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There is no horizontal scroll when I call this method in Delphi 3 under Windows 7:

const MOUSEEVENTF_HWHEEL = $1000;
mouse_event(MOUSEEVENTF_HWHEEL, 0, 0, 120, 0);

Vertical scroll with MOUSEEVENTF_WHEEL works well. Result is same with SendInput, and return value indicates a success. My current mouse supports horizontal tilt, but has no horizontal scroller.

What is needed to use MOUSEEVENTF_HWHEEL?

SDK documentation: http://bit.ly/mouse_event

Mouse Hook

I created a second 32 bit exe program under Windows 7 only to see if the mouse sends messages when the horizontal wheel is scrolled. This hook receives VSCROLL but no HSCROLL messages.

MouseHook := SetWindowsHookEx(WH_MOUSE_LL, @MouseProc, hInstance, 0);
rjobidon
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  • Since this seems to be Delphi or some other Pascal dialect, you should probably add another tag. Although no special knowledge in that dialect would be required to answer an API question – 0xC0000022L Nov 30 '11 at 13:53
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    I searched for hours on discussion forums and other QA websites... Many people have the same issue, with well known programming languages: VB, C, etc. I quickly rejected this assumption. However I keep in the suspect list my exe header, XML manifest, constant and function declaration. But I believe another X factor is missing. I set a system-wide windows hook on wheel mouse messages. VSCROLL are detected but hook is silent with HSCROLL. – rjobidon Nov 30 '11 at 23:51
  • btw: is the hook low-level or not? Can you please post the type of hook you are setting ...? ... `WH_MOUSE` or `WH_MOUSE_LL`? ... also, since this is a hook, are you running on x64 or x86 Windows and is the hook DLL 32bit or 64bit ... do you even use a DLL? – 0xC0000022L Dec 01 '11 at 00:09
  • The hook is a low level mouse one declared as following: MouseHook := SetWindowsHookEx(WH_MOUSE_LL, @MouseProc, hInstance, 0). The program is a 32 bit exe file under Windows 7 64 bit. Callback function is fired for vertical scroll events, but not horizontal ones. I hope you will see something suspect. – rjobidon Dec 01 '11 at 00:28
  • Okay, now one more thing, because the question does not list those details: you call `mouse_event` from inside your hook function or from the outside in order to verify that the hook works? – 0xC0000022L Dec 01 '11 at 08:59
  • The hook and the mouse_event are two separate 32-bit exe programs. – rjobidon Dec 01 '11 at 11:10

1 Answers1

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int main()
{
    Sleep(20000); // enough time to switch windows and position the mouse pointer
    mouse_event(MOUSEEVENTF_HWHEEL, 0, 0, 120, 0);
    return 0;
}

scrolled my selected firefox page to the right. the window had to be selected and the mouse pointer had to be over the page. i did that with the mouse enabled. Or also turned the mouse off while testing (using the on/off switch on the mouse itself), the result was the same. My mouse has a horizontal tilt as well, no scroller. (windows 7 ultimate)

EDIT

One thing to note: The program itself needs to handle the message. Firefox for example does. It shows the same behaviour as tilting the mouse wheel: the page scrolls left/right accordingly. Other programs, like IE, seem not to handle this message, so no scrolling at all. Even using the mouse (Logitech Performance MX without any addional software package) nothing scrolls. So, it seems there is no 100% solution to this problem by just sending the mouse_event messages.

esskar
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  • You suggestion has no success in my code. I'm going to try a new empty app in C++ like yours. Do you have a Microsoft mouse (Intellipoint driver) or Logitech mouse (SetPoint driver). If Windows 7 doesn't yet support HSCROLL maybe the mouse driver sends WM_HSCROLL messages directly to scrollbars... – rjobidon Nov 30 '11 at 23:56
  • I am using a Microsoft mouse. Will try this Code tomorrow in my Laptop with no mouse attached – esskar Dec 01 '11 at 00:12
  • My original code and yours work in Chrome and Safari but not in Internet Explorer or Adobe Acrobat reader. Still missing a small hack. – rjobidon Dec 01 '11 at 01:34
  • @rjobidon added some additional findings! – esskar Dec 01 '11 at 02:12
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    +275 for your time esskar! Thanks also to STATUS_ACCESS_DENIED. However my initial problem is not solved. I must figure out the message chain between the mouse tilt and the window horizontal scroll. Then I could emulate what the mouse driver does. I'm pretty sure the driver doesn't keep a list of applications and specific events to send in reaction to HSCROLL. – rjobidon Dec 08 '11 at 03:23
  • @rjobidon, thanks for that. let me know if you find a satifying solution for that! – esskar Dec 08 '11 at 13:59