I'm working with Fabric js inside a Phonegap application and although the touch events work, the handles are very hard to catch and use. Specifically the rotate and resize handles. If you touch them 90% of the time they just disappear. I tired fingers and styles. Same result. Confirmed the same behavior on ipad pro and my Galaxy note 4. I'm copy/pasting the same demo from their site:
http://fabricjs.com/touch-events
Has anyone experienced this? How can I make those handles easier to touch?
Solved it. All I needed to do was increase the size of the handles. It's a property passed to each object type you make.
Let me say at outset that I'm using old technology by today's standards! This happens in MFC on Visual Studio 2005 and running under WinXP. (If it 'aint broke.... ;-) )
I have a dialog based app which has a CTabCtrl with two tabs. Each contains a CListCtrl. These work perfectly under normal circumstances. They populate correctly and show and hide as they should. When I first open the application the display selection is correct. If I then minimize the dialog and restore, the CList Ctrl does not show, the tab is blank. It is the only control which has this problem. Another CListCtrl outside of the CTabCtrl does show up correctly. If I then swap tabs and back again, the other tab shows up then the first appears as normal.
This does not happen if I access any other part of the dialog before minimising, it is only when minimising is the absolute first action I take. It also happens with the CListCtrl I have in the other tab if I set this tab to be selected on startup in OnInitDialog where I set up the CTabCtrl.
I have actually solved the effect of this problem by adding into my OnSysCommand(...) the following:
if ((nID & 0xFFF0) == SC_RESTORE)
{
m_ctrlReadList.Invalidate();
}
but it bugs me that I'm adding code to solve a problem which only happens in such odd circumstances. I can't help thinking that there is something I have missed in the setup which is leading to this behaviour. Can anyone offer any explanation as to what is causing it in the first place?
My explanation is based on the facts of what I have found but this has been a learning experience for me so apologies if I get some of it a little confused, I'm still letting it settle in my mind.
Along with this problem I found another which turned out to be relevant. From the nature of the program I'm writing, my CListCtrls needed fixed width headers. Now that turned out to be another thing I couldn't set up! I just needed to prevent the user from grabbing and resizing the header's dividers or double clicking them to autosize, and of course there is functionality in the CListCtrl based on its child CHeaderCtrl to set this up isn't there? Well apparently not. LVS_EX_HEADERDRAGDROP for example isn't the way.
So I explored trying to capture messages which would allow me to myself, and what do you know, I couldn't! I could trap a few but not the ones I needed. I was looking for HDN_BEGINTRACK and HDN_DIVIDERDBLCLICK. (We won't go into the fact that you HAVE TO deal with both A and W versions of those separately!) The CHeaderCtrl is a child of the CListCtrl but it sends its messages back to the CDialog as the CListCtrl's parent. I tried there using both my list's and 0 as ID which headers apparently use. Many of them just plain didn't appear there at all.
So I created my own CListCtrl class inheriting from CListCtrl, overrode OnNotify and they turned up there. I simply prevented CListCtrl::On Notify from being called for those messages and it worked, no resize functionality at all.
I also played with the Z-order too which could have been relevant. I didn't explain earlier but this and another list are on two tabs, exactly aligned over each other. Selecting the tabs HIDEs and SHOWs each of the lists in turn. The other list had no display problems even when I changed the default display in OnInitDialog to show it at start up.
It was under the problematic one. So changing the Z-order in OnInitDialog where I set them up - did nothing! And to rub it in that second list was also unresizeable by default just as I wanted and I couldn't find out why. Their Properties listed exactly the same and there was nowhere in the code where any different aspect was set manually for either, they were effectively theoretically identical, but practically not so. So frustrating!!!
And the upshot of it is that now that the header resize issue is solved my display problem has vanished too! It looks to me and to a few others out there too who report similar symptoms as myself as though the CListCtrl is another one of the slightly flaky ones and needs a little massaging to get the best out of it.
I hope that makes sense to those of you out there who know this control well. I was surprised how simple the solution was, but it also surprised me that the diagnostic process was so difficult. It may of course come down to the ageing system I work within. Nowadays I do this only for fun and the expense of updating VS from 2005 for occasional use is not a high priority. I am sure that some of the symptoms will not show under other build and run environments but it may be worth having the issue and my solution on record somewhere for Google to find for others.
I have an SDL2 windowed window accessed via Derelict 3.
It is supposed to strobe black and white (not because I hate epileptics), and it does this successfully. However, after a certain period of time, Ubuntu 13.10 marks the window as 'unresponsive', grays it out, and dulls the strobe effect.
This is highly irritating and totally kills the effect required by the application for visual stimulation to retrieve SSVEP readings from my EEG headset.
How do I get my OS to realize that the window is doing exactly what it should be doing?
Code
As I have wrapped the SDL calls in my actual code, I'm going to provide pseudo-code and the SDL methods called in those sections (I've checked that I'm not calling any other SDL functions):
make a window using SDL_CreateWindow (no set flags)
make a renderer using SDL_CreateRenderer (with presentvsync flag set)
for( ... )
{
fill screen black using SDL_RenderFillRect and SDL_SetRenderDrawColor
update screen using SDL_RenderPresent
fill screen white (same as above filling)
update screen (same as above update)
}
exit
I pedantically check error codes and return values for all SDL calls in the wrapper lib. They're all fine. What I need to know is what I must add to provide the heartbeat to my OS so it stops graying out my window.
