public MainPage()
{
InitializeComponent();
var model = new MainPageModel(Navigation);
BindingContext = model;
#region Set left icon on button (usin a svg)
var svgRefresh = new SvgImageSource {
Svg = "res:images.refresh", Height = 15
}; //ColorMapping = "ffffff=00ff00"
//FileImageSource imageThatCanBeUsedInTabsWithACustomTabRenderer = svgRefresh.Image;
ColorMappingSelectedButton.Image = svgRefresh.CreateFileImageSource();
#endregion
model.PropertyChanged += (sender, args) =>
{
if (args.PropertyName == nameof(MainPageModel.Zoom) || args.PropertyName == nameof(MainPageModel.Translation))
{
var emptyZoom = Math.Abs(model.ZoomValue) < float.Epsilon;
var emptyPan = model.Translation.IsEmpty;
if (emptyZoom && emptyPan)
{
TheSvg.ViewportTransform = null;
}
else
{
var matrixFinal = DependencyService.Get <IMatrixFactory>().Create();
if (!emptyPan)
{
var matrix = DependencyService.Get <IMatrixFactory>().Create();
var innerSize = TheSvg.InnerSize;
var translation = model.Translation;
matrix.Translate(
(float)(-translation.X * innerSize.Width / (TheSvg.Width * model.ZoomValue)),
(float)(-translation.Y * innerSize.Height / (TheSvg.Height * model.ZoomValue)));
matrixFinal.Concat(matrix);
}
if (!emptyZoom)
{
//Rotation whose pivot point is at center
var matrix1 = DependencyService.Get <IMatrixFactory>().Create();
matrix1.Scale((float)(1 / model.ZoomValue), (float)(1 / model.ZoomValue));
var innerSize = TheSvg.InnerSize;
var matrix0 = DependencyService.Get <IMatrixFactory>().Create();
matrix0.Translate(-(float)(innerSize.Width / 2), -(float)(innerSize.Height / 2));
var matrix2 = DependencyService.Get <IMatrixFactory>().Create();
matrix2.Translate((float)(innerSize.Width / 2), (float)(innerSize.Height / 2));
matrix1.Concat(matrix0);
matrix2.Concat(matrix1);
matrixFinal.Concat(matrix2);
}
TheSvg.ViewportTransform = matrixFinal;
}
}
};
}