I'm writing a custom control and I'd like the control to switch from an editing state to it's normal state when a user clicks off of the control. I'm handling the LostFocus event and that helps when a user tabs away or if they click on to another control that's Focusable. But if they don't click on something Focusable, it won't switch out of it's editing state. So I have two solutions in mind:
Walk up the tree to the top most element when it goes in to an editing state and add a handler for MouseDownEvent (and handle "handled" events). In the handler I'd kick the control out of it's editing state and remove the handler from the top most element. This seems like a bit of a hack, but it would probably work well.
Example code:
private void RegisterTopMostParentMouseClickEvent()
{
_topMostParent = this.FindLastVisualAncestor<FrameworkElement>();
if ( _topMostParent == null )
return;
_topMostParent.AddHandler( Mouse.MouseDownEvent, new MouseButtonEventHandler( CustomControlMouseDownEvent ), true );
}
private void UnRegisterTopMostParentMouseClickEvent()
{
if ( _topMostParent == null )
return;
_topMostParent.RemoveHandler( Mouse.MouseDownEvent, new MouseButtonEventHandler( CustomControlMouseDownEvent ) );
_topMostParent = null;
}
Use Mouse.PreviewMouseDownOutsideCapturedElement and add a handler to my control. In the handler I'd kick the control out of it's editing state. But I don't seem to get the event to fire. When does the Mouse.PreviewMouseDownOutsideCapturedElement get kicked off?
Example code:
AddHandler( Mouse.PreviewMouseDownOutsideCapturedElementEvent, new MouseButtonEventHandler( EditableTextBlockPreviewMouseDownOutsideCapturedElementEvent ), true );
Just to clarify the answer provided about mouse focus - it was useful but I had to do some further digging + mucking about to get something that actually worked:
I was trying to implement something like a combobox and needed similar behaviour - to get the drop down to disapear when clicking on something else, without the control having knowledge of what something else was.
I had the following event for a drop down button:
private void ClickButton(object sender, RoutedEventArgs routedEventArgs)
{
//do stuff (eg activate drop down)
Mouse.Capture(this, CaptureMode.SubTree);
AddHandler();
}
The CaptureMode.SubTree means you only get events that are outside the control and any mouse activity in the control is passed through to things as normal. You dont have the option to provide this Enum in UIElement's CaptureMouse, this means you will get calls to HandleClickOutsideOfControl INSTEAD of calls to any child controls or other handlers within the control. This is the case even if you dont subscribe to the events they are using - full Mouse capture is a bit too much!
private void AddHandler()
{
AddHandler(Mouse.PreviewMouseDownOutsideCapturedElementEvent, new MouseButtonEventHandler(HandleClickOutsideOfControl), true);
}
You would also need to hang on to + remove the handler at the appropriate points but I've left that out here for the sake of clarity/brevity.
Finally in the handler you need to release the capture again.
private void HandleClickOutsideOfControl(object sender, MouseButtonEventArgs e)
{
//do stuff (eg close drop down)
ReleaseMouseCapture();
}
Capture the mouse.
When an object captures the mouse, all mouse related events are treated as if the object with mouse capture perform the event, even if the mouse pointer is over another object.
I usually get the parent window and add a preview handler, even if already handled. Sometimes when MouseCapture is not enough, this technique comes handy:
Window.GetWindow(this).AddHandler
(
UIElement.MouseDownEvent,
(MouseButtonEventHandler)TextBox_PreviewMouseDown,
true
);
I would approach this a different way - have the form that contains the control remove focus from the control when a user clicks on another part of the form.
Having the control actually loose focus is far cleaner than attempting to have the control "simulate" focus being lost in certain situations, when in fact it hasn't. Bear in mind that unless the control has really lost focus it will still accept things like keyboard input.
Related
I would like to simulate/route right click on a WPF "control".
To make a long story short. I have an Adorner which should react to left click (so is hit test visible must be true) but at the same time I would like it to be "transparent" for the right clicks. (In another words i would like for a control under it to receive this click - btw right click makes Adorner disappear).
I tried to raise MouseRightButtonUp event on control directly under mouse (after Adorner disappears but it doesn't seem to work). I would like to avoid calling system functions (like mouse_event through P/Invoke). Can it be even done in wpf?
As far as I remember, I had troubles with routing events and changing Adorners IsHitTestVisible property. The main problem was, if I recall it correctly, that adorner and controls are on different branches of visual tree, so routed events spawned on the adorner won't make it to your controls.
