// (c) Copyright Microsoft Corporation.
// This source is subject to the Microsoft Public License (Ms-PL).
// Please see http://go.microsoft.com/fwlink/?LinkID=131993 for details.
// All other rights reserved.using System.Collections.Generic;
using System.Diagnostics;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;namespace System.Windows
{/// <summary>/// A utility class that overlays a designer-friendly grid on top of the /// application frame, for use similar to the performance counters in/// App.xaml.cs. The color and opacity are configurable. The grid contains /// a number of squares that are 24x24, offset with 12px gutters, and all/// 24px away from the edge of the device./// </summary>public static class MetroGridHelper{private static bool _visible;private static double _opacity = 0.15;private static Color _color = Colors.Red;private static List<Rectangle> _squares;private static Grid _grid;/// <summary>/// Gets or sets a value indicating whether the designer grid is /// visible on top of the application's frame./// </summary>public static bool IsVisible{get{return _visible;}set{_visible = value;UpdateGrid();}}/// <summary>/// Gets or sets the color to use for the grid's squares./// </summary>public static Color Color{get { return _color; }set{_color = value;UpdateGrid();}}/// <summary>/// Gets or sets a value indicating the opacity for the grid's squares./// </summary>public static double Opacity{get { return _opacity; }set{_opacity = value;UpdateGrid();}}/// <summary>/// Updates the grid (if it already has been created) or initializes it/// otherwise./// </summary>private static void UpdateGrid(){if (_squares != null){var brush = new SolidColorBrush(_color);foreach (var square in _squares){square.Fill = brush;}if (_grid != null){_grid.Visibility = _visible ? Visibility.Visible : Visibility.Collapsed;_grid.Opacity = _opacity;}}else{BuildGrid();}}/// <summary>/// Builds the grid./// </summary>private static void BuildGrid(){_squares = new List<Rectangle>();var frame = Application.Current.RootVisual as Frame;if (frame == null || VisualTreeHelper.GetChildrenCount(frame) == 0){Deployment.Current.Dispatcher.BeginInvoke(BuildGrid);return;}var child = VisualTreeHelper.GetChild(frame, 0);var childAsBorder = child as Border;var childAsGrid = child as Grid;if (childAsBorder != null){// Not a pretty way to control the root visual, but I did not// want to implement using a popup.var content = childAsBorder.Child;if (content == null){Deployment.Current.Dispatcher.BeginInvoke(BuildGrid);return;}childAsBorder.Child = null;Deployment.Current.Dispatcher.BeginInvoke(() =>{Grid newGrid = new Grid();childAsBorder.Child = newGrid;newGrid.Children.Add(content);PrepareGrid(frame, newGrid);});}else if (childAsGrid != null){PrepareGrid(frame, childAsGrid);}else{Debug.WriteLine("Dear developer:");Debug.WriteLine("Unfortunately the design overlay feature requires that the root frame visual");Debug.WriteLine("be a Border or a Grid. So the overlay grid just isn't going to happen.");return;}}/// <summary>/// Does the actual work of preparing the grid once the parent frame is/// in the visual tree and we have a Grid instance to work with for/// placing the chilren./// </summary>/// <param name="frame">The phone application frame.</param>/// <param name="parent">The parent grid to insert the sub-grid into.</param>private static void PrepareGrid(Frame frame, Grid parent){var brush = new SolidColorBrush(_color);_grid = new Grid();_grid.IsHitTestVisible = false;// To support both orientations, unfortunately more visuals need to// be used. An alternate implementation would be to react to the// orientation change event and re-draw/remove squares.double width = frame.ActualWidth;double height = frame.ActualHeight;double max = Math.Max(width, height);for (int x = 24; x < /*width*/ max; x += 37){for (int y = 24; y < /*height*/ max; y += 37){var rect = new Rectangle{Width = 25,Height = 25,VerticalAlignment = System.Windows.VerticalAlignment.Top,HorizontalAlignment = System.Windows.HorizontalAlignment.Left,Margin = new Thickness(x, y, 0, 0),IsHitTestVisible = false,Fill = brush,};_grid.Children.Add(rect);_squares.Add(rect);}}_grid.Visibility = _visible ? Visibility.Visible : Visibility.Collapsed;_grid.Opacity = _opacity;// For performance reasons a single surface should ideally be used// for the grid._grid.CacheMode = new BitmapCache();// Places the grid into the visual tree. It is never removed once// being added.
            parent.Children.Add(_grid);}}
}