[PATCH 0/2] MR8045: comctl32: Implement EVENT_OBJECT_VALUECHANGE for trackbars.

[Esme Povirk (＠madewokherd)]

Unfortunately, this can't be properly tested because of todo's in the message sequence. The event does show up in response to TPM_SETPOS, at least.

[PATCH 1/2] comctl32: Add tests for trackbar MSAA events.

[Esme Povirk]

From: Esme Povirk

---
 dlls/comctl32/tests/trackbar.c | 56 +++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/dlls/comctl32/tests/trackbar.c b/dlls/comctl32/tests/trackbar.c
index a367b7e699c..71c68b2974c 100644
--- a/dlls/comctl32/tests/trackbar.c
+++ b/dlls/comctl32/tests/trackbar.c
@@ -50,10 +50,56 @@ static LRESULT WINAPI trackbar_no_wmpaint_proc(HWND hwnd, UINT message, WPARAM w

static struct msg_sequence *sequences[NUM_MSG_SEQUENCE];

+static void CALLBACK msg_winevent_proc(HWINEVENTHOOK hevent,
+                                       DWORD event,
+                                       HWND hwnd,
+                                       LONG object_id,
+                                       LONG child_id,
+                                       DWORD thread_id,
+                                       DWORD event_time)
+{
+    struct message msg = {0};
+    char class_name[256];
+
+    /* ignore window and other system events */
+    if (object_id != OBJID_CLIENT) return;
+
+    /* ignore events not from a progress bar control */
+    if (!GetClassNameA(hwnd, class_name, ARRAY_SIZE(class_name)) ||
+        strcmp(class_name, TRACKBAR_CLASSA) != 0)
+        return;
+
+    msg.message = event;
+    msg.flags = winevent_hook|wparam|lparam;
+    msg.wParam = object_id;
+    msg.lParam = child_id;
+    add_message(sequences, TRACKBAR_SEQ_INDEX, &msg);
+}
+
+static void init_winevent_hook(void) {
+    hwineventhook = SetWinEventHook(EVENT_MIN, EVENT_MAX, GetModuleHandleA(0), msg_winevent_proc,
+                                    0, GetCurrentThreadId(), WINEVENT_INCONTEXT);
+    if (!hwineventhook)
+        win_skip( "no win event hook support\n" );
+}
+
+static void uninit_winevent_hook(void) {
+    if (!hwineventhook)
+        return;
+
+    UnhookWinEvent(hwineventhook);
+    hwineventhook = 0;
+}
+
 static const struct message empty_seq[] = {
     {0}
 };

+static const struct message create_trackbar_wnd_seq[] = {
+    { EVENT_OBJECT_FOCUS, winevent_hook|wparam|lparam, OBJID_CLIENT, 0 },
+    {0}
+};
+
 static const struct message parent_create_trackbar_wnd_seq[] = {
     { WM_NOTIFYFORMAT, sent},
     { WM_QUERYUISTATE, sent|optional},
@@ -130,10 +176,14 @@ static const struct message position_test_seq[] = {
     { TBM_GETPOS, sent},
     { TBM_SETPOS, sent|wparam|lparam, TRUE, 5},
     { WM_PAINT, sent|defwinproc},
+    { EVENT_OBJECT_STATECHANGE, winevent_hook|wparam|lparam|optional, OBJID_CLIENT, 0 }, /* v6 only */
+    { EVENT_OBJECT_VALUECHANGE, winevent_hook|wparam|lparam, OBJID_CLIENT, 0 },
     { TBM_GETPOS, sent},
     { TBM_SETPOS, sent|wparam|lparam, TRUE, 5},
     { TBM_SETPOS, sent|wparam|lparam, TRUE, 1000},
     { WM_PAINT, sent|defwinproc},
+    { EVENT_OBJECT_STATECHANGE, winevent_hook|wparam|lparam|optional, OBJID_CLIENT, 0 }, /* v6 only */
+    { EVENT_OBJECT_VALUECHANGE, winevent_hook|wparam|lparam, OBJID_CLIENT, 0 },
     { TBM_GETPOS, sent},
     { TBM_SETPOS, sent|wparam|lparam, FALSE, 20},
     { TBM_GETPOS, sent},
@@ -1355,7 +1405,7 @@ static void test_create(void)

