internal void Initialize(Window window, FrameworkElement element = null)
{
if (window == null)
{
throw new ArgumentNullException(nameof(window));
}
if (!window.IsInitialized)
{
throw new InvalidOperationException("Target Window has not been initialized.");
}
_targetWindow = window;
_targetElement = element;
ForbearScaling = WillForbearScalingIfUnnecessary && BuiltinFunction.IsScalingSupported(_targetWindow);
if (IsPerMonitorDpiAware)
{
MonitorDpi = DpiChecker.GetDpiFromVisual(_targetWindow);
if (MonitorDpi.Equals(SystemDpi) || ForbearScaling)
{
WindowDpi = MonitorDpi;
}
else
{
var newInfo = new WindowInfo
{
Dpi = MonitorDpi,
Width = _targetWindow.Width * (double)MonitorDpi.X / SystemDpi.X,
Height = _targetWindow.Height * (double)MonitorDpi.Y / SystemDpi.Y,
};
Interlocked.Exchange(ref _dueInfo, newInfo);
ChangeDpi();
}
}
else
{
MonitorDpi = SystemDpi;
WindowDpi = MonitorDpi;
}
ColorProfilePath = ColorProfileChecker.GetColorProfilePath(_targetWindow);
_targetSource = PresentationSource.FromVisual(_targetWindow) as HwndSource;
_targetSource?.AddHook(WndProc);
}
private void ChangeDpi(WindowStatus status = WindowStatus.None)
{
if (Interlocked.CompareExchange(ref _blocker, new object(), null) != null)
{
return;
}
try
{
// Take information which is to be tested from _dueInfo and set null in return.
var testInfo = Interlocked.Exchange(ref _dueInfo, null);
while (testInfo != null)
{
var testRect = new Rect(new Point(_targetWindow.Left, _targetWindow.Top), testInfo.Size);
bool changesNow = true;
switch (status)
{
case WindowStatus.None:
case WindowStatus.SizeChanged:
// None.
break;
case WindowStatus.LocationChanged:
// Determine whether to reflect information now.
var testDpi = DpiChecker.GetDpiFromRect(testRect);
changesNow = testInfo.Dpi.Equals(testDpi);
break;
}
if (changesNow)
{
// Update WindowDpi first so that it can provide new DPI during succeeding changes in target
// Window.
var oldDpi = WindowDpi;
WindowDpi = testInfo.Dpi;
switch (status)
{
case WindowStatus.None:
case WindowStatus.LocationChanged:
// Change location and size of target Window. Setting these properties may fire
// LocationChanged and SizeChanged events twice in target Window. However, to use
// SetWindowPos function, a complicated conversion of coordinates is required.
// Also, it may cause a problem in applying styles if used in OnSourceInitialized
// method.
Debug.WriteLine($"Old Size: {_targetWindow.Width}-{_targetWindow.Height}");
_targetWindow.Left = testRect.Left;
_targetWindow.Top = testRect.Top;
_targetWindow.Width = testRect.Width;
_targetWindow.Height = testRect.Height;
Debug.WriteLine($"New Size: {_targetWindow.Width}-{_targetWindow.Height}");
break;
case WindowStatus.SizeChanged:
// None.
break;
}
// Scale contents of target Window.
var content = _targetElement ?? _targetWindow.Content as FrameworkElement;
if (content != null)
{
content.LayoutTransform = (testInfo.Dpi.Equals(SystemDpi))
? Transform.Identity
: new ScaleTransform(
(double)WindowDpi.X / SystemDpi.X,
(double)WindowDpi.Y / SystemDpi.Y);
}
// Fire DpiChanged event last so that it can be utilized to supplement preceding changes
// in target Window.
DpiChanged?.Invoke(this, new DpiChangedEventArgs(oldDpi, WindowDpi));
// Take new information which is to be tested from _dueInfo again for the case where new
// information has been stored during this operation. If there is new information, repeat
// the operation.
testInfo = Interlocked.Exchange(ref _dueInfo, null);
}
else
{
// Store old information which has been tested but determined not to be reflected now to
// _dueInfo and take new information in return. If there is new information, repeat
// the operation. If not, old information stored back may be overwritten by new information
// later but has a chance to be tested again in the case where it is the last information
// at this move/resize. In such case, the information may be tested at next move/resize.
testInfo = Interlocked.Exchange(ref _dueInfo, testInfo);
}
}
}
finally
{
Interlocked.Exchange(ref _blocker, null);
}
}