protected override void WndProc(ref Message m)
{
var message = m;
var groupHitInfo = new Lazy <ListViewGroupHitInfo>(() => GetGroupHitInfo(message));
switch (m.Msg)
{
case NativeMethods.WM_LBUTTONUP when groupHitInfo.Value?.IsCollapseButton == true:
DefWndProc(ref m); // collapse / expand by clicking button in group header
break;
case NativeMethods.WM_PAINT:
_isInWmPaintMsg = true;
base.WndProc(ref m);
_isInWmPaintMsg = false;
break;
case NativeMethods.WM_REFLECT_NOTIFY when IsCustomDraw(m) && !_isInWmPaintMsg:
case NativeMethods.WM_RBUTTONUP when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Right, isDown: false) :
case NativeMethods.WM_RBUTTONDOWN when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Right, isDown: true) :
case NativeMethods.WM_LBUTTONUP when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Left, isDown: false) :
case NativeMethods.WM_LBUTTONDOWN when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Left, isDown: true) :
break;
default:
base.WndProc(ref m);
break;
}
bool IsGroupMouseEventHandled(ListViewGroupHitInfo hitInfo, MouseButtons button, bool isDown)
{
if (hitInfo == null)
{
return(false);
}
var eventArgs = new ListViewGroupMouseEventArgs(button, hitInfo, 1, 0);
if (isDown)
{
GroupMouseDown?.Invoke(this, eventArgs);
}
else
{
GroupMouseUp?.Invoke(this, eventArgs);
}
return(eventArgs.Handled);
}
bool IsCustomDraw(Message msg)
{
var nmhdr = (NativeMethods.NMHDR)msg.GetLParam(typeof(NativeMethods.NMHDR));
return(nmhdr.code == NativeMethods.NM_CUSTOMDRAW);
}
}
protected override void WndProc(ref Message m)
{
var message = m;
switch (m.Msg)
{
case WM_LBUTTONUP when GetGroupHitInfo(message.LParam.ToPoint())?.IsCollapseButton == true:
DefWndProc(ref m); // collapse / expand by clicking button in group header
break;
case LVM_INSERTGROUP:
base.WndProc(ref m);
HandleAddedGroup(m);
break;
case WM_RBUTTONUP when IsGroupMouseEventHandled(MouseButtons.Right, isDown: false) :
case WM_RBUTTONDOWN when IsGroupMouseEventHandled(MouseButtons.Right, isDown: true) :
case WM_LBUTTONUP when IsGroupMouseEventHandled(MouseButtons.Left, isDown: false) :
case WM_LBUTTONDOWN when IsGroupMouseEventHandled(MouseButtons.Left, isDown: true) :
break;
default:
HandleScroll(m);
base.WndProc(ref m);
break;
}
void HandleScroll(Message msg)
{
ScrollEventType type;
int? newValue = null;
switch (msg.Msg)
{
case WM_VSCROLL:
type = (ScrollEventType)LowWord(msg.WParam.ToInt64());
newValue = HighWord(msg.WParam.ToInt64());
break;
case WM_MOUSEWHEEL:
type = HighWord(msg.WParam.ToInt64()) > 0
? ScrollEventType.SmallDecrement
: ScrollEventType.SmallIncrement;
break;
case WM_KEYDOWN:
switch ((Keys)msg.WParam.ToInt32())
{
case Keys.Up:
type = ScrollEventType.SmallDecrement;
break;
case Keys.Down:
type = ScrollEventType.SmallIncrement;
break;
case Keys.PageUp:
type = ScrollEventType.LargeDecrement;
break;
case Keys.PageDown:
type = ScrollEventType.LargeIncrement;
break;
case Keys.Home:
type = ScrollEventType.First;
break;
case Keys.End:
type = ScrollEventType.Last;
break;
default:
return;
}
break;
default:
return;
}
newValue ??= GetScrollPos(Handle, SB.VERT);
Scroll?.Invoke(this, new ScrollEventArgs(type, newValue.Value));
short LowWord(long number) =>
unchecked ((short)(number & 0x0000ffff));
short HighWord(long number) =>
unchecked ((short)(number >> 16));
}
void HandleAddedGroup(Message msg)
{
if (!IsGroupStateSupported || !AllowCollapseGroups)
{
return;
}
int groupIndex = GetGroupIndex();
if (groupIndex < _minGroupInsertionIndex)
{