hWndTrackbar = create_trackbar(defaultstyle, hWndParent);
     ok(hWndTrackbar != NULL, "Expected non NULL value\n");
-    ok_sequence(sequences, TRACKBAR_SEQ_INDEX, empty_seq, "create Trackbar Window", FALSE);
+    ok_sequence(sequences, TRACKBAR_SEQ_INDEX, create_trackbar_wnd_seq, "create Trackbar Window", FALSE);
     ok_sequence(sequences, PARENT_SEQ_INDEX, parent_create_trackbar_wnd_seq, "parent trackbar window", TRUE);

DestroyWindow(hWndTrackbar);
@@ -1386,6 +1436,8 @@ START_TEST(trackbar)
         return;
     }

+    init_winevent_hook();
+
     test_create();
     test_trackbar_buddy();
     test_line_size();
@@ -1420,6 +1472,8 @@ START_TEST(trackbar)
     test_ignore_selection();
     test_initial_state();

+    uninit_winevent_hook();
+
     unload_v6_module(cookie, ctxt);

DestroyWindow(hWndParent);

[PATCH 2/2] comctl32: Implement EVENT_OBJECT_VALUECHANGE for trackbars.

[Esme Povirk]

From: Esme Povirk

---
 dlls/comctl32/trackbar.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dlls/comctl32/trackbar.c b/dlls/comctl32/trackbar.c
index f2cb2a07a8d..461f3f3e437 100644
--- a/dlls/comctl32/trackbar.c
+++ b/dlls/comctl32/trackbar.c
@@ -1237,6 +1237,8 @@ TRACKBAR_SetPos (TRACKBAR_INFO *infoPtr, BOOL fPosition, LONG lPosition)
     {
         TRACKBAR_UpdateThumb(infoPtr);
         TRACKBAR_InvalidateThumbMove(infoPtr, oldPos, lPosition);
+
+        NotifyWinEvent( EVENT_OBJECT_VALUECHANGE, infoPtr->hwndSelf, OBJID_CLIENT, CHILDID_SELF );
     }

return 0;

[Nikolay Sivov (＠nsivov)]

Nikolay Sivov (@nsivov) commented about dlls/comctl32/trackbar.c:
>  {
>      TRACKBAR_UpdateThumb(infoPtr);
>      TRACKBAR_InvalidateThumbMove(infoPtr, oldPos, lPosition);
> -
> -
>    NotifyWinEvent( EVENT_OBJECT_VALUECHANGE, infoPtr->hwndSelf, OBJID_CLIENT, CHILDID_SELF );
>
> }
>
> return 0;

This is not the only place where the value changes. Also here it's only notified when both changed and invalidated, is this correct?

[Esme Povirk (＠madewokherd)]

On Sat May 17 09:21:24 2025 +0000, Nikolay Sivov wrote:
> This is not the only place where the value changes. Also here it's only
> notified when both changed and invalidated, is this correct?

This is what the results on Windows seem to indicate. `position_test_seq` shows a VALUECHANGE event only for the TBM_SETPOS messages that cause a WM_PAINT. `range_test_seq` doesn't show any events even when it causes a repaint, and if I understand it correctly, it should be moving the thumb in some of those cases.

Unfortunately, this seems to be a case where MSAA events are insufficient to follow some changes, and one needs hooks or polling.

[PATCH 0/2] MR8045: comctl32: Implement EVENT_OBJECT_VALUECHANGE for trackbars. - approved

[Nikolay Sivov (＠nsivov)]

This merge request was approved by Nikolay Sivov.