BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Drawing On A Transparent Form          BorlandTalk.com Forum Index -> Delphi Graphics View previous topic :: View next topic   Author Message harrie Guest Posted: Fri Apr 06, 2007 7:25 pm    Post subject: Drawing On A Transparent Form Hi there, I've been trying to emulate a [adobe] apollo sample program in Delphi that draws on a transparent window such that the windows underneath continue to update. But I can't crack it >:| Is anybody else up for the challenge? The sample [ScreenPlay] is available here: http://labs.adobe.com/wiki/index.php/Apollo:Applications:Samples Cheers, harrie. Back to top JD Guest Posted: Sun Apr 08, 2007 8:11 am    Post subject: Re: Drawing On A Transparent Form harrie <user (AT) domain (DOT) invalid> wrote: Quote: I've been trying to emulate [...] that draws on a transparent window such that the windows underneath continue to update. It's unclear what it is that you want to accomplish. Quote: Is anybody else up for the challenge? The sample [ScreenPlay] is available here: I would suggest that your lack of response is directly related to the vagary of the the link that you posted. IOW, exectly what should I be looking at from that link? I'm thinking that you want to go one of two ways so the odds are 50/50 that I'll spend the next 20 minutes explaining some thing that you don't want so I'll reserve comment until I know exactly what it is that you want to accomplish. ~ JD Back to top harrie Guest Posted: Tue Apr 10, 2007 5:01 am    Post subject: Re: Drawing On A Transparent Form Hi JD, thanks for your response. JD wrote: Quote: harrie <user (AT) domain (DOT) invalid> wrote: I've been trying to emulate [...] that draws on a transparent window such that the windows underneath continue to update. It's unclear what it is that you want to accomplish. Is anybody else up for the challenge? The sample [ScreenPlay] is available here: I would suggest that your lack of response is directly related to the vagary of the the link that you posted. IOW, exectly what should I be looking at from that link? I'm trying to create a delphi program with the same functionality as the Apollo demo program called ScreenPlay - which unfortunately requires the installation of the Apollo runtime to work. I've tried to explain it's functionality where it has a full-screen transparent window upon which you can draw lines in different colours and thickness - that's it. I know it doesn't make sense .. drawing on a transparent window .. but I guess you need to run it to understand .. The direct link to the demo is: http://download.macromedia.com/pub/labs/apollo/sample_apps/ScreenPlay.air But you will need to install the runtime - which requires an Adobe Labs registration to be able to download. I thought this might have been the reason no one was interested?? If anyone really objects to having to register the direct link to the installer is: http://download.macromedia.com/pub/labs/apollo/installers/apollo_win_alpha1_031907.msi Quote: I'm thinking that you want to go one of two ways so the odds are 50/50 that I'll spend the next 20 minutes explaining some thing that you don't want so I'll reserve comment until I know exactly what it is that you want to accomplish. ~ JD Back to top Jens Gruschel Guest Posted: Wed Apr 11, 2007 2:13 am    Post subject: Re: Drawing On A Transparent Form Quote: I'm trying to create a delphi program with the same functionality as the Apollo demo program called ScreenPlay - which unfortunately requires the installation of the Apollo runtime to work. I've tried to explain it's functionality where it has a full-screen transparent window upon which you can draw lines in different colours and thickness - that's it. I know it doesn't make sense .. drawing on a transparent window .. but I guess you need to run it to understand .. You can a) capture the screen to a bitmap b) create a borderless form c) draw the bitmap you captured onto your form d) draw lines or whatever onto the form However this is very static, you won't see any changes which might occur below your window (let's say there is a clock with moving hands). On Windows 2K/XP you can make use of transparent windows supported by the OS, which allows to define a color, which is used for transparency. Delphi 6 and later versions support that directly (see TransparentColor and TransparentColorValue properties of your form). Otherwise take a look at SetLayeredWindowAttributes (http://preview.tinyurl.com/yjd3p7) or search for a 3rd party Delphi component encapsulating it. A third approach is to draw to the zero device context directly, however I don't really recommend it. -- Jens Gruschel http://www.pegtop.net Back to top Eddie Shipman Guest Posted: Wed Apr 11, 2007 2:19 am    Post