Windows QPA: Fix window frame calculation in multi-monitor setups

When introducing EnableNonClientDpiScaling() for QTBUG-53255, the window
frame calculation was not adapted. That is, window frames were calculated
from the style for the primary screen only, causing

- minimum size constraints not being calculated correctly for applications
  on secondary screens when populating the MINMAXINFO structure.
- warnings about not being able to apply a geometry when moving fixed
  size windows across screens.

The calculation of the frames for propagating size hints is also no longer
required after 3035400f36731c400adb9204b94e9afe346a71b7, which retrieves
them from the WM_NCCALCSIZE message; QWindowsWindow::fullFrameMargins() can
be used instead.

For newly created windows, use the newly added AdjustWindowRectExForDpi()
function to calculate the initial frame size.

Change QWindowsGeometryHint from a class to a collection of static functions
and add overloads to calculate the frame.

In checkForScreenChanged(), update the margins until WM_NCCALCSIZE is
received.

Task-number: QTBUG-67777
Task-number: QTBUG-65580
Task-number: QTBUG-53255
Change-Id: Iff2d382b2b316adec6c1a0622ae8015dba6de371
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
Reviewed-by: Andre de la Rocha <andre.rocha@qt.io>

1 files changed, 14 insertions, 17 deletions

diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index 2675990cf1..5e44511e5d 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -59,24 +59,23 @@ class QDebug;
 
 struct QWindowsGeometryHint
 {
-    QWindowsGeometryHint() = default;
-    explicit QWindowsGeometryHint(const QWindow *w, const QMargins &customMargins);
-    static QMargins frame(DWORD style, DWORD exStyle);
+    static QMargins frameOnPrimaryScreen(DWORD style, DWORD exStyle);
+    static QMargins frameOnPrimaryScreen(HWND hwnd);
+    static QMargins frame(DWORD style, DWORD exStyle, qreal dpi);
+    static QMargins frame(HWND hwnd, DWORD style, DWORD exStyle);
+    static QMargins frame(const QWindow *w, const QRect &geometry,
+                          DWORD style, DWORD exStyle);
     static bool handleCalculateSize(const QMargins &customMargins, const MSG &msg, LRESULT *result);
-    void applyToMinMaxInfo(DWORD style, DWORD exStyle, MINMAXINFO *mmi) const;
-    void applyToMinMaxInfo(HWND hwnd, MINMAXINFO *mmi) const;
-    bool validSize(const QSize &s) const;
-
+    static void applyToMinMaxInfo(const QWindow *w, const QMargins &margins,
+                                  MINMAXINFO *mmi);
+    static void frameSizeConstraints(const QWindow *w, const QMargins &margins,
+                                     QSize *minimumSize, QSize *maximumSize);
     static inline QPoint mapToGlobal(HWND hwnd, const QPoint &);
     static inline QPoint mapToGlobal(const QWindow *w, const QPoint &);
     static inline QPoint mapFromGlobal(const HWND hwnd, const QPoint &);
     static inline QPoint mapFromGlobal(const QWindow *w, const QPoint &);
 
     static bool positionIncludesFrame(const QWindow *w);
-
-    QSize minimumSize;
-    QSize maximumSize;
-    QMargins customMargins;
 };
 
 struct QWindowCreationContext
@@ -85,13 +84,9 @@ struct QWindowCreationContext
                                     const QRect &geometryIn, const QRect &geometry,
                                     const QMargins &customMargins,
                                     DWORD style, DWORD exStyle);
-    void applyToMinMaxInfo(MINMAXINFO *mmi) const
-        { geometryHint.applyToMinMaxInfo(style, exStyle, mmi); }
+    void applyToMinMaxInfo(MINMAXINFO *mmi) const;
 
-    QWindowsGeometryHint geometryHint;
     const QWindow *window;
-    DWORD style;
-    DWORD exStyle;
     QRect requestedGeometryIn; // QWindow scaled
     QRect requestedGeometry; // after QPlatformWindow::initialGeometry()
     QRect obtainedGeometry;
@@ -221,7 +216,8 @@ public:
         HasBorderInFullScreen = 0x200000,
         WithinDpiChanged = 0x400000,
         VulkanSurface = 0x800000,
-        ResizeMoveActive = 0x1000000
+        ResizeMoveActive = 0x1000000,
+        DisableNonClientScaling = 0x2000000
     };
 
     QWindowsWindow(QWindow *window, const QWindowsWindowData &data);
@@ -262,6 +258,7 @@ public:
     QMargins frameMargins() const override;
     QMargins fullFrameMargins() const override;
     void setFullFrameMargins(const QMargins &newMargins);
+    void updateFullFrameMargins();
 
     void setOpacity(qreal level) override;
     void setMask(const QRegion &region) override;