I'm diving into WPF here and I can't figure some things with multitouch.
I've got two questions about SurfaceScrollViewer.
Easier one first: I've got a large photo I'm displaying with SurfaceScrollViewer, so I can pan around, but I can't figure out how to get the content to start out centered in the screen. I can't find any native alignment properties in SScrollViewer. If I give the content margins, it crops it. Same if I do a RenderTransform. If I do a LayoutTransform, it doesn't seem to do change. Any ideas?
I also want to give this content Zoom functionality while inside SurfaceScrollViewer. Really I'm trying to zoom and pan with the elastic effects of SSV. Should I write the manipulations out by hand or can I patch the functions in SSV to be able to zoom? It seems like SSV absorbs 2nd touches into its panning function. I'd have to write a Manipulation handler to send multi touches to the content, right?
My code looks something like this right now:
<Grid x:Name="LayoutGrid" Width="1950" Height="1118" HorizontalAlignment="Center" >
<s:SurfaceScrollViewer x:Name="scrollViewer" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden" >
<local:FloorView x:Name="floorViewer" Width="4209" Height="1442" >
<local:FloorView.LayoutTransform>
<TranslateTransform X="1000" />
</local:FloorView.LayoutTransform>
</local:FloorView>
</s:SurfaceScrollViewer>
</Grid>
Any help is much appreciated. Thanks!
figured out the first part:
scrollViewer.ScrollToHorizontalOffset(x);
scrollViewer.ScrollToVerticalOffset(y);
looks like i'll have to control manipulation events on the SSV to add zoom.
figured out the second part to zoom inside scrollviewer
handle touchdown events on the scrollviewer
send one touches to surfacescrollviewer and
send two touches to the content
enable manipulations on content
handle manipulations with the scrollviewer as the container
then use the delta manipulations to add a ScaleTransform to the content
don't forget to handle touchup events
private void floorViewer_TouchDown(object sender, TouchEventArgs e) //catch touch events on floorviewer
{
Touch1ID = e.TouchDevice.Id - 16777216; ;
if (Touch1ID == 0) //if one touch present, TouchDevice.Id is 2^24, two then 2^24+1 (this might just be my machine)
{
floorViewer.IsManipulationEnabled = false;
floorViewer.ReleaseTouchCapture(e.TouchDevice);
scrollViewer.CaptureTouch(e.TouchDevice);
}
else {
floorViewer.IsManipulationEnabled = true;
foreach(TouchDevice device in scrollViewer.TouchesOver){
scrollViewer.ReleaseTouchCapture(device);
floorViewer.CaptureTouch(device);
}
}
StartTimeout();
e.Handled = true;
}
void scrollViewer_TouchUp(object sender,TouchEventArgs e)
{
clearID();
e.Handled = true;
}
private void clearID()
{
Touch1ID = 0;
}
private void floorview_TouchUp(object sender, TouchEventArgs e)
{
clearID();
e.Handled = true;
}
//manipulators on floorviewer when it gets touches passed to it
private void scrollViewer_ManipulationStarting(object sender, ManipulationStartingEventArgs e)
{
e.ManipulationContainer = scrollViewer;
e.Handled = true;
}
private void scrollViewer_ManipulationDelta(object sender, ManipulationDeltaEventArgs e)
{
double oldScale = flrScale;
flrScale *= e.DeltaManipulation.Scale.X;
if (flrScale < .95 | flrScale > 2) flrScale = oldScale;
floorViewer.RenderTransform = new ScaleTransform(flrScale, flrScale, e.ManipulationOrigin.X + flrInitX, e.ManipulationOrigin.Y + flrInitY);
e.Handled = true;
}
boom!
Related
Just wanted to know if its possible to do it like winform? Where i can add a button to where i last click. I tried googling but dont think i found anything similar. Will the grid for WPF be an issue where i can place my button freely on click?
Idea is to click on the coordinate and then press the button to add an image/button.
