ScaleTransform transforms non-linearly
- by Chris
I am using scale transform to allow a user to resize a control. What happens though is that when you start to move the mouse the control jumps to a new size, and then scales oddly. The further you move your mouse from the starting location the larger the increase in size becomes.
I expect its the way I calculate the scale to be applied. Here is the code:
private void ResizeGrip_MouseDown(object sender, MouseButtonEventArgs e)
{
ResizeHandle.CaptureMouse();
//Get the initial coordinate cursor location on the window
initBtmX = e.GetPosition(this).X;
bottomResize = true;
}
private void ResizeGrip_MouseUp(object sender, MouseButtonEventArgs e)
{
bottomResize = false;
ResizeHandle.ReleaseMouseCapture();
}
private void ResizeGrip_MouseMove(object sender, MouseEventArgs e)
{
if( bottomResize == true)
{
//Get the new Y coordinate cursor location
double newBtmX = e.GetPosition(this).X;
//Get the smallest change between the initial and new cursor location
double diffX = initBtmX - newBtmX;
// Let our rectangle capture the mouse
ResizeHandle.CaptureMouse();
double newWidth = e.GetPosition(this).X - diffX;
double scaler = newWidth / ResizeContainer.ActualWidth;
Console.WriteLine("newWidth: {0}, scalar: {1}", newWidth, scaler);
if (scaler < 0.75 || scaler > 3)
return;
ScaleTransform scale = new ScaleTransform(scaler, scaler);
ResizeContainer.LayoutTransform = scale;
}
}