return;
}
var listViewGroup = Groups[groupIndex];
SetGroupState(listViewGroup, LVGS.Collapsible);
Invalidate();
int GetGroupIndex()
{
// https://docs.microsoft.com/en-us/windows/desktop/controls/lvm-insertgroup
int index = msg.WParam.ToInt32();
if (index == -1)
{
// -1 because addition already happened
return(Groups.Count - 1);
}
return(index - 1 + _minGroupInsertionIndex);
}
}
bool IsGroupMouseEventHandled(MouseButtons button, bool isDown)
{
var hitInfo = GetGroupHitInfo(message.LParam.ToPoint());
if (hitInfo is null)
{
return(false);
}
var eventArgs = new ListViewGroupMouseEventArgs(button, hitInfo, 1, 0);
if (isDown)
{
GroupMouseDown?.Invoke(this, eventArgs);
}
else
{
GroupMouseUp?.Invoke(this, eventArgs);
}
return(eventArgs.Handled);
}
}
protected override void WndProc(ref Message m)
{
var message = m;
switch (m.Msg)
{
case NativeMethods.WM_LBUTTONUP when GetGroupHitInfo(message.LParam.ToPoint())?.IsCollapseButton == true:
DefWndProc(ref m); // collapse / expand by clicking button in group header
break;
case NativeMethods.LVM_INSERTGROUP:
base.WndProc(ref m);
HandleAddedGroup(m);
break;
case NativeMethods.WM_PAINT:
_isInWmPaintMsg = true;
base.WndProc(ref m);
_isInWmPaintMsg = false;
break;
case NativeMethods.WM_REFLECT_NOTIFY when IsCustomDraw(m) && !_isInWmPaintMsg:
case NativeMethods.WM_RBUTTONUP when IsGroupMouseEventHandled(MouseButtons.Right, isDown: false) :
case NativeMethods.WM_RBUTTONDOWN when IsGroupMouseEventHandled(MouseButtons.Right, isDown: true) :
case NativeMethods.WM_LBUTTONUP when IsGroupMouseEventHandled(MouseButtons.Left, isDown: false) :
case NativeMethods.WM_LBUTTONDOWN when IsGroupMouseEventHandled(MouseButtons.Left, isDown: true) :
break;
default:
base.WndProc(ref m);
break;
}
HandleScroll(m);
void HandleScroll(Message msg)
{
ScrollEventType type;
int? newValue = null;
switch (msg.Msg)
{
case NativeMethods.WM_VSCROLL:
type = (ScrollEventType)(msg.WParam.ToInt32() & 0xffff);
newValue = msg.WParam.ToInt32() & 0x0000ffff;
break;
case NativeMethods.WM_MOUSEWHEEL:
type = ScrollEventType.EndScroll;
break;
case NativeMethods.WM_KEYDOWN:
switch ((Keys)msg.WParam.ToInt32())
{
case Keys.Up:
type = ScrollEventType.SmallDecrement;
break;
case Keys.Down:
type = ScrollEventType.SmallIncrement;
break;
case Keys.PageUp:
type = ScrollEventType.LargeDecrement;
break;
case Keys.PageDown:
type = ScrollEventType.LargeIncrement;
break;
case Keys.Home:
type = ScrollEventType.First;
break;
case Keys.End:
type = ScrollEventType.Last;
break;
default:
return;
}
break;
default:
return;
}
newValue = newValue ?? NativeMethods.GetScrollPos(Handle, NativeMethods.SB_VERT);
Scroll?.Invoke(this, new ScrollEventArgs(type, newValue.Value));
}
void HandleAddedGroup(Message msg)
{
if (!IsGroupStateSupported || !AllowCollapseGroups)
{
return;
}
int groupIndex = GetGroupIndex();
if (groupIndex < _minGroupInsertionIndex)
{
return;
}
var listViewGroup = Groups[groupIndex];
SetGrpState(listViewGroup, ListViewGroupState.Collapsible);
Invalidate();
int GetGroupIndex()
{
// https://docs.microsoft.com/en-us/windows/desktop/controls/lvm-insertgroup
int index = msg.WParam.ToInt32();
if (index == -1)
{
// -1 because addition already happened
return(Groups.Count - 1);
}
return(index - 1 + _minGroupInsertionIndex);
}
void SetGrpState(ListViewGroup grp, ListViewGroupState state)
{
int groupId = GetGroupId(grp);
if (groupId < 0)
{
groupId = Groups.IndexOf(grp) - _minGroupInsertionIndex;
}
var lvgroup = new NativeMethods.LVGROUP();
lvgroup.CbSize = Marshal.SizeOf(lvgroup);
