I was wondering how can I read text of a control that doesn't have an HWND. For instance, the print dialog in office 2007 doesn't have HWND on all of its controls (only a few).
Is there anyway to get the text from these controls?
I believe they're simply drawn on the window and react using HITTEST, but I'm not sure, so I'm asking you guys :-).
Thanks for your help!
Generally, there is no guaranteed way to do that. However, chances are you can get the text (and other info about the controls) using the IAccessible interface. Most Microsoft products implement this interface on most of the UI elements: this is how screen readers for disabled people work
For a generic windowless control, all you can assume is that the text exists only as pixels on the screen, so the only way to read it is with OCR.
If you can learn more information about the specific controls you want to inspect, then you might learn that the windowless control has a parent window that handles messages on its behalf, or that the control has a COM object you can manipulate, or that the control honors the Windows accessibility API. If you don't know anything else about the control, then all you have are the pixels.
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Is it possible to create a keyboard shortcut to switch between the monitor and portion selection of this wacom preferences window, via a c++ console program?
Sorry if this is poorly worded, I've had trouble trying to find the right words to search for ways to do it.
I think it should be possible, although a bit tedious. You should be able to use the Windows API, and try to EnumWindows/EnumDesktopWindows to identify the respective application Window, and its respective controls (which are also Windows).
You should identify the window title, and class ids, for the app window, and the checkbox button controls, then when you enumerate through all the desktop windows, you can identify the ones you are interested in.
Then you can use the SendMessage() API to send messages to the controls (Windows) of interest to manipulate them.
It's a bit tedious, but sounds possible.
An example of use here to get an idea:
http://www.cplusplus.com/forum/windows/25280/
Here is a description of my use case:
I have a Windows application that comprised of the main window and it also creates child windows (think of MS Word for instance). What i want to do is draw frames around certain children windows of a given application. Note that when i say window i mean any visible HWND (handle) in the system. This could be a certain window in Excel, or an open pdf document in Abode reader or whatever.
My question is:
Can this be implemented as AN independent API where one would for instance be able to call the following ?
DrawOutline(HWND, OutlineColor, Thikness);
Any pointers as to how to approach this ? Any limitations one might think of? This would not be a plugin to a specific application but a stand alone API. MFC is also OK. Thanx
The Spy++ tool draws frames around any window. Source code for several Spy++ versions is available on the net.
How to know the name/ID of window in focus specifically in OpenCV.
Is there any event handling/callback or windows api that make this possible if it is not possible with OpenCV.
I am working on Windows 7 and 8.1.
I want to do something similar to (but not limited to):
If a window is in focus, and some event like mouse or key press happens,
then update that particular window
.
As suggested by Kris, there exists a solution on window. Use windows api to take handle of active window as using:
HWND WINAPI GetActiveWindow(void);
Now use GetWindowText() function to extract out title, if any. It may not be portable. There should exist similar api for other OS.
first of all, I don't know if windows or any other api can help.
I have an idea to take screen-shot, somehow, and then use opencv itself for image processing. Assumption is that the focused window will be on the top and most focused so we can see the name easily. We can process color to separate focused window from others, if any. And using OCR to extract windows name.
I am new to Windows programming, mostly done Java(Java SE, Java ME, Android, Java EE), so be detailed and gentle.
I want to capture "the name of the file/path that was clicked in windows, like clicking a file on the desktop"?
Further research http://www.codeproject.com/Articles/6362/Global-System-Hooks-in-NET, which is a small c#/c++ nice app that uses Global System Hooks, to capture mouse events such as coordinates,clicks,etc.
So what is the right API or Global System Hook that captures events on file icons?
There is no single API that provides that level of detail.
The WH_MOUSE and WH_MOUSE_LL hooks of SetWindowsHookEx(), or the WM_INPUT message delivered by RegisterRawInputDevices(), can tell when the mouse is being intereacted with, and the GetCursorPos() function can tell you where the mouse cursor is located onscreen at the time of a click, but it cannot tell you what it is clicking on. You have to figure that out manually.
For instance, the Desktop is implemented as a ListView control, so you can use the WindowFromPoint() and GetDesktopWindow() functions to check if the mouse is located at coordinates corresponding to the desktop window itself instead of an application window, and if so then use the LVM_HITTEST and LVM_GETITEM messages to determine which icon onthe desktop is being clicked on and extract its display text. Then use the SHGetDesktopFolder() function and the IShellFolder interface, or the SHParseDisplayName() function, to parse that text and see if it returns a PIDL that represents a path/file, and if so then use SHGetPathFromIDList() to get the actual path/file name.
If you want to do the same thing with the Windows Explorer app, it gets a bit more complicated. Use WindowFromPoint(), GetWindowThreadProcessId(), OpenProcess(), and EnumProcessModules() to determine if the mouse is over the Windows Explorer app. However, its UI changes from on Windows version to the next, but the jist is that you have to manually locate the focused control via AttachThreadInput() and GetActiveWindow(), check if it is a TreeView/ListView control, and if so then use control-specific messages to get information about the item/icon underneath the mouse cursor coordinates, and use IShellFolder again to figure out what the text of that item/icon actually represents.
Shell programming is very complex system and not for the feint of heart to interact with. So you need to ask yourself, why do you need this information in the first place?
I have developed my own Report Control which is simply nothing but drawing text on a CDC of the control window's client DC. I have got the printing function to work too. The report output is sent to the printer directly. However I want to let the user know the output before the report is actually printed.
I cannot do this using MFC's print preview architecture as my project is not using the doc/view architecture. Is it possible for me to create a print preview window myself ? How does MFC handle this ? Are there any special processing need to be done or keep in mind when showing the printer output on screen ? I've read that MFC used 2 DCs for print preview purposes. Do I need to do this as well if Im goin for a custom print preview ?
Your input is highly appreciated !
tia.
P.S. i use Visual Studio 6 and there is no option to change this to a newer version just as there is no way for me to add doc/view support.
Print preview isn't that special. It just means that you have to render to screen (or bitmap) what you'd otherwise would render to the printer DC. This primarly means using the page size, and providing a UI control for the prev/next page.
I had tweeked this code in order to compile it as static lib. It is for dialog based applications.If you don't need special functionality it will work ok for you.
I had to dig through MFC mechanisms to add extra functionality but at the end I dropped it. If you know other programming languages, try to find a print preview control in that language, make it a dll and use it from your MFC application.
For example, I found the NicePreview control for Delphi and it worked, for me, beautifully !
if you managed to print your output to a file in an RTF format and displayed it on screen would this solve the problem?
There is a class CPreviewView in MFC. Maybe you can find a way to instantiate it without MDI structure.
Otherwise, you can simply paint on screen whatever you are painting on the printer DC. Just remember that you will probably need to scale it down for lower dpi.