Move an image over a canvas in windows store app - c#

I need to move an image over a canvas on tap and slide. How can I achieve this. I tried the following. The image is moving but not as the user moves it.
XAML
<Canvas Background="White">
<Image Name="img" Width="200" Height="200" Source="Assets/11.png" ManipulationMode="All" ManipulationStarted="img_ManipulationStarted" ManipulationDelta="img_ManipulationDelta"/>
</Canvas>
C#
private Point initialPt;
private void img_ManipulationStarted(object sender, ManipulationStartedRoutedEventArgs e)
{
initialPt = e.Position;
}
private void img_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
Point currentPt = e.Position;
double x = currentPt.X - initialPt.X;
double y = currentPt.Y - initialPt.Y;
if (x != 0 || y != 0)
{
TranslateTransform posTransform = new TranslateTransform();
posTransform.X = currentPt.X;
posTransform.Y = currentPt.Y;
img.RenderTransform = posTransform;
e.Complete();
}
}

Instead of using a TranslateTransform, you should directly set the absolute position in the canvas, so you have to bind the ManipulationDelta event to the Canvas, and detect if the point of impact is inside of the image.
<Canvas Background="White" ManipulationMode="All" ManipulationDelta="canvas_ManipulationDelta">
<Image Name="img" Width="200" Height="200" Source="Assets/11.png"/>
</Canvas>
Here is the new event handling function:
private void canvas_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
if ((e.Position.X > Canvas.GetLeft(img) && e.Position.X < Canvas.GetLeft(img) + img.Width)
|| (e.Position.Y > Canvas.GetTop(img) && e.Position.Y < Canvas.GetTop(img) + img.Height)) {
{
Canvas.SetLeft(img, e.Position.X);
Canvas.SetTop(img, e.Position.Y);
}
}
Simple as pie. You can remove initialPt and img_ManipulationStarted.

Related

How can I move a Picture with just "drag" the picture?

