I've implemented dragging to external applications in my WPF application and it works. However after dropping onto a target I continue to get spurious drop events on my application after I bring the cursor back onto it. This continues 'forever'.
As far as I can tell from online searches after calling DragDrop.DoDragDrop() I shouldn't need to do anything else. I have tried adding some code to cancel the event but it has no effect even though it runs:
private void UIElement_OnPreviewMouseMove(object sender, MouseEventArgs e)
{
var frameworkElement = (FrameworkElement) sender;
if (frameworkElement.DataContext is IDragSource dragSource)
{
var position = e.GetPosition((IInputElement) sender);
if (dragSource.DragCanStart(new Point {X = position.X, Y = position.Y}))
{
var dragStart = true;
void OnFrameworkElementOnQueryContinueDrag(object o, QueryContinueDragEventArgs e2)
{
if (!dragStart)
{
e2.Action = DragAction.Cancel;
frameworkElement.QueryContinueDrag -= OnFrameworkElementOnQueryContinueDrag;
}
}
frameworkElement.QueryContinueDrag += OnFrameworkElementOnQueryContinueDrag;
dragSource.DragInitiate(sender);
e.Handled = true;
dragStart = false;
}
}
}
I've tracked it down to our code initiating multiple drags. Our guard logic wasn't quite good enough which meant every time the mouse moved over the source component it triggered another drag.
Tricky to debug :)
Related
I got the following sticky note example:
If the sticky note has more than 9 rows, the additional rows are not visible.
I'm able to navigate through the note with my arrow keys. If I'm going to scroll with the mouse wheel, it seems to ignore the popup and just changes the page.
Is it possible to activate scrolling for sticky note popups?
Edit:The solution outlined below will soon be available as part of the samples included in the PDFTron SDK download. In the meanwhile, I hope that the below solution helps.
Yes, it is possible to activate scrolling for sticky notes.
The problem is most apparent when using the single page view. It appears to work as expected in continuous mode.
However it is not as simple as setting VerticalScrollVisibility = ScrollBarVisibility.Auto;. There are a few files that need to be modified to get this working.
The good news is that we can get the expected behaviour by modifying the code in the provided samples.
Solution
The solution is to add some handling for the PreviewMouseWheel event coming from the PDFViewWPF class.
In the downloaded samples, the following changes were made to get things running as expected:
Add a method to handle the PreviewMouseWheel event in the NoteHost class (Samples/PDFViewWPFTools/CS/Utilities/NoteHost.cs)
internal void HandlePreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
var originalSource = (UIElement)e.OriginalSource;
if (originalSource.IsDescendantOf(mNoteBorder) && mTextBox.IsFocused)
{
mTextBox.ScrollToVerticalOffset(mTextBox.VerticalOffset - e.Delta);
e.Handled = true;
}
}
Also make sure to add mTextBox.VerticalScrollBarVisibility = ScrollBarVisibility.Auto; in the NoteHost.CreateNoteAndArrow() method, after the mTextBox object is instantiated (~line 183).
Next, edit the NoteManager class - Samples/PDFViewWPFTools/CS/Utilities/NoteManager.cs - and add a HandlePreviewMouseWheel method. This will internally call the HandlePreviewMouseWheel on each displayed (opened) note and break at the first one where the event gets handled.
