fix: handle WM_GETMINMAXINFO instead of letting chromium do it (electron#19928) (electron#20001)

brenca · ckerr · commit fb82bfa7071b · 2019-08-28T09:32:26.000-05:00
* fix: remove WM_GETMINMAXINFO workaround since it's no longer needed

* fix: handle WM_GETMINMAXINFO ourselves

* fix: remove part of the chromium WM_GETMINMAXINFO handler
diff --git a/atom/browser/native_window_views_win.cc b/atom/browser/native_window_views_win.cc
@@ -345,24 +345,35 @@ bool NativeWindowViews::PreHandleMSG(UINT message,
       return false;
     }
     case WM_GETMINMAXINFO: {
-      WINDOWPLACEMENT wp;
-      wp.length = sizeof(WINDOWPLACEMENT);
-
-      // We do this to work around a Windows bug, where the minimized Window
-      // would report that the closest display to it is not the one that it was
-      // previously on (but the leftmost one instead). We restore the position
-      // of the window during the restore operation, this way chromium can
-      // use the proper display to calculate the scale factor to use.
-      if (!last_normal_placement_bounds_.IsEmpty() &&
-          GetWindowPlacement(GetAcceleratedWidget(), &wp)) {
-        last_normal_placement_bounds_.set_size(gfx::Size(0, 0));
-        wp.rcNormalPosition = last_normal_placement_bounds_.ToRECT();
-        SetWindowPlacement(GetAcceleratedWidget(), &wp);
-
-        last_normal_placement_bounds_ = gfx::Rect();
+      // We need to handle GETMINMAXINFO ourselves because chromium tries to
+      // get the scale factor of the window during it's version of this handler
+      // based on the window position, which is invalid at this point. The
+      // previous method of calling SetWindowPlacement fixed the window
+      // position for the scale factor calculation but broke other things.
+      MINMAXINFO* info = reinterpret_cast<MINMAXINFO*>(l_param);
+
+      display::Display display =
+          display::Screen::GetScreen()->GetDisplayNearestPoint(
+              last_normal_placement_bounds_.origin());
+
+      gfx::Size min_size = gfx::ScaleToCeiledSize(
+          widget()->GetMinimumSize(), display.device_scale_factor());
+      gfx::Size max_size = gfx::ScaleToCeiledSize(
+          widget()->GetMaximumSize(), display.device_scale_factor());
+
+      info->ptMinTrackSize.x = min_size.width();
+      info->ptMinTrackSize.y = min_size.height();
+      if (max_size.width() || max_size.height()) {
+        if (!max_size.width())
+          max_size.set_width(GetSystemMetrics(SM_CXMAXTRACK));
+        if (!max_size.height())
+          max_size.set_height(GetSystemMetrics(SM_CYMAXTRACK));
+        info->ptMaxTrackSize.x = max_size.width();
+        info->ptMaxTrackSize.y = max_size.height();
       }
 
-      return false;
+      *result = 1;
+      return true;
     }
     case WM_NCCALCSIZE: {
       if (!has_frame() && w_param == TRUE) {
