winhlp32: Prevent cursor flicker on mouse moves over richedit control.

Previously the cursor was being set by winhlp32 on WM_MOUSEMOVE, then the richedit control would change it again on WM_SETCURSOR. Since the cursor set in both of these places was different, the cursor would flicker from being frequently changed. The reason winhlp32 is setting the cursor, rather than letting the richedit control set the cursor, is that winhlp32 needs the hand cursor to be shown over a link. My first instinct was to just add the CFE_LINK effect to the link characters, however this also forced a colour for the link that was inconsistent with native winhlp32. Native winhlp32 doesn't seem to load any richedit dll, so this doesn't imply that there is an undocumented way of changing the colour of characters with CFE_LINK. This patch has winhlp32 override the WNDPROC for the richedit control to handle the WM_SETCURSOR. It simply sets the cursor to the hand if the cursor is over the link, otherwise it just calls the original richedit window proc.

winhlp32: Prevent cursor flicker on mouse moves over richedit control.
a36b408f · Dylan Smith · Alexandre Julliard · 908ff583 · a36b408f · a36b408f
Commit a36b408f authored Mar 10, 2009 by Dylan Smith Committed by Alexandre Julliard Mar 11, 2009
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Showing with 63 additions and 42 deletions

winhelp.c programs/winhlp32/winhelp.c +61 -42

winhelp.h programs/winhlp32/winhelp.h +2 -0

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--- a/programs/winhlp32/winhelp.c
+++ b/programs/winhlp32/winhelp.c
@@ -581,6 +581,64 @@ static void WINHELP_RememberPage(WINHELP_WINDOW* win, WINHELP_WNDPAGE* wpage)

 /***********************************************************************
 *
+ *           WINHELP_FindLink
+ */
+static HLPFILE_LINK* WINHELP_FindLink(WINHELP_WINDOW* win, LPARAM pos)
+{
+    HLPFILE_LINK*           link;
+    POINTL                  mouse_ptl, char_ptl, char_next_ptl;
+    DWORD                   cp;
+
+    if (!win->page) return NULL;
+
+    mouse_ptl.x = (short)LOWORD(pos);
+    mouse_ptl.y = (short)HIWORD(pos);
+    cp = SendMessageW(GetDlgItem(win->hMainWnd, CTL_ID_TEXT), EM_CHARFROMPOS,
+                      0, (LPARAM)&mouse_ptl);
+
+    for (link = win->page->first_link; link; link = link->next)
+    {
+        if (link->cpMin <= cp && cp <= link->cpMax)
+        {
+            /* check whether we're at end of line */
+            SendMessageW(GetDlgItem(win->hMainWnd, CTL_ID_TEXT), EM_POSFROMCHAR,
+                         (LPARAM)&char_ptl, cp);
+            SendMessageW(GetDlgItem(win->hMainWnd, CTL_ID_TEXT), EM_POSFROMCHAR,
+                         (LPARAM)&char_next_ptl, cp + 1);
+            if (char_next_ptl.y != char_ptl.y || mouse_ptl.x >= char_next_ptl.x)
+                link = NULL;
+            break;
+        }
+    }
+    return link;
+}
+
+static LRESULT CALLBACK WINHELP_RicheditWndProc(HWND hWnd, UINT msg,
+                                                WPARAM wParam, LPARAM lParam)
+{
+    WINHELP_WINDOW *win = (WINHELP_WINDOW*) GetWindowLongPtr(GetParent(hWnd), 0);
+    DWORD messagePos;
+    POINT pt;
+    switch(msg)
+    {
+        case WM_SETCURSOR:
+            messagePos = GetMessagePos();
+            pt.x = (short)LOWORD(messagePos);
+            pt.y = (short)HIWORD(messagePos);
+            ScreenToClient(hWnd, &pt);
+            if (win->page && WINHELP_FindLink(win, MAKELPARAM(pt.x, pt.y)))
+            {
+                SetCursor(win->hHandCur);
+                return 0;
+            }
+            /* fall through */
+        default:
+            return CallWindowProcA(win->origRicheditWndProc, hWnd, msg, wParam, lParam);
+    }
+}
+
+/***********************************************************************
+ *
 *           WINHELP_CreateHelpWindow
 */
 BOOL WINHELP_CreateHelpWindow(WINHELP_WNDPAGE* wpage, int nCmdShow, BOOL remember)
@@ -701,6 +759,8 @@ BOOL WINHELP_CreateHelpWindow(WINHELP_WNDPAGE* wpage, int nCmdShow, BOOL remembe
                                0, 0, 0, 0, win->hMainWnd, (HMENU)CTL_ID_TEXT, Globals.hInstance, NULL);
        SendMessage(hTextWnd, EM_SETEVENTMASK, 0,
                    SendMessage(hTextWnd, EM_GETEVENTMASK, 0, 0) | ENM_MOUSEEVENTS);
+        win->origRicheditWndProc = (WNDPROC)SetWindowLongPtr(hTextWnd, GWLP_WNDPROC,
+                                                             (LONG_PTR)WINHELP_RicheditWndProc);
    }