So I want to make a funtunality like in Windows when you display a Picture that when you zoom in you can just move the Picture with the mouse. I already got the zoom part in my project:
<ScrollViewer Name="scroll" Margin="40"
HorizontalScrollBarVisibility="Auto"
VerticalScrollBarVisibility="Auto">
<Canvas
MouseWheel="Container_MouseWheel" x:Name="canvas">
<Viewbox>
<Image x:Name="img" Source="{Binding imageSource}" Grid.ColumnSpan="2" />
</Viewbox>
</Canvas>
</ScrollViewer>
and the Code in the MouseWheel Event:
var element = sender as UIElement;
var position = e.GetPosition(element);
var transform = element.RenderTransform as MatrixTransform;
var matrix = transform.Matrix;
var scale = e.Delta >= 0 ? 1.1 : (1.0 / 1.1); // choose appropriate scaling factor
matrix.ScaleAtPrepend(scale, scale, position.X, position.Y);
element.RenderTransform = new MatrixTransform(matrix);
but now Ive got the Problem that when I zoom I cant just click and hold the Image with the mouse and move to an another part of the picture, if you dont really know what I mean just open an Image on windows zoom in and then hold the mouse and move in the picture.
What I have tried was to add these 3 Events to my Canvas and this is the code behind for the 3 Events:
private Image draggedImage;
private Point mousePosition;
private void Canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
var image = e.Source as Image;
if (image != null && canvas.CaptureMouse())
{
mousePosition = e.GetPosition(canvas);
draggedImage = image;
Panel.SetZIndex(draggedImage, 1); // in case of multiple images
}
}
private void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
if (draggedImage != null)
{
canvas.ReleaseMouseCapture();
Panel.SetZIndex(draggedImage, 0);
draggedImage = null;
}
}
private void Canvas_MouseMove(object sender, MouseEventArgs e)
{
if (draggedImage != null)
{
var position = e.GetPosition(canvas);
var offset = position - mousePosition;
mousePosition = position;
Canvas.SetLeft(draggedImage, Canvas.GetLeft(draggedImage) + offset.X);
Canvas.SetTop(draggedImage, Canvas.GetTop(draggedImage) + offset.Y);
}
}
but this didnt work saddly, does anyone has an Idea on how to make it work?
You should not mix layout (i.e. set Canvas.Left/Top) and render transformations. If you zoom by means of a RenderTransform, you should also pan by the same RenderTransform.
Here is a simple example where the MouseMove handler also manipulates the RenderTransform of the Image element.
<Canvas x:Name="canvas"
Background="Transparent"
MouseLeftButtonDown="CanvasMouseLeftButtonDown"
MouseLeftButtonUp="CanvasMouseLeftButtonUp"
MouseMove="CanvasMouseMove"
MouseWheel="CanvasMouseWheel">
<Image x:Name="image" Source=...>
<Image.RenderTransform>
<MatrixTransform/>
</Image.RenderTransform>
</Image>
</Canvas>
Note that mouse positions are determined differently for pan and zoom, in order to get an "unscaled" offset for panning, but an origin point relative to the Image for zooming.
private Point? mousePosition;
private void CanvasMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
if (canvas.CaptureMouse())
{
mousePosition = e.GetPosition(canvas); // position in Canvas
}
}
private void CanvasMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
canvas.ReleaseMouseCapture();
mousePosition = null;
}
private void CanvasMouseMove(object sender, MouseEventArgs e)
{
if (mousePosition.HasValue)
{
var position = e.GetPosition(canvas); // position in Canvas
var translation = position - mousePosition.Value;
mousePosition = position;
var transform = (MatrixTransform)image.RenderTransform;
var matrix = transform.Matrix;
matrix.Translate(translation.X, translation.Y);
transform.Matrix = matrix;
}
}
private void CanvasMouseWheel(object sender, MouseWheelEventArgs e)
{
var position = e.GetPosition(image); // position in Image
var scale = e.Delta >= 0 ? 1.1 : (1.0 / 1.1);
var transform = (MatrixTransform)image.RenderTransform;
var matrix = transform.Matrix;
matrix.ScaleAtPrepend(scale, scale, position.X, position.Y);
transform.Matrix = matrix;
}

Clipping InkPresenter to drawing area

I am trying to capture a signature in windows phone 7.1.
I can draw on the screen yet I can not limit the drawing area to the InkPresenter control except by adding some handling in the mousemove event.
How can I limit the drawing area using XAML or is this not possible?
XAML Code
<InkPresenter Name="inkTest" Background="White" MinHeight="180" MinWidth="250" />
Code Behind
private Stroke _currentStroke;
private void inkTest_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
_currentStroke = null;
}
private void inkTest_MouseMove(object sender, MouseEventArgs e)
{
if (_currentStroke == null) return;
//HACK: want to set this in XAML
var position = e.GetPosition(inkTest);
if (position.X <= inkTest.ActualWidth &&
position.Y <= inkTest.ActualHeight)
_currentStroke.StylusPoints.Add(GetStylusPoint(position));
}
private void inkTest_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
inkTest.CaptureMouse();
_currentStroke = new Stroke();
_currentStroke.StylusPoints.Add(GetStylusPoint(e.GetPosition(inkTest)));
_currentStroke.DrawingAttributes.Color = Colors.Blue;
inkTest.Strokes.Add(_currentStroke);
}
private StylusPoint GetStylusPoint(Point position)
{
return new StylusPoint(position.X, position.Y);
}
Untested, but try clipping:
<InkPresenter Name="inkTest" Background="White" MinHeight="180" MinWidth="250">
<InkPresenter.Clip>
<RectangleGeometry Rect="0,0,180,250"/>
</InkPresenter.Clip>
</InkPresenter>
Change the boundaries of the RectangleGeometry to what you want (or change the RectangleGeometry element itself if you need a different shape).

