c#wpfalgorithmxamladorner
WPF Adorner for Control User resizable
I created a simple adorner for the TextBlock element which allows the user to change its size. You can change the size in four corners of the block, that is, two sizes change at once(upper left thumb, upper right thumb, lower left thumb, lower right thumb). Everything works well, you can see it on the first gif:
Also, I want to add the ability to resize proportionally with the shift key held down. The result of this you can see on the second gif:
As you can see, the upper-left thumb and lower-right thumb allow you to change the dimensions correctly. However, the other two thumb elements don't work, I don't understand how made it.
XAML:
<Window x:Class="BagControlResize.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Canvas x:Name="canvas">
<TextBlock x:Name="testBlock" Canvas.Left="250" Canvas.Top="120" Width="300" Height="200" Background="Green"/>
</Canvas>
</Window>
CREATE ADORNER:
using System.Windows;
using System.Windows.Documents;
namespace BagControlResize
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
Loaded += (sender, e) =>
{
var adorner = AdornerLayer.GetAdornerLayer(canvas);
adorner.Add(new TextBlockAdorner(testBlock));
};
}
}
}
ADORNER:
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
namespace BagControlResize
{
public class TextBlockAdorner : Adorner
{
private double angle = 0.0;
private Point transformOrigin = new Point(0, 0);
private TextBlock childElement;
private VisualCollection visualChilderns;
private Thumb leftTop, rightTop, leftBottom, rightBottom;
public TextBlockAdorner(UIElement element) : base(element)
{
visualChilderns = new VisualCollection(this);
childElement = element as TextBlock;
CreateThumbPart(ref leftTop);
leftTop.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
double _max = hor > vert ? hor : vert;
hor = _max;
vert = _max;
}
ResizeX(hor);
ResizeY(vert);
e.Handled = true;
};
CreateThumbPart(ref rightTop);
rightTop.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
// THIS: NO WORKED
double _max = Math.Abs(hor) > Math.Abs(vert) ? Math.Abs(hor) : Math.Abs(vert);
if (hor >= 0 && vert <= 0)
{
hor = _max;
vert = -_max;
}
else
{
hor = -_max;
vert = _max;
}
}
ResizeWidth(hor);
ResizeY(vert);
e.Handled = true;
};
CreateThumbPart(ref leftBottom);
leftBottom.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
// THIS: NO WORKED
double _max = Math.Abs(hor) > Math.Abs(vert) ? Math.Abs(hor) : Math.Abs(vert);
if (hor <= 0 && vert >= 0)
{
hor = -_max;
vert = _max;
}
else
{
hor = _max;
vert = -_max;
}
}
ResizeX(hor);
ResizeHeight(vert);
e.Handled = true;
};
CreateThumbPart(ref rightBottom);
rightBottom.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
double _max = hor > vert ? hor : vert;
hor = _max;
vert = _max;
}
ResizeWidth(hor);
ResizeHeight(vert);
e.Handled = true;
};
}
private void ResizeWidth(double e)
{
double deltaHorizontal = Math.Min(-e, childElement.ActualWidth - childElement.MinWidth);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) - transformOrigin.X * deltaHorizontal * Math.Sin(angle));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) + (deltaHorizontal * transformOrigin.X * (1 - Math.Cos(angle))));
childElement.Width -= deltaHorizontal;
}
private void ResizeX(double e)
{
double deltaHorizontal = Math.Min(e, childElement.ActualWidth - childElement.MinWidth);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) + deltaHorizontal * Math.Sin(angle) - transformOrigin.X * deltaHorizontal * Math.Sin(angle));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) + deltaHorizontal * Math.Cos(angle) + (transformOrigin.X * deltaHorizontal * (1 - Math.Cos(angle))));
childElement.Width -= deltaHorizontal;
}
private void ResizeHeight(double e)
{
double deltaVertical = Math.Min(-e, childElement.ActualHeight - childElement.MinHeight);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) + (transformOrigin.Y * deltaVertical * (1 - Math.Cos(-angle))));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) - deltaVertical * transformOrigin.Y * Math.Sin(-angle));
childElement.Height -= deltaVertical;
}
private void ResizeY(double e)
{