I can't say much without you providing the code, but the simplest thing that should work would be to find a control under your mouse position and do
private void myAdorner_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
MouseButtonEventArgs revent = new MouseButtonEventArgs(e.MouseDevice, e.Timestamp, MouseButton.Right);
revent.RoutedEvent = e.RoutedEvent;
//find you control
control.RaiseEvent(revent);
}
I am developing a custom user control in WPF and trying to receive all touch events OUTSIDE of my control (so I can implement "cancel touches", where the user cancels an action by tapping somewhere else). Is there any good way to do this? Obviously, if I use TouchDown or other events I will only get notified of touches inside my control.
I tried receiving PreviewTouchDown events from Application.Current.MainWindow, but besides the fact it feels kind of dirty it also doesn't work that well - as soon as I capture those events, the SurfaceListBox inside my custom control stops working (it does not recognize touches anymore).
Is there a good way to solve this? Receiving simply ALL touch events would be sufficient as well, I can then check if they are inside my control.
In WPF, events travel the tree of elements. Events starting with "Preview" are the ones that travel up to bottom, meaning from the parent to the elements it contains. In your case, TouchDown event will travel from the control in which it originates and then it will bubble up towards the parents. PreviewTouchDown will travel in the opposite direction: from the parent towards the control.
Your idea of handling PreviewTouchDown event in the Application.Current.MainWindow is a good one and should handle all PreviewTouchDown events, if this is what you want. But in your case, if you want to check if the event originates in your custom control, you should catch all the TouchDown events in your MainWindow and check their Source property, like this:
private void CommonClickHandler(object sender, RoutedEventArgs e)
{
FrameworkElement feSource = e.Source as FrameworkElement;
if(feSource.Name == "MyCustomControlName")
{
//cancel whatever you want to cancel
e.Handled=true;
}
}
Do not catch the PreviewTouchDown event as this one will first pop in the MainWindow and just later will go all the way to your control.
This msdn link should give you more information: http://msdn.microsoft.com/en-us/library/ms742806.aspx
I'm creating a custom dropdown box, and I want to register when the mouse is clicked outside the dropdown box, in order to hide it. Is it possible to detect a click outside a control? or should I make some mechanism on the containing form and check for mouseclick when any dropdownbox is open?
So I finally understand that you only want it to close when the user clicks outside of it. In that case, the Leave event should work just fine... For some reason, I got the impression you wanted it to close whenever they moved the mouse outside of your custom dropdown. The Leave event is raised whenever your control loses the focus, and if the user clicks on something else, it will certainly lose focus as the thing they clicked on gains the focus.
The documentation also says that this event cascades up and down the control chain as necessary:
The Enter and Leave events are hierarchical and will cascade up and down the parent chain until the appropriate control is reached. For example, assume you have a Form with two GroupBox controls, and each GroupBox control has one TextBox control. When the caret is moved from one TextBox to the other, the Leave event is raised for the TextBox and GroupBox, and the Enter event is raised for the other GroupBox and TextBox.
Overriding your UserControl's OnLeave method is the best way to handle this:
protected override void OnLeave(EventArgs e)
{
// Call the base class
base.OnLeave(e);
// When this control loses the focus, close it
this.Hide();
}
And then for testing purposes, I created a form that shows the drop-down UserControl on command:
public partial class Form1 : Form
{
private UserControl1 customDropDown;
public Form1()
{
InitializeComponent();
// Create the user control
customDropDown = new UserControl1();
// Add it to the form's Controls collection
Controls.Add(customDropDown);
customDropDown.Hide();
}
private void button1_Click(object sender, EventArgs e)
{
// Display the user control
customDropDown.Show();
customDropDown.BringToFront(); // display in front of other controls
customDropDown.Select(); // make sure it gets the focus
}
}
Everything works perfectly with the above code, except for one thing: if the user clicks on a blank area of the form, the UserControl doesn't close. Hmm, why not? Well, because the form itself doesn't want the focus. Only controls can get the focus, and we didn't click on a control. And because nothing else stole the focus, the Leave event never got raised, meaning that the UserControl didn't know it was supposed to close itself.