Smooth image clipping while scrolling

So I'm trying to achieve an affect like the native cropper when you use a PhotoChooserTask. If you aren't familiar, there's an image in the background with a border over top, and the image appears to change opacity when in and out of the border. The following code works fine, but it's not terribly smooth (the clipped image slightly lags behind the dragging movement). Is there any way to speed up the clipping or change things so that there's less lag? I have the following XAML:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0" HorizontalAlignment="Center" VerticalAlignment="Center">
<Grid x:Name="cropContainer" Width="375" MouseLeftButtonDown="cropContainer_MouseLeftButtonDown" MouseLeftButtonUp="cropContainer_MouseLeftButtonUp" MouseMove="cropContainer_MouseMove">
<Grid.RenderTransform>
<TranslateTransform x:Name="cropTransform" />
</Grid.RenderTransform>
<Image x:Name="fullImage" Source="{Binding Image}" Opacity=".5" />
<Image x:Name="clippedImage" Source="{Binding Image}">
<Image.Clip>
<RectangleGeometry Rect="0,0,375,267" />
</Image.Clip>
</Image>
</Grid>
</Grid>
<Border x:Name="cropBorder" Grid.Row="1" BorderThickness="1" BorderBrush="White" Opacity="1" Height="267.90571169537624660018132366274" Width="375">
</Border>
and here is the code for tracking and clipping during the sliding:
private Point _cropBorderOffset, _original, _newPosition;
private bool _moving;
private double _maxUp, _maxDown;
void Page_Loaded(object sender, RoutedEventArgs e)
{
var transform = cropBorder.TransformToVisual(Application.Current.RootVisual);
_cropBorderOffset = transform.Transform(new Point(0, 0));
_maxDown = ((fullImage.ActualHeight - cropBorder.ActualHeight) / 2);
_maxUp = -_maxDown;
var rect = (clippedImage.Clip as RectangleGeometry).Rect;
(clippedImage.Clip as RectangleGeometry).Rect = new Rect(rect.X, (fullImage.ActualHeight / 2) - 134, rect.Width, rect.Height);
}
private void cropContainer_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
cropContainer.CaptureMouse();
_original = e.GetPosition(cropBorder);
_moving = true;
}
private void cropContainer_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
cropContainer.ReleaseMouseCapture();
_moving = false;
}
private void cropContainer_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
{
_newPosition = e.GetPosition(cropBorder);
if(_moving)
{
var deltaY = _newPosition.Y - _original.Y;
var transform = fullImage.TransformToVisual(Application.Current.RootVisual);
var fullImageOffset = transform.Transform(new Point(0, 0));
var marginTop = deltaY;
//Too far down
if (marginTop > _maxDown)
{
marginTop = _maxDown;
}
//Too far up
else if (marginTop < _maxUp)
{
marginTop = _maxUp;
}
cropTransform.Y = marginTop;
var rect = (clippedImage.Clip as RectangleGeometry).Rect;
(clippedImage.Clip as RectangleGeometry).Rect = new Rect(rect.X, _cropBorderOffset.Y - fullImageOffset.Y, rect.Width, rect.Height);
}
}
Instead of drawing the image twice, once with clipping and once without, could you not simply draw semi-transparent rectangles to block out the sides and draw a white outlined for the center? That should reduce lag considerably.
You could then use the left, top, width and height of the clipping rectangle once the position is chosen to actually do the crop in-memory.

Pinch-to-zoom on huge images?

