Listing 1. Redrawing Screen
// For either the AUTO_SCALE or TRACKING modes, we
// may need to schedule a new rendering with a new
// mapping. In AUTO_SCALE mode, a new rendering
// is needed if _allPointsBBBox != _map.viewPort.
// Or in TRACKING mode, it is needed if
// _trackingPort != _map.viewPort.
BBox *testBox;
testBox = (AUTO_SCALE == _viewMode) ?
&_allPointsBBox : &_trackingPort;
if ( (AUTO_SCALE == _viewMode)
&& memcmp(&_allPointsBBox, &(_map.viewPort),
sizeof(BBox)) )
_render.quePrivateRender(_allPointsBBox,
this->size());
// For TRACKING mode, we must also make sure that
// the range following has not eaten up all our
// resolution.
else if ( (TRACKING == _viewMode)
&& memcmp(&_trackingPort, &(_map.viewPort),
sizeof(BBox)) )
{
BBox tmpPort;
tmpPort = _trackingPort; // Need copy for
// rtpResCheck to modify
if (!rtpResCheck(&tmpPort))
_render.quePrivateRender(_trackingPort,
this->size());
else // Notify user of problem, switch to
// USER_FIXED mode.
// Mode change must come before message box
// to avoid recursion.
{
_viewMode = USER_FIXED;
QMessageBox::warning(this, caption(),
"Resolution is insufficient to track new points.\n"
"Fixing view port in current position.\n",
QMessageBox::Ok | QMessageBox::Default, 0, 0);
}
}
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