How capture the active url based in a substring without repetition? - delphi

Question

I want capture the url of active window based in a substring and add to Memo only if sActiveURL is different of sOldURL.
The trouble in my code is that always is added to Memo the same url ignoring the verification if sActiveURL <> sOldURL.
How fix this?
Main:
type
TForm1 = class(TForm)
tmr1: TTimer;
mmo1: TMemo;
procedure tmr1Timer(Sender: TObject);
private
{ Private declarations }
sActiveURL,sOldURL : string;
public
{ Public declarations }
end;
var
Form1: TForm1;
Flag: Boolean;
implementation
uses
UIAutomationClient_TLB, Activex, StrUtils;
{$R *.dfm}
function GetURL(hTargetWnd: HWND): string;
function Enumerar(pParent: IUIAutomationElement; Scope: TreeScope; pCondition: IUIAutomationCondition): String;
var
found : IUIAutomationElementArray;
ALen : Integer;
i : Integer;
iElement : IUIAutomationElement;
retorno: integer;
value : WideString;
iInter: IInterface;
ValPattern : IUIAutomationValuePattern;
begin
Result := '';
Flag := false;
if pParent = nil then
Exit;
pParent.FindAll(Scope, pCondition, found);
found.Get_Length(ALen);
for i := 1 to ALen - 1 do
begin
found.GetElement(i, iElement);
iElement.Get_CurrentControlType(retorno);
if (
(retorno = UIA_EditControlTypeId) or
(retorno = UIA_GroupControlTypeId)
) then
begin
iElement.GetCurrentPattern(UIA_ValuePatternId, iInter);
if Assigned(iInter) then
begin
if iInter.QueryInterface(IID_IUIAutomationValuePattern, ValPattern) = S_OK then
begin
ValPattern.Get_CurrentValue(value);
Result := trim(value);
Flag := true;
Break;
end;
end;
end;
if not Flag then
begin
Result := Enumerar(iElement, Scope, pCondition);
end;
end;
end;
var
UIAuto : IUIAutomation;
Ret : Integer;
RootElement : IUIAutomationElement;
Scope : TreeScope;
varProp : OleVariant;
pCondition : IUIAutomationCondition;
begin
Result := '';
try
UIAuto := CoCUIAutomation.Create;
if Succeeded(UIAuto.ElementFromHandle(hTargetWnd, RootElement)) then
begin
TVariantArg(varProp).vt := VT_BOOL;
TVariantArg(varProp).vbool := True;
UIAuto.CreatePropertyCondition(UIA_IsControlElementPropertyId,
varProp,
pCondition);
Scope := TreeScope_Element or TreeScope_Children;
Result := Enumerar(RootElement, Scope, pCondition);
end;
except
Result := '';
end;
end;
procedure TForm1.tmr1Timer(Sender: TObject);
begin
sActiveURL := GetURL(GetForegroundWindow);
if sActiveURL <> sOldURL then
begin
if AnsiContainsText(sActiveURL, 'stackoverflow.com') then
begin
sOldURL := sActiveURL;
mmo1.Lines.Add('['+sActiveURL+']<'+DateToStr(Date)+'>');
end;
end;
end;
UIAutomationClient_TLB.pas
EDITION:
On debug i discovered that none value is attrib to sOldURL variable.
procedure TForm1.tmr1Timer(Sender: TObject);
var
sActiveURL,sOldURL : string;
begin
sActiveURL := GetURL(GetForegroundWindow);
mmo1.Lines.Add('[sOldURL = '+sOldURL+' ]');
mmo1.Lines.Add('[sActiveURL = '+sActiveURL+' ]');
mmo1.Lines.Add('');
if sActiveURL <> sOldURL then
begin
if AnsiContainsText(sActiveURL, 'stackoverflow.com') then
begin
sOldURL := sActiveURL;
mmo1.Lines.Add(sActiveURL);
mmo1.Lines.Add('');
mmo1.Lines.Add('');
end;
end;
end;

Answer 1

The reason is as I shortly described in comments and is visible when the focused window is not your browser, for example your applications wiindow with the mmo1: TMemo:
GetForegroundWindow() returns the window that has focus.
Your GetURL(GetForegroundWindow) searches for an edit control (UIA_EditControlTypeId), of the focused window, and finds your memo control and returns the content of the memo.
Further, if you change focus to your browser, its URL will be correctly recorded in the memo, and if you return focus to your application, the condition if AnsiContainsText(sActiveURL, 'stackoverflow.com') will be true.
You then write to the memo, adding what you think is a real URL, and then this will be repeated for every timer event.
You need to only check the real browser window (skip all other) for its current URL. Try this, if you are using IE, otherwise you must modify FindWindow():
procedure TForm24.tmr1Timer(Sender: TObject);
var //
hIEWnd: HWND; //
begin
hIEWnd := FindWindow('IEFrame', nil); //
sActiveURL := GetURL(hIEWnd); //
// sActiveURL := GetURL(GetForegroundWindow);
if sActiveURL <> sOldURL then
begin
if AnsiContainsText(sActiveURL, 'stackoverflow.com') then
begin
sOldURL := sActiveURL;
mmo1.Lines.Add('[' + sActiveURL + ']<' + DateToStr(Date) + '>');
end;
end;
end;
Modified lines are marked with //