From: Gabriel Ivăncescu Subject: [PATCH 2/6] user32/listbox: Handle Mouse Wheel scrolling for multi-column listboxes properly Message-Id: <676f9c85680c569218cb73fedb391145804bbe3b.1549286237.git.gabrielopcode@gmail.com> Date: Mon, 4 Feb 2019 15:19:39 +0200 In-Reply-To: <0bb6ab9b6f43d36db4373f6dfe0aa7a1f634f998.1549286237.git.gabrielopcode@gmail.com> References: <0bb6ab9b6f43d36db4373f6dfe0aa7a1f634f998.1549286237.git.gabrielopcode@gmail.com> Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=22253 Signed-off-by: Gabriel Ivăncescu --- dlls/user32/listbox.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/dlls/user32/listbox.c b/dlls/user32/listbox.c index 594c956..26d5410 100644 --- a/dlls/user32/listbox.c +++ b/dlls/user32/listbox.c @@ -2025,9 +2025,11 @@ static LRESULT LISTBOX_HandleHScroll( LB_DESCR *descr, WORD scrollReq, WORD pos static LRESULT LISTBOX_HandleMouseWheel(LB_DESCR *descr, SHORT delta ) { - UINT pulScrollLines = 3; + INT pulScrollLines; + UINT tmp = 3; - SystemParametersInfoW(SPI_GETWHEELSCROLLLINES,0, &pulScrollLines, 0); + SystemParametersInfoW(SPI_GETWHEELSCROLLLINES,0, &tmp, 0); + pulScrollLines = tmp; /* if scrolling changes direction, ignore left overs */ if ((delta < 0 && descr->wheel_remain < 0) || @@ -2038,10 +2040,21 @@ static LRESULT LISTBOX_HandleMouseWheel(LB_DESCR *descr, SHORT delta ) if (descr->wheel_remain && pulScrollLines) { - int cLineScroll; - pulScrollLines = min((UINT) descr->page_size, pulScrollLines); - cLineScroll = pulScrollLines * (float)descr->wheel_remain / WHEEL_DELTA; - descr->wheel_remain -= WHEEL_DELTA * cLineScroll / (int)pulScrollLines; + INT cLineScroll; + if (descr->style & LBS_MULTICOLUMN) + { + pulScrollLines = min((UINT)descr->width / descr->column_width, pulScrollLines); + pulScrollLines = max(1U, pulScrollLines); + cLineScroll = (pulScrollLines * descr->wheel_remain) / WHEEL_DELTA; + descr->wheel_remain -= (cLineScroll * WHEEL_DELTA) / pulScrollLines; + cLineScroll *= descr->page_size; + } + else + { + pulScrollLines = min((UINT)descr->page_size, pulScrollLines); + cLineScroll = (pulScrollLines * descr->wheel_remain) / WHEEL_DELTA; + descr->wheel_remain -= (cLineScroll * WHEEL_DELTA) / pulScrollLines; + } LISTBOX_SetTopItem( descr, descr->top_item - cLineScroll, TRUE ); } return 0; -- 2.19.1