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Re: how to write an eraser for layers rainfallc16-Apr-02 15:39 rainfallc 16-Apr-02 15:39  i don`t use GDI+, the way i draw the shapes is that i offer a virtual function called Draw and pass the CDC* as the argument, then in the view, i rewrite the OnLButtonDown ,OnLButtonUp, OnMoveMove, to change the shapes` shape( there is another virtual function to change each shapes` member variables), then in the view`s WM_PAINT message, i draw the shapes into a bitmap , then bitblt to the screen, i used another CArray to keep track of which layer is hiding. please give me more hints do u mean use GDI+ is more eaiser than GDI to solve these kinds of problems? thank u for help Re: how to write an eraser for layers Christian Graus16-Apr-02 16:55 Christian Graus 16-Apr-02 16:55  So to recap: you have an array of layers. Each layer has an array of pointers to a base class. Your WM_PAINT steps through these arrays in order and draws everything again to a CBitmap, then to the screen. rainfallc wrote: i used another CArray to keep track of which layer is hiding. Why not make a layer class that has a hidden property and holds all the things you are drawing, if you're doing it that way ? You're risking fragmentation between different aspects of what should be the same data. rainfallc wrote: please give me more hints OK. 1/ If you don't need W95 support, use GDI+. It's the easiest way to do layering 2/ Don't use CBitmap, because when you come to save & load images, you'll only be able to deal with images the same bit depth as your screen. Use GDI+::Bitmap, which has the advantange of letting you load and save a ton of formats as well. 3/ Don't draw everything to the screen every time, unless you want to be able to reselect items you have previously drawn to edit/move/delete them. If you're trying to write a drawing package, you're stuck with this, but I'd still impliment suggestion 4, and redraw a layer using your array only when you want to select/delete something 4/ Make a vector of layer objects, a class that encapsulates the bitmap that represents the layer ( which has it's alpha channel set so that it can be drawn on top of lower layers correctly ), the objects in the layer if you want to select them, if the layer is to be drawn or not, etc. Christian The tragedy of cyberspace - that so much can travel so far, and yet mean so little. "But there isn't a whole lot out there that pisses me off more than someone leaving my code looking like they leaned on the keyboard and prayed that it would compile. - Jamie Hale, 17/4/2002 Re: how to write an eraser for layers rainfallc16-Apr-02 18:28 rainfallc 16-Apr-02 18:28  thanks for reply i create a tool class called Eraser, now i show three layers on the screen, the topmost one i am editing, i draw a line on it, i want to ERASE someparts of the line, but those parts are inside the lower layers`s shapes` region. How could i set the Eraser`s mode , which just delete the current layers` content,.after i release the mouse button, lower layers show as before, but current layer`s image has changed? u said: Make a vector of layer objects, a class that encapsulates the bitmap that represents the layer ( which has it's alpha channel set so that it can be drawn on top of lower layers correctly ) could u offer a short program for the suggestion above? do u mean to draw a bitmap with its alpha channel set on other layers` images? thanks again Re: how to write an eraser for layers Christian Graus16-Apr-02 19:03 Christian Graus 16-Apr-02 19:03  rainfallc wrote: How could i set the Eraser`s mode , which just delete the current layers` content,.after i release the mouse button, lower layers show as before, but current layer`s image has changed? By erasing by reseting the alpha channel in just the layer you are drawing on. Making an eraser would seem to suggest you'd be better not keeping track of individual shapes, but just bitmaps. It's not going to take long for your paint method to groan under the strain of rerendering all this stuff. rainfallc wrote: u said: Make a vector of layer objects, a class that encapsulates the bitmap that represents the layer ( which has it's alpha channel set so that it can be drawn on top of lower layers correctly ) could u offer a short program for the suggestion above? do u mean to draw a bitmap with its alpha channel set on other layers` images? thanks again A short program ? No. Which part do you need help with ? Christian The tragedy of cyberspace - that so much can travel so