IDCMP class: Reports about mouse movements
Source position: intuition.pas line 712
const IDCMP_MOUSEMOVE = 1 shl 4; |
Reports about mouse movements, sent in the form of x and y coordinates relative to the upper left corner of the window. One message will be sent to the application for each "tick" of the mouse.
The application can opt to receive IDCMP_MOUSEMOVE events only while certain gadgets are active, or during normal window operation. These events are sent whenever a gadget with GACT_FOLLOWMOUSE gadget is active, or for any window that has the WA_ReportMouse attribute set. This window attribute can be set or cleared by the application at will.
Requesting IDCMP_MOUSEMOVE messages can create a very large volume of messages arriving at the window's IDCMP. Do not request these messages unless the program is prepared to keep up with them. Intuition limits the number of mouse move events that pile up at your IDCMP.
All IDCMP messages contain a mouse x and y position that can be absolute values or delta values. See IDCMP_DELTAMOVE. If the application requires a less frequent reporting of the mouse position, consider using IDCMP_INTUITICKS. While IDCMP_MOUSEMOVE events are generated by changes in the mouse's position, IDCMP_INTUITICKS IntuiMessages are based on a timer. Since they contain mouse coordinates, they effectively sample the mouse position. These message come often enough for many applications, but not so frequently as to swamp the application.
The program will not be sent IDCMP_MOUSEMOVE messages while Intuition has the layers of the screen locked (during menu operations and window sizing/dragging). This avoids problems of messages accumulating while the program is blocked, waiting to render into a locked layer.
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Intuition message structure |
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Window structure |
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New window structure |
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Future TNewWindow |
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Tag for OpenWindowTagList(). Which events should be reported |