/// <summary>
/// Creates all the views we'll ever need. DOES NOT CONFIGURE the views at all.
/// </summary>
private void CreateViews()
{
if (ViewModelCreator == null || ViewCreator == null || WallSizer == null)
{
Monitor.Throw($"Cannot Initialize, ViewModelCreator={ViewModelCreator}, ViewCreator={ViewCreator}, WallSizer={WallSizer}");
return;
}
var size = CrossScreen.Current.Size;
var maxScreenWidth = size.Width;
var maxScreenHeight = size.Height;
var normalWallSize = WallSizer.Size(maxScreenWidth, maxScreenHeight);
var rotatedWallSize = WallSizer.Size(maxScreenHeight, maxScreenWidth);
var maxNumViews = Math.Max(normalWallSize.MaxNumItems, rotatedWallSize.MaxNumItems);
Monitor.Debug($"Guessing Max Views for {size.Width}x{size.Height}");
Monitor.Debug($"Landscape. Table = {rotatedWallSize.NumRows}x{rotatedWallSize.NumColumns}, Padding = {rotatedWallSize.PaddingX}x{rotatedWallSize.PaddingY}, ItemSize = {rotatedWallSize.ItemSize.Width}x{rotatedWallSize.ItemSize.Height}");
// setup our initial data & views.
for (var i = 0; i < maxNumViews; i++)
{
var view = ViewCreator();
view.BindingContext = null;
AbsoluteLayout.Children.Add(view);
}
numVisibleViews = maxNumViews;
WidthRequest = size.Width;
HeightRequest = size.Height;
}
private bool SetupViewSizesAndVisibility(double screenWidth, double screenHeight)
{
var sizeChanged = screenWidth != lastWidth || screenHeight != lastHeight;
if (sizeChanged)
{
// account for the new view size
var newSize = WallSizer.Size(screenWidth, screenHeight);
// go through and layout and make all views that we need visible
double x = newSize.PaddingX, y = newSize.PaddingY;
var childIndex = 0;
for (var row = 0; row < newSize.NumRows; row++)
{
for (var column = 0; column < newSize.NumColumns; column++)
{
var view = AbsoluteLayout.Children[childIndex++];
Xamarin.Forms.AbsoluteLayout.SetLayoutBounds(view, new Rectangle(x, y, newSize.ItemSize.Width, newSize.ItemSize.Height));
//this might speed things up, not sure, hard to tell with Xamarin and whatever C# optimizations do here
if (!view.IsVisible)
{
view.IsVisible = true;
numVisibleViews++;
}
x += newSize.ItemSizeWithPadding.Width;
}
x = newSize.PaddingX;
y += newSize.ItemSizeWithPadding.Height;
}
// If we can't fit a view on the screen, make it invisible
for (; childIndex < AbsoluteLayout.Children.Count; childIndex++)
{
var child = AbsoluteLayout.Children[childIndex];
//this might speed things up, not sure, hard to tell with Xamarin and whatever C# optimizations do here
if (child.IsVisible)
{
child.IsVisible = false;
numVisibleViews--;
}
}
lastWidth = screenWidth;
lastHeight = screenHeight;
WidthRequest = screenWidth;
HeightRequest = screenHeight;
Monitor.Debug($"Size Allocated: {screenWidth}x{screenHeight}, Grid = {newSize.NumRows}x{newSize.NumColumns}, Paddings = {newSize.PaddingX}x{newSize.PaddingY}, ItemSize = {newSize.ItemSize.Width}x{newSize.ItemSize.Height}");
}
return(sizeChanged);
}
