Creational mechanism for resourced and non-resourced FMX forms

Author: lmbelo

Source/fmx/WrapFmxForms.pas

@@ -5,7 +5,8 @@
 interface
 
 uses
- FMX.Forms, PythonEngine, WrapDelphiClasses, WrapFmxTypes, WrapFmxControls;
+ System.Classes, FMX.Forms,
+ PythonEngine, WrapFmxTypes, WrapDelphiClasses, WrapFmxControls;
 
 type
  TPyDelphiApplication = class(TPyDelphiComponent)
@@ -23,7 +24,9 @@ TPyDelphiCommonCustomForm = class(TPyDelphiFmxObject)
  private
  function GetDelphiObject: TCommonCustomForm;
  procedure SetDelphiObject(const Value: TCommonCustomForm);
+ function HasFormRes(const AClass: TClass): boolean;
  public
+ function CreateComponent(AOwner: TComponent): TComponent; override;
  // Class methods
  class function DelphiObjectClass: TClass; override;
  // Properties
@@ -88,7 +91,7 @@ TPyDelphiScreen = class(TPyDelphiComponent)
 implementation
 
 uses
- WrapDelphi;
+ WrapDelphi, System.Types;
 
 { Register the wrappers, the globals and the constants }
 type
@@ -153,6 +156,46 @@ procedure TPyDelphiApplication.SetDelphiObject(const Value: TApplication);
 
 { TPyDelphiCommonCustomForm }
 
+function TPyDelphiCommonCustomForm.CreateComponent(
+ AOwner: TComponent): TComponent;
+type
+ TCommonCustomFormClass = class of TCommonCustomForm;
+var
+ LClass: TClass;
+ LFormClass: TCommonCustomFormClass;
+ LClassName: string;
+begin
+ //if we have a subclass of our Form wrapper, then check if we can find a
+ //Delphi class that would have the same name as the Python class.
+ //This would allow Python to instanciate an existing Delphi form class,
+ //insted of only using a blank form.
+ if (ob_type <> PythonType.TheTypePtr) then begin
+ LClassName := string(ob_type.tp_name);
+ LClass := GetClass(LClassName);
+ if not Assigned(LClass) then
+ LClass := GetClass('T' + LClassName);
+ if Assigned(LClass) and LClass.InheritsFrom(TCommonCustomForm) then
+ LFormClass := TCommonCustomFormClass(LClass);
+ end else begin
+ //get de default form class
+ if DelphiObjectClass.InheritsFrom(TCommonCustomForm) then
+ LFormClass := TCommonCustomFormClass(DelphiObjectClass);
+ end;
+
+ //if it's not a design form, so we create it as a non-resourced form,
+ //using the non-resourced constructor.
+ //if the Owner is TApplication, then we have to call its CreateForm method,
+ //otherwise we won't have a mian form defined, as the main form is the first
+ //created form. Of course, this is a concern only when Python controls all the
+ //GUI and calls Apllication.Run by itself.
+ if not HasFormRes(LFormClass) then
+ Result := LFormClass.CreateNew(AOwner)
+ else if (AOwner = Application) then
+ Application.CreateForm(LFormClass, Result)
+ else
+ Result := LFormClass.Create(AOwner);
+end;
+
 class function TPyDelphiCommonCustomForm.DelphiObjectClass: TClass;
 begin
  Result := TCommonCustomForm;
@@ -163,6 +206,13 @@ function TPyDelphiCommonCustomForm.GetDelphiObject: TCommonCustomForm;
  Result := TCommonCustomForm(inherited DelphiObject);
 end;
 
+function TPyDelphiCommonCustomForm.HasFormRes(const AClass: TClass): boolean;
+begin
+ Result := FindResource(
+ FindResourceHInstance(FindClassHInstance(AClass)),
+ PChar(AClass.ClassName), PChar(RT_RCDATA)) <> 0;
+end;
+
 procedure TPyDelphiCommonCustomForm.SetDelphiObject(
  const Value: TCommonCustomForm);
 begin