Getting mouse cursor position and button state on Windows - c++

What is the most appropriate way of getting the mouse cursor position or button state on Windows (Windows 7 and above)? I previously used DirectInput, but I am not longer using it and do not wish to. I saw there is GetCursorPos, however, I do not see anything for getting mouse button states. I have read previously that just reading the window messages (such as WM_LBUTTONUP) was considered "slow" for real time applications, so I do not know of any other option.

If you want to poll/query the current cursor position, you can use GetCursorPos. To see the button states, use GetAsyncKeyState.
If you are implementing a message loop in a window, the notification you will get for a mouse movement is WM_MOUSEMOVE. You will be notified of mouse inputs through the notifications listed here.

WM_LBUTTONUP is as good as any window message, for windowed games is great because it is generated only when the mouse clicks the client area, so you can resize and move the window freely.
As an alternative to direct input, you can use raw inputs which take up some more code to initialize, but it's the best way to go with the mouse movement since WM_INPUT is generated when the physical mouse moves, not the cursor, so you can clip the cursor in the client area without worrying that the user may hit the side of the clip rect and the mouse movement messages won't be generated anymore.
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Related

Qt MouseMoveEvent only triggers with a mouse button press

I have an odd problem here.
I'm working on an application, and within one of my classes I'm monitoring my mouse events.
The weird thing is, my mouse move event will only get called if any mouse button is pressed.
I'm not even filtering for any button presses within the method; the method itself doesn't even get called unless I click on this object itself (the one that's monitoring it).
What generally causes this type of error to happen?
I'm not sure if it's relevant, but I have 2 different things monitoring my mouse inputs: 1) the main program monitoring the global mouse coordinates, and 2) an object within my program monitoring the mouse coordinates within itself.
Edit
So the problem has to be because mouse move event is generally used when people are dragging the cursor along the screen right?
My reason for not needing it like that is because I'm building a custom context menu of sorts, and I need to know when an item is hovered over.
It turns out that I didn't truly set everything within my class to enable mouse tracking.
I somehow thought if the class itself was set to have it enabled, I wouldn't need to set it to all the sub objects, but now I see how that wouldn't make any sense at all.
So just to clarify my solution:
The items that I needed to track my cursor's position needed to have
setMouseTracking(true);

Mouse click on a background window without moving mouse c++

I need to know if there is a code in c++ that allows to simulate a click, on a background window (if that's impossible, a foreground window will do fine), without moving the mouse.
I also need to click on specific coordinates, and drag an item to some other position (always without moving the mouse).
Example:
my mouse pointer is at (500,700),
but i need to left click at (100,150),
and drag to (700,300).
I need to be able to move my mouse pointer without affecting the program,
and the program must run correctly without moving, or locking, the mouse pointer.
If this action is impossible in c++, a VB code will be apreciated.
From a C++ Windows application, you can call Windows API directly by first finding the window using FindWindow that will give you the window handle you want, then finding the area within this window that you want to click. You can use API like GetWindowRect for this.
Finally, you can send this window, or an area within it, mouse messages using mouse_event function to cause the mouse to move, click, drag and let go at a new location.

How do I get the mouse's position off the dialog continuously? (MFC)

My question is:
How do i continuously get the mouse's position even when it isn't on any dialogs, in mfc?
It depends on your specific requirements. If you need to direct mouse input temporarily to a control you can call SetCapture. This will request the system to send all mouse messages to a specific window until you not longer need it by calling ReleaseCapture, or you lose it, when another window gains input focus. The latter is signaled through a WM_CAPTURECHANGED message.
If, on the other hand, you need continuous information about mouse positions you can install a timer (SetTimer) and call GetCursorPos.
You can always install a mouse hook. It's a bit overkill, but, it will give you what you want.

How to check if a mouse is over a control

How does one check if the mouse is over a certain HWND? I have tried using the WM_MOUSELEAVE and WM_MOUSEMOVE messages to keep track, but if you click a button and drag the mouse out of the button, it doesn't receive the WM_MOUSELEAVE until the mouse is released, which is too late, because:
When you click a button, the WM_COMMAND message is only sent if:
1. The mouse was originally depressed over the button
2. The mouse is over the button
3. The mouse is released over the button
I need to replicate this functionality.
To duplicate this functionality, just call SetCapture() so that mouse messages are sent to your window even if the mouse leaves it. You can read the current mouse position as it moves and determine if it is still over your window/button (I'm still not 100% sure what you are doing). And, when the mouse button is released, you can call ReleaseCapture() to restore where mouse messages are sent.
EDIT: Oh, and you can use the Windows API function WindowFromPoint() to determine which window the mouse is over.
This is built-in to Windows, it is called 'mouse capture', SetCapture(hWnd). It ensures you get mouse messages even though the mouse has moved outside of the window. You call it on the WM_LBUTTONDOWN message notification.

Constraining window position to desktop working area

I want to allow a user to drag my Win32 window around only inside the working area of the desktop. In other words, they shouldn't be able to have any part of the window extend outside the monitor(s) nor should the window overlap the taskbar.
I'd like to do it in a way that does cause any stuttering. Handling WM_MOVE messages and calling MoveWindow() to reposition the window if it goes off works, but I don't like the flickering effect that's caused by MoveWindow().
I also tried handling WM_MOVING which prevents the need to call MoveWindow() by altering the destination rectangle before the move actually happens. This resolves the flickering problem, but another issue I run into is that the cursor some times gets aways from the window when a drag occurs allowing the user to drag the window around while the cursor is not even inside the window.
How do I constrain my window without running into these issues?
Windows are, ultimately, positioned via the SetWindowPos API.
SetWindowPos starts by validating its parameters by sending the window being sized or moved a WM_WINDOWPOSCHANGING message, and then a WM_WINDOWPOSCHANGED message notifying the window proc of the changed size and/or position.
DefWindowProc handling of these messages is to, in turn, send WM_GETMINMAXINFO and then WM_SIZE or WM_MOVE messages.
Anyway, handle WM_WINDOWPOSCHANGING to filter both user, and code, based attempts to position a window out of bounds.
Keep in mind that users with multi-monitor setups may have a desktop that extends into negative x- and y-coordinates, or that is not rectangular. Also, some users use alternative window managers such as LiteStep, which implement virtual desktops by moving them off-screen; if you try to fight this, your application will break for these users.
You can do this by handling the WM_MOVING message and changing the RECT pointed to by the lParam.
lParam: Pointer to a RECT structure with the current position of the window, in screen coordinates. To change the position of the drag rectangle, an application must change the members of this structure.
you may also want to handle WM_ENTERSIZEMOVE to know when the window is beginning to move, and WM_EXITSIZEMOVE
WM_GETMINMAXINFO is what you seem to be looking for.