If you need the UserControl to close itself when the user clicks on a blank area in the form, you need some special case handling for that. Since you say that you're only concerned about clicks, you can just handle the Click event for the form, and set the focus to a different control:
protected override void OnClick(EventArgs e)
{
// Call the base class
base.OnClick(e);
// See if our custom drop-down is visible
if (customDropDown.Visible)
{
// Set the focus to a different control on the form,
// which will force the drop-down to close
this.SelectNextControl(customDropDown, true, true, true, true);
}
}
Yes, this last part feels like a hack. The better solution, as others have mentioned, is to use the SetCapture function to instruct Windows to capture the mouse over your UserControl's window. The control's Capture property provides an even simpler way to do the same thing.
Technically, you'll need to p/invoke SetCapture() in order to receive click events that happen outside of your control.
But in your case, handling the Leave event, as #Martin suggests, should be sufficient.
EDIT: While looking for an usage example for SetCapture(), I came across the Control.Capture property, of which I was not aware. Using that property means you won't have to p/invoke anything, which is always a good thing in my book.
So, you'll have to set Capture to true when showing the dropdown, then determine if the mouse pointer lies inside the control in your click event handler and, if it doesn't, set Capture to false and close the dropdown.
UPDATE:
You can also use the Control.Focused property to determine if the control has got or lost focus when using a keyboard or mouse instead of using the Capture with the same example provided in the MSDN Capture page.
Handle the Form's MouseDown event, or override the Form's OnMouseDown
method:
enter code here
And then:
protected override void OnMouseDown(MouseEventArgs e)
{
if (!theListBox.Bounds.Contains(e.Location))
{
theListBox.Visible = false;
}
}
The Contains method old System.Drawing.Rectangle can be used to indicate if
a point is contained inside a rectangle. The Bounds property of a Control is
the outer Rectangle defined by the edges of the Control. The Location
property of the MouseEventArgs is the Point relative to the Control which
received the MouseDown event. The Bounds property of a Control in a Form is
relative to the Form.
You are probably looking for the leave event:
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.leave.aspx
Leave occurs when the input focus leaves the control.
I just wanted to share this. It is probably not a good way of doing it that way, but looks like it works for drop down panel that closes on fake "MouseLeave", I tried to hide it on Panel MouseLeave but it does not work because moving from panel to button leaves the panel because the button is not the panel itself. Probably there is better way of doing this but I am sharing this because I used about 7 hours figuring out how to get it to work. Thanks to #FTheGodfather
But it works only if the mouse moves on the form. If there is a panel this will not work.
private void click_to_show_Panel_button_MouseDown(object sender, MouseEventArgs e)
{
item_panel1.Visible = true; //Menu Panel
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (!item_panel1.Bounds.Contains(e.Location))
{
item_panel1.Visible = false; // Menu panel
}
}
I've done this myself, and this is how I did it.
When the drop down is opened, register a click event on the control's parent form:
this.Form.Click += new EventHandler(CloseDropDown);
But this only takes you half the way. You probably want your drop down to close also when the current window gets deactivated. The most reliable way of detecting this has for me been through a timer that checks which window is currently active:
[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern IntPtr GetForegroundWindow();
and
var timer = new Timer();
timer.Interval = 100;
timer.Tick += (sender, args) =>
{
IntPtr f = GetForegroundWindow();
if (this.Form == null || f != this.Form.Handle)
{
CloseDropDown();
}
};
You should of course only let the timer run when the drop down is visible. Also, there's probably a few other events on the parent form you'd want to register when the drop down is opened:
this.Form.LocationChanged += new EventHandler(CloseDropDown);
this.Form.SizeChanged += new EventHandler(CloseDropDown);
Just don't forget to unregister all these events in the CloseDropDown method :)
EDIT:
I forgot, you should also register the Leave event on you control to see if another control gets activated/clicked:
this.Leave += new EventHandler(CloseDropDown);
I think I've got it now, this should cover all bases. Let me know if I'm missing something.
If you have Form, you can simply use Deactivate event just like this :
protected override void OnDeactivate(EventArgs e)
{
this.Dispose();
}
I am pasting text in textbox1.text and I need textbox1 should fire its leave event by itself.
For now I am using this following code. but i will appreciate if anyone can suggest me an elegant or better way:-
private void event()
{
textbox1.Text = SearchedText;
textbox1.Focus();
textbox2.Focus();
}
First I am pasting text, then setting up Focus on the control, then set up focus again on second control. It is firing leave event of textbox1, but any thing better?
Just call the code directly, no need to wait for an event:
private void textBox1_Leave(object sender, EventArgs e) {
mumble();
}
private void someEvent() {
textBox1.Text = SearchedText;
mumble();
}
void mumble() {
// etc...
