private IList <MdiTab> AddNewTabs(IList <MdiTab> tabs, HashSet <Form> skipForms)
{
// RemoveClosedTabs should have gotten rid of any tabs with null AssociatedForms,
// but filtering them out again just to be sure is safe and quick.
Dictionary <Form, MdiTab> formToTabMap = tabs.Where(t => t.AssociatedForm != null).ToDictionary(tab => tab.AssociatedForm !);
bool addedTabs = false;
foreach (Form form in this.MdiChildren)
{
if (IsAvailable(form) && !skipForms.Contains(form) && !formToTabMap.TryGetValue(form, out MdiTab? tab))
{
tab = new MdiTab(form);
tab.Click += this.Tab_Click;
tab.CloseClicked += this.Tab_CloseClicked;
if (this.UseFormIconAsNewTabImage && form.Icon != null)
{
tab.Image = WindowsUtility.GetSmallIconImage(form.Icon);
// Note: I originally set tab.ImageTransparentColor = Color.Transparent here,
// but that made some white areas in the icons appear transparent even though
// they shouldn't have been. That seems like a .NET bug since icons already
// have explicitly transparent areas.
}
form.FormClosed += this.ChildForm_FormClosed;
form.TextChanged += this.ChildForm_TextChanged;
// Add it to the beginning like VS does. This keeps new tabs from immediately going
// into the overflow area when lots of forms are open. This is also consistent with
// how activating a tab from the overflow area moves it to the beginning of the tab list.
this.Items.Insert(0, tab);
addedTabs = true;
}
}
// Update the tab list if any were added.
IList <MdiTab> result = addedTabs ? this.GetTabs() : tabs;
return(result);
}
internal void BeginDragTimer(MdiTab tab)
{
if (!this.dragTimer.Enabled)
{
this.dragTab = tab;
this.Capture = true;
// This is slow enough that most normal, quick left clicks won't begin a drag
// but fast enough that pressing and holding to begin a drag doesn't make
// you wait an awkward amount of time.
const int BeginDragMilliseconds = 200;
// The drag timer ensures that normal, quick left clicks won't begin a drag,
// which would change the cursor to a Move cursor. The default seems like a
// good response time to me, but if the mouse hover time is quicker, then we'll
// use that. Setting this on each timer usage allows us to react to system
// setting changes. It also prevents us from getting a CA1601 code analysis
// warning about mobility power management concerns with fast timers:
// http://msdn.microsoft.com/en-us/library/ms182230.aspx
this.dragTimer.Interval = Math.Min(BeginDragMilliseconds, SystemInformation.MouseHoverTime);
this.dragTimer.Enabled = true;
}
}