subject: Re: Drawing On A Transparent Form <SNIP> Quote: I'm trying to create a delphi program with the same functionality as the Apollo demo program called ScreenPlay - which unfortunately requires the installation of the Apollo runtime to work. I've tried to explain it's functionality where it has a full-screen transparent window upon which you can draw lines in different colours and thickness - that's it. I know it doesn't make sense .. drawing on a transparent window .. but I guess you need to run it to understand .. SNIP Problem is, if you create a transparent desktop window, anything you draw on it will be transparent, too. I see no way of doing this with straight GDI, maybe it is something new in GDI+? Back to top harrie Guest Posted: Wed Apr 11, 2007 4:22 am    Post subject: Re: Drawing On A Transparent Form Quote: Problem is, if you create a transparent desktop window, anything you draw on it will be transparent, too. I used a transparent form to track mouse movements and actions and then drew to the desktop window but of course as soon as another window was given focus the drawings over it would be lost. Whereas the ScreenPlay program is able to repaint the lines drawn so it must be masking the drawings over a transparent form/window in some way. Quote: I see no way of doing this with straight GDI, maybe it is something new in GDI+? good tip .. I'll look into GDI+ a curious thing is that my program that drew on the desktop window was not able to draw on the ScreenPlay window when it was a background window but any kind of program window could repaint over it? Back to top harrie Guest Posted: Wed Apr 11, 2007 4:25 am    Post subject: Re: Drawing On A Transparent Form Quote: You can a) capture the screen to a bitmap b) create a borderless form c) draw the bitmap you captured onto your form d) draw lines or whatever onto the form However this is very static, you won't see any changes which might occur below your window (let's say there is a clock with moving hands). On Windows 2K/XP you can make use of transparent windows supported by the OS, which allows to define a color, which is used for transparency. Delphi 6 and later versions support that directly (see TransparentColor and TransparentColorValue properties of your form). Otherwise take a look at SetLayeredWindowAttributes (http://preview.tinyurl.com/yjd3p7) or search for a 3rd party Delphi component encapsulating it. A third approach is to draw to the zero device context directly, however I don't really recommend it. None of these methods reproduce the behaviour of the ScreenPlay program. I'm going to look into GDI+ as suggested by Eddie. Back to top Jens Gruschel Guest Posted: Wed Apr 11, 2007 4:35 am    Post subject: Re: Drawing On A Transparent Form Quote: None of these methods reproduce the behaviour of the ScreenPlay program. Sorry, I don't want to install the runtime library you mentioned, so I don't know what exactly is wrong with the approaches I suggested. Drawing any kind of things should be possible, however you might need to combine it with other techniques for example when it comes to capture the mouse cursor. Transparent forms Windows provides by the way are not limited to a single transparent color, you can also work with an alpha mask, however that's a bit more difficult and not supported by Delphi directly. -- Jens Gruschel http://www.pegtop.net Back to top Eddie Shipman Guest Posted: Thu Apr 12, 2007 12:52 am    Post subject: Re: Drawing On A Transparent Form harrie wrote: Quote: You can a) capture the screen to a bitmap b) create a borderless form c) draw the bitmap you captured onto your form d) draw lines or whatever onto the form However this is very static, you won't see any changes which might occur below your window (let's say there is a clock with moving hands). On Windows 2K/XP you can make use of transparent windows supported by the OS, which allows to define a color, which is used for transparency. Delphi 6 and later versions support that directly (see TransparentColor and TransparentColorValue properties of your form). Otherwise take a look at SetLayeredWindowAttributes (http://preview.tinyurl.com/yjd3p7) or search for a 3rd party Delphi component encapsulating it. A third approach is to draw to the zero device context directly, however I don't really recommend it. None of these methods reproduce the behaviour of the ScreenPlay program. I'm going to look into GDI+ as suggested by Eddie. Have you asked in the Adobe forums how they do it? Sometimes they will give you an idea of how it's being done if you ask the right queestion nicely. ;-) -- Back to top harrie Guest Posted: Thu Apr 12, 2007 4:32 pm    Post subject: Re: Drawing On A Transparent Form Hi Jens, apologies for my statement below as I've got it working