internal void HandlePreviewMouseWheel(object sender, System.Windows.Input.MouseWheelEventArgs e)
{
foreach(var note in mActiveNotes)
{
note.Value.HandlePreviewMouseWheel(sender, e);
if(e.Handled)
{
break;
}
}
}
Next, edit the ToolManager class to ensure that the note manager gets a chance to handle the PreviewMouseWheel before attempting a page change. Open Samples/PDFViewWPFTools/CS/ToolManager.cs and navigate to the PDFView_PreviewMouseWheel. The existing method should look like this:
private void PDFView_PreviewMouseWheel(object sender, System.Windows.Input.MouseWheelEventArgs e)
{
if (mCurrentTool != null && _IsEnabled)
{
ToolManager.ToolType prev_tm = mCurrentTool.ToolMode;
ToolManager.ToolType next_tm;
while (true)
{
mCurrentTool.PreviewMouseWheelHandler(sender, e);
next_tm = mCurrentTool.NextToolMode;
if (prev_tm != next_tm)
{
mCurrentTool = CreateTool(next_tm, mCurrentTool);
prev_tm = next_tm;
}
else
{
break;
}
}
}
}
Replace it with the below code:
private void PDFView_PreviewMouseWheel(object sender, System.Windows.Input.MouseWheelEventArgs e)
{
if (mCurrentTool != null && _IsEnabled)
{
ToolManager.ToolType prev_tm = mCurrentTool.ToolMode;
ToolManager.ToolType next_tm;
while (true)
{
mNoteManager.HandlePreviewMouseWheel(sender, e);
if (!e.Handled)
{
mCurrentTool.PreviewMouseWheelHandler(sender, e);
next_tm = mCurrentTool.NextToolMode;
if (prev_tm != next_tm)
{
mCurrentTool = CreateTool(next_tm, mCurrentTool);
prev_tm = next_tm;
}
else
{
break;
}
}
else
{
break;
}
}
}
}
By doing the above, we are giving the NoteManager a chance to handle the PreviewMouseWheel before doing anything else with it.
Another point to note is that we have to now "do the scrolling" in code, using the mTextBox.ScrollToVerticalOffset method in the NoteHost class.
I have a WPF app with two canvases which overlay each other . . .
<Canvas Name="GeometryCnv" Canvas.Top="0" Canvas.Left="0" Margin="10,21,315,251" />
<Canvas Name="ROIcnv" Background ="Transparent" Canvas.Top="0" Canvas.Left="0" Margin="10,21,315,251" MouseDown="ROIcnvMouseDown" MouseUp="ROIcnvMouseUp" MouseMove="ROIcnvMouseMove"/>
I draw some geometry on the first canvas and I draw a rectangle to denote a Region on Interest (ROI) on the second one, using the Mouse-down event to start the drawing, Mouse-move events while drawing (resizing or positioning) the rectangle, and the Mouse-up event to end the drawing.
Except that it's not handling the events reliably. It gets the initial Mouse-down event to start it. It gets Mouse-move events continuously - regardless of whether the mouse is moving - and it does not get the Mouse-up event at all, nor does it get any subsequent mouse down events, say if I double-click the mouse.
The event-handler code looks like this . . .
private void ROIcnvMouseDown(object sender, MouseButtonEventArgs e)
{
MouseLineBegin = Mouse.GetPosition(ROIcnv);
bMouseDown = true;
}
private void ROIcnvMouseUp(object sender, MouseButtonEventArgs e)
{
MouseLineEnd = Mouse.GetPosition(ROIcnv);
bMouseDown = false;
}
private void ROIcnvMouseMove(object sender, MouseEventArgs e)
{
iMM++; // counting mouse move events
ROIcnv.Children.Clear(); // clear the ROI canvas
if (bMouseDown) // if we're drawing now
{
MouseLineEnd = Mouse.GetPosition(ROIcnv);
// get the upper left and lower right = coords from the beginning and end points . . .
int ulx = 0;
int uly = 0;
int lrx = 0;
int lry = 0;
if (MouseLineEnd.X >= MouseLineBegin.X)
{
ulx = (int) MouseLineBegin.X;
lrx = (int) MouseLineEnd.X;
}
else
{
lrx = (int)MouseLineBegin.X;
ulx = (int)MouseLineEnd.X;
}
if (MouseLineEnd.Y >= MouseLineBegin.Y)
{
uly = (int)MouseLineBegin.Y;
lry = (int)MouseLineEnd.Y;
}
else
{
lry = (int)MouseLineBegin.Y;
uly = (int)MouseLineEnd.Y;
}
int h = Math.Abs(lry-uly);
int w = Math.Abs(lrx-ulx);
var rect = new Path
{
Data = new RectangleGeometry(new Rect(ulx, uly, w, h)),
Stroke = Brushes.Black,
StrokeThickness = 2
};
ROIcnv.Children.Add(rect);
}
}
... I've tried suspending the mouse in mid-air and resting it on towels to eliminate any vibrations that might cause spurious move events with no benefit, any anyway that wouldn't account for not getting subsequent up and down events.
