static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);
/// <summary>
/// Get the min/max window size for this window
/// Correctly accounting for the task bar size and position
/// </summary>
/// <param name="hwnd"></param>
/// <param name="lParam"></param>
private void WmGetMinMaxInfo(System.IntPtr hwnd, System.IntPtr lParam)
{
// Get the point position to determine what screen we are on
GetCursorPos(out var lMousePosition);
// Now get the current screen
var lCurrentScreen = mBeingMoved ?
// If being dragged get it from the mouse position
MonitorFromPoint(lMousePosition, MonitorOptions.MONITOR_DEFAULTTONULL) :
// Otherwise get it from the window position (for example being moved via Win + Arrow)
// in case the mouse is on another monitor
MonitorFromWindow(hwnd, MonitorOptions.MONITOR_DEFAULTTONULL);
var lPrimaryScreen = MonitorFromPoint(new POINT(0, 0), MonitorOptions.MONITOR_DEFAULTTOPRIMARY);
// Try and get the current screen information
var lCurrentScreenInfo = new MONITORINFO();
if (GetMonitorInfo(lCurrentScreen, lCurrentScreenInfo) == false)
{
return;
}
// Try and get the primary screen information
var lPrimaryScreenInfo = new MONITORINFO();
if (GetMonitorInfo(lPrimaryScreen, lPrimaryScreenInfo) == false)
{
return;
}
// NOTE: Always update it
// If this has changed from the last one, update the transform
//if (lCurrentScreen != mLastScreen || mMonitorDpi == null)
mMonitorDpi = VisualTreeHelper.GetDpi(mWindow);
// Store last know screen
mLastScreen = lCurrentScreen;
// Get work area sizes and rations
var currentX = lCurrentScreenInfo.RCWork.Left - lCurrentScreenInfo.RCMonitor.Left;
var currentY = lCurrentScreenInfo.RCWork.Top - lCurrentScreenInfo.RCMonitor.Top;
var currentWidth = (lCurrentScreenInfo.RCWork.Right - lCurrentScreenInfo.RCWork.Left);
var currentHeight = (lCurrentScreenInfo.RCWork.Bottom - lCurrentScreenInfo.RCWork.Top);
var currentRatio = (float)currentWidth / (float)currentHeight;
var primaryX = lPrimaryScreenInfo.RCWork.Left - lPrimaryScreenInfo.RCMonitor.Left;
var primaryY = lPrimaryScreenInfo.RCWork.Top - lPrimaryScreenInfo.RCMonitor.Top;
var primaryWidth = (lPrimaryScreenInfo.RCWork.Right - lPrimaryScreenInfo.RCWork.Left);
var primaryHeight = (lPrimaryScreenInfo.RCWork.Bottom - lPrimaryScreenInfo.RCWork.Top);
var primaryRatio = (float)primaryWidth / (float)primaryHeight;
if (lParam != IntPtr.Zero)
{
// Get min/max structure to fill with information
var lMmi = (MINMAXINFO)Marshal.PtrToStructure(lParam, typeof(MINMAXINFO));
//
// NOTE: The below setting of max sizes we no longer do
// as through observations, it appears Windows works
// correctly only when the max window size is set to
// EXACTLY the size of the primary window
//
// Anything else and the behavior is wrong and the max
// window width on a secondary monitor if larger than the
// primary then goes too large
//
// lMmi.PointMaxPosition.X = 0;
// lMmi.PointMaxPosition.Y = 0;
// lMmi.PointMaxSize.X = lCurrentScreenInfo.RCMonitor.Right - lCurrentScreenInfo.RCMonitor.Left;
// lMmi.PointMaxSize.Y = lCurrentScreenInfo.RCMonitor.Bottom - lCurrentScreenInfo.RCMonitor.Top;
//
// Instead we now just add a margin to the window itself
// to compensate when maximized
//
//
// NOTE: rcMonitor is the monitor size
// rcWork is the available screen size (so the area inside the task bar start menu for example)
// Size limits (used by Windows when maximized)
// relative to 0,0 being the current screens top-left corner
// Set to primary monitor size
lMmi.PointMaxPosition.X = lPrimaryScreenInfo.RCMonitor.Left;
lMmi.PointMaxPosition.Y = lPrimaryScreenInfo.RCMonitor.Top;
lMmi.PointMaxSize.X = lPrimaryScreenInfo.RCMonitor.Right;
lMmi.PointMaxSize.Y = lPrimaryScreenInfo.RCMonitor.Bottom;
// Set min size
var minSize = new Point(mWindow.MinWidth * mMonitorDpi.Value.DpiScaleX, mWindow.MinHeight * mMonitorDpi.Value.DpiScaleX);
lMmi.PointMinTrackSize.X = (int)minSize.X;
lMmi.PointMinTrackSize.Y = (int)minSize.Y;
// Now we have the max size, allow the host to tweak as needed
Marshal.StructureToPtr(lMmi, lParam, true);
}
// Set monitor size
CurrentMonitorSize = new Rectangle(currentX, currentY, currentWidth + currentX, currentHeight + currentY);
// Get margin around window
CurrentMonitorMargin = new Thickness(
(lCurrentScreenInfo.RCWork.Left - lCurrentScreenInfo.RCMonitor.Left) / mMonitorDpi.Value.DpiScaleX,
(lCurrentScreenInfo.RCWork.Top - lCurrentScreenInfo.RCMonitor.Top) / mMonitorDpi.Value.DpiScaleY,
(lCurrentScreenInfo.RCMonitor.Right - lCurrentScreenInfo.RCWork.Right) / mMonitorDpi.Value.DpiScaleX,
(lCurrentScreenInfo.RCMonitor.Bottom - lCurrentScreenInfo.RCWork.Bottom) / mMonitorDpi.Value.DpiScaleY
);
// Store new size
mScreenSize = new Rect(lCurrentScreenInfo.RCWork.Left, lCurrentScreenInfo.RCWork.Top, currentWidth, currentHeight);
}