Below is what i did so far, havent added the button function yet, just wanted to know if its possible to do it as i have done so for winform before.
public MainWindow()
{
InitializeComponent();
MainWindow.xCoord = -1;
MainWindow.yCoord = -1;
}
private void AddEvent_Click(object sender, EventArgs e)
{
if (MainWindow.xCoord < 0 || MainWindow.yCoord < 0)
{
MessageBox.Show("Please select a coordinate");
return;
}
}
public void MainWindow_Mouseup(object sender, MouseEventArgs e)
{
Point p = e.GetPosition(this);
textBox1.Text = "x-" + p.X + "y- " + p.Y;
MainWindow.xCoord = (int)p.X;
MainWindow.yCoord = (int)p.Y;
}
Yes you can do it, and you would need to use a Canvas to draw the button. This can be contained inside the Grid, but AFAIK the Canvas is the only way to have a sort of "Draw" function with UI Controls.
You will want to capture the MouseUp event within the Canvas and then add your button at the location you can retrieve in the Handler.
XAML:
<Grid>
<Canvas x:Name="ButtonCanvas" MouseUp="ButtonCanvas_MouseUp"/>
</Grid>
Code Behind:
private void ButtonCanvas_MouseUp(object sender, MouseButtonEventArgs e)
{
Point p = e.GetPosition(ButtonCanvas);
textBox1.Text = "x-" + p.X + "y- " + p.Y;
MainWindow.xCoord = (int)p.X;
MainWindow.yCoord = (int)p.Y;
}
Then just have a function that will create and add a Button at these coordinates (I will assume you have some sort of "Add Button to Canvas" Button):
private void AddButtonToCoord_Click(object sender, EventArgs e)
{
var button = new Button();
//--change button properties if you want--
//add to canvas
Canvas.Childen.Add(button);
//set Control coordinates within the canvas
Canvas.SetLeft(button, MainWindow.xCoord);
Canvas.SetTop(button, MainWindow.yCoord);
}
You can get fancier for your needs, like if you want the center of the button to be at the Coordinates, or if you want to prevent the Button from being drawn outside the canvas (like if the user click the very bottom right corner). But this should be enough to get a minimum working example.
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?
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 have an Accordion and the height of its content can be dynamically resized. I would like to see the Accordion dynamically respond to the child item's height, but I'm having trouble doing this.
<lt:Accordion Name="MyAccordion"
SelectionMode="ZeroOrOne"
HorizontalAlignment="Stretch">
<lt:AccordionItem Name="MyAccordionItem"
Header="MyAccordion"
IsSelected="True"
HorizontalContentAlignment="Stretch"
VerticalAlignment="Stretch">
<StackPanel>
<Button Content="Grow" Click="Grow"/>
<Button Content="Shrink" Click="Shrink"/>
<TextBox Name="GrowTextBox"
Text="GrowTextBox"
Height="400"
Background="Green"
SizeChanged="GrowTextBox_SizeChanged"/>
</StackPanel>
</lt:AccordionItem>
</lt:Accordion>
private void Grow(object sender, System.Windows.RoutedEventArgs e)
{
GrowTextBox.Height += 100;
}
private void Shrink(object sender, System.Windows.RoutedEventArgs e)
{
GrowTextBox.Height -= 100;
}
private void GrowTextBox_SizeChanged(object sender, System.Windows.SizeChangedEventArgs e)
{
MyAccordion.UpdateLayout();
MyAccordionItem.UpdateLayout();
}
Mind you, if I collapse and then re-open the accordion, it takes shape just the way I want, but I'd like this resizing to occur immediately when the child resizes.
I feebly attempted to fix this by adding a SizeChanged event handler that calls UpdateLayout() on the Accordion and AccordionItem, but this doesn't have any visual effect. I can't figure out where proper resizing takes place inside the Accordion control. Does anyone have an idea?
Try this one
//here i am creating a size object depending on child items height and width
// and 25 for accordian item header...
// if it works you can easily update the following code to avoid exceptional behaviour
Size size = new Size();
size.Width = GrowTextBox.ActualWidth;
size.Height = grow.ActualHeight + shrink.ActualHeight + GrowTextBox.ActualHeight + 25;
MyAccordion.Arrange(new Rect(size));
In the above code i am just rearranging accordion depending on child item size.
I have a similar problem, my simple hack is as follows:
private void GrowTextBox_SizeChanged(object sender, System.Windows.SizeChangedEventArgs e)
{
MyAccordionItem.Measure(new Size());
MyAccordionItem.UpdateLayout();
}
Hope it works for you too..
