1/26/2024 0 Comments Scroll reverser os xIf an application has not captured mouse input and the user releases the mouse button outside the window, the window does not receive the button-up message.Ī thread can use the GetCapture function to determine whether one of its windows has captured the mouse. For example, an application typically tracks the cursor position after a mouse button down event, following the cursor until a mouse button up event occurs. When a background window attempts to capture mouse input, it receives messages only for mouse events that occur when the cursor hot spot is within the visible portion of the window.Ĭapturing mouse input is useful if a window must receive all mouse input, even when the cursor moves outside the window. Only the foreground window can capture mouse input. The lParam parameter of the message specifies a handle to the window that is gaining the mouse capture. When the mouse capture changes, the system sends a WM_CAPTURECHANGED message to the window that is losing the mouse capture. The window receives all mouse messages until the application calls the ReleaseCapture function or specifies another capture window, or until the user clicks a window created by another thread. An application can change this behavior by using the SetCapture function to route mouse messages to a specific window. The system typically posts a mouse message to the window that contains the cursor hot spot when a mouse event occurs. For more information about mouse cursors, see Cursors. You can use the SystemParametersInfo function with the SPI_GETMOUSE or SPI_SETMOUSE flag to retrieve or set mouse speed. The system maintains a variable that controls mouse speed-that is, the distance the cursor moves when the user moves the mouse. The window need not be active or have the keyboard focus to receive a mouse message. When a mouse event occurs, the window that contains the hot spot typically receives the mouse message resulting from the event. The mouse cursor contains a single-pixel point called the hot spot, a point that the system tracks and recognizes as the position of the cursor. When the user moves the mouse, the system moves a bitmap on the screen called the mouse cursor. This section covers the following topics: The application should provide full keyboard support as well.Īn application receives mouse input in the form of messages that are sent or posted to its windows. A well-written application should include a mouse interface, but it should not depend solely on the mouse for acquiring user input. The mouse is an important, but optional, user-input device for applications.
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