/// <summary>
/// If possible, gets whether the window is DPI-scaled/virtualized, and gets physical and logical rects if scaled.
/// Returns false if !osVersion.minWin10_1607 or if cannot get that info.
/// Gets that info in a fast and reliable way.
/// </summary>
internal static bool GetScalingInfo_(wnd w, out bool scaled, out RECT rPhysical, out RECT rLogical)
{
scaled = false; rPhysical = default; rLogical = default;
if (!osVersion.minWin10_1607)
{
return(false);
}
var awareness = WindowDpiAwareness(w); //fast on Win10
if (awareness is Awareness.System or Awareness.Unaware) //tested: unaware-gdi-scaled same as unaware
{
if (awareness == Awareness.System && Api.GetDpiForWindow(w) != System) /*fast*/
//Cannot get rLogical. It's rare and temporary, ie when the user recently changed DPI of the primary screen.
//Even if this func isn't used to get rects, without this fast code could be unreliable.
{
Debug_.Print("w System DPI != our System DPI");
return(false);
}
for (; ;)
{
RECT r1 = w.Rect, r2, r3; //note: with ClientRect 4 times faster, but unreliable if small rect. Now fast enough.
bool rectWorkaround = false;
using (var u = new AwarenessContext(awareness == Awareness.System ? -2 : -1)) {
if (Api.GetAwarenessFromDpiAwarenessContext(u.Previous_) != Awareness.PerMonitor) /*fast*/
//cannot get rPhysical. But let's set PM awareness and get it. Works even if this process is Unaware.
{
rectWorkaround = _GetRect(w, out r1);
Debug_.Print("bad DPI awareness of this thread; workaround " + (rectWorkaround ? "OK" : "failed"));
if (!rectWorkaround)
{
return(false); //unlikely. Then the caller probably will call the legacy func, it works with any DPI awareness.
}
}
r2 = w.Rect;
if (r2 == r1)
{
break;
}
}
if (!rectWorkaround)
{
r3 = w.Rect;
}
else
{
_GetRect(w, out r3);
}
if (r3 != r1)
{
continue; //moved, resized or closed between Rect and Rect
}
scaled = true;
rPhysical = r1;
rLogical = r2;
break;
}
static bool _GetRect(wnd w, out RECT r)
{
using (var u2 = new AwarenessContext(-4)) { //per-monitor-v2
if (u2.Previous_ == 0)
{
r = default; return(false);
} //API failed. Unlikely. Works even if this process is Unaware.
r = w.Rect;
}
return(true);
}