}
Just calling textBox1_Leave(this, EventArgs.Empty) works fine too.
You should handle the TextChanged or Validated events instead of the Leave event.
To FORCE Leave, Validating and so on Events, no matter what, I've found ONE working solution.
First i tried:
ProcessTabStop(true);
ProcessTabStop(false);
instead of:
textbox1.Focus();
textbox2.Focus();
Problem with the TextBox 1 and 2 Focus() is that its only Active Component that needs Leave, Validating and so on fired, not other Controls, and besides, what if the form is dynamic, you as a programmer not necessarily have any idea what Control you are trying to Leave, that's why i changed Control.Focus() method to ProcessTabStop method above. The problem is then, if only ONE Control has TabStop true, there is no control to go to and back from. So Events are NOT Fired.
Next problem is that i not necessarily Close the Form with the mouse so Focus doesn't change, I use a Key (Ctrl+Enter) to Accept the Form, and then Leave, validating and so on are NOT fired, when i Send Form Close, as Form Close registers weather there are changes or not. But Values are set in Leave on TextBoxes, so I had to find a solution that worked no matter what i did to it. I almost gave up, actually i had a problem report all filled out, when I thought, what if i set ActiveControl to Null and then to the Control it came from. It worked, but had som "Flicker" due to color change on Parent Panel depending on Active or Inactive.
The "Workaround" that works in all cases is:
Control Old = ActiveControl;
// ActiveControl.SuspendLayout();
// ActiveControl.FindForm().SuspendLayout();
ActiveControl = null;
ActiveControl = Old;
// ActiveControl.FindForm().ResumeLayout();
// ActiveControl.ResumeLayout();
That seems to fire Leave, Validating and so on Events, no matter number of Form Controls and TabStopped Controls. You MAY need to SuspendLayout on either ActiveControl, or Form. My Control (Parent Panel) changes color when Active/Inactive, if I do not Suspend Layout on Form, parent panel gets an unwanted "flicker" effect.
Looking at the solution, it is very obvious, now I've found it, but took me half a day to try different things that solved one or another problem, but not all.
I know this a VERY old thread, but one of very few articles I've found on the subject of Forcing Leave Event to be Fired.
I got a form with a number of buttons on it (assume 20). In the middle, I got a User Control which is completely empty. The question is: how can I make it so that when the User Control is clicked, it will get keyboard focus?
Reason: I paint shapes in that User Control, with my mouse. The shapes are actually other User Controls. What I want to do is be able to use the keyboard to move those shapes. But I cannot seem to correctly be able to grab the Keyboard focus. The Key_Down events just don't reach my main (drawing into) User Control.
So, in other words, how can we have keyboard focus in a control has no focusable items on it? How can one make an keyboard-unfocusable control, catch those events? Any way of grabbing these events window-wide, other than going raw-WIN32 API hardcore?
A UserControl was very much designed to be a container control for other controls. It abhors getting the focus and tries to pass it off first chance it gets. You should not be using a UserControl here, given that you don't put any controls inside of it. A Panel control will suffice. Which has the exact same problem, it doesn't want to get focus either.
Surgery is required to override its behavior. Everything you need is in this answer.
Add this to your user control code to capture keyboard input:
/// <summary>Keys which can generate OnKeyDown event.</summary>
private static readonly Keys[] InputKeys = new []
{ Keys.Left, Keys.Up, Keys.Right, Keys.Down, };
protected override void OnPreviewKeyDown(PreviewKeyDownEventArgs e)
{
if(Array.IndexOf<Keys>(InputKeys, e.KeyCode) != -1)
{
e.IsInputKey = true;
}
base.OnPreviewKeyDown(e);
}
protected override void OnKeyDown(KeyEventArgs e)
{
base.OnKeyDown(e);
// just to illustrate this works
MessageBox.Show("KeyDown: " + e.KeyCode);
}
See http://msdn.microsoft.com/en-us/library/aa969768.aspx. You can assign keyboard focus by
1. Set the usercontrol.Focusable=true;
2. Use Keyboard.Focus(usercontrol).
You need to set the CommandRouting flag on your control to true.
The command routing dependency property is defined in a public API (MS.VS.Editor.dll) and your adornment will want to use that API to indicate that it is handling its commands instead of allowing the containing text view handle them. You can do this with from your control’s initialization.
Microsoft.VisualStudio.Editor.CommandRouting.SetInterceptsCommandRouting(this, true);