Note: I tried this on another computer with exactly the same results.
You'll have much better responses if you provide a minimal, working example of your problem (specifically both your ROIcnvMouseDown and ROIcnvMouseUp methods are missing as are all of your property declarations). The problem is possibly due to your newly-created Path object interfering with the mouse messages, if so then it can be fixed by setting it's IsHitTestVisible property to false. Need a minimal example to determine this for sure though.
UPDATE: Sorry, my bad, I must have stuffed up the cut-n-paste into my test app. Try capturing the mouse in response to the mouse down event:
private void ROIcnvMouseDown(object sender, MouseButtonEventArgs e)
{
MouseLineBegin = Mouse.GetPosition(ROIcnv);
bMouseDown = true;
Mouse.Capture(sender as IInputElement);
}
And of course you need to release it in response to MouseUp:
private void ROIcnvMouseUp(object sender, MouseButtonEventArgs e)
{
MouseLineEnd = Mouse.GetPosition(ROIcnv);
bMouseDown = false;
Mouse.Capture(sender as IInputElement, CaptureMode.None);
ROIcnv.Children.Clear();
}
The other thing I've done is call ROIcnv.Children.Clear(); in response to MouseUp as I assume you no longer want the selection rectangle to be visible. On my machine this doesn't result in any spurious mouse move events.
Does that answer the question?
I have a control that is similar to a Popup or Menu. I want to display it and when the user clicks outside the bounds of the box, have it hide itself. I've used Mouse.Capture(this, CaptureMode.SubTree) as well as re-acquired the capture the same way Menu/Popup do in OnLostMouseCapture.
When the user clicks outside the bounds of the control, I release the mouse capture in OnPreviewMouseDown. I don't set e.Handled to true. The mouse click will make it to other controls on the main UI, but not to the close button (Red X) for the window. It requires 2 clicks to close the app.
Is there a way to tell WPF to restart the mouse click, or to send a repeated mouse click event?
Here's my code. Note I renamed it to MainMenuControl - I'm not building a Menu, so Menu/MenuItem and Popup aren't options.
public class MainMenuControl : Control
{
static MainMenuControl()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(MainMenuControl), new FrameworkPropertyMetadata(typeof(MainMenuControl)));
}
public MainMenuControl()
{
this.Loaded += new RoutedEventHandler(MainMenuControl_Loaded);
Mouse.AddPreviewMouseDownOutsideCapturedElementHandler(this, OnPreviewMouseDownOutsideCapturedElementHandler);
}
void MainMenuControl_Loaded(object sender, RoutedEventArgs e)
{
this.IsVisibleChanged += new DependencyPropertyChangedEventHandler(MainMenuControl_IsVisibleChanged);
}
void MainMenuControl_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (this.IsVisible)
{
Mouse.Capture(this, CaptureMode.SubTree);
Debug.WriteLine("Mouse.Capture");
}
}
// I was doing this in OnPreviewMouseDown, but changing to this didn't have any effect
private void OnPreviewMouseDownOutsideCapturedElementHandler(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("OnPreviewMouseDownOutsideCapturedElementHandler");
if (!this.IsMouseInBounds())
{
if (Mouse.Captured == this)
{
Mouse.Capture(this, CaptureMode.None);
Debug.WriteLine("Mouse.Capture released");
}
Debug.WriteLine("Close Menu");
}
}
protected override void OnLostMouseCapture(MouseEventArgs e)
{
base.OnLostMouseCapture(e);
Debug.WriteLine("OnLostMouseCapture");
MainMenuControl reference = e.Source as MainMenuControl;
if (Mouse.Captured != reference)
{
if (e.OriginalSource == reference)
{
if ((Mouse.Captured == null) || (!reference.IsAncestorOf(Mouse.Captured as DependencyObject)))
{
//TODO: Close
Debug.WriteLine("Close Menu");
}
}
// if a child caused use to lose the capture, then recapture.
