comctl32: implement LISTVIEW_ApproximateViewRect for icon and small icon.

[Nikolay Sivov]

Aric Stewart wrote:
> ---
>  dlls/comctl32/listview.c |   39 ++++++++++++++++++++++++++++++++++-----
>  1 files changed, 34 insertions(+), 5 deletions(-)
>
Hi, Aric.

I don't think it's a right way:

---

+    if (infoPtr->nItemCount > 0)
+    {
+      LISTVIEW_GetItemBox(infoPtr, 0, &rcBox);
+      if (wWidth == 0xffff)
+          wWidth = infoPtr->rcList.right - infoPtr->rcList.left;
+
+      row_count = wWidth / (rcBox.right - rcBox.left);
+      if (row_count == 0)
+      {
+        row_count = 1;
+        wWidth = rcBox.right - rcBox.left;
+      }
+      rows = infoPtr->nItemCount / row_count;
+      if (rows == 0)
+        rows = 1;
+
+      wHeight = (rcBox.bottom - rcBox.top) * rows;
+    }

---

You don't respect item spacing here while native does: just tested with 
ControlSpy and it does return rectangle with item spacing -
item aren't placed close to each other.

I think you should use a logic we use to position items - place to row 
until it wraps to next etc. The difference is that if width is greater 
by a value less then itemwidth we should return a minimal rectangle here.

Using LISTVIEW_GetItemBox(infoPtr, 0, &rcBox) for 0 item assuming it's 
the same for the rest isn't correct - box depends on label so, it could 
differ.

Also this is unsafe:
---
+ row_count = wWidth / (rcBox.right - rcBox.left);
---

Could add some tests for that? Not so strict maybe, but to check that 
approx. rectangle is wider then item placed close.