FMX – Developer Experts

Setting the correct Xcode build number for Delphi FMX Apps

Published on 1. Juni 20171. Juni 2017 by Olaf Monien

If your Xcode version updates (manually or by Apple’s updating mechanism) then make sure to re-import the iOS/macOS SDK from within Delphi.

To build and deploy iOS/macOS apps with Delphi, you need Xcode for the final steps, even though the actual binary is compiled by Delphi. Apple frequently delivers minor updates to Xcode. Current version as of the writing of this article is 8.3.2. This version number of the Xcode build used for preparing apps is apparently checked by Apple, when uploading an IPA file to App Store/iTunes Connect. They don’t do any spooky things, they just check the DTXcodeBuild key in your app’s info.plist file:

This info.plist file is generated by Delphi, and contains various essential settings, such as version number, device requirements etc. Many of these settings can directly be configured, by modifying the values in Delphi – Project – Options – Version Information

DTXCodeBuild is filled in by Delphi automatically though. When you import iOS/macOS SDK, then PAServer obviously issues this command:

/usr/bin/xcodebuild -version -sdk

That returns the available SDK versions and the Xcode build number:

iPhoneOS10.3.sdk - iOS 10.3 (iphoneos10.3)
SDKVersion: 10.3
Xcode 8.3.2
Build version 8E2002

This build version number is apparently stored and used to fill the DTXcodeBuild key’s value.

To bring this number in Delphi in sync with the actual Xcode version, after Xcode was updated (or switched with xcode-select), you have to delete the SDK from Delphi and re-import it using Delphi – Tools – Options – SDK Manager.

This is especially important if you imported the 10.3 SDK while having Xcode 8.3.0 installed. In that case your Delphi iOS apps would be tagged with being built with exactly that version – no matter if you downgraded to Xcode 8.2.1 or applied my „Package Application fix“ – which is required due to a tool chain change that Apple imposed with Xcode 8.3 and up. Any iOS app tagged with being built with Xcode 8.3.0 will be refused by Apple, as that version has been deprecated.

Firemonkey TMemo Scrolling

Published on 28. März 201728. März 2017 by Olaf Monien

When you add lines to a TMemo in Delphi Applications, then you might want to scroll to the very end of that particular Memo, so that the newest lines are kept in view.

In FireMonkey it’s as easy as just calling GoToTextEnd:

procedure TFormMain.AddLog(AMessage: string);
begin
  Memo1.Lines.Add(AMessage);
  Memo1.GoToTextEnd;
end;

You might notice though, that when you clear the Memo at certain times, the scrollbars may get out of sync. To avoid that, you need to call ProcessMessages right after „clear“. Apparently the scrollbars get confused, when you add lines directly after clear command, because the actual position needs to be rendered first (which the ProcessMessages does).

procedure TFormMain.AddLog(AMessage: string);
begin
  if Memo1.Lines.Count > 100 then 
    begin
      Memo1.Lines.Clear;
      Application.ProcessMessages; //without this, scrollbars will show wrong size/position
    end;
  Memo1.Lines.Add(AMessage);
  Memo1.GoToTextEnd;
end;

Sharing DataModules between VCL and FMX projects

Published on 8. Februar 201710. Februar 2017 by Olaf Monien

When you start implementing cross-platform applications in Delphi’s FireMonkey framework, then you might consider reusing TDataMdoule instances from your existing VCL applications. If your code is clean enough, i.e. your DataModules are separated from any UI code, that is contain no references to WinApi, Forms, Controls or other UI relevant units, then this is actually a reasonable approach.

You might run into a weird problem though: The IDE will sometimes insist on adding VCL-dependant units to your DataModul, even if you actually compile for FireMonkey. One example is FireDAC.VCL.Wait which will get added automatically under certain conditions (and which won’t compile under FMX).

There is a property that controls this behaviour in shared TDataModule instances:

ClassGroup is basically a „Pseudo Property“, which adds some magic to the project so that the IDE will behave differently depending on the properties value. To make your DataModule really platform independent set it to: System.Classes.TPersistent

That way, the IDE stops inserting references to either FMX or VCL units in the DataModule’s uses clause. In the case of FireDAC applications, it will just add FireDAC.ConsoleUI.Wait, which will compile just fine on all platforms. You would then add the actual Wait unit in the app’s main form (or in the DPR).