I have a layered window that I want all clicks to pass through no matter where the mouse is located. Some parts of it are color keyed, and others are not. Clicks pass through the window whenever the mouse is on a transparent part but whenever the mouse is on a non-transparent part, the window captures the click. An easy solution would be just to add the WS_EX_TRANSPARENT flag to the window but I DO NOT want to do that. I tried returning -1 on WM_NCHITTEST in WndProc since WM_NCHITTEST is called every time the mouse enters a non-transparent zone but that didn't work and clicks still didn't pass through non-color keyed areas of the window.
Thanks in advance
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I have created a borderless window using these styles: WS_VISIBLE | WS_POPUP | WS_OVERLAPPED
The problem is that the window can't be moved. I know that I could do something like getting mouse click position, and then calculate where the window would end up everytime there comes a WM_MOUSEMOVE.
But this solution is not stable, because when I move my mouse too fast, it gets out of the window, and then it won't react. I dont want to set up a hook, because they are too slow. I have searched the internet, but nothing came up at all.
What I ideally want to, is to create a window, that is able to be moved without borders or captions, where I don't need to track the mouse myself, but where Windows does it for me, like making the whole window a caption.
I know that I could do something like getting mouse click position, and then calculate where the window would end up everytime there comes a WM_MOUSEMOVE. But this solution is not stable, because when I move my mouse too fast, it gets out of the window, and then it won't react.
You can fix that by calling SetCapture when you receive the mouse click. You then will continue to receive WM_MOUSEMOVE even after the mouse cursor leaves your window. When the user is finished dragging and release the mouse cursor, you then should call ReleaseCapture.
What I ideally want to, is to create a window, that is able to be moved without borders or captions, where I don't need to track the mouse myself, but where Windows does it for me, like making the whole window a caption.
If you really want to do that, you could respond to the WM_NCHITTEST message and return HTCAPTION.
try PostMessage(hwnd,WM_SYSCOMMAND,SC_SIZE+9,0) on WM_LBUTTONDOWN.
I have a MFC application where I have a Picture Control in the dialog. Eventually, I want to allow a user to draw a resizeable rectangle via mouse drag in the picture control over an image that I loaded.
I defined my own picture control class as a sub class of CStatic and am working with the mouse down, mouse up, and mouse move events but I can't seem to figure out how to allow the user to draw a rectangle. Any guidance on this would be appreciated.
Most of the examples I've looked at show me how to draw a rectangle in a CView:CWnd, but I'm not too familiar with MFC yet so I'm a bit lost. Thanks.
The usual technique for drawing a drag rect on top of the window contents is illustrated here:
http://msdn.microsoft.com/en-us/library/windows/desktop/dd145184(v=vs.85).aspx
That is Win32 API coding instead of MFC coding but the differences are minimal. The basic idea is that by drawing with SetROP2(hdc, R2_NOTXORPEN); you invert the existing pixels, then drawing the same rect again re-inverts those pixels back to the original image.
When the user clicks the mouse button you need to record the mouse coordinates so you know where the rectangle starts. You should also set some type of flag to indicate that the user is dragging the mouse. When the user moves the mouse get the current mouse position and use DrawDragRect or similar function to draw the rectangle. When the user releases the mouse button clear the previously mentioned "flag" and you're done with that part of the process.
You will also need to handle other events such as the control and/or parent window losing focus so that you can cancel the drag/draw operation. Since you did not include any code in your question it's hard to say what else you will need to do but those are the basics.
I want to implement a simple volume up/down button using a custom bitmap, and all it's going to have is a simple hover effect, and mouse down effect.
My first idea was to process WM_MOUSEMOVE for the hover, and process WM_LBUTTONUP and WM_LBUTTONDOWN for the mouse down effect.
First, is this the easiest way to do this? I could superclass a button and just paint the bitmap and forget about the text...
Then I have the problem with the background, which should be transparent, I know I can use a mask by passing SRCAND to BitBlt, but this requires me to have 2 images for each button. Is there any way to do this with just one image? Like if I put a green background on it in my image editor, could I mask that out with a green screen like effect?
