richedit: Scrollinfo stored as 16-bit values externally.

The application Blitzin2 was sending WM_VSCROLL messages to the richedit control directly, when normally this message is supposed to be a notification sent after the scrollinfo is set. Native richedit controls always use the 16-bit value passed to this message to set the scroll position for SB_THUMBPOSITION, rather than trying to find a 32-bit value through GetScrollInfo like I had previously done.

richedit: Scrollinfo stored as 16-bit values externally.
0deb3d04 · Dylan Smith · Alexandre Julliard · e5f4c802 · 0deb3d04 · 0deb3d04
Commit 0deb3d04 authored Jul 21, 2009 by Dylan Smith Committed by Alexandre Julliard Jul 22, 2009
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Showing with 31 additions and 20 deletions

editor.c dlls/riched20/editor.c +13 -18

paint.c dlls/riched20/paint.c +18 -2

No files found.
--- a/dlls/riched20/editor.c
+++ b/dlls/riched20/editor.c
@@ -3587,6 +3587,11 @@ LRESULT ME_HandleMessage(ME_TextEditor *editor, UINT msg, WPARAM wParam,
    POINT *point = (POINT *)lParam;
    point->x = editor->horz_si.nPos;
    point->y = editor->vert_si.nPos;
+    /* 16-bit scaled value is returned as stored in scrollinfo */
+    if (editor->horz_si.nMax > 0xffff)
+      point->x = MulDiv(point->x, 0xffff, editor->horz_si.nMax);
+    if (editor->vert_si.nMax > 0xffff)
+      point->y = MulDiv(point->y, 0xffff, editor->vert_si.nMax);
    return 1;
  }
  case EM_GETTEXTRANGE:
@@ -4012,15 +4017,10 @@ LRESULT ME_HandleMessage(ME_TextEditor *editor, UINT msg, WPARAM wParam,
      case SB_THUMBTRACK:
      case SB_THUMBPOSITION:
      {
-        SCROLLINFO sbi;
-        sbi.cbSize = sizeof(sbi);
-        sbi.fMask = SIF_TRACKPOS;
-        /* Try to get 32-bit track position value. */
-        if (!GetScrollInfo(editor->hWnd, SB_HORZ, &sbi))
-          /* GetScrollInfo failed, settle for 16-bit value in wParam. */
-          sbi.nTrackPos = HIWORD(wParam);
-
-        ME_HScrollAbs(editor, sbi.nTrackPos);
+        int pos = HIWORD(wParam);
+        if (editor->horz_si.nMax > 0xffff)
+          pos = MulDiv(pos, editor->horz_si.nMax, 0xffff);
+        ME_HScrollAbs(editor, pos);
        break;
      }
    }
@@ -4064,15 +4064,10 @@ LRESULT ME_HandleMessage(ME_TextEditor *editor, UINT msg, WPARAM wParam,
      case SB_THUMBTRACK:
      case SB_THUMBPOSITION:
      {
-        SCROLLINFO sbi;
-        sbi.cbSize = sizeof(sbi);
-        sbi.fMask = SIF_TRACKPOS;
-        /* Try to get 32-bit track position value. */
-        if (!GetScrollInfo(editor->hWnd, SB_VERT, &sbi))
-          /* GetScrollInfo failed, settle for 16-bit value in wParam. */
-          sbi.nTrackPos = HIWORD(wParam);
-
-        ME_VScrollAbs(editor, sbi.nTrackPos);
+        int pos = HIWORD(wParam);
+        if (editor->vert_si.nMax > 0xffff)
+          pos = MulDiv(pos, editor->vert_si.nMax, 0xffff);
+        ME_VScrollAbs(editor, pos);
        break;
      }
    }

--- a/dlls/riched20/paint.c
+++ b/dlls/riched20/paint.c
@@ -1036,17 +1036,21 @@ void ME_ScrollAbs(ME_TextEditor *editor, int x, int y)
  if (editor->horz_si.nPos != x) {
    x = min(x, editor->horz_si.nMax);
    x = max(x, editor->horz_si.nMin);
-    ITextHost_TxSetScrollPos(editor->texthost, SB_HORZ, x, TRUE);
    scrollX = editor->horz_si.nPos - x;
    editor->horz_si.nPos = x;
+    if (editor->horz_si.nMax > 0xFFFF) /* scale to 16-bit value */
+      x = MulDiv(x, 0xFFFF, editor->horz_si.nMax);
+    ITextHost_TxSetScrollPos(editor->texthost, SB_HORZ, x, TRUE);
  }

  if (editor->vert_si.nPos != y) {
    y = min(y, editor->vert_si.nMax - (int)editor->vert_si.nPage);
    y = max(y, editor->vert_si.nMin);
-    ITextHost_TxSetScrollPos(editor->texthost, SB_VERT, y, TRUE);
    scrollY = editor->vert_si.nPos - y;
    editor->vert_si.nPos = y;
+    if (editor->vert_si.nMax > 0xFFFF) /* scale to 16-bit value */
+      y = MulDiv(y, 0xFFFF, editor->vert_si.nMax);
+    ITextHost_TxSetScrollPos(editor->texthost, SB_VERT, y, TRUE);
  }

  if (abs(scrollX) > editor->sizeWindow.cx ||
@@ -1170,6 +1174,12 @@ void ME_UpdateScrollBar(ME_TextEditor *editor)
    if ((bScrollBarWillBeVisible || bScrollBarWasVisible) &&
        editor->styleFlags & WS_HSCROLL)
    {
+      if (si.nMax > 0xFFFF)
+      {
+        /* Native scales the scrollbar info to 16-bit external values. */
+        si.nPos = MulDiv(si.nPos, 0xFFFF, si.nMax);
+        si.nMax = 0xFFFF;
+      }
      if (editor->hWnd) {
        SetScrollInfo(editor->hWnd, SB_HORZ, &si, TRUE);
      } else {
@@ -1219,6 +1229,12 @@ void ME_UpdateScrollBar(ME_TextEditor *editor)
    if ((bScrollBarWillBeVisible || bScrollBarWasVisible) &&
        editor->styleFlags & WS_VSCROLL)
    {
+      if (si.nMax > 0xFFFF)
+      {
+        /* Native scales the scrollbar info to 16-bit external values. */
+        si.nPos = MulDiv(si.nPos, 0xFFFF, si.nMax);
+        si.nMax = 0xFFFF;
+      }
      if (editor->hWnd) {
        SetScrollInfo(editor->hWnd, SB_VERT, &si, TRUE);
      } else {