Cheers
I had a slightly different problem - resizing my window sometimes didn't correctly adjust the Accordion item size, so the header of the next item would be stuck below the window or in the middle of it.
I solved this by creating a timer that is started in SizeChanged, and that deselects and immediately reselects the current item, after which the layout seems to be readjusted and turns up correct. Might help you as well. You could dispense with the timer, I introduced it to prevent continuous calls when the user drag resizes the window, it also gives a kind of feathery effect because of the delay.
public partial class MyAccordion : System.Windows.Controls.Accordion
{
private Timer _layoutUpdateTimer = new Timer(100);
public MyAccordion
{
this.SizeChanged += (s, e) =>
{
_layoutUpdateTimer.Stop(); // prevents continuous calls
_layoutUpdateTimer.Start();
};
_layoutUpdateTimer.Elapsed += (s, e) => ReselectItem();
}
private void ReselectItem()
{
Application.Current.Dispatcher.BeginInvoke((Action)(() =>
{
// backup values
int selectedIndex = this.SelectedIndex;
AccordionSelectionMode mode = this.SelectionMode;
// deselect
this.SelectionMode = AccordionSelectionMode.ZeroOrOne; // allow null selection
this.SelectedItem = null;
// restore values (reselect)
this.SelectionMode = mode;
this.SelectedIndex = selectedIndex;
}));
_layoutUpdateTimer.Stop();
}
}
When trying to animate objects time/frame based in Silverlight (in contrast to using something like DoubleAnimation or Storyboard, which is not suitable e.g. for fast paced games), for example moving a spaceship in a particular direction every frame, the movement is jumpy and not really smooth. The screen even seems to tear.
There seems to be no difference between CompositionTarget and DistpatcherTimer.
I use the following approach (in pseudocode):
Register Handler to Tick-Event of a DispatcherTimer
In each Tick:
Compute the elapsed time from the last frame in milliseconds
Object.X += movementSpeed * ellapsedMilliseconds
This should result in a smooth movement, right? But it doesn't.
Here is an example (Controls: WASD and Mouse): Silverlight Game.
Although the effect I described is not too prevalent in this sample, I can assure you that even moving a single rectangle over a canvas produces a jumpy animation.
Does someone have an idea how to minimize this. Are there other approaches to to frame based animation exept using Storyboards/DoubleAnimations which could solve this?
Edit: Here a quick and dirty approach, animating a rectangle with minimum code (Controls: A and D) Animation Sample
Xaml:
<Grid x:Name="LayoutRoot" Background="Black">
<Canvas Width="1000" Height="400" Background="Blue">
<Rectangle x:Name="rect" Width="48" Height="48"
Fill="White"
Canvas.Top="200"
Canvas.Left="0"/>
</Canvas>
</Grid>
C#:
private bool isLeft = false;
private bool isRight = false;
private DispatcherTimer timer = new DispatcherTimer();
private double lastUpdate;
public Page()
{
InitializeComponent();
timer.Interval = TimeSpan.FromMilliseconds(1);
timer.Tick += OnTick;
lastUpdate = Environment.TickCount;
timer.Start();
}
private void OnTick(object sender, EventArgs e)
{
double diff = Environment.TickCount - lastUpdate;
double x = Canvas.GetLeft(rect);
if (isRight)
x += 1 * diff;
else if (isLeft)
x -= 1 * diff;
Canvas.SetLeft(rect, x);
lastUpdate = Environment.TickCount;
}
private void UserControl_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.D)
isRight = true;
if (e.Key == Key.A)
isLeft = true;
}
private void UserControl_KeyUp(object sender, KeyEventArgs e)
{
if (e.Key == Key.D)
isRight = false;
if (e.Key == Key.A)
isLeft = false;
}
Thanks!
Andrej
Updating the position every 1 millisecond is overkill because silverlight will simply not update the screen that fast. When you modify the position of an object like that (or any other ui update) silverlight marks the framebuffer as dirty and then it will eventually redraw the screen, however it will not redraw the screen more often than the MaxFrameRate.
To set the MaxFrameRate just:
Application.Current.Host.Settings.MaxFrameRate = 60;
This will limit your application to 60 frames per second which should be more than enough.
Don't use a DispatchTimer for the animation. Reasons for this. Use a storyboard, if you can, or the CompositionTarget.Rendering event.