You need to create a regular button, and subclass it with SetWindowSubclass. The button must have the owner-draw style on it, which means in the parent WndProc, you are handling WM_DRAWITEM. As you correctly say, you will be BitBlt'ing or StretchBlt'ing the background of the image on.
For hover events you must do the following:
Have some sort of shared boolean between the parent and subclassed WndProc, eg. IsMousedOver
In the subclassed WndProc, process WM_MOUSEMOVE. When this message is hit, you should set IsMousedOver, then invalidate the control with InvalidateRect (this will trigger WM_DRAWITEM in the parent)
In the parent WndProc, if you receive WM_MOUSEMOVE, you should clear IsMousedOver
In WM_DRAWITEM in the parent WndProc, you should check IsMousedOver and BitBlt based on that state
If you want to process MouseUp/MouseDown, you can change the boolean to an int instead and have a tri-state. However, most implementations have MouseDown being the same as the regular button, and MouseUp is then simply the regular moused over background.
As for your query about 2 images, it may well be possible to do it with one but I haven't tried that before.
How would i make a button that will change it's position on MouseMove Event if the cursor is close enough to the center of the button in MFC ?
WM_MOUSEMOVE is not delivered to the button if the cursor is not over it (and is not captured, but you don't want that). So you have to process WM_MOUSEMOVE in the parent dialog. If you want your button to be a self-contained control, you have to subclass the parent window upon button creation.
Subclassing, in this context, means:
- you retrieve and store the parent's window proc address with GetParent()->GetWindowLong(GWL_WNDPROC)
- you set it to your procedure with SetWindowLong()
- in the procedure, you call the parent's previous window proc, after handling WM_MOUSEMOVE the way you want.
The WM_MOUSEMOVE coordinates will be relative to the screen, but you'll probably want to track the button position relative to the window that contains it. Use the ScreenToClient method on the parent window to convert, then you can compare the coordinates to see if it's close. Then use MoveWindow to move the button.
If you track the mouse cursor position you can determine when the cursor gets close to or enters the button window rect. You can then use the SetWindowPos() function to reposition the button window in the parent window client area.
I have a window with its own H and V scrolling. I'm handling the event like this:
case WM_VSCROLL:
SetScrollPos(hWnd, SB_VERT, (int)HIWORD(wParam), TRUE);
break;
all I want is for the position of the scroll bar to stay once I release my mouse but what it's doing is just going back to the top after. What am I doing wrong?
Thanks
The wParam parameter of the WM_VSCROLL message is either SB_TOP, SB_BOTTOM, SB_PAGEUP, SB_PAGEDOWN, SB_LINEUP, SB_LINEDOWN, SB_THUMBPOSITION, or SB_THUMBTRACK, where the names ought to explain themselves.
SB_TOP and SB_BOTTOM means that the scrolling window is to go to the top or bottom, respectively. These messages can be sent by right-clicking a vertical scroll bar and selecting "Top" and "Bottom". (Look in Windows Notepad, Win XP+, for instance.)
SB_PAGEUP and SB_PAGEDOWN means a page (screen) up or down. These are sent if you click somwhere on the scrollbar beside on the thumb or the up or down arrows, or if you use the scrollbar's right-click menu.
SB_LINEUP and SB_LINEDOWN are sent when the user clicks the up and down buttons on the scrollbar, or selects the appropriate right-click menu commands.
SB_THUMBTRACK is sent continuously when the user scrolls by dragging the thumb of the scrollbar.
SB_THUMBPOSITION is sent when the user has released the thumb.
See the MSDN article WM_VSCROLL for more information.
So, when you receive a WM_VSCROLL message, you first need to do the scrolling itself. If, for instance, you are writing a text editor, then you need to redraw the text, but with a different row at the top of the window. Then you need to update the scrollbar to its new position, preferably by means of SetScrollInfo, but you can also use the old SetScrollPos function.
In the case section, the system is processing a WM_VSCROLL message. It will run the default window procedure after your SetScrollPos. In the default window procedure, the system itself will set the scroll bar's thumb position. So, although SetScrollPos takes effects, the system change the thumb position after that anyway. I think you should do your SetScrollPos after calling the default window procedure, i.e., maybe after returning this funciton, and then you can SetScrollPos.