I found this Pinch-to-zoom example at http://forums.create.msdn.com
Here is the xaml:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<StackPanel>
<TextBlock Text="Tap to center" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock Text="Tap and hold to reset" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock Text="Touch and move to drag" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock Text="Pinch (touch with two fingers) to scale and rotate" Style="{StaticResource PhoneTextNormalStyle}" TextWrapping="Wrap"/>
<TextBlock Text="Flick (drag and release the touch while still moving) will show flick data on bottom of screen." Style="{StaticResource PhoneTextNormalStyle}" TextWrapping="Wrap"/>
</StackPanel>
<TextBlock x:Name="flickData" Text="Flick:" Style="{StaticResource PhoneTextNormalStyle}" VerticalAlignment="Bottom"/>
<Image x:Name="image" Source="/map.jpg" RenderTransformOrigin="0.5,0.5" CacheMode="BitmapCache">
<Image.RenderTransform>
<CompositeTransform x:Name="transform"/>
</Image.RenderTransform>
<toolkit:GestureService.GestureListener>
<toolkit:GestureListener
Tap="OnTap" Hold="OnHold"
DragStarted="OnDragStarted" DragDelta="OnDragDelta" DragCompleted="OnDragCompleted"
Flick="OnFlick"
PinchStarted="OnPinchStarted" PinchDelta="OnPinchDelta" PinchCompleted="OnPinchCompleted"/>
</toolkit:GestureService.GestureListener>
</Image>
</Grid>
And the cs source:
public partial class GestureSample : PhoneApplicationPage
{
double initialAngle;
double initialScale;
public GestureSample()
{
InitializeComponent();
}
private void OnTap(object sender, GestureEventArgs e)
{
transform.TranslateX = transform.TranslateY = 0;
}
private void OnDoubleTap(object sender, GestureEventArgs e)
{
transform.ScaleX = transform.ScaleY = 1;
}
private void OnHold(object sender, GestureEventArgs e)
{
transform.TranslateX = transform.TranslateY = 0;
transform.ScaleX = transform.ScaleY = 1;
transform.Rotation = 0;
}
private void OnDragStarted(object sender, DragStartedGestureEventArgs e)
{
image.Opacity = 0.3;
}
private void OnDragDelta(object sender, DragDeltaGestureEventArgs e)
{
transform.TranslateX += e.HorizontalChange;
transform.TranslateY += e.VerticalChange;
}
private void OnDragCompleted(object sender, DragCompletedGestureEventArgs e)
{
image.Opacity = 1.0;
}
private void OnPinchStarted(object sender, PinchStartedGestureEventArgs e)
{
Point point0 = e.GetPosition(image, 0);
Point point1 = e.GetPosition(image, 1);
Point midpoint = new Point((point0.X + point1.X) / 2, (point0.Y + point1.Y) / 2);
image.RenderTransformOrigin = new Point(midpoint.X / image.ActualWidth, midpoint.Y / image.ActualHeight);
initialAngle = transform.Rotation;
initialScale = transform.ScaleX;
image.Opacity = 0.8;
}
private void OnPinchDelta(object sender, PinchGestureEventArgs e)
{
transform.Rotation = initialAngle + e.TotalAngleDelta;
transform.ScaleX = transform.ScaleY = initialScale * e.DistanceRatio;
}
private void OnPinchCompleted(object sender, PinchGestureEventArgs e)
{
image.Opacity = 1.0;
}
private void OnFlick(object sender, FlickGestureEventArgs e)
{
flickData.Text = string.Format("{0} Flick: Angle {1} Velocity {2},{3}",
e.Direction, Math.Round(e.Angle), e.HorizontalVelocity, e.VerticalVelocity);
}
}
It works pretty well for small images (less then 2000x2000 pixels). But in my example, i have this huge metro map (http://www.vasttrafik.se/upload/Linjekartor_hogupplost/Goteborg2010/Linjen%C3%A4tskarta-101212.png or vector http://www.vasttrafik.se/upload/Linjekartor_hogupplost/Goteborg2010/Linjen%C3%A4tskarta-101212.pdf). It would be even nicer if the user could scale a vector image but even importing such a huge vector is a serious performance issue.
Maybe i could split the image up into several "multi-scale images" and use this http://dotnetbyexample.blogspot.com/2010/08/windows-phone-7-multi-touch-panzoom.html, but i don't really know how to use his class :(
Any ideas? How would you guys solve this problem?
Thanks
Richard
The ideal approach for your solution is to use MultiScaleImage, which is specifically designed to display large image data. However, in order to work with MultiScaleImage you need to get your iamge data prepared int he right format. Basically, you need the image sliced up and rescaled, etc so that the user loads as little information as possible while they zoom in and out of your image.
The DeepZoom documentation describes the process and has links to the DeepZoom Composer tool, which you use to prepare your image data.
Once you've got the MultiScaleImage approach working, you can then look at using Laurent's Multitouch Behavior (if necessary) to provide additional user interactions.
Have you heard of Silverlight Deep-Zoom?
http://msdn.microsoft.com/en-us/library/cc645050(v=vs.95).aspx
There is a size limit on Silverlight UIElements on the phone. As you have discovered, this is 2000x2000 pixels. No single control can be larger than this—hence your issue.
If you must use an image larger than this look at the MultiScaleImage.
Also be aware of the potential for memory issues if you're using very large image files.

