mb2, mb3, mb4, mb1, mb6, mb7); Of course instead of mb0, mb1 etc. should be really meaningful names, without numbers.

You can write it as If ((b and $01) > 0) or ((b and $08) > 0) or ((b and $80) > 0) then ... Or you can create an enumeration and use meaningful names for each bit. type TMyEnum = (mb0, mb1, mb2, mb3, mb4, mb5, mb6, mb7); TMyBits = set of TMyEnum; // = Byte in size function Test: Byte; var mbs: TMyBits; begin mbs := [mb0, mb3, mb7]; Byte(mbs) := $89; // It's equivalent of mbs := [mb0, mb3, mb7]; if mbs * [mb0, mb3, mb7] <> [] then // If one of bit is set ;//... if mbs * [mb0, mb3, mb7] = [mb0, mb3, mb7] then // If all 3 bits are set ;//... if mbs - [mb0, mb3, mb7] = [] then // If no other bits are set ;//... Include(mbs, mb1); // Set 2nd bit mbs := mbs - [mb3, mb7]; // Unset 4th and 8th bit //etc... Result := Byte(mbs); end; It's always better to deal with clearly named typed variables and constants.

@A.M. Hoornweg In newer Delphi versions you must put the $RTTI directive on each library unit. This is the main difference from XE. @Rollo62 I brought some statistics for my applications here:

I would write it as localVar := ParameterValue; if localVar = None then localVar := DefaultValue; Presume that ParameterValue is assigned in most cases, then DefaultValue will not be accessed in most cases.

Perhaps this will help:

https://stackoverflow.com/questions/2113182/fillchar-but-for-integer-cardinal

Using the Group Policy Editor it is possible to prevent users from accessing to Ctrl-Alt-Del options. https://ccm.net/faq/41738-how-to-prevent-users-from-accessing-the-task-manager

You're right. We can compare the squares of distances: checkDistance2 := Sqr(checkDistance); ... dist2 := Sqr(X1-X2) + Sqr(Y1-Y2); if dist2 < checkDistance2 then .....

@Lars Fosdal Sorry I cannot help you with it. I tried the attribute [JsonReflectAttribute(ctObject???,rtObject???,TArrayElementInterceptor)] but there is no a converter/reverter type that accepts values of any type: strings, numbers, and objects. Perhaps you may need to create a descendant of TJSONUnMarshal to handle all the options. It would be great if Embarcadero improves JSON support and allow to convert other types to a custom record if this record can take values of other types: type TSwitch = class private FSwitch: Boolean; public property Switch: Boolean read FSwitch write FSwitch; end; TArrayElement = record private FValue: Variant; public class operator Implicit(const Value: Integer): TArrayElement; class operator Implicit(const Value: string): TArrayElement; class operator Implicit(const Value: TSwitch): TArrayElement; end;

@Schokohase In fact RTTI is generated for types declared in a DPR file. But it is not findable by TRttiContext.FindType(AQualifiedName: string). In the Delphi help for the function FindType it is written: But there is no information what types have qualified names. And only in System.Rtti.pas I found this comment: @Lars Fosdal Unfortunately, this will not work for the Variant type without additional processing. You can try to declare a custom reverter for an element of the inner array.

@Schokohase It worked, thanks! Can you explain why?

May be TMessageArray = array of array of Variant; ? program TestJson; {$APPTYPE CONSOLE} {$R *.res} uses System.SysUtils, REST.Json; const JsonData = '{' + ' "message": [' + ' [ 0, "a text" ],' + ' [ 1 ],' + ' [ 1, { "switch": true } ],' + ' [ 2, "text one", "text line two" ]' + ' ]' + '}'; type TMessageArray = array of array of Variant; TJsonMessage = class private Fmessage: TMessageArray; public property message: TMessageArray read FMessage write FMessage; end; var Message: TJsonMessage; begin try if TypeInfo(TJsonMessage) = nil then Writeln('No RTTI for ', TJsonMessage.ClassName); Message := TJson.JsonToObject<TJsonMessage>(JsonData); Writeln('Length = ', Length(Message.message)); Message.Free; except on E: Exception do begin Writeln(E.ClassName, ': ', E.Message); Readln; end; end; end. I tried this option, but my test application gives the exception: "Exception class EConversionError with message 'Internal: Cannot instantiate type TestJson.TJsonMessage'.". I still do not understand why.