else if (reference.IsAncestorOf(e.OriginalSource as DependencyObject))
{
if (Mouse.Captured == null)
{
Mouse.Capture(reference, CaptureMode.SubTree);
Debug.WriteLine("Mouse.Capture");
e.Handled = true;
}
}
else
{
//TODO: Close
Debug.WriteLine("Close Menu");
}
}
}
private bool IsMouseInBounds()
{
Point point = Mouse.GetPosition(this);
Rect bounds = new Rect(0, 0, this.Width, this.Height);
return bounds.Contains(point);
}
}
The problem is that the mouse handling you are talking about is outside the WPF eventing system and part of the operating system so we're really talking about two fairly different mouse message queues that interact well enough most of the time but in these edge case we see that the interoperability is not perfect.
You could try to generate Win32 mouse messages or send your own window a close message but all those approaches are hacks. Since popups and menus exhibit exactly the same symptoms you describe, it doesn't seem like there is going to be an easy to way to accomplish what you want as you've described it.
Instead, I suggest that you consider giving up the mouse capture when the mouse leaves the north client area of the window or some other heuristic such as a specified distance from the control. I know this is probably not ideal but it might be a satisfactory compromise if you want the close button to work badly enough.
Clicking the middle mouse button (aka: mouse wheel) and then moving the mouse down slightly lets users scroll in IE, and most Windows apps. This behavior appears to be missing in WPF controls by default? Is there a setting, a workaround, or something obvious that I'm missing?
I have found how to achieve this using 3 mouse events (MouseDown, MouseUp, MouseMove). Their handlers are attached to the ScrollViewer element in the xaml below:
<Grid>
<ScrollViewer MouseDown="ScrollViewer_MouseDown" MouseUp="ScrollViewer_MouseUp" MouseMove="ScrollViewer_MouseMove">
<StackPanel x:Name="dynamicLongStackPanel">
</StackPanel>
</ScrollViewer>
<Canvas x:Name="topLayer" IsHitTestVisible="False" />
</Grid>
It would be better to write a behaviour instead of events in code-behind, but not everyone has the necessary library, and also I don't know how to connect it with the Canvas.
The event handlers:
private bool isMoving = false; //False - ignore mouse movements and don't scroll
private bool isDeferredMovingStarted = false; //True - Mouse down -> Mouse up without moving -> Move; False - Mouse down -> Move
private Point? startPosition = null;
private double slowdown = 200; //The number 200 is found from experiments, it should be corrected
private void ScrollViewer_MouseDown(object sender, MouseButtonEventArgs e)
{
if (this.isMoving == true) //Moving with a released wheel and pressing a button
this.CancelScrolling();
else if (e.ChangedButton == MouseButton.Middle && e.ButtonState == MouseButtonState.Pressed)
{
if (this.isMoving == false) //Pressing a wheel the first time
{
this.isMoving = true;
this.startPosition = e.GetPosition(sender as IInputElement);
this.isDeferredMovingStarted = true; //the default value is true until the opposite value is set
this.AddScrollSign(e.GetPosition(this.topLayer).X, e.GetPosition(this.topLayer).Y);
}
}
}
private void ScrollViewer_MouseUp(object sender, MouseButtonEventArgs e)
{
if (e.ChangedButton == MouseButton.Middle && e.ButtonState == MouseButtonState.Released && this.isDeferredMovingStarted != true)
this.CancelScrolling();
}
private void CancelScrolling()
{
this.isMoving = false;
this.startPosition = null;
this.isDeferredMovingStarted = false;
this.RemoveScrollSign();
}