moving a textbox with mouse

I have a custom WPF control which consist of single TextBox
<UserControl HorizontalAlignment="Left" x:Class="WPFDiagramDesignerControl.Components.UcWBSBlock"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Height="100" Width="100" IsEnabled="True">
<Grid >
<TextBox x:Name="txtBox" IsEnabled="True" Background="AntiqueWhite" Margin="10,10,10,10" TextWrapping="Wrap"> </TextBox>
</Grid>
</UserControl>
The control is placed on Canvas called MyDesigner.
I want to move my control on canvas only if I click on textbox and move mouse. I don't want to move control when I click on margin between borders of control and textbox.
I started writting a code and it looks like that
public partial class UcWBSBlock : UserControl
{
bool textChanged = false;
bool isClicked = false;
Point startPoint;
DesignerItem parentItem;
DesignerCanvas parentCanvas;
public UcWBSBlock()
{
InitializeComponent();
txtBox.MouseDoubleClick+=new MouseButtonEventHandler(txtBox_MouseDoubleClick);
txtBox.MouseMove+=new MouseEventHandler(txtBox_MouseMove);
txtBox.PreviewMouseDown+=new MouseButtonEventHandler(txtBox_PreviewMouseDown);
txtBox.PreviewMouseUp+=new MouseButtonEventHandler(txtBox_PreviewMouseUp);
txtBox.Cursor = Cursors.SizeAll;
}
private void txtBox_MouseMove(object sender, RoutedEventArgs e)
{
if (isClicked)
{
Point mousePos = Mouse.GetPosition(parentCanvas);
parentItem = this.Parent as DesignerItem;
parentCanvas = parentItem.Parent as DesignerCanvas;
Point relativePosition = Mouse.GetPosition(parentCanvas);
DesignerCanvas.SetLeft(parentItem,DesignerCanvas.GetLeft(parentItem) - (startPoint.X - mousePos.X));
DesignerCanvas.SetTop(parentItem, DesignerCanvas.GetTop(parentItem) - (startPoint.Y - mousePos.Y));
}
}
private void txtBox_PreviewMouseDown(object sender, RoutedEventArgs e)
{
if (!isClicked)
{
isClicked = true;
parentItem = this.Parent as DesignerItem;
parentCanvas = parentItem.Parent as DesignerCanvas;
startPoint = Mouse.GetPosition(parentCanvas);
}
}
private void txtBox_PreviewMouseUp(object sender, RoutedEventArgs e)
{
isClicked = false;
}
}
}
However my control doesn't move :( What did I do wrong ?? It's hard to debug this :)
you are setting the left/top of the parent item, not your control:
DesignerCanvas.SetLeft(parentItem,DesignerCanvas.GetLeft(parentItem) - (startPoint.X - mousePos.X));
DesignerCanvas.SetTop(parentItem, DesignerCanvas.GetTop(parentItem) - (startPoint.Y - mousePos.Y));
should (probably) be like this:
DesignerCanvas.SetLeft(this,DesignerCanvas.GetLeft(this) - (startPoint.X - mousePos.X));
DesignerCanvas.SetTop(this, DesignerCanvas.GetTop(this) - (startPoint.Y - mousePos.Y));

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