double deltaVertical = Math.Min(e, childElement.ActualHeight - childElement.MinHeight);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) + deltaVertical * Math.Cos(-angle) + (transformOrigin.Y * deltaVertical * (1 - Math.Cos(-angle))));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) + deltaVertical * Math.Sin(-angle) - (transformOrigin.Y * deltaVertical * Math.Sin(-angle)));
childElement.Height -= deltaVertical;
}
public void CreateThumbPart(ref Thumb cornerThumb)
{
cornerThumb = new Thumb { Width = 25, Height = 25, Background= Brushes.Black };
visualChilderns.Add(cornerThumb);
}
public void EnforceSize(FrameworkElement element)
{
if (element.Width.Equals(Double.NaN))
element.Width = element.DesiredSize.Width;
if (element.Height.Equals(Double.NaN))
element.Height = element.DesiredSize.Height;
FrameworkElement parent = element.Parent as FrameworkElement;
if (parent != null)
{
element.MaxHeight = parent.ActualHeight;
element.MaxWidth = parent.ActualWidth;
}
}
protected override Size ArrangeOverride(Size finalSize)
{
base.ArrangeOverride(finalSize);
double desireWidth = AdornedElement.DesiredSize.Width;
double desireHeight = AdornedElement.DesiredSize.Height;
double adornerWidth = this.DesiredSize.Width;
double adornerHeight = this.DesiredSize.Height;
leftTop.Arrange(new Rect(-adornerWidth / 2 - 15, -adornerHeight / 2 - 15, adornerWidth, adornerHeight));
rightTop.Arrange(new Rect(desireWidth - adornerWidth / 2 + 15, -adornerHeight / 2 - 15, adornerWidth, adornerHeight));
leftBottom.Arrange(new Rect(-adornerWidth / 2 - 15, desireHeight - adornerHeight / 2 + 15, adornerWidth, adornerHeight));
rightBottom.Arrange(new Rect(desireWidth - adornerWidth / 2 + 15, desireHeight - adornerHeight / 2 + 15, adornerWidth, adornerHeight));
return finalSize;
}
protected override int VisualChildrenCount => visualChilderns.Count;
protected override Visual GetVisualChild(int index) => visualChilderns[index];
protected override void OnRender(DrawingContext drawingContext) => base.OnRender(drawingContext);
}
}
I show the minimum a self-sufficient example so that you can see exactly what I'm doing. The code is easily compiled. I marked two places in the code where I was stuck.
Thanks
UPD 1:
Solution
@Frenchy's solution helps, but there are still problems with the code. Try shift-clicking the top left or the bottom left and immediately dragging directly up, or dragging top right very slowly at a constant speed to the left.
The issue is caused by calculating the proportional drag direction in every call to DragDelta, based on the direction of the biggest move. The code can easily change direction and get confused, or not even know which way it's meant to be going correctly.
One way around this is to decide the drag direction when the proportional drag starts, and carry on with that until it ends. This seems to work better, and fixes the issues above. The code is below.
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
namespace BagControlResize
{
public class TextBlockAdorner : Adorner
{
private double angle = 0.0;
private Point transformOrigin = new Point(0, 0);
private TextBlock childElement;
private VisualCollection visualChilderns;
public Thumb leftTop, rightTop, leftBottom, rightBottom;
private bool dragStarted = false;
private bool isHorizontalDrag = false;
public TextBlockAdorner(UIElement element) : base(element)
{
visualChilderns = new VisualCollection(this);
childElement = element as TextBlock;
CreateThumbPart(ref leftTop);
leftTop.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
if (dragStarted) isHorizontalDrag = Math.Abs(hor) > Math.Abs(vert);
if (isHorizontalDrag) vert = hor; else hor = vert;
}
ResizeX(hor);
ResizeY(vert);
dragStarted = false;
e.Handled = true;
};
CreateThumbPart(ref rightTop);
rightTop.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
System.Diagnostics.Debug.WriteLine(hor + "," + vert + "," + (Math.Abs(hor) > Math.Abs(vert)) + "," + childElement.Height + "," + childElement.Width + "," + dragStarted + "," + isHorizontalDrag);
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
if (dragStarted) isHorizontalDrag = Math.Abs(hor) > Math.Abs(vert);
if (isHorizontalDrag) vert = -hor; else hor = -vert;
}
ResizeWidth(hor);
ResizeY(vert);
dragStarted = false;
e.Handled = true;
};
CreateThumbPart(ref leftBottom);
leftBottom.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