far, and yet mean so little. "But there isn't a whole lot out there that pisses me off more than someone leaving my code looking like they leaned on the keyboard and prayed that it would compile. - Jamie Hale, 17/4/2002 Re: how to write an eraser for layers rainfallc16-Apr-02 19:52 rainfallc 16-Apr-02 19:52  oh i see, thanks very much, if i have any more questions , please offer the help again Re: how to write an eraser for layers Christian Graus16-Apr-02 19:59 Christian Graus 16-Apr-02 19:59  Always glad to help - just try to impliment what I've suggested and ask when you get stuck. I've also written a GDI+ paint program called Doodle on CP, which may help you get started in GDI+. Christian The tragedy of cyberspace - that so much can travel so far, and yet mean so little. "But there isn't a whole lot out there that pisses me off more than someone leaving my code looking like they leaned on the keyboard and prayed that it would compile. - Jamie Hale, 17/4/2002 getting a dialog's dc John Oliver16-Apr-02 0:35 John Oliver 16-Apr-02 0:35  I'm calling the Win32 api function SHBrowseForFolder to display a Browse folder dialog. It allows a callback fn to be specified. Can anybody tell me, using the hwmd supplied in the callback is it possible to access the dialog's device context. Can this be done with Subclassing. Thanks for reading John Re: getting a dialog's dc Paul M Watt16-Apr-02 5:33 Paul M Watt 16-Apr-02 5:33  I have never used this function before, but does the HWND represent the dialog or the owner of the dialog. Anyway, you can always call GetDC to get the DC of a window. The thing that you will need to worry about is if that handle is the dialog or not. If that handle is the parent of the dialog, you can always enumerate through the windows to get your dialog handle, or cache a handle somewhere. Checkout my Guide to Win32 Paint for Intermediates Multiple Selection with drag and Drop between TreeCtrls Luis Reina16-Apr-02 0:16 Luis Reina 16-Apr-02 0:16  I´m developing a program and I need a class for CtreeCtrl, with multiple selection of items and Drag and Drop of them between two CTreeCtrls(or Ctreeview). Thanks in advance. Using Visual C++ 6.0. Windows 2000. Toolbars in Dialogs? funbag15-Apr-02 23:33 funbag 15-Apr-02 23:33  Is it possible to add a toolbar to a modal dialog? I tried, but ended up with assertion errors, was just wondering if it can be done! Thanx funbag! skydiving....if at first you don't succeed, you're fecked! Re: Toolbars in Dialogs? Christian Graus16-Apr-02 2:02 Christian Graus 16-Apr-02 2:02  In theory, no, but I believe in practise it is possible to hack a solution, so long as you don't want them to float. Christian The tragedy of cyberspace - that so much can travel so far, and yet mean so little. "I'm somewhat suspicious of STL though. My (test,experimental) program worked first time. Whats that all about??!?! - Jon Hulatt, 22/3/2002 Distributed compiling with VStudio 6.0 Braulio Dez15-Apr-02 23:23 Braulio Dez 15-Apr-02 23:23  Hi, We have a big monolitic ( ), project, that takes half an hour to compile ( Scassi HD, and 500 Mb. Memory), we don´t have time to chop it into smaller pieces ( now it´s not the time for that )... ... But we have like three more computers free, so would it be possible to send to that computers a bunch of files, and that machines could compile them ? ( so if I have 400 files I could compile 50 here, 50 there, 50..., in paralel). Does can be done on VStudio 6.0 ? And .net ? ... or that´s to good to be true ? Thanks in advance, Greetings Braulio Blocking Sockets - and don´t get the last byte BtK15-Apr-02 23:12 BtK 15-Apr-02 23:12  Hi i got a serious Problem with the Blocking Sockets Part of WinSock2. A Java Applet is connecting to my TCP/IP Server (written in C++) - and now they are talking... and it works - ... but everytime the Java Applet sends a Message to the C++ the LAST BYTE doesn´t arrive. Its there when the next message is sent from the Applet - but until then.... no LAST BYTE.... does anybody know how to workaround - or WHY the H**** this is occuring ? Daniel Re: Blocking Sockets - and don´t get the last byte Le centriste16-Apr-02 3:17 Le centriste 16-Apr-02 3:17  Do you have more information? What protocol do you use on your socket? HTTP, FTP, in-house? If the protocol you use specifies in its header the number of incoming bytes, make sure you don't miscalculate. Michel If I am wrong or said something stupid, I apologize in advance Why I Can't get WIM_DATA message in callback function 'waveInProc' ? Cloudway15-Apr-02 