using SetLayeredWindowAttributes as you suggested :-$ It's quite crude but effective using two forms. First I set the main form's AlphaBlendValue to 1 and use this to catch mouse movements and actions and then have a second form over this that is totally transparent using SetLayeredWindowAttributes with LWA_COLORKEY and then simply draw on this form using any colour other than the transparent colour. Thanks again for the tip. here's the wrapper function I used if anyone's interested: function SetLayeredWindowAttributes(Wnd: HWND; ColorKey: Cardinal; BlendLevel: Integer): Boolean; type TSetLayeredWindowAttributes = function(Handle: HWND; crKey: DWORD; bAlpha: Byte; dwFlags: DWORD): BOOL; stdcall; const WS_EX_LAYERED = $00080000; LWA_COLORKEY = $00000001; LWA_ALPHA = $00000002; var SetLayeredWindowAttributes: TSetLayeredWindowAttributes; h: THandle; dwStyle: DWORD; Alpha: byte; begin Result := False; h := LoadLibrary('user32.dll'); if (h <> 0) then begin try @SetLayeredWindowAttributes := GetProcAddress(h, 'SetLayeredWindowAttributes'); Alpha := (255 * BlendLevel) div 100; dwStyle := GetWindowLong(Wnd, GWL_EXSTYLE); SetWindowLong(Wnd, GWL_EXSTYLE, dwStyle or WS_EX_LAYERED); if (@SetLayeredWindowAttributes <> nil) then SetLayeredWindowAttributes(Wnd, ColorKey, Alpha, LWA_COLORKEY); Result := True; finally FreeLibrary(h); end; end; end; Cheers, harrie Quote: None of these methods reproduce the behaviour of the ScreenPlay program. Sorry, I don't want to install the runtime library you mentioned, so I don't know what exactly is wrong with the approaches I suggested. Drawing any kind of things should be possible, however you might need to combine it with other techniques for example when it comes to capture the mouse cursor. Transparent forms Windows provides by the way are not limited to a single transparent color, you can also work with an alpha mask, however that's a bit more difficult and not supported by Delphi directly. Back to top Jens Gruschel Guest Posted: Fri Apr 13, 2007 12:35 am    Post subject: Re: Drawing On A Transparent Form Quote: It's quite crude but effective using two forms. First I set the main form's AlphaBlendValue to 1 and use this to catch mouse movements and actions I guess the main problem is to keep the z-order of both forms. Just some loud thinking... an alternative might be to setup a mouse hook (see SetWindowsHookEx), but IMO that might create more problems than it solves, or simply to poll the mouse (call GetCursorPos and GetAsyncKeyState for VK_LBUTTON in a timer), but it might be less exact. Maybe using SetCapture will also work to get mouse messages for the transparent area, but the initial mouse down event might be problematic. -- Jens Gruschel http://www.pegtop.net Back to top harrie Guest Posted: Fri Apr 13, 2007 6:53 pm    Post subject: Re: Drawing On A Transparent Form Quote: I guess the main problem is to keep the z-order of both forms. Just some loud thinking... an alternative might be to setup a mouse hook (see SetWindowsHookEx), but IMO that might create more problems than it solves, or simply to poll the mouse (call GetCursorPos and GetAsyncKeyState for VK_LBUTTON in a timer), but it might be less exact. Maybe using SetCapture will also work to get mouse messages for the transparent area, but the initial mouse down event might be problematic. I haven't noticed [or understood] any problems with the z-order .. but there were issues with the drawings on the [2nd form] canvas being lost on when the application or desktop was minimised. i got around this by duplicating all drawings to a bitmap which I copy back to the canvas when the application is activated or restored. BTW the colour key functionality I used with SetLayeredWindowAttributes is actaully available on a Delphi form using TransparentColorValue and TransparentColor. Cheers, harrie. Back to top Jens Gruschel Guest Posted: Fri Apr 13, 2007 10:07 pm    Post subject: Re: Drawing On A Transparent Form Quote: I haven't noticed [or understood] any problems with the z-order .. but there were issues with the drawings on the [2nd form] canvas being lost on when the application or desktop was minimised. i got around this by duplicating all drawings to a bitmap which I copy back to the canvas when the application is activated or restored. Better draw to the bitmap all the time because the same problem appears if another window is in front of your windows temporary. Quote: BTW the colour key functionality I used with SetLayeredWindowAttributes is actaully available on a Delphi form using TransparentColorValue and TransparentColor. What I said before :-) -- Jens Gruschel http://www.pegtop.net Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> Delphi Graphics 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.