Subject:
Mouse events
From:
"Dave Stuart" ####@####.####
Date:
16 Oct 2005 21:09:19 +0100
Message-Id: <009901c5d28d$657ade60$2003a8c0@house>
I am trying to write code to drag windows around the screen. I have
tried using MOUSE_POSITION and MOUSE_MOTION but they don't seem to do
what I need. If you drag the windows slowly it works fine but if you
move the mouse too fast the screen goes wonky. Any help would be
appreciated. I can't seem to attach the whole program but here is the pertinent area.
Also, is there a way to search the mailing list archive
without having to go through month by month?
Thanks
dave
Sample Program:
/* Draw a main window with borders and background */
wid = GrNewWindow(GR_ROOT_WINDOW_ID, MARGIN, MARGIN,
si.cols - MARGIN * 2, si.rows - MARGIN * 2,
1, BACKGROUND_COLOR, BORDER_COLOR);
GrSelectEvents(wid, GR_EVENT_MASK_BUTTON_DOWN |
GR_EVENT_MASK_MOUSE_MOTION |
GR_EVENT_MASK_EXPOSURE);
GrMapWindow(wid);
/* Define the windows that are being used */
for (i = 0; i < 50; i++) {
if (devices[i].in_use) {
devices[i].window_id = GrNewWindow (wid,
devices[i].horizontal_location,
devices[i].vertical_location,
devices[i].horizontal_size,
devices[i].vertical_size,
1, devices[i].background, devices[i].foreground);
GrSelectEvents (devices[i].window_id, GR_EVENT_MASK_EXPOSURE);
GrMapWindow (devices[i].window_id);
}
}
gc = GrNewGC();
while (1) {
GrGetNextEvent(&event);
switch (event.type) {
case GR_EVENT_TYPE_MOUSE_MOTION:
if (mouse_down_window >= 0) {
devices[mouse_down_window].horizontal_location -= mouse_down_horizontal - event.mouse.rootx;
devices[mouse_down_window].vertical_location -= mouse_down_vertical - event.mouse.rooty;
mouse_down_vertical = event.mouse.rooty;
mouse_down_horizontal = event.mouse.rootx;
GrMoveWindow (event.mouse.subwid, devices[mouse_down_window].horizontal_location, devices[mouse_down_window].vertical_location);
}
break;
case GR_EVENT_TYPE_BUTTON_UP:
if (!(event.button.changebuttons & GR_BUTTON_L))
break;
/* Left mouse button released */
/* Drop the window and don't look for mouse up data anymore */
if (mouse_down_window >= 0) {
GrSelectEvents (wid, GR_EVENT_MASK_BUTTON_DOWN |
GR_EVENT_MASK_MOUSE_MOTION |
GR_EVENT_MASK_EXPOSURE);
mouse_down_window = -1;
}
break;
case GR_EVENT_TYPE_BUTTON_DOWN:
if (event.button.subwid == wid) {
GrClose();
exit(0);
}
if (!(event.button.changebuttons & GR_BUTTON_L))
break;
/* Left mouse button pressed down */
/* Remember where we started and which window we're dragging and watch for mouse button up. */
GrSelectEvents (wid, GR_EVENT_MASK_BUTTON_UP |
GR_EVENT_MASK_MOUSE_MOTION |
GR_EVENT_MASK_EXPOSURE);
mouse_down_horizontal = event.button.rootx;
mouse_down_vertical = event.button.rooty;
for (i = 0; i < 50; i++)
if (devices[i].in_use)
if (event.button.subwid == devices[i].window_id)
mouse_down_window = i;
break;
case GR_EVENT_TYPE_EXPOSURE:
/* Display the windows when exposed */
for (i = 0; i < 50; i++) {
if (devices[i].in_use)
if (event.exposure.wid == devices[i].window_id) {
GrSetGCBackground (gc, devices[i].background);
GrSetGCForeground (gc, devices[i].foreground);
GrSetGCFont (gc, small_font);
GrGetGCTextSize (gc, devices[i].name, strlen(devices[i].name),
0, &width, &height, &base);
GrText (devices[i].window_id, gc,
((devices[i].horizontal_size - width)/2),
10, devices[i].name, strlen(devices[i].name), 0);
GrSetGCFont (gc, big_font);
sprintf(temp, "%d %s", devices[i].current_value[0],
devices[i].units);
GrGetGCTextSize (gc, temp, strlen (temp), 0, &width, &height, &base);
GrText (devices[i].window_id, gc,
((devices[i].horizontal_size - width)/2),
35, temp, strlen (temp), 0);
}
}
break;
}
}
}