System.Diagnostics.Debug.WriteLine(hor + "," + vert + "," + (Math.Abs(hor) > Math.Abs(vert)) + "," + childElement.Height + "," + childElement.Width + "," + dragStarted + "," + isHorizontalDrag);
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
if (dragStarted) isHorizontalDrag = Math.Abs(hor) > Math.Abs(vert);
if (isHorizontalDrag) vert = -hor; else hor = -vert;
}
ResizeX(hor);
ResizeHeight(vert);
dragStarted = false;
e.Handled = true;
};
CreateThumbPart(ref rightBottom);
rightBottom.DragDelta += (sender, e) =>
{
double hor = e.HorizontalChange;
double vert = e.VerticalChange;
if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
{
if (dragStarted) isHorizontalDrag = Math.Abs(hor) > Math.Abs(vert);
if (isHorizontalDrag) vert = hor; else hor = vert;
}
ResizeWidth(hor);
ResizeHeight(vert);
dragStarted = false;
e.Handled = true;
};
}
public void CreateThumbPart(ref Thumb cornerThumb)
{
cornerThumb = new Thumb { Width = 25, Height = 25, Background = Brushes.Black };
cornerThumb.DragStarted += (object sender, DragStartedEventArgs e) => dragStarted = true;
visualChilderns.Add(cornerThumb);
}
private void ResizeWidth(double e)
{
double deltaHorizontal = Math.Min(-e, childElement.ActualWidth - childElement.MinWidth);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) - transformOrigin.X * deltaHorizontal * Math.Sin(angle));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) + (deltaHorizontal * transformOrigin.X * (1 - Math.Cos(angle))));
childElement.Width -= deltaHorizontal;
}
private void ResizeX(double e)
{
double deltaHorizontal = Math.Min(e, childElement.ActualWidth - childElement.MinWidth);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) + deltaHorizontal * Math.Sin(angle) - transformOrigin.X * deltaHorizontal * Math.Sin(angle));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) + deltaHorizontal * Math.Cos(angle) + (transformOrigin.X * deltaHorizontal * (1 - Math.Cos(angle))));
childElement.Width -= deltaHorizontal;
}
private void ResizeHeight(double e)
{
double deltaVertical = Math.Min(-e, childElement.ActualHeight - childElement.MinHeight);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) + (transformOrigin.Y * deltaVertical * (1 - Math.Cos(-angle))));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) - deltaVertical * transformOrigin.Y * Math.Sin(-angle));
childElement.Height -= deltaVertical;
}
private void ResizeY(double e)
{
double deltaVertical = Math.Min(e, childElement.ActualHeight - childElement.MinHeight);
Canvas.SetTop(childElement, Canvas.GetTop(childElement) + deltaVertical * Math.Cos(-angle) + (transformOrigin.Y * deltaVertical * (1 - Math.Cos(-angle))));
Canvas.SetLeft(childElement, Canvas.GetLeft(childElement) + deltaVertical * Math.Sin(-angle) - (transformOrigin.Y * deltaVertical * Math.Sin(-angle)));
childElement.Height -= deltaVertical;
}
//public void EnforceSize(FrameworkElement element)
//{
// if (element.Width.Equals(Double.NaN))
// element.Width = element.DesiredSize.Width;
// if (element.Height.Equals(Double.NaN))
// element.Height = element.DesiredSize.Height;
// FrameworkElement parent = element.Parent as FrameworkElement;
// if (parent != null)
// {
// element.MaxHeight = parent.ActualHeight;
// element.MaxWidth = parent.ActualWidth;
// }
//}
protected override Size ArrangeOverride(Size finalSize)
{
base.ArrangeOverride(finalSize);
double desireWidth = AdornedElement.DesiredSize.Width;
double desireHeight = AdornedElement.DesiredSize.Height;
double adornerWidth = this.DesiredSize.Width;
double adornerHeight = this.DesiredSize.Height;
leftTop.Arrange(new Rect(-adornerWidth / 2 - 15, -adornerHeight / 2 - 15, adornerWidth, adornerHeight));
rightTop.Arrange(new Rect(desireWidth - adornerWidth / 2 + 15, -adornerHeight / 2 - 15, adornerWidth, adornerHeight));
leftBottom.Arrange(new Rect(-adornerWidth / 2 - 15, desireHeight - adornerHeight / 2 + 15, adornerWidth, adornerHeight));
rightBottom.Arrange(new Rect(desireWidth - adornerWidth / 2 + 15, desireHeight - adornerHeight / 2 + 15, adornerWidth, adornerHeight));
return finalSize;
}
protected override int VisualChildrenCount => visualChilderns.Count;
protected override Visual GetVisualChild(int index) => visualChilderns[index];
//protected override void OnRender(DrawingContext drawingContext) => base.OnRender(drawingContext);
}
}