private HRESULT UpdateTaskbarThumbButtons()
{
Debug.Assert(null != _taskbarList);
var nativeButtons = new THUMBBUTTON[c_MaximumThumbButtons];
TaskbarItemInfo taskbarInfo = TaskbarItemInfo;
ThumbButtonInfoCollection thumbButtons = null;
if (taskbarInfo != null)
{
thumbButtons = taskbarInfo.ThumbButtonInfos;
}
var nativeIcons = new List<NativeMethods.IconHandle>();
try
{
uint currentButton = 0;
if (null != thumbButtons)
{
foreach (ThumbButtonInfo wrappedTB in thumbButtons)
{
var nativeTB = new THUMBBUTTON
{
iId = (uint)currentButton,
dwMask = THB.FLAGS | THB.TOOLTIP | THB.ICON,
};
switch (wrappedTB.Visibility)
{
case Visibility.Collapsed:
// HIDDEN removes the button from layout logic.
nativeTB.dwFlags = THBF.HIDDEN;
break;
case Visibility.Hidden:
// To match WPF's notion of hidden, we want this not HIDDEN
// but disabled, without background, and without icon.
nativeTB.dwFlags = THBF.DISABLED | THBF.NOBACKGROUND;
nativeTB.hIcon = IntPtr.Zero;
break;
default:
case Visibility.Visible:
nativeTB.szTip = wrappedTB.Description ?? "";
if (wrappedTB.ImageSource != null)
{
NativeMethods.IconHandle nativeIcon = IconHelper.CreateIconHandleFromImageSource(wrappedTB.ImageSource, _overlaySize);
nativeTB.hIcon = nativeIcon.CriticalGetHandle();
nativeIcons.Add(nativeIcon);
}
if (!wrappedTB.IsBackgroundVisible)
{
nativeTB.dwFlags |= THBF.NOBACKGROUND;
}
if (!wrappedTB.IsEnabled)
{
nativeTB.dwFlags |= THBF.DISABLED;
}
else
{
nativeTB.dwFlags |= THBF.ENABLED;
}
// This is separate from enabled/disabled
if (!wrappedTB.IsInteractive)
{
nativeTB.dwFlags |= THBF.NONINTERACTIVE;
}
if (wrappedTB.DismissWhenClicked)
{
nativeTB.dwFlags |= THBF.DISMISSONCLICK;
}
break;
}
nativeButtons[currentButton] = nativeTB;
++currentButton;
if (currentButton == c_MaximumThumbButtons)
{
break;
}
}
}
// If we're not attached, or the list is less than the maximum number of buttons
// then fill in the rest with collapsed, empty buttons.
for (; currentButton < c_MaximumThumbButtons; ++currentButton)
{
nativeButtons[currentButton] = new THUMBBUTTON
{
iId = (uint)currentButton,
dwFlags = THBF.NOBACKGROUND | THBF.DISABLED | THBF.HIDDEN,
dwMask = THB.FLAGS | THB.ICON | THB.TOOLTIP
};
}
// Finally, apply the update.
return _taskbarList.ThumbBarUpdateButtons(CriticalHandle, (uint)nativeButtons.Length, nativeButtons);
}
finally
{
foreach (var icon in nativeIcons)
{
icon.Dispose();
}
}
}
private HRESULT RegisterTaskbarThumbButtons()
{
Debug.Assert(null != _taskbarList);
// The ITaskbarList3 API requires that the maximum number of buttons to ever be used
// are registered at the beginning. Modifications can be made to this list later.
var nativeButtons = new THUMBBUTTON[c_MaximumThumbButtons];
for (int i = 0; i < c_MaximumThumbButtons; ++i)
{
nativeButtons[i] = new THUMBBUTTON
{
iId = (uint)i,
dwFlags = THBF.NOBACKGROUND | THBF.DISABLED | THBF.HIDDEN | THBF.NONINTERACTIVE,
dwMask = THB.FLAGS | THB.ICON | THB.TOOLTIP
};
}
// If this gets called (successfully) more than once it usually returns E_INVALIDARG. It's not really
// a failure and we potentially want to retry this operation.
HRESULT hr = _taskbarList.ThumbBarAddButtons(CriticalHandle, (uint)nativeButtons.Length, nativeButtons);
if (hr == HRESULT.E_INVALIDARG)
{
hr = HRESULT.S_FALSE;
}
return hr;
}