22:57 Cloudway 15-Apr-02 22:57  I want to record sound with callback function. I call waveInOpen, waveInPrepareHeader, waveInAddBuffer etc. successfully. And I can get WIM_OPEN and WIM_CLOSE message in the callback function. BUT I CAN'T get WIM_DATA message! Why??? BTW: I can get MM_WIM_DATA message when I use threads instead of callback function, and I can get WOM_DONE message when using callback function waveOutProc. Re: Why I Can't get WIM_DATA message in callback function 'waveInProc' ? Cloudway15-Apr-02 23:09 Cloudway 15-Apr-02 23:09  Hey! I found the answer. I forget to call waveInStart. How to set the size of a scrollbox on the scrollbar? Feng Qin15-Apr-02 22:46 Feng Qin 15-Apr-02 22:46  As title. I'm amumu, and you? System's ImageList Flatline15-Apr-02 21:45 Flatline 15-Apr-02 21:45  iS it possible to get the system's image list and use that to a tree control so that it the images in the tree control of Windows Explorer is the same as with the images of the tree control my application?? Getting the whole viewport size of SCrollView Flatline15-Apr-02 21:00 Flatline 15-Apr-02 21:00  How do i capture the whole viewport size of a CScrollView to a bitmap?... I'm making a paint program and i want to save the whole drawing including the hidden part of the bitmap.... (the part which is not scrolled)... I tried Bitbliting the ScreenDC into memDC which has a bitmap attached to it but it only captured the visible part.. worst it also captured the Scrollbars... Message Box problem Yamuna15-Apr-02 18:27 Yamuna 15-Apr-02 18:27  Hi, I am using AfxMessageBox() API in my application.Sometimes the message box doesn't come up and when I debugged and saw found that the return value is 0 which means that there is no enough memory to display the message box.What do I do to solve this problem? Thank You. Yamuna.E. Yamuna.E. Re: Message Box problem Christian Graus15-Apr-02 22:57 Christian Graus 15-Apr-02 22:57  Buy more RAM ? I've NEVER had AfxMessageBox fail, what makes you think it's memory related ? When does it happen ? Christian The tragedy of cyberspace - that so much can travel so far, and yet mean so little. "I'm somewhat suspicious of STL though. My (test,experimental) program worked first time. Whats that all about??!?! - Jon Hulatt, 22/3/2002 Re: Message Box problem Yamuna15-Apr-02 23:18 Yamuna 15-Apr-02 23:18  Even for me this is the first time AfxMessageBox fails. MSDN tells that AfxMessageBox on failure returns 0 and that it is due to no enough memory. I forgot to mention the scenario. This messagebox I call from within a thread function(via CreateThread) which takes as its parameter the string to be displayed and I am sure there is no problem with string passing.This I made sure by hard-coding the string just to check whether it works fine with hard-coded string value.But even in that case I got the same problem. But now I tried using MessageBox API instead of AfxMessageBox.Its working fine.But couldn't get the reason behind the problem. Thank You. Yamuna.E. Yamuna.E. Re: Message Box problem Christian Graus15-Apr-02 23:26 Christian Graus 15-Apr-02 23:26  It's certainly an odd problem. In the future, TRACE or OutputDebugString will allow you to check a variable value in Debug mode without having to bring up a dialog. Christian The tragedy of cyberspace - that so much can travel so far, and yet mean so little. "I'm somewhat suspicious of STL though. My (test,experimental) program worked first time. Whats that all about??!?! - Jon Hulatt, 22/3/2002 Re: Message Box problem 15-Apr-02 23:39 15-Apr-02 23:39  Fine Thank You. Yamuna.E. Yamuna.E. Hiding Web Browser Control in a dialog Alex Cramer15-Apr-02 18:08 Alex Cramer 15-Apr-02 18:08  Hi all! I want to do next: user clicks the button, and Web Browser replaces by richedit control (in a dialog). TROUBLE: after hiding of web browser, its window handle become not valid. Here's a code: void CCalendarDlg::OnViewEditSwitch() { CString strBtnText; m_btnEditView.GetWindowText(strBtnText); if(strBtnText == EDIT_BUTTON_TEXT) { m_btnEditView.SetWindowText(VIEW_BUTTON_TEXT); m_Browser.ShowWindow(SW_HIDE); m_wndRichEdit.ShowWindow(SW_SHOW); } else { m_btnEditView.SetWindowText(EDIT_BUTTON_TEXT); m_wndRichEdit.ShowWindow(SW_HIDE); m_Browser.ShowWindow(SW_SHOW); } } ERROR: Debug assertion failed here: BOOL CWnd::ShowWindow(int nCmdShow) { ASSERT(::IsWindow(m_hWnd)); if (m_pCtrlSite == NULL) return ::ShowWindow(m_hWnd, nCmdShow); else return m_pCtrlSite->ShowWindow(nCmdShow); } Help, please!

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