    hIcon = (wpage->page) ? wpage->page->file->hIcon : NULL;
@@ -769,40 +829,6 @@ BOOL WINHELP_OpenHelpWindow(HLPFILE_PAGE* (*lookup)(HLPFILE*, LONG, ULONG*),
    return WINHELP_CreateHelpWindow(&wpage, nCmdShow, TRUE);
 }

-/***********************************************************************
- *
- *           WINHELP_FindLink
- */
-static HLPFILE_LINK* WINHELP_FindLink(WINHELP_WINDOW* win, LPARAM pos)
-{
-    HLPFILE_LINK*           link;
-    POINTL                  mouse_ptl, char_ptl, char_next_ptl;
-    DWORD                   cp;
-
-    if (!win->page) return NULL;
-
-    mouse_ptl.x = (short)LOWORD(pos);
-    mouse_ptl.y = (short)HIWORD(pos);
-    cp = SendMessageW(GetDlgItem(win->hMainWnd, CTL_ID_TEXT), EM_CHARFROMPOS,
-                      0, (LPARAM)&mouse_ptl);
-
-    for (link = win->page->first_link; link; link = link->next)
-    {
-        if (link->cpMin <= cp && cp <= link->cpMax)
-        {
-            /* check whether we're at end of line */
-            SendMessageW(GetDlgItem(win->hMainWnd, CTL_ID_TEXT), EM_POSFROMCHAR,
-                         (LPARAM)&char_ptl, cp);
-            SendMessageW(GetDlgItem(win->hMainWnd, CTL_ID_TEXT), EM_POSFROMCHAR,
-                         (LPARAM)&char_next_ptl, cp + 1);
-            if (char_next_ptl.y != char_ptl.y || mouse_ptl.x >= char_next_ptl.x)
-                link = NULL;
-            break;
-        }
-    }
-    return link;
-}
-
 /******************************************************************
 *             WINHELP_HandleTextMouse
 *
@@ -815,14 +841,7 @@ static BOOL WINHELP_HandleTextMouse(WINHELP_WINDOW* win, UINT msg, LPARAM lParam

    switch (msg)
    {
-    case WM_MOUSEMOVE:
-        if (WINHELP_FindLink(win, lParam))
-            SetCursor(win->hHandCur);
-        else
-            SetCursor(LoadCursor(0, IDC_ARROW));
-        break;
-
-     case WM_LBUTTONDOWN:
+    case WM_LBUTTONDOWN:
         if ((win->current_link = WINHELP_FindLink(win, lParam)))
             ret = TRUE;
         break;

--- a/programs/winhlp32/winhelp.h
+++ b/programs/winhlp32/winhelp.h
@@ -80,6 +80,8 @@ typedef struct tagWinHelp
    HWND                hShadowWnd;
    HWND                hHistoryWnd;

+    WNDPROC             origRicheditWndProc;
+
    HFONT*              fonts;
    UINT                fonts_len;