private void ScrollViewer_MouseMove(object sender, MouseEventArgs e)
{
var sv = sender as ScrollViewer;
if (this.isMoving && sv != null)
{
this.isDeferredMovingStarted = false; //standard scrolling (Mouse down -> Move)
var currentPosition = e.GetPosition(sv);
var offset = currentPosition - startPosition.Value;
offset.Y /= slowdown;
offset.X /= slowdown;
//if(Math.Abs(offset.Y) > 25.0/slowdown) //Some kind of a dead space, uncomment if it is neccessary
sv.ScrollToVerticalOffset(sv.VerticalOffset + offset.Y);
sv.ScrollToHorizontalOffset(sv.HorizontalOffset + offset.X);
}
}
If to remove the method calls AddScrollSign and RemoveScrollSign this example will work. But I have extended it with 2 methods which set scroll icon:
private void AddScrollSign(double x, double y)
{
int size = 50;
var img = new BitmapImage(new Uri(#"d:\middle_button_scroll.png"));
var adorner = new Image() { Source = img, Width = size, Height = size };
//var adorner = new Ellipse { Stroke = Brushes.Red, StrokeThickness = 2.0, Width = 20, Height = 20 };
this.topLayer.Children.Add(adorner);
Canvas.SetLeft(adorner, x - size / 2);
Canvas.SetTop(adorner, y - size / 2);
}
private void RemoveScrollSign()
{
this.topLayer.Children.Clear();
}
Example of icons:
And one last remark: there are some problems with the way Press -> Immediately Release -> Move. It is supposed to cancel scrolling if a user clicks the mouse left button, or any key of keyboard, or the application looses focus. There are many events and I don't have time to handle them all.
But standard way Press -> Move -> Release works without problems.
vorrtex posted a nice solution, please upvote him!
I do have some suggestions for his solution though, that are too lengthy to fit them all in comments, that's why I post a separate answer and direct it to him!
You mention problems with Press->Release->Move. You should use MouseCapturing to get the MouseEvents even when the Mouse is not over the ScrollViewer anymore. I have not tested it, but I guess your solution also fails in Press->Move->Move outside of ScrollViewer->Release, Mousecapturing will take care of that too.
Also you mention using a Behavior. I'd rather suggest an attached behavior that doesn't need extra dependencies.
You should definately not use an extra Canvas but do this in an Adorner.
The ScrollViewer itsself hosts a ScrollContentPresenter that defines an AdornerLayer. You should insert the Adorner there. This removes the need for any further dependency and also keeps the attached behavior as simple as IsMiddleScrollable="true".
I wrote a very simple newbie app with a 6-sided polyhedron (a "box") which rotates 180 degrees when I click a button. and then rotates back again on the next click. Every rotation grabs another 90MB and it doesn't let go until I close the app. The box is defined in the XAML. The Storyboard, DoubleAnimation and PropertyPath, etc, are all created ONCE, in the constructor. The button code looks like this:
private void button_Storyboard1_Click(object sender, RoutedEventArgs e)
{
GC.Collect();
if (_bFront)
{
_myDoubleAnimation.From = 0;
_myDoubleAnimation.To = 180;
_bFront = false;
}
else
{
_myDoubleAnimation.From = 180;
_myDoubleAnimation.To = 0;
_bFront = true;
}
_myDoubleAnimation.Duration = _Duration;
Storyboard.SetTargetName(_myDoubleAnimation, "rotate_me");
Storyboard.SetTargetProperty(_myDoubleAnimation, _PropP);
_sb.Children.Add(_myDoubleAnimation);
_sb.Begin(this.viewport3D1);
}
After a few rotations I'm out of memory! What's going on?
Could be totally wrong here, but aren't you adding _myDoubleAnimation to _sb.Children on each click, instead of just updating it?