lvgroup.State = state;
lvgroup.Mask = NativeMethods.ListViewGroupMask.State;
lvgroup.IGroupId = groupId;
var handleRef = new HandleRef(this, Handle);
NativeMethods.SendMessage(handleRef, NativeMethods.LVM_SETGROUPINFO, (IntPtr)groupId, ref lvgroup);
}
}
bool IsGroupMouseEventHandled(MouseButtons button, bool isDown)
{
var hitInfo = GetGroupHitInfo(message.LParam.ToPoint());
if (hitInfo == null)
{
return(false);
}
var eventArgs = new ListViewGroupMouseEventArgs(button, hitInfo, 1, 0);
if (isDown)
{
GroupMouseDown?.Invoke(this, eventArgs);
}
else
{
GroupMouseUp?.Invoke(this, eventArgs);
}
return(eventArgs.Handled);
}
bool IsCustomDraw(Message msg)
{
var nmhdr = (NativeMethods.NMHDR)msg.GetLParam(typeof(NativeMethods.NMHDR));
return(nmhdr.code == NativeMethods.NM_CUSTOMDRAW);
}
}
protected override void WndProc(ref Message m)
{
var message = m;
var groupHitInfo = new Lazy <ListViewGroupHitInfo>(() => GetGroupHitInfo(message));
switch (m.Msg)
{
case NativeMethods.WM_LBUTTONUP when groupHitInfo.Value?.IsCollapseButton == true:
DefWndProc(ref m); // collapse / expand by clicking button in group header
break;
case NativeMethods.LVM_INSERTGROUP:
base.WndProc(ref m);
HandleAddedGroup(m);
break;
case NativeMethods.WM_PAINT:
_isInWmPaintMsg = true;
base.WndProc(ref m);
_isInWmPaintMsg = false;
break;
case NativeMethods.WM_REFLECT_NOTIFY when IsCustomDraw(m) && !_isInWmPaintMsg:
case NativeMethods.WM_RBUTTONUP when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Right, isDown: false) :
case NativeMethods.WM_RBUTTONDOWN when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Right, isDown: true) :
case NativeMethods.WM_LBUTTONUP when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Left, isDown: false) :
case NativeMethods.WM_LBUTTONDOWN when IsGroupMouseEventHandled(groupHitInfo.Value, MouseButtons.Left, isDown: true) :
break;
default:
base.WndProc(ref m);
break;
}
void HandleAddedGroup(Message msg)
{
if (!IsGroupStateSupported || !AllowCollapseGroups)
{
return;
}
int groupIndex = GetGroupIndex();
if (groupIndex < _minGroupInsertionIndex)
{
return;
}
var listViewGroup = Groups[groupIndex];
SetGrpState(listViewGroup, ListViewGroupState.Collapsible);
Invalidate();
int GetGroupIndex()
{
// https://docs.microsoft.com/en-us/windows/desktop/controls/lvm-insertgroup
int index = msg.WParam.ToInt32();
if (index == -1)
{
// -1 because addition already happened
return(Groups.Count - 1);
}
return(index - 1 + _minGroupInsertionIndex);
}
void SetGrpState(ListViewGroup grp, ListViewGroupState state)
{
int groupId = GetGroupId(grp);
if (groupId < 0)
{
groupId = Groups.IndexOf(grp) - _minGroupInsertionIndex;
}
var lvgroup = new NativeMethods.LVGROUP();
lvgroup.CbSize = Marshal.SizeOf(lvgroup);
lvgroup.State = state;
lvgroup.Mask = NativeMethods.ListViewGroupMask.State;
lvgroup.IGroupId = groupId;
var handleRef = new HandleRef(this, Handle);
NativeMethods.SendMessage(handleRef, NativeMethods.LVM_SETGROUPINFO, (IntPtr)groupId, ref lvgroup);
}
}
bool IsGroupMouseEventHandled(ListViewGroupHitInfo hitInfo, MouseButtons button, bool isDown)
{
if (hitInfo == null)
{
return(false);
}
var eventArgs = new ListViewGroupMouseEventArgs(button, hitInfo, 1, 0);
if (isDown)
{
GroupMouseDown?.Invoke(this, eventArgs);
}
else
{
GroupMouseUp?.Invoke(this, eventArgs);
}
return(eventArgs.Handled);
}
bool IsCustomDraw(Message msg)
{
var nmhdr = (NativeMethods.NMHDR)msg.GetLParam(typeof(NativeMethods.NMHDR));
return(nmhdr.code == NativeMethods.NM_CUSTOMDRAW);
}
}