Another thing...
Could someone please add an SDL2 tag? SDL2 has a very different API from SDL1.2...
Added event processing into the loop via SDL_PollEvent(null). This satisfied the OS.
For anyone using Ubuntu 16.04 and SDL2.0x -
The solution that worked for me was:
SDL_SetHint(SDL_HINT_VIDEO_X11_NET_WM_PING,"0");
set immediately after your SDL_Init(); call.
see : SDL2 wiki here.
I'm working on a I/O verification tool based on Linux in a game project. It is written in C++, and,since using the same I/O module as our game, it's based on OIS 1.2. Thus, though all I need is to print users' inputs on the console, I still need to create a window for OIS.
So here comes my question: How can I create a mapped window while it is still invisible and processes keyboard events?
I can't unmapped the window in that it won't process any keyboard event anymore. I also can't find function for show/hide a window.(maybe I search through a wrong diretion...)
My little tool works fine now except there is a stupid top-level empty window which needs to be focused for processing keyboard events...
Any advise is welcomed.
Thanks!!!
After reading this post: Linux/X11 input library without creating a window,
I realized my problem was that I misunderstood the philosophy of X11. All I need to do is simply pass the root window handle to OIS, and set the x11_grabkeyboard flag as true. The only drawback is maybe I can hardly debug my program with gdb since the keyboard is grabbed...
Though my situation is solved, there is one thing left.
Every article I read said an InputOnly window won't be visible and is capable for handling input events, while my InputOnly window is absolutely visible after mapped...
Maybe it's my Linux, or again, a misunderstanding...
We've got some in-house applications built in MFC, with OpenGL drawing routines. They all use the same code to draw on the screen and either print the screen or save it to a JPEG file. Everything's been working fine in Windows XP, and I need to find a way to make them work on Vista.
In three of our applications, everything works. In the remaining one, I can get the window border, title bar, menus, and task bar, but the interior never shows up. As I said, these applications use the exact same code to write to the screen and capture the window image, and the only difference I see that looks like it might be relevant is that the problem application uses the MFC multiple document interface, while the ones that work use the single document interface.
Either the answer isn't on the net, or I'm worse at Googling than I thought. I asked on the MSDN forums, and the only practical suggestion I got was to use GDI+ rather than GDI, and that did nothing different. I have tried different things with every part of the code that captures and prints or save, given a pointer to the window, so apparently it's a matter of the window itself. I haven't rebuilt the offending application using SDI yet, and I really don't have any other ideas.
Has anybody seen anything like this?
What I've got is four applications. They use a lot of common code, and share the actual .h and .cpp files, so I know the drawing and screen capture code is identical.
There is a WindowtoDIB() routine that takes a *pWnd, and a source rectangle and destination size. It looks like very slightly adapted Microsoft code, and I've found other functions in this file on the Microsoft website. Of my four applications, three handle this just fine, but one doesn't. The most obvious difference is that the problem one is MDI.
It looks to me like the *pWnd is the problem. I'm not a MFC guru by a long shot, and it seems to me that the problem may be that we've got one window setup in the SDIs, and more than one in the MDI. I may be passing the wrong *pWnd to the function.
In the meantime, it has started working properly on the 64-bit Vista test machine, although it still doesn't work on the 32-bit Vista machine. I have no idea why. I haven't changed anything since the last tests, and I didn't think anybody else had. (On the 32-bit version, the Print Screen key works as expected, but it does not save the screen as a JPEG.)
Your question title mentions screen capture but your actual question doesn't. Please elaborate more clearly. Is the problem that you can do screen capture of three of your applications, but not the fourth one? You can use different screen capture software that can capture OpenGL/DirectX windows. Those surfaces are handled directly by the Window Manager and won't show up with a simple 'PrtScn'.
Switching to GDI+ won't solve it, nor will switching to SDI.
If it's the content of the CView that you want, then yes, that should be right one. If it's the content of the whole screen (at least the content, without the toolbar(s) and status bar), then you should pass it the CMainFrame (that's the default name which may have been changed, the one that is derived from CMDIFrameWnd).
Can you post the code of WindowToDIB()? I've just tried it and It Works For Me (TM), but without OpenGL code in the view. Try passing the following windows to your WindowToDIB() function:
CMainFrame* mainfrm = static_cast<CMainFrame*>(::AfxGetMainWnd());
- mainfrm
- mainfrm->MDIGetActive()
- mainfrm->MDIGetActive()->GetActiveView()
and see what you get.
The contents of each window are directX surfaces and are only assembled by the window manager in the graphics card. You'd not be able to capture this unless you switch off the new interface (DWM) or code specifically for screen capture from the DWM.
Wikipedia has a good description of the Desktop Window Manager (DWM)
Sorry, I still don't understand. You're trying to get the Print Screen key to work on all four applications? Or you're trying to get the WindowtoDIB() function to work, which takes a 'screenshot' (from within your own application) of the application itself, so that it can be saved as an image file?
Also, what do you mean with 'he Print Screen key works as expected, but it does not save the screen as a JPEG.'? Print Screen only copies to the clipboard, what happens when you paste in Paint?
If your WindowtoDIB() function only 'captures' the window you pass to it, then yes, your MDI child windows are not going to show up.
We eventually solved this by creating a different OpenGL context, and drawing everything to that. We gave up on the screen capture.