BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  TImage::OnProgress          BorlandTalk.com Forum Index -> C++ Builder (VCL Components Usage) View previous topic :: View next topic   Author Message Vincent Guest Posted: Thu Jun 17, 2004 10:12 am    Post subject: TImage::OnProgress Little problem : I just want to show a progress bar when loading a image into a Timage. But it doesn't work, here's the code void __fastcall TForm5::Image2Progress(TObject *Sender, TProgressStage Stage, BYTE PercentDone, bool RedrawNow, const TRect &R, const AnsiString Msg) { switch (Stage) { case psStarting: CGauge1->Progress=0; CGauge1->Visible=true; break; case psRunning: CGauge1->Progress=PercentDone; break; case psEnding: CGauge1->Visible=false; break; } } using breakpoint i can see that i never enter in the routine. I thought that this routine will called "periodically" when i load a file intio my image with : Image2->Picture->Bitmap->LoadFromFile(FileListBox1->FileName); Any Idea Thanks Vincent Back to top nicolasr Guest Posted: Thu Jun 17, 2004 1:34 pm    Post subject: Re: TImage::OnProgress Hi, I guess that this event is only used with image types that need to decompress the data before displaying it. Try #include <jpeg.hpp> //needed to register jpg file type .... Image2->Picture->LoadFromFile(FileListBox1->FileName); .... with a large jpg file and see if the handler is then called. Nick Quote: Little problem : I just want to show a progress bar when loading a image into a Timage. But it doesn't work, here's the code void __fastcall TForm5::Image2Progress(TObject *Sender, TProgressStage Stage, BYTE PercentDone, bool RedrawNow, const TRect &R, const AnsiString Msg) { switch (Stage) { case psStarting: CGauge1->Progress=0; CGauge1->Visible=true; break; case psRunning: CGauge1->Progress=PercentDone; break; case psEnding: CGauge1->Visible=false; break; } } using breakpoint i can see that i never enter in the routine. I thought that this routine will called "periodically" when i load a file intio my image with : Image2->Picture->Bitmap->LoadFromFile(FileListBox1->FileName); Any Idea Thanks Vincent Back to top Remy Lebeau (TeamB) Guest Posted: Thu Jun 17, 2004 5:38 pm    Post subject: Re: TImage::OnProgress "nicolasr" <nicolasrNOSPAMATSIGNgmx.net> wrote Quote: I guess that this event is only used with image types that need to decompress the data before displaying it. The OnProgress event is optional in TGraphic classes. They are not required to trigger it during loading/saving. In fact, none of the default graphic classes (TBitmap, TIcon, TMetaFile, etc) use it at all. Gambit Back to top Andy Guest Posted: Mon Aug 02, 2004 7:11 am    Post subject: Re: TImage::OnProgress Hi Vincent, I had the same problem showing a progress bar when loading a large RTF-File into a TRichEdit with LoadingFromFile. I found this solution: First I opened the file with a TFileStream and loaded the data with the LoadFromStream function (which also exists for the TGraphic class). LoadFromStream access the stream data via the Read method, which is a virtual Method of TFileStream. So I wrote my own class TMyFileStream derived from TFileStream and overloaded the Read methode: class TMyFileStream : public TFileStream { public: TProgressBar* progressBar; public: TMyFileStream (const String fileName, Word Mode, TProgressBar* progBar) : TFileStram (fileName, Mode), progressBar (progBar) {}; virtual int __fastcall Read(void *Buffer, int Count) { progressBar->Position = (float)(Position/Size)* progressBar->Max; Application->ProcessMessages (); return TFileStream::Read (Buffer, Count); } } So whenever LoadFromStream is reading new data via Read I can update the ProgressBar. Best regards Andy Vincent <vincent.vandendaele (AT) trump (DOT) be> wrote: Quote: Little problem : I just want to show a progress bar when loading a image into a Timage. But it doesn't work, here's the code void __fastcall TForm5::Image2Progress(TObject *Sender, TProgressStage Stage, BYTE PercentDone, bool RedrawNow, const TRect &R, const AnsiString Msg) { switch (Stage) { case psStarting: CGauge1->Progress=0; CGauge1->Visible=true; break; case psRunning: CGauge1->Progress=PercentDone; break; case psEnding: CGauge1->Visible=false; break; } } using breakpoint i can see that i never enter in the routine. I thought that this routine will called "periodically" when i load a file intio my image with : Image2->Picture->Bitmap->LoadFromFile(FileListBox1->FileName); Any Idea Thanks Vincent Back to top Remy Lebeau (TeamB) Guest Posted: Mon Aug 02, 2004 8:29 am    Post subject: Re: TImage::OnProgress "Andy" <Andy-Bauer (AT) gmx (DOT) de> wrote Quote: So I wrote my own class TMyFileStream derived from TFileStream and overloaded the Read methode: Just as a suggestion, I would recommend exposing an OnProgress event for that class rather than having it update a progress bar directly. That will make the code more flexible so that you can use the same code for different purposes. For example: enum TFileStreamReadProgressStage { psFileReadStarting, psFileReading, psFileReadEnding }; typedef void __fastcall (__closure *TMyFileStreamProgress)(TObject *Sender, TFileStreamReadProgressStage Stage, Byte PercentDone); class TMyFileStream : public TFileStream { protected: TMyFileStreamProgress FOnProgress; bool FStarting; Byte FLastPercent; public: __fastcall TMyFileStream(const AnsiString &FileName, Word Mode) : TFileStream(FileName, Mode), FStarting(true), FLastPercent(0) { } virtual __fastcall ~TMyFileStream() { if( (FLastPercent < 100) && (FOnProgress) ) FOnProgress(this, psFileReadEnding, 100); } virtual int __fastcall Read(void *Buffer, int Count) { if( bStarting ) { if( FOnProgress ) FOnProgress(this, psFileReadStarting, 0); bStarting = false; } int Result = TFileStream::Read(Buffer, Count); if( FOnProgress ) { Byte CurrentProgress = ((Position*100)/Size); if( CurrentProgress != FLastPercent ) { FLastPercent = CurrentProgress; FOnProgress(this, (CurrentProgress < 100) ? psFileReading : psFileReadEnding, CurrentProgress); } } return Result; } __property TMyFileStreamProgress OnProgress = {read=FOnProgress, write=FOnProgress}; }; void __fastcall TForm1::LoadRichEdit() { TMyFileStream *Strm = new TMyFileStream("somefile", fmOpenRead | fmShareDenyWrite); try { Strm->OnProgress = RichEditLoadProgress; RichEdit1->LoadFromStream(Strm); } __finally{ delete Strm; } } void __fastcall TForm1::RichEditLoadProgress(TObject *Sender, TFileStreamReadProgressStage Stage, Byte PercentDone) { switch( Stage ) { case psFileReadStarting: ProgressBar1->Position = 0; ProgressBar1->Max = 100; break; case psFileReading: ProgressBar1->Position = PercentDone; break; case psFileReadEnding: ProgressBar1->Position = 0; break; } ProgressBar1->Update(); } Gambit Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> C++ Builder (VCL Components Usage) All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.