Improve window layout.

This reverts much of 97f0a27.

1. It turns out not to be a good idea to resize the list view columns
   based on the list view window's own rectangle, as it will change
   depending on whether a scrollbar is visible. The problem is that
   resizing the columns may add a horizontal scrollbar -- which in
   turn may add a vertical scrollbar.

2. The WS_EX_CLIENTEDGE style does not look very good in "modern"
   (non-classic) themes. In 97f0a27, I tried solving this by extending
   the dimensions of the child windows such that their edges were
   hidden. However, this type of overlapping causes problems with the
   status bar. My new solution is to instead *reduce* the child
   windows' dimensions. This achieves a visual impression similar to
   the thicker (more well-designed) edges of the "classically themed"
   list view control. To make it look even better, the main window
   background is changed from COLOR_WINDOWFRAME (white) to
   COLOR_WINDOW (light gray).

1 files changed, 4 insertions, 0 deletions

diff --git a/c/common.h b/c/common.h
index fb21e6f..709a258 100644
--- a/c/common.h
+++ b/c/common.h
@@ -55,6 +55,10 @@ std::optional<T> maybe_make(U... xs)
 	}
 }
 
+/* Variable template for caching values from GetSystemMetrics. */
+template <int I>
+const auto Metric = GetSystemMetrics(I);
+
 /* Check result of Windows API call, throwing error on NULL. */
 template <typename